Patent Publication Number: US-2022238818-A1

Title: Light-emitting device and electronic apparatus including the light-emitting device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to and the benefit of Korean Patent Application No. 10-2021-0012652, filed on Jan. 28, 2021, in the Korean Intellectual Property Office, the entire content of which is incorporated by reference herein in its entirety. 
     BACKGROUND 
     1. Field 
     The present disclosure relates to a light-emitting device and an electronic apparatus including the same. 
     2. Description of the Related Art 
     Organic light-emitting devices (OLEDs), among light-emitting devices, are self-emissive devices that have wide viewing angles, high contrast ratios, short response times, and/or suitable (e.g., excellent) characteristics in terms of luminance, driving voltage, and/or response speed, compared to devices in the art. 
     Organic light-emitting devices may include a first electrode located on a substrate, and a hole transport region, an emission layer, an electron transport region, and a second electrode sequentially stacked on the first electrode. Holes provided from the first electrode may move toward the emission layer through the hole transport region, and electrons provided from the second electrode may move toward the emission layer through the electron transport region. Carriers, such as holes and electrons, recombine in the emission layer to produce excitons. These excitons transition from an excited state to a ground state to thereby generate light. 
     SUMMARY 
     Aspects according to one or more embodiments are directed toward a light-emitting device having suitable (e.g., excellent) emission efficiency and long lifespan, and an electronic apparatus including the same. 
     Additional aspects will be set forth in part in the description, which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments of the disclosure. 
     According to one or more embodiments, a light-emitting device includes a first electrode, 
     a second electrode facing the first electrode, and 
     an interlayer including an emission layer between the first electrode and the second electrode and an electron transport region between the emission layer and the second electrode, 
     wherein the electron transport region includes a first buffer layer and a second buffer layer between the first buffer layer and the second electrode, 
     and the first buffer layer includes a silicon-containing nonpolar compound. 
     According to one or more embodiments, an electronic apparatus includes the light-emitting device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features, and enhancements of certain embodiments of the disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a schematic cross-sectional view of a light-emitting device according to an embodiment; 
         FIG. 2  is a cross-sectional view of a light-emitting apparatus according to an embodiment; and 
         FIG. 3  is a cross-sectional view of a light-emitting apparatus according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in more detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout the specification. In this regard, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the embodiments are merely described below, by referring to the figures, to explain aspects of the present description. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Throughout the disclosure, the expression “at least one of a, b and c” indicates only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof. 
     A light-emitting device according to an embodiment of the present disclosure may include: a first electrode; 
     a second electrode facing the first electrode; and 
     an interlayer including an emission layer between the first electrode and the second electrode and an electron transport region between the emission layer and the second electrode, 
     wherein the electron transport region may include a first buffer layer and a second buffer layer located between the first buffer layer and the second electrode, 
     and the first buffer layer may include a silicon-containing nonpolar compound. 
     In an embodiment, the silicon-containing nonpolar compound in the light-emitting device may be represented by Formula 1-1 or 1-2: 
     
       
         
         
             
             
         
       
     
     L 1  to L 5  and L 21  to L 23  in Formulae 1-1 and 1-2 may each independently be a single bond, a C 1 -C 20  alkylene group unsubstituted or substituted with at least one R 20a , a C 2 -C 20  alkenylene group unsubstituted or substituted with at least one R 20a , or a π electron-rich C 3 -C 60  cyclic group unsubstituted or substituted with at least one R 20a . R 20a  is the same as to be described in the present specification. 
     In an embodiment, the π electron-rich C 3 -C 60  cyclic group may be a) a first ring or b) a condensed cyclic ring in which at least two first rings are condensed, and 
     the first ring may be a benzene group, a cyclopentadiene group, a pyrrole group, a furan group, a thiophene group, or a silole group. 
     In an embodiment, the π electron-rich C 3 -C 60  cyclic group may be a benzene group, a heptalene group, an indene group, a naphthalene group, an azulene group, an indacene group, an acenaphthylene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentacene group, a hexacene group, a pentaphene group, a rubicene group, a coronene group, an ovalene group, a pyrrole group, a furan group, a thiophene group, an isoindole group, an indole group, an indene group, a benzofuran group, a benzothiophene group, a benzosilole group, a naphthopyrrole group, a naphthofuran group, a naphthothiophene group, naphthosilole group, a benzocarbazole group, a dibenzocarbazole group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, a dibenzosilole group, an indenocarbazole group, an indolocarbazole group, a benzofurocarbazole group, a benzothienocarbazole group, a benzosilolocarbazole group, a triindolobenzene group, a pyrrolophenanthrene group, a furanophenanthrene group, thienophenanthrene group, a benzonaphthofuran group, a benzonaphthothiophene group, an (indolo)phenanthrene group, a (benzofurano)phenanthrene group, or a (benzothieno)phenanthrene group, each unsubstituted or substituted with at least one R 20a . 
     In an embodiment, L 1  to L 5  and L 21  to L 23  may each independently be a single bond; 
     a C 1 -C 20  alkylene group unsubstituted or substituted with at least one R 20a ; or 
     a benzene group or a naphthalene group, each unsubstituted or substituted with at least one R 20a . 
     a1 to a5 and a21 to a23 in Formulae 1-1 and 1-2 may each independently be an integer from 0 to 10. 
     For example, a1 to a5 and a21 to a23 may each independently be an integer from 0 to 5, but embodiments of the present disclosure are not limited thereto. 
     R 1  to R 4  and R 21  to R 23  in Formulae 1-1 and 1-2 may each independently be a C 1 -C 60  alkyl group unsubstituted or substituted with at least one R 20a , a C 2 -C 60  alkenyl group unsubstituted or substituted with at least one R 20a , a C 2 -C 60 alkynyl group unsubstituted or substituted with at least one R 20a , a C 1 -C 60  alkoxy group unsubstituted or substituted with at least one R 20a , a π electron-rich C 3 -C 60  cyclic group unsubstituted or substituted with at least one R 20a , —C(Q 1 )(Q 2 )(Q 3 ), —B(Q 1 )(Q 2 ) or —P(Q 1 )(Q 2 ), 
     R 1  and R 4  may optionally be linked to each other via a single bond, a C 1 -C 5  alkylene group unsubstituted or substituted with at least one R 20a , or a C 2 -C 5  alkenylene group unsubstituted or substituted with at least one R 20a  to form a C 8 -C 60  polycyclic group unsubstituted or substituted with at least one R 20a , and 
     R 21  and R 22  may optionally be linked to each other via a single bond, a C 1 -C 5  alkylene group unsubstituted or substituted with at least one R 20a , or a C 2 -C 5  alkenylene group unsubstituted or substituted with at least one R 20a  to form a C 8 -C 60  polycyclic group unsubstituted or substituted with at least one R 20a . 
     The term “R 20a ” as used herein refers to: 
     deuterium (-D), a hydroxyl group, or a nitro group; 
     a C 1 -C 60  alkyl group, a C 2 -C 60  alkenyl group, a C 2 -C 60 alkynyl group, or a C 1 -C 60  alkoxy group, each unsubstituted or substituted with deuterium, a hydroxyl group, a nitro group, a π electron-rich C 3 -C 60  cyclic group, a C 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, —Si(Q 41 )(Q 42 )(Q 43 ), —C(Q 41 )(Q 42 )(Q 43 ), —B(Q 41 )(Q 42 ), —P(Q 41 )(Q 42 ), or any combination thereof; 
     a π electron-rich C 3 -C 60  cyclic group, a C 6 -C 60  aryloxy group, or a C 6 -C 60  arylthio group, each unsubstituted or substituted with deuterium, a hydroxyl group, a nitro group, a C 1 -C 60  alkyl group, a C 2 -C 60  alkenyl group, a C 2 -C 60  alkynyl group, a C 1 -C 60  alkoxy group, a π electron-rich C 3 -C 60  cyclic group, a C 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, —Si(Q 51 )(Q 52 )(Q 53 ), —C(Q 51 )(Q 52 )(Q 53 ), —B(Q 51 )(Q 52 ), —P(Q 51 )(Q 52 ), or any combination thereof; or 
     —Si(Q 61 )(Q 62 )(Q 63 ), —C(Q 61 )(Q 62 )(Q 63 ), —B(Q 61 )(Q 62 ), or —P(Q 61 )(Q 62 ). 
     Q 1  to Q 3 , Q 41  to Q 43 , Q 51  to Q 53 , and Q 61  to Q 63  may each independently be: hydrogen; deuterium; a hydroxyl group; a nitro group; a C 1 -C 60  alkyl group; a C 2 -C 60  alkenyl group; a C 2 -C 60  alkynyl group; a C 1 -C 60  alkoxy group; or a π electron-rich C 3 -C 60  cyclic group unsubstituted or substituted with deuterium, a C 1 -C 60  alkyl group, a C 1 -C 60  alkoxy group, a phenyl group, a biphenyl group, or any combination thereof. 
     In an embodiment, R 1  to R 4  and R 21  to R 23  may each independently be: 
     hydrogen, deuterium, a hydroxyl group, or a nitro group; 
     a C 1 -C 20  alkyl group, a C 2 -C 20  alkenyl group, a C 2 -C 20  alkynyl group, or a C 1 -C 20  alkoxy group, each unsubstituted or substituted with deuterium, -CD 3 , -CD 2 H, -CDH 2 , a hydroxyl group, a nitro group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, —Si(Q 61 )(Q 62 )(Q 63 ), —C(Q 61 )(Q 62 )(Q 63 ), —B(Q 61 )(Q 62 ), —P(Q 61 )(Q 62 ), or any combination thereof; 
     a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an isoindolyl group, an indolyl group, a carbazolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, or a dibenzocarbazolyl group, each unsubstituted or substituted with deuterium, -CD 3 , -CD 2 H, -CDH 2 , a hydroxyl group, a nitro group, a C 1 -C 20  alkyl group, a C 2 -C 20  alkenyl group, a C 2 -C 20  alkynyl group, a C 1 -C 20  alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an isoindolyl group, an indolyl group, a carbazolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, —Si(Q 61 )(Q 62 )(Q 63 ), —C(Q 61 )(Q 62 )(Q 63 ), —B(Q 61 )(Q 62 ), —P(Q 61 )(Q 62 ), or any combination thereof, or 
     —C(Q 1 )(Q 2 )(Q 3 ), —B(Q 1 )(Q 2 ), or —P(Q 1 )(Q 2 ). Q 1  to Q 3  and Q 61  to Q 63  are each the same as described in the present specification. 
     n1 in Formula 1-2 may be an integer from 1 to 10. 
     For example, n1 in Formula 1-2 may be an integer from 1 to 4, but embodiments of the present disclosure are not limited thereto. 
     In an embodiment, the silicon-containing nonpolar compound may be at least one selected from Compounds 1 to 8. 
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     In an embodiment, the difference between a singlet (Si) energy level and a triplet (T 1 ) energy level of the silicon-containing nonpolar compound may be 0.5 eV or less. 
     Because the first buffer layer in the light-emitting device includes the silicon-containing nonpolar compound, the first buffer layer may have electron transporting characteristics and may also prevent or reduce charge trapping, thereby lowering the possibility of occurrence of triplet polaron quenching due to the interaction between triplet excitons in the emission layer and negative electric charges in the first buffer layer. Therefore, the light-emitting device may have a low driving voltage, a high emission efficiency and a long lifespan. 
     Synthesis methods of the silicon-containing nonpolar compound may be recognizable by one of ordinary skill in the art by referring to Synthesis Examples and/or Examples provided below. 
     In an embodiment, the first electrode of the organic light-emitting device may be an anode, 
     the second electrode may be a cathode, 
     the interlayer may further include a hole transport region between the first electrode and the emission layer, 
     the hole transport region may include a hole injection layer, a hole transport layer, an emission auxiliary layer, an electron blocking layer, or any combination thereof, and 
     the electron transport region may further include a hole blocking layer, an electron transport layer, an electron injection layer, or any combination thereof. 
     In an embodiment, the emission layer may be in direct contact with the first buffer layer in the light-emitting device. 
     In an embodiment, the first buffer layer may be in direct contact with the second buffer layer in the light-emitting device. 
     In an embodiment, the thickness of the first buffer layer in the light-emitting device may be more than 0 nm and be 10 nm or less. That is, the thickness of the first buffer layer in the light-emitting device may be in a range from more than 0 nm to 10 nm. 
     For example, the thickness of the first buffer layer in the light-emitting device may be 1 nm or more and 5 nm or less, but embodiments of the present disclosure are not limited thereto. 
     In an embodiment, the thickness of the first buffer layer may be equal to or less than the thickness of the second buffer layer in the light-emitting device. 
     In an embodiment, the emission layer may further include a dopant in the light-emitting device. 
     In an embodiment, the dopant in the light-emitting device may emit phosphorescence. 
     In an embodiment, the emission layer in the light-emitting device may emit blue light having a maximum emission wavelength of 450 nm or more and 490 nm or less. That is, the emission layer in the light-emitting device may emit blue light having a maximum emission wavelength in a range from 450 nm to 490 nm. 
     In an embodiment, the second buffer layer in the light-emitting device may include a silicon-containing compound, a phosphine oxide-containing compound, a sulfur oxide-containing compound, a phosphorus oxide-containing compound, a triazine-containing compound, a pyrimidine-containing compound, a pyridine-containing compound, a dibenzofuran-containing compound, a dibenzothiophene-containing compound, or any combination thereof. 
     In an embodiment, the second buffer layer in the light-emitting device may include a triazine-containing compound, a pyrimidine-containing compound, a pyridine-containing compound, or any combination thereof. 
     The expression “(an interlayer and/or capping layer) includes a silicon-containing nonpolar compound” as used herein may include a case in which “(an interlayer and/or capping layer) includes identical silicon-containing nonpolar compounds” and a case in which “(an interlayer and/or capping layer) includes two or more different silicon-containing nonpolar compounds.” 
     For example, the interlayer and/or capping layer may include only Compound 1 as the silicon-containing nonpolar compound. In this regard, Compound 1 may exist in the emission layer of the light-emitting device. In an embodiment, the interlayer may include, as the silicon-containing nonpolar compound, both Compounds 1 and 2. In this regard, Compound 1 and Compound 2 may exist in an identical layer (for example, Compound 1 and Compound 2 may both exist in an emission layer), or different layers (for example, Compound 1 may exist in an emission layer and Compound 2 may exist in an electron transport region). 
     The term “interlayer” as used herein refers to a single layer and/or all of a plurality of layers located between a first electrode and a second electrode of a light-emitting device. 
     According to one or more embodiments, an electronic apparatus may include the light-emitting device. The electronic apparatus may further include a thin-film transistor. In an embodiment, the electronic apparatus may further include a thin-film transistor including a source electrode and a drain electrode, and the first electrode of the light-emitting device may be electrically connected to the source electrode or the drain electrode. In an embodiment, the electronic apparatus may further include a color filter, a color conversion layer, a touch screen layer, a polarizing layer, or any combination thereof. More details on the electronic apparatus may be the same as described in the present specification. 
     Description of FIG.  1   
       FIG. 1  is a schematic cross-sectional view of a light-emitting device  10  according to an embodiment. The light-emitting device  10  may include a first electrode  110 , an interlayer  130  (including an emission layer  131  and an electron transport region  140 , which may include a first buffer layer  141  and a second buffer layer  142 ), and second electrode  150 . 
     Hereinafter, the structure of the light-emitting device  10  according to an embodiment and a method of manufacturing the light-emitting device  10  will be described in connection with  FIG. 1 . 
     First Electrode  110   
     In  FIG. 1 , a substrate may be additionally located under the first electrode  110  or above the second electrode  150 . As the substrate, a glass substrate or a plastic substrate may be utilized. In an embodiment, the substrate may be a flexible substrate, and may include plastics with suitable (e.g., excellent) heat resistance and durability, such as polyimide, polyethylene terephthalate (PET), polycarbonate, polyethylene naphthalate, polyarylate (PAR), polyetherimide, or any combination thereof. 
     The first electrode  110  may be formed by, for example, depositing or sputtering a material for forming the first electrode  110  on the substrate. When the first electrode  110  is an anode, a material for forming the first electrode  110  may be a high work function material that facilitates injection of holes. 
     The first electrode  110  may be a reflective electrode, a transflective electrode, or a transmissive electrode. When the first electrode  110  is a transmissive electrode, a material for forming the first electrode  110  may include indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO 2 ), zinc oxide (ZnO), or any combination thereof. In an embodiment, when the first electrode  110  is a transflective electrode or a reflective electrode, magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), or any combination thereof may be utilized as a material for forming a first electrode. 
     The first electrode  110  may have a single layer consisting of a single-layered structure or a multilayer structure including a plurality of layers. For example, the first electrode  110  may have a three-layered structure of ITO/Ag/ITO. 
     Interlayer  130   
     The interlayer  130  may be located on the first electrode  110 . The interlayer  130  may include an emission layer  131 . 
     The interlayer  130  may further include a hole transport region between the first electrode  110  and the emission layer  131  and an electron transport region  140  between the emission layer  131  and the second electrode  150 . 
     The interlayer  130  may further include, in addition to various suitable organic materials, a metal-containing compound such as an organometallic compound, an inorganic material such as quantum dots, and/or the like. 
     In an embodiment, the interlayer  130  may include, i) two or more emitting units sequentially stacked between the first electrode  110  and the second electrode  150  and ii) a charge generation layer located between two adjacent emitting units. When the interlayer  130  includes the two or more emitting units and the charge generation layer as described above, the light-emitting device  10  may be a tandem light-emitting device. 
     Hole Transport Region in Interlayer  130   
     The hole transport region may have: i) a single-layered structure consisting of a single layer consisting of a single material, ii) a single-layered structure consisting of a single layer including (e.g., consisting of) a plurality of different materials, or iii) a multi-layered structure including a plurality of layers including different materials. 
     The hole transport region may include a hole injection layer, a hole transport layer, an emission auxiliary layer, an electron blocking layer, or any combination thereof. 
     In some embodiments, the hole transport region may have a multi-layered structure including a hole injection layer/hole transport layer structure, a hole injection layer/hole transport layer/emission auxiliary layer structure, a hole injection layer/emission auxiliary layer structure, a hole transport layer/emission auxiliary layer structure, or a hole injection layer/hole transport layer/electron blocking layer structure, wherein, in each structure, layers are stacked sequentially from the first electrode  110  in the respective stated order. 
     The hole transport region may include a compound represented by Formula 201, a compound represented by Formula 202, or any combination thereof: 
     
       
         
         
             
             
         
       
     
     wherein, in Formulae 201 and 202, 
     L 201  to L 204  may each independently be a C 3 -C 60  carbocyclic group unsubstituted or substituted with at least one R 10a  or a C 1 -C 60  heterocyclic group unsubstituted or substituted with at least one R 10a , 
     L 205  may be *—O—*′, *—S—*′, *—N(Q 201 )—*′, a C 1 -C 20  alkylene group unsubstituted or substituted with at least one R 10a , a C 2 -C 20  alkenylene group unsubstituted or substituted with at least one R 10a , a C 3 -C 60  carbocyclic group unsubstituted or substituted with at least one R 10a , or a C 1 -C 60  heterocyclic group unsubstituted or substituted with at least one R 10a , 
     xa1 to xa4 may each independently be an integer from 0 to 5, 
     xa5 may be an integer from 1 to 10, 
     R 201  to R 204  and Q 201  may each independently be a C 3 -C 60  carbocyclic group unsubstituted or substituted with at least one R 10a  or a C 1 -C 60  heterocyclic group unsubstituted or substituted with at least one R 10a , 
     R 201  and R 202  may optionally be linked to each other, via a single bond, a C 1 -C 5  alkylene group unsubstituted or substituted with at least one R 10a , or a C 2 -C 5  alkenylene group unsubstituted or substituted with at least one R 10a , to form a C 8 -C 60  polycyclic group (for example, a carbazole group and/or the like) unsubstituted or substituted with at least one R 10a  (for example, Compound HT16), 
     R 203  and R 204  may optionally be linked to each other, via a single bond, a C 1 -C 5  alkylene group unsubstituted or substituted with at least one R 10a , or a C 2 -C 5  alkenylene group unsubstituted or substituted with at least one R 10a , to form a C 8 -C 60  polycyclic group unsubstituted or substituted with at least one R 10a , and 
     R 10a  is the same as to be described herein, * and *′ each indicate a binding site to a neighboring atom, and na1 may be an integer from 1 to 4. 
     In an embodiment, each of Formulae 201 and 202 may include at least one of the groups represented by Formulae CY201 to CY217. 
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     R 10b  and R 10c  in Formulae CY201 to CY217 may each independently be the same as described in connection with R 10a , ring CY 201  to ring CY 204  may each independently be a C 3 -C 20  carbocyclic group or a C 1 -C 20  heterocyclic group, and at least one hydrogen in Formulae CY201 to CY217 may be unsubstituted or substituted with R 10a , wherein R 10a  is the same as to be described herein. 
     In an embodiment, ring CY201 to ring CY204 in Formulae CY201 to CY217 may each independently be a benzene group, a naphthalene group, a phenanthrene group, or an anthracene group. 
     In an embodiment, each of Formulae 201 and 202 may include at least one of the groups represented by Formulae CY201 to CY203. 
     In an embodiment, Formula 201 may include at least one of the groups represented by Formulae CY201 to CY203 and at least one of the groups represented by Formulae CY204 to CY217. 
     In an embodiment, xa1 in Formula 201 may be 1, R 201  may be a group represented by one of Formulae CY201 to CY203, xa2 may be 0, and R 202  may be a group represented by one of Formulae CY204 to CY217. 
     In an embodiment, each of Formulae 201 and 202 may not include any of the groups represented by Formulae CY201 to CY203. 
     In an embodiment, each of Formulae 201 and 202 may not include any of the groups represented by Formulae CY201 to CY203, and may include at least one of the groups represented by Formulae CY204 to CY217. 
     In an embodiment, each of Formulae 201 and 202 may not include any of the groups represented by Formulae CY201 to CY217. 
     In an embodiment, the hole transport region may include one of Compounds HT1 to HT46, m-MTDATA, TDATA, 2-TNATA, NPB(NPD), β-NPB, TPD, Spiro-TPD, Spiro-NPB, methylated NPB, TAPC, HMTPD, 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA), polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA), poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS), polyaniline/camphor sulfonic acid (PANI/CSA), polyaniline/poly(4-styrenesulfonate) (PANI/PSS), or any combination thereof: 
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     A thickness of the hole transport region may be in a range of about 50 Å to about 10,000 Å, for example, about 100 Å to about 4,000 Å. When the hole transport region includes a hole injection layer, a hole transport layer, or any combination thereof, a thickness of the hole injection layer may be in a range of about 100 Å to about 9,000 Å, for example, about 100 Å to about 1,000 Å, and a thickness of the hole transport layer may be in a range of about 50 Å to about 2,000 Å, for example, about 100 Å to about 1,500 Å. When the thicknesses of the hole transport region, the hole injection layer and the hole transport layer are within these ranges, satisfactory hole transporting characteristics may be obtained without a substantial increase in driving voltage. 
     The emission auxiliary layer may increase light-emission efficiency by compensating for an optical resonance distance according to the wavelength of light emitted by the emission layer, and the electron blocking layer may block the flow (e.g., leakage) of electrons from an emission layer to a hole transport region. Materials that may be included in the hole transport region may be included in the emission auxiliary layer and the electron blocking layer. 
     p-Dopant 
     The hole transport region may further include, in addition to these materials, a charge-generation material for the improvement of conductive properties. The charge-generation material may be uniformly or non-uniformly dispersed in the hole transport region (for example, in the form of a single layer consisting of a charge-generation material). 
     The charge-generation material may be, for example, a p-dopant. 
     In an embodiment, the lowest unoccupied molecular orbital (LUMO) energy level of the p-dopant may be −3.5 eV or less. 
     In an embodiment, the p-dopant may include a quinone derivative, a cyano group-containing compound, a compound containing element EL1 and element EL2 (to be described in more detail below), or any combination thereof. 
     Examples of the quinone derivative may include (e.g., may be) TCNQ, F4-TCNQ, etc. 
     Examples of the cyano group-containing compound may include (e.g., may be) HAT-CN, and a compound represented by Formula 221 below. 
     
       
         
         
             
             
         
       
     
     In Formula 221, 
     R 221  to R 223  may each independently be a C 3 -C 60  carbocyclic group unsubstituted or substituted with at least one R 10a  or a C 1 -C 60  heterocyclic group unsubstituted or substituted with at least one R 10a , wherein R 10a  is the same as to be described herein, and 
     at least one of R 221  to R 223  may each independently be a C 3 -C 60  carbocyclic group or a C 1 -C 60  heterocyclic group, each substituted with a cyano group; —F; —Cl; —Br; —I; a C 1 -C 20  alkyl group substituted with a cyano group, —F, —Cl, —Br, —I, or any combination thereof; or any combination thereof. 
     In the compound containing element EL1 and element EL2, element EL1 may be a metal, a metalloid, or a combination thereof, and element EL2 may be a non-metal, a metalloid, or a combination thereof. 
     Examples of the metal may include (e.g., may be) an alkali metal (for example, lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), etc.); an alkaline earth metal (for example, beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), etc.); a transition metal (for example, titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), technetium (Tc), rhenium (Re), iron (Fe), ruthenium (Ru), osmium (Os), cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni), palladium (Pd), platinum (Pt), copper (Cu), silver (Ag), gold (Au), etc.); a post-transition metal (for example, zinc (Zn), indium (In), tin (Sn), etc.); and a lanthanide metal (for example, lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), etc.). 
     Examples of the metalloid may include (e.g., may be) silicon (Si), antimony (Sb), and tellurium (Te). 
     Examples of the non-metal may include (e.g., may be) oxygen (O) and halogen (for example, F, Cl, Br, I, etc.). 
     In an embodiment, examples of the compound containing element EL1 and element EL2 may include (e.g., may be) a metal oxide, a metal halide (for example, a metal fluoride, a metal chloride, a metal bromide, and/or a metal iodide), a metalloid halide (for example, a metalloid fluoride, a metalloid chloride, a metalloid bromide, and/or a metalloid iodide), a metal telluride, or any combination thereof. 
     Examples of the metal oxide may include (e.g., may be) tungsten oxide (for example, WO, W 2 O 3 , WO 2 , WO 3 , W 2 O 5 , etc.), vanadium oxide (for example, VO, V 2 O 3 , VO 2 , V 2 O 5 , etc.), molybdenum oxide (for example, MoO, Mo 2 O 3 , MoO 2 , MoO 3 , Mo 2 O 5 , etc.), and rhenium oxide (for example, ReO 3 , etc.). 
     Examples of the metal halide may include (e.g., may be) alkali metal halide, alkaline earth metal halide, transition metal halide, post-transition metal halide, and lanthanide metal halide. 
     Examples of the alkali metal halide may include (e.g., may be) LiF, NaF, KF, RbF, CsF, LiCl, NaCl, KCl, RbCl, CsCl, LiBr, NaBr, KBr, RbBr, CsBr, LiI, NaI, KI, RbI, and CsI. 
     Examples of the alkaline earth metal halide may include (e.g., may be) BeF 2 , MgF 2 , CaF 2 , SrF 2 , BaF 2 , BeCl 2 , MgCl 2 , CaCl 2 ), SrCl 2 , BaCl 2 , BeBr 2 , MgBr 2 , CaBr 2 , SrBr 2 , BaBr 2 , BeI 2 , MgI 2 , CaI 2 , SrI 2 , and BaI 2 . 
     Examples of the transition metal halide may include (e.g., may be) titanium halide (for example, TiF 4 , TiCl 4 , TiBr 4 , TiI 4 , etc.), zirconium halide (for example, ZrF 4 , ZrCl 4 , ZrBr 4 , ZrI 4 , etc.), hafnium halide (for example, HfF 4 , HfCl 4 , HfBr 4 , HfI 4 , etc.), vanadium halide (for example, VF 3 , VCl 3 , VBr 3 , VI 3 , etc.), niobium halide (for example, NbF 3 , NbCl 3 , NbBr 3 , NbI 3 , etc.), tantalum halide (for example, TaF 3 , TaCl 3 , TaBr 3 , TaI 3 , etc.), chromium halide (for example, CrF 3 , CrCl 3 , CrBr 3 , CrI 3 , etc.), molybdenum halide (for example, MoF 3 , MoCl 3 , MoBr 3 , MoI 3 , etc.), tungsten halide (for example, WF 3 , WCl 3 , WBr 3 , WI 3 , etc.), manganese halide (for example, MnF 2 , MnCl 2 , MnBr 2 , MnI 2 , etc.), technetium halide (for example, TcF 2 , TcCl 2 , TcBr 2 , TcI 2 , etc.), rhenium halide (for example, ReF 2 , ReCl 2 , ReBr 2 , ReI 2 , etc.), iron halide (for example, FeF 2 , FeCl 2 , FeBr 2 , FeI 2 , etc.), ruthenium halide (for example, RuF 2 , RuCl 2 , RuBr 2 , RuI 2 , etc.), osmium halide (for example, OsF 2 , OsCl 2 , OsBr 2 , OsI 2 , etc.), cobalt halide (for example, CoF 2 , CoCl 2 , CoBr 2 , CoI 2 , etc.), rhodium halide (for example, RhF 2 , RhCl 2 , RhBr 2 , RhI 2 , etc.), iridium halide (for example, IrF 2 , IrCl 2 , IrBr 2 , IrI 2 , etc.), nickel halide (for example, NiF 2 , NiCl 2 , NiBr 2 , NiI 2 , etc.), palladium halide (for example, PdF 2 , PdCl 2 , PdBr 2 , PdI 2 , etc.), platinum halide (for example, PtF 2 , PtCl 2 , PtBr 2 , PtI 2 , etc.), copper halide (for example, CuF, CuCl, CuBr, CuI, etc.), silver halide (for example, AgF, AgCl, AgBr, AgI, etc.), and gold halide (for example, AuF, AuCl, AuBr, AuI, etc.). 
     Examples of the post-transition metal halide may include (e.g., may be) zinc halide (for example, ZnF 2 , ZnCl 2 , ZnBr 2 , ZnI 2 , etc.), indium halide (for example, InI 3 , etc.), and tin halide (for example, SnI 2 , etc.). 
     Examples of the lanthanide metal halide may include (e.g., may be) YbF, YbF 2 , YbF 3 , SmF 3 , YbCl, YbCl 2 , YbCl 3 , SmCl 3 , YbBr, YbBr 2 , YbBr 3 , SmBr 3 , YbI, YbI 2 , YbI 3 , and Sm 13 . 
     An example of the metalloid halide may include (e.g., may be) antimony halide (for example, SbCl 5 , etc.). 
     Examples of the metal telluride may include (e.g., may be) alkali metal telluride (for example, Li 2 Te, Na 2 Te, K 2 Te, Rb 2 Te, Cs 2 Te, etc.), alkaline earth metal telluride (for example, BeTe, MgTe, CaTe, SrTe, BaTe, etc.), transition metal telluride (for example, TiTe 2 , ZrTe 2 , HfTe 2 , V 2 Te 3 , Nb 2 Te 3 , Ta 2 Te 3 , Cr 2 Te 3 , Mo 2 Te 3 , W 2 Te 3 , MnTe, TcTe, ReTe, FeTe, RuTe, OsTe, CoTe, RhTe, IrTe, NiTe, PdTe, PtTe, Cu 2 Te, CuTe, Ag 2 Te, AgTe, Au 2 Te, etc.), post-transition metal telluride (for example, ZnTe, etc.), and lanthanide metal telluride (for example, LaTe, CeTe, PrTe, NdTe, PmTe, EuTe, GdTe, TbTe, DyTe, HoTe, ErTe, TmTe, YbTe, LuTe, etc.). 
     Emission Layer  131  in Interlayer  130   
     When the light-emitting device  10  is a full-color light-emitting device, the emission layer  131  may be patterned into a red emission layer, a green emission layer, and/or a blue emission layer, according to a sub-pixel. In an embodiment, the emission layer  131  may have a stacked structure of two or more layers selected from a red emission layer, a green emission layer, and a blue emission layer, in which the two or more layers contact each other or are separated from each other. In an embodiment, the emission layer  131  may include two or more materials selected from a red light-emitting material, a green light-emitting material, and a blue light-emitting material, in which the two or more materials are mixed with each other in a single layer to emit white light. 
     The emission layer  131  may include a host and a dopant. The dopant may include a phosphorescent dopant, a fluorescent dopant, or any combination thereof. 
     The amount of the dopant in the emission layer may be from about 0.01 to about 15 parts by weight based on 100 parts by weight of the host. 
     In an embodiment, the emission layer  131  may include a quantum dot. 
     Meanwhile, the emission layer  131  may include a delayed fluorescence material. The delayed fluorescence material may act (e.g., serve) as a host or a dopant in the emission layer. 
     A thickness of the emission layer may be in a range of about 100 Å to about 1,000 Å, for example, about 200 Å to about 600 Å. When the thickness of the emission layer is within these ranges, suitable (e.g., excellent) light-emission characteristics may be obtained without a substantial increase in driving voltage. 
     Host 
     In an embodiment, the host may include a compound represented by Formula 301 below: 
       [Ar 301 ] xb11 -[(L 301 ) xb1 -R 301 ] xb21   Formula 301
 
     In Formula 301, 
     Ar 301  and L 301  may each independently be a C 3 -C 60  carbocyclic group unsubstituted or substituted with at least one R 10a  or a C 1 -C 60  heterocyclic group unsubstituted or substituted with at least one R 10a , 
     xb11 may be 1, 2, or 3, 
     xb1 may be an integer from 0 to 5, 
     R 301  may be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C 1 -C 60  alkyl group unsubstituted or substituted with at least one R 10a , a C 2 -C 60  alkenyl group unsubstituted or substituted with at least one R 10a , a C 2 -C 60  alkynyl group unsubstituted or substituted with at least one R 10a , a C 1 -C 60  alkoxy group unsubstituted or substituted with at least one R 10a , a C 3 -C 60  carbocyclic group unsubstituted or substituted with at least one R 10a , a C 1 -C 60  heterocyclic group unsubstituted or substituted with at least one R 10a , —Si(Q 301 )(Q 302 )(Q 303 ), —N(Q 301 )(Q 302 ), —B(Q 301 )(Q 302 ), —C(═O)(Q 301 ), —S(═O) 2 (Q 301 ), or —P(═O)(Q 301 )(Q 302 ), 
     xb21 may be an integer from 1 to 5, R 10a  is the same as to be described herein, and 
     Q 301  to Q 303  may each independently be the same as described in connection with Q 1 . 
     In one or more embodiments, when xb11 in Formula 301 is 2 or more, two or more of Ar 301 (s) may be linked to each other via a single bond. 
     In an embodiment, the host may include a compound represented by Formula 301-1, a compound represented by Formula 301-2, or any combination thereof: 
     
       
         
         
             
             
         
       
     
     In Formulae 301-1 and 301-2, 
     ring A 301  to ring A 304  may each independently be a C 3 -C 60  carbocyclic group unsubstituted or substituted with at least one R 10a  or a C 1 -C 60  heterocyclic group unsubstituted or substituted with at least one R 10a , wherein R 10a  is the same as to be described herein, 
     X 301  may be O, S, N-[(L 304 ) xb4 -R 304 ], C(R 304 )(R 305 ), or Si(R 304 )(R 305 ), 
     xb22 and xb23 may each independently be 0, 1, or 2, 
     L 301 , xb1, and R 301  may each be the same as respectively described in the present specification, 
     L 302  to L 304  may each independently be the same as described in connection with L 301 , 
     xb2 to xb4 may each independently be the same as described in connection with xb1, and 
     R 302  to R 305  and R 311  to R 314  may each independently be the same as described in connection with R 301 . 
     In an embodiment, the host may include an alkali earth metal complex, a post-transition metal complex, or a combination thereof. In an embodiment, the host may include a Be complex (for example, Compound H55), an Mg complex, a Zn complex, or any combination thereof. 
     In an embodiment, the host may include one of Compounds H1 to H125, 9,10-di(2-naphthyl)anthracene (ADN), 2-methyl-9,10-bis(naphthalen-2-yl)anthracene (MADN), 9,10-di-(2-naphthyl)-2-t-butyl-anthracene (TBADN), 4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP), 1,3-di-9-carbazolylbenzene (mCP), 1,3,5-tri(carbazol-9-yl)benzene (TCP), 3,3-di(9H-carbazol-9-yl)biphenyl (mCBP), or any combination thereof: 
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     Phosphorescent Dopant 
     In an embodiment, the phosphorescent dopant may include at least one transition metal as a central metal (e.g., a central metal atom). 
     The phosphorescent dopant may include a monodentate ligand, a bidentate ligand, a tridentate ligand, a tetradentate ligand, a pentadentate ligand, a hexadentate ligand, or any combination thereof. 
     The phosphorescent dopant may be electrically neutral. 
     For example, the phosphorescent dopant may include an organometallic compound represented by Formula 401: 
     
       
         
         
             
             
         
       
     
     In Formulae 401 and 402, 
     M may be a transition metal (for example, iridium (Ir), platinum (Pt), palladium (Pd), osmium (Os), titanium (Ti), gold (Au), hafnium (Hf), europium (Eu), terbium (Tb), rhodium (Rh), rhenium (Re), and/or thulium (Tm)), 
     L 401  may be a ligand represented by Formula 402, and xc1 may be 1, 2, or 3, wherein when xc1 is two or more, two or more of L 401 (s) may be identical to or different from each other, 
     L 402  may be an organic ligand, and xc2 may be 0, 1, 2, 3, or 4, and when xc2 is 2 or more, two or more of L 402 (s) may be identical to or different from each other, 
     X 401  and X 402  may each independently be nitrogen or carbon, 
     ring A 401  and ring A 402  may each independently be a C 3 -C 60  carbocyclic group or a C 1 -C 60  heterocyclic group, 
     T 401  may be a single bond, *—O—*′, *—S—*′, *—C(═O)—*′, *—N(Q 411 )—*′ *—C(Q 411 )(Q 412 )*′, *—C(Q 411 )═C(Q 412 )—*′, *—C(Q 411 )=*′, or *═C=*′, 
     X 403  and X 404  may each independently be a chemical bond (for example, a covalent bond or a coordination bond), O, S, N(Q 413 ), B(Q 413 ), P(Q 413 ), C(Q 413 )(Q 414 ), or Si(Q 413 )(Q 414 ), 
     Q 411  to Q 414  may each independently be the same as described in connection with Q 1 , 
     R 401  and R 402  may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C 1 -C 20  alkyl group unsubstituted or substituted with at least one R 10a , a C 1 -C 20  alkoxy group unsubstituted or substituted with at least one R 10a , a C 3 -C 60  carbocyclic group unsubstituted or substituted with at least one R 10a , a C 1 -C 60  heterocyclic group unsubstituted or substituted with at least one R 10a , —Si(Q 401 )(Q 402 )(Q 403 ), —N(Q 401 )(Q 402 ), —B(Q 401 )(Q 402 ), —C(═O)(Q 401 ), —S(═O) 2 (Q 401 ), or —P(═O)(Q 401 )(Q 402 ), 
     Q 401  to Q 403  may each independently be the same as described in connection with Q 1 , 
     xc11 and xc12 may each independently be an integer from 0 to 10, R 10a  is the same as to be described herein, and 
     * and *′ in T 401  each indicate a binding site to a neighboring atom, and * and *′ in Formula 402 each indicate a binding site to M in Formula 401. 
     n an embodiment, in Formula 402, i) X 401  may be nitrogen, and X 402  may be carbon, or ii) each of X 401  and X 402  may be nitrogen. 
     In an embodiment, when xc1 in Formula 401 is 2 or more, two ring A 401 (s) in two or more of L 401 (s) may be optionally linked to each other via T 402 , which is a linking group, and/or two ring A 402 (s) in two or more of L 401 (s) may optionally be linked to each other via T 403 , which is a linking group (see Compounds PD1 to PD4 and PD7). T 402  and T 403  may each independently be the same as described in connection with T 401 . 
     L 402  in Formula 401 may be an organic ligand. For example, L 402  may include a halogen group, a diketone group (for example, an acetylacetonate group), a carboxylic acid group (for example, a picolinate group), —C(═O), an isonitrile group, —CN group, a phosphorus-containing group (for example, a phosphine group, a phosphite group, etc.), or any combination thereof. 
     The phosphorescent dopant may include, for example, one of Compounds PD1 to PD26, or any combination thereof: 
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     Fluorescent Dopant 
     The fluorescent dopant may include an amine group-containing compound, a styryl group-containing compound, or any combination thereof. 
     In an embodiment, the fluorescent dopant may include a compound represented by Formula 501: 
     
       
         
         
             
             
         
       
     
     wherein, in Formula 501, 
     Ar 501 , L 501  to L 503 , R 501 , and R 502  may each independently be a C 3 -C 60  carbocyclic group unsubstituted or substituted with at least one R 10a  or a C 1 -C 60  heterocyclic group unsubstituted or substituted with at least one R 10a , wherein R 10a  is the same as to be described herein, 
     xd1 to xd3 may each independently be 0, 1, 2, or 3, and 
     xd4 may be 1, 2, 3, 4, 5, or 6. 
     In an embodiment, Ar 501  in Formula 501 may be a condensed cyclic group (for example, an anthracene group, a chrysene group, or a pyrene group) in which three or more monocyclic groups are condensed together. 
     In an embodiment, xd4 in Formula 501 may be 2. 
     In an embodiment, the fluorescent dopant may include: one of Compounds FD1 to FD36; DPVBi; DPAVBi; or any combination thereof: 
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     Delayed Fluorescence Material 
     The emission layer may include a delayed fluorescence material. 
     In the present specification, the delayed fluorescence material may be at least one selected from compounds capable of emitting delayed fluorescence based on a delayed fluorescence emission mechanism. 
     The delayed fluorescence material included in the emission layer may act (e.g., serve) as a host or a dopant depending on the kind (e.g., type) of other materials included in the emission layer. 
     In an embodiment, the difference between the triplet energy level (eV) of the delayed fluorescence material and the singlet energy level (eV) of the delayed fluorescence material may be greater than or equal to 0 eV and less than or equal to 0.5 eV. When the difference between the triplet energy level (eV) of the delayed fluorescence material and the singlet energy level (eV) of the delayed fluorescence material satisfies the above-described range, up-conversion from the triplet state to the singlet state of the delayed fluorescence material(s) may occur effectively, and thus, the emission efficiency of the light-emitting device  10  may be improved. 
     In an embodiment, the delayed fluorescence material may include i) a material including at least one electron donor (for example, a π electron-rich C 3 -C 60  cyclic group, such as a carbazole group) and at least one electron acceptor (for example, a sulfoxide group, a cyano group, and/or a π electron-deficient nitrogen-containing C 1 -C 60  cyclic group), and/or ii) a material including a C 8 -C 60  polycyclic group in which two or more cyclic groups are condensed while sharing boron (B). 
     In an embodiment, the delayed fluorescence material may include at least one of the following compounds DF1 to DF9: 
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     Quantum Dot 
     The emission layer may include a quantum dot. 
     In the present specification, a quantum dot refers to a crystal of a semiconductor compound, and may include any material capable of emitting light of various suitable emission wavelengths according to the size of the crystal. 
     A diameter of the quantum dot may be, for example, in a range of about 1 nm to about 10 nm. 
     The quantum dot may be synthesized by a wet chemical process, a metal organic (e.g., organometallic) chemical vapor deposition process, a molecular beam epitaxy process, or any process similar thereto. 
     According to the wet chemical process, a precursor material is mixed with an organic solvent to grow a quantum dot crystal particle. When the crystal grows, the organic solvent naturally acts (e.g., serves) as a dispersant coordinated on the surface of the quantum dot crystal and controls the growth of the crystal. Therefore, the growth of quantum dot particles can be controlled through a low-cost process which is more easily performed than vapor deposition methods, such as metal organic (e.g., organometallic) chemical vapor deposition (MOCVD) and/or molecular beam epitaxy (MBE). 
     The quantum dot may include Group II-VI semiconductor compounds, Group III-V semiconductor compounds, Group III-VI semiconductor compounds, Group I-III-VI semiconductor compounds, Group IV-VI semiconductor compounds, Group IV element or compound; or any combination thereof. 
     Examples of the Group II-VI semiconductor compound may include a binary compound, such as CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, and/or MgS; a ternary compound, such as CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, and/or MgZnS; a quaternary compound, such as CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and/or HgZnSTe; or any combination thereof. 
     Examples of the Group III-V semiconductor compound may include a binary compound, such as GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, and/or the like; a ternary compound, such as GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InNP, InAlP, InNAs, InNSb, InPAs, InPSb, and/or the like; a quaternary compound, such as GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, and/or the like; or any combination thereof. In one or more embodiments, the Groups III-V semiconductor compound may further include a Group II element. Examples of the Groups III-V semiconductor compound further including the Group II element may include InZnP, InGaZnP, InAlZnP, etc. 
     Examples of the Group III-VI semiconductor compound may include a binary compound, such as GaS, GaSe, Ga 2 Se 3 , GaTe, InS, InSe, In 2 S 3 , In 2 Se 3 , and/or InTe; a ternary compound, such as InGaS 3 , and/or InGaSe 3 ; or any combination thereof. 
     Examples of the Group I-III-VI semiconductor compound may include a ternary compound, such as AgInS, AgInS 2 , CuInS, CuInS 2 , CuGaO 2 , AgGaO 2 , and/or AgAlO 2 ; or any combination thereof. 
     Examples of the Group IV-VI semiconductor compound may include a binary compound, such as SnS, SnSe, SnTe, PbS, PbSe, PbTe, and/or the like; a ternary compound, such as SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, and/or the like; a quaternary compound, such as SnPbSSe, SnPbSeTe, SnPbSTe, and/or the like; or any combination thereof. 
     The Group IV element or compound may include a single element material, such as Si and/or Ge; a binary compound, such as SiC and/or SiGe; or any combination thereof. 
     Each element included in a multi-element compound such as the binary compound, the ternary compound and/or the quaternary compound, may exist in a particle with a uniform concentration or non-uniform concentration. 
     In some embodiments, the quantum dot may have a single structure or a dual core-shell structure. In the case of the quantum dot having a single structure, the concentration of each element included in the corresponding quantum dot may be uniform. In an embodiment, in a quantum dot with a core-shell structure, the material contained in the core and the material contained in the shell may be different from each other. 
     The shell of the quantum dot may act (e.g., serve) as a protective layer to prevent or reduce chemical degeneration of the core to maintain semiconductor characteristics and/or serve as a charging layer to impart electrophoretic characteristics to the quantum dot. The shell may be a single layer or a multi-layer. The interface between the core and the shell may have a concentration gradient in which the concentration of elements existing in the shell decreases toward the center of the core. 
     Examples of the shell of the quantum dot may include (e.g., may be) a metal oxide, a metalloid oxide, a non-metal oxide, a semiconductor compound, and any combination thereof. Examples of the metal oxide, the metalloid oxide, and the non-metal oxide may include (e.g., may be) a binary compound, such as SiO 2 , Al 2 O 3 , TiO 2 , ZnO, MnO, Mn 2 O 3 , Mn 3 O 4 , CuO, FeO, Fe 2 O 3 , Fe 3 O 4 , CoO, Co 3 O 4 , and/or NiO; a ternary compound, such as MgAl 2 O 4 , CoFe 2 O 4 , NiFe 2 O 4 , and/or CoMn 2 O 4 ; and any combination thereof. Examples of the semiconductor compound may include (e.g., may be), as described herein, Group II-VI semiconductor compounds; Group III-V semiconductor compounds; Group III-VI semiconductor compounds; Group I-III-VI semiconductor compounds; Group IV-VI semiconductor compounds; and any combination thereof. In addition, the semiconductor compound may include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, AlSb, or any combination thereof. 
     A full width at half maximum (FWHM) of an emission wavelength spectrum of the quantum dot may be about 45 nm or less, for example, about 40 nm or less, for example, about 30 nm or less, and within these ranges, color purity or color gamut (e.g., color reproducibility) may be increased. In addition, because the light emitted through the quantum dot is emitted in all directions, a wide viewing angle may be improved. 
     In addition, the quantum dot may be a spherical nanoparticle, a pyramidal nanoparticle, a multi-arm nanoparticle, a cubic nanoparticle, a nanotube, a nanowire, a nanofiber, and/or a nanoplate. 
     Because the energy band gap may be adjusted by controlling the size of the quantum dot, light having various suitable wavelength bands may be obtained from the quantum dot emission layer. Therefore, by utilizing quantum dots of different sizes, a light-emitting device that emits light of various suitable wavelengths may be implemented. In an embodiment, the size of the quantum dot may be selected to emit red, green and/or blue light. In addition, the size of the quantum dot may be configured to emit white light by combining light of various suitable colors. 
     Electron Transport Region  140  in Interlayer  130   
     The electron transport region  140  may have: i) a single-layered structure consisting of a single layer consisting of a single material, ii) a single-layered structure consisting of a single layer including (e.g., consisting of) a plurality of different materials, or iii) a multi-layered structure including a plurality of layers including different materials. 
     The electron transport region  140  may include a buffer layer, a hole blocking layer, an electron control layer, an electron transport layer, an electron injection layer, or any combination thereof. 
     In an embodiment, the electron transport region  140  may have an electron transport layer/electron injection layer structure, a hole blocking layer/electron transport layer/electron injection layer structure, an electron control layer/electron transport layer/electron injection layer structure, or a buffer layer/electron transport layer/electron injection layer structure, wherein, for each structure, constituting layers are sequentially stacked from the emission layer in the respective stated order. 
     In an embodiment, the buffer layer in the electron transport region  140  may include a first buffer layer  141  and a second buffer layer  142 . The first buffer layer  141  and the second buffer layer  142  may be the same as respectively described in the present specification. 
     In an embodiment, the electron transport region  140  (for example, the buffer layer, the hole blocking layer, the electron control layer, and/or the electron transport layer in the electron transport region  140 ) may include a metal-free compound including at least one π electron-deficient nitrogen-containing C 1 -C 60  cyclic group. 
     In an embodiment, the electron transport region  140  may include a compound represented by Formula 601 below: 
       [Ar 601 ] xe11 -[(L 601 ) xe1 -R 601 ] xe21   Formula 601
 
     wherein, in Formula 601, 
     Ar 601  and L 601  may each independently be a C 3 -C 60  carbocyclic group unsubstituted or substituted with at least one R 10a  or a C 1 -C 60  heterocyclic group unsubstituted or substituted with at least one R 10a , 
     xe11 may be 1, 2, or 3, 
     xe1 may be 0, 1, 2, 3, 4, or 5, 
     R 601  may be a C 3 -C 60  carbocyclic group unsubstituted or substituted with at least one R 10a , a C 1 -C 60  heterocyclic group unsubstituted or substituted with at least one R 10a , —Si(Q 601 )(Q 602 )(Q 603 ), —C(═O)(Q 601 ), —S(═O) 2 (Q 601 ), or —P(═O)(Q 601 )(Q 602 ), 
     Q 601  to Q 603  may each independently be the same as described in connection with Q 1 , 
     xe21 may be 1, 2, 3, 4, or 5, and 
     at least one of Ar 601 , L 601 , and R 601  may each independently be a π electron-deficient nitrogen-containing C 1 -C 60  cyclic group unsubstituted or substituted with at least one R 10a . 
     In an embodiment, when xe11 in Formula 601 is 2 or more, two or more of Ar 601 (s) may be linked to each other via a single bond. 
     In an embodiment, Ar 601  in Formula 601 may be a substituted or unsubstituted anthracene group. 
     In an embodiment, the electron transport region may include a compound represented by Formula 601-1: 
     
       
         
         
             
             
         
       
     
     In Formula 601-1, 
     X 614  may be N or C(R 614 ), X 615  may be N or C(R 615 ), X 616  may be N or C(R 616 ), at least one of X 614  to X 616  may be N, 
     L 611  to L 613  may each independently be the same as described in connection with L 601 , 
     xe611 to xe613 may each independently be the same as described in connection with xe1, 
     R 611  to R 613  may each independently be the same as described in connection with R 601 , and 
     R 614  to R 616  may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C 1 -C 20  alkyl group, a C 1 -C 20  alkoxy group, a C 3 -C 60  carbocyclic group unsubstituted or substituted with at least one R 10a , or a C 1 -C 60  heterocyclic group unsubstituted or substituted with at least one R 10a . 
     In an embodiment, xe1 and xe611 to xe613 in Formulae 601 and 601-1 may each independently be 0, 1, or 2. 
     The electron transport region  140  may include one of Compounds ET1 to ET46, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), Alq3, BAlq, TAZ, NTAZ, or any combination thereof: 
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     The thickness of the electron transport region  140  may be from about 100 Å to about 5,000 Å, for example, from about 100 Å to about 4,000 Å. When the electron transport region  140  includes a buffer layer, a hole blocking layer, an electron control layer, an electron transport layer, or any combination thereof, the thickness of the buffer layer, the thickness of the hole blocking layer, and/or the thickness of the electron control layer may each independently be from about 20 Å to about 1000 Å, for example, about 30 Å to about 300 Å, and the thickness of the electron transport layer may be from about 100 Å to about 1000 Å, for example, about 150 Å to about 500 Å. When the thickness(es) of the buffer layer, the hole blocking layer, the electron control layer, the electron transport layer and/or the electron transport region are within these ranges, satisfactory electron transporting characteristics may be obtained without a substantial increase in driving voltage. 
     The electron transport region  140  (for example, the electron transport layer in the electron transport region  140 ) may further include, in addition to the materials described above, a metal-containing material. 
     The metal-containing material may include an alkali metal complex, an alkaline earth metal complex, or any combination thereof. The metal ion of the alkali metal complex may be a Li ion, a Na ion, a K ion, a Rb ion, or a Cs ion, and the metal ion of the alkaline earth metal complex may be a Be ion, a Mg ion, a Ca ion, a Sr ion, or a Ba ion. A ligand coordinated with the metal ion of the alkali metal complex or the alkaline earth-metal complex may include a hydroxyquinoline, a hydroxyisoquinoline, a hydroxybenzoquinoline, a hydroxyacridine, a hydroxyphenanthridine, a hydroxyphenyloxazole, a hydroxyphenylthiazole, a hydroxyphenyloxadiazole, a hydroxyphenylthiadiazole, a hydroxyphenylpyridine, a hydroxyphenylbenzimidazole, a hydroxyphenylbenzothiazole, a bipyridine, a phenanthroline, a cyclopentadiene, or any combination thereof. 
     For example, the metal-containing material may include a Li complex. The Li complex may include, for example, Compound ET-D1 (Liq) or ET-D2: 
     
       
         
         
             
             
         
       
     
     The electron transport region  140  may include an electron injection layer that facilitates the injection of electrons from the second electrode  150 . The electron injection layer may be in direct contact with the second electrode  150 . 
     The electron injection layer may have: i) a single-layered structure consisting of a single layer consisting of a single material, ii) a single-layered structure consisting of a single layer including (e.g., consisting of) a plurality of different materials, or iii) a multi-layered structure including a plurality of layers including different materials. 
     The electron injection layer may include an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal-containing compound, an alkaline earth metal-containing compound, a rare earth metal-containing compound, an alkali metal complex, an alkaline earth metal complex, a rare earth metal complex, or any combination thereof. 
     The alkali metal may include Li, Na, K, Rb, Cs, or any combination thereof. The alkaline earth metal may include Mg, Ca, Sr, Ba, or any combination thereof. The rare earth metal may include Sc, Y, Ce, Tb, Yb, Gd, or any combination thereof. 
     The alkali metal-containing compound, the alkaline earth metal-containing compound, and the rare earth metal-containing compound may be one or more oxides, halides (for example, fluorides, chlorides, bromides, and/or iodides), and/or tellurides of the alkali metal, the alkaline earth metal, and the rare earth metal, or any combination thereof. 
     The alkali metal-containing compound may include alkali metal oxides (such as Li 2 O, Cs 2 O, and/or K 2 O), alkali metal halides (such as LiF, NaF, CsF, KF, LiI, NaI, CsI, and/or KI), or any combination thereof. The alkaline earth metal-containing compound may include an alkaline earth metal compound, such as BaO, SrO, CaO, Ba x Sr 1-x O (x is a real number satisfying the condition of 0&lt;x&lt;1), Ba x Ca 1-x O (x is a real number satisfying the condition of 0&lt;x&lt;1), and/or the like. The rare earth metal-containing compound may include YbF 3 , ScF 3 , Sc 2 O 3 , Y 2 O 3 , Ce 2 O 3 , GdF 3 , TbF 3 , YbI 3 , ScI 3 , TbI 3 , or any combination thereof. In an embodiment, the rare earth metal-containing compound may include lanthanide metal telluride. Examples of the lanthanide metal telluride may include (e.g., may be) LaTe, CeTe, PrTe, NdTe, PmTe, SmTe, EuTe, GdTe, TbTe, DyTe, HoTe, ErTe, TmTe, YbTe, LuTe, La 2 Te 3 , Ce 2 Te 3 , Pr 2 Te 3 , Nd 2 Te 3 , Pm 2 Te 3 , Sm 2 Te 3 , Eu 2 Te 3 , Gd 2 Te 3 , Tb 2 Te 3 , Dy 2 Te 3 , Ho 2 Te 3 , Er 2 Te 3 , Tm 2 Te 3 , Yb 2 Te 3 , and Lu 2 Te 3 . 
     The alkali metal complex, the alkaline earth-metal complex, and the rare earth metal complex may include i) one of ions of the alkali metal, the alkaline earth metal, and the rare earth metal and ii), as a ligand bonded to the metal ion, for example, hydroxyquinoline, hydroxyisoquinoline, hydroxybenzoquinoline, hydroxyacridine, hydroxyphenanthridine, hydroxyphenyloxazole, hydroxyphenylthiazole, hydroxyphenyloxadiazole, hydroxyphenylthiadiazole, hydroxyphenylpyridine, hydroxyphenyl benzimidazole, hydroxyphenylbenzothiazole, bipyridine, phenanthroline, cyclopentadiene, or any combination thereof. 
     The electron injection layer may include (e.g., consist of) an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal-containing compound, an alkaline earth metal-containing compound, a rare earth metal-containing compound, an alkali metal complex, an alkaline earth metal complex, a rare earth metal complex, or any combination thereof, as described above. In an embodiment, the electron injection layer may further include an organic material (for example, a compound represented by Formula 601). 
     In an embodiment, the electron injection layer may include (e.g., consist of) i) an alkali metal-containing compound (for example, an alkali metal halide), or ii) a) an alkali metal-containing compound (for example, an alkali metal halide); and b) an alkali metal, an alkaline earth metal, a rare earth metal, or any combination thereof. In an embodiment, the electron injection layer may be a KI:Yb co-deposited layer, an RbI:Yb co-deposited layer, and/or the like. 
     When the electron injection layer further includes an organic material, the alkali metal, the alkaline earth metal, the rare earth metal, the alkali metal-containing compound, the alkaline earth metal-containing compound, the rare earth metal-containing compound, the alkali metal complex, the alkaline earth-metal complex, the rare earth metal complex, or any combination thereof may be homogeneously or non-homogeneously dispersed in a matrix including the organic material. 
     A thickness of the electron injection layer may be in a range of about 1 Å to about 100 Å, and, for example, about 3 Å to about 90 Å. When the thickness of the electron injection layer is within the ranges described above, the electron injection layer may have satisfactory electron injection characteristics without a substantial increase in driving voltage. 
     Second Electrode  150   
     The second electrode  150  may be located on the interlayer  130  having a structure as described above. The second electrode  150  may be a cathode, which is an electron injection electrode, and as the material for the second electrode  150 , a metal, an alloy, an electrically conductive compound, or any combination thereof, each having a low work function, may be utilized. 
     In an embodiment, the second electrode  150  may include lithium (Li), silver (Ag), magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), ytterbium (Yb), silver-ytterbium (Ag—Yb), ITO, IZO, or any combination thereof. The second electrode  150  may be a transmissive electrode, a transflective electrode, or a reflective electrode. 
     The second electrode  150  may have a single-layered structure or a multi-layered structure including two or more layers. 
     Capping Layer 
     A first capping layer may be located outside the first electrode (e.g., on the side opposite to (e.g., facing oppositely away from) the second electrode)  110 , and/or a second capping layer may be located outside the second electrode (e.g., on the side opposite to (e.g., facing oppositely away from) the first electrode)  150 . In one or more embodiments, the light-emitting device  10  may have a structure in which the first capping layer, the first electrode  110 , the interlayer  130 , and the second electrode  150  are sequentially stacked in this stated order, a structure in which the first electrode  110 , the interlayer  130 , the second electrode  150 , and the second capping layer are sequentially stacked in this stated order, or a structure in which the first capping layer, the first electrode  110 , the interlayer  130 , the second electrode  150 , and the second capping layer are sequentially stacked in this stated order. 
     Light generated in the emission layer  131  of the interlayer  130  of the light-emitting device  10  may be extracted toward (e.g., transmitted or provided to) the outside through the first electrode  110 , which is a transflective electrode or a transmissive electrode, and the first capping layer, and/or light generated in an emission layer  131  of the interlayer  130  of the light-emitting device  10  may be extracted toward (e.g., transmitted or provided to) the outside through the second electrode  150 , which is a transflective electrode or a transmissive electrode, and the second capping layer. 
     The first capping layer and the second capping layer may increase external emission efficiency according to the principle of constructive interference. Accordingly, the light extraction efficiency of the light-emitting device  10  may be increased, so that the emission efficiency of the light-emitting device  10  may be improved. 
     Each of the first capping layer and second capping layer may include a material having a refractive index (at 589 nm) of 1.6 or more. 
     The first capping layer and the second capping layer may each independently be an organic capping layer including an organic material, an inorganic capping layer including an inorganic material, or an organic-inorganic composite capping layer including an organic material and an inorganic material. 
     At least one selected from the first capping layer and the second capping layer may each independently include a carbocyclic compound, a heterocyclic compound, an amine group-containing compound, a porphine derivative, a phthalocyanine derivative, a naphthalocyanine derivative, an alkali metal complex, an alkaline earth metal complex, or any combination thereof. The carbocyclic compound, the heterocyclic compound, and/or the amine group-containing compound may be optionally substituted with a substituent containing O, N, S, Se, Si, F, Cl, Br, I, or any combination thereof. In an embodiment, at least one of the first capping layer and the second capping layer may each independently include an amine group-containing compound. 
     In an embodiment, at least one of the first capping layer and the second capping layer may each independently include a compound represented by Formula 201, a compound represented by Formula 202, or any combination thereof. 
     In an embodiment, at least one of the first capping layer and the second capping layer may each independently include one of Compounds HT28 to HT33, one of Compounds CP1 to CP6, p-NPB, or any combination thereof: 
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     Film 
     The silicon-containing nonpolar compound may be included in various suitable films (e.g., members or parts). Therefore, according to an embodiment, a film including the silicon-containing nonpolar compound may be provided. The film may be, for example, an optical member (or light control means) (for example, a color filter, a color conversion member, a capping layer, an optical extraction efficiency improvement layer, an optional light absorbing layer, a polarizing layer, a quantum dot-containing layer, etc.), a light-shielding member (for example, a light reflection layer, a light absorbing layer, etc.), a protective member (for example, an insulating layer, a dielectric layer, etc.), etc. 
     Electronic Apparatus 
     The light-emitting device may be included in various suitable electronic apparatuses. In an embodiment, the electronic apparatus including the light-emitting device may be a light-emitting apparatus, an authentication apparatus, and/or the like. 
     The electronic apparatus (for example, a light-emitting apparatus) may further include, in addition to the light-emitting device, i) a color filter, ii) a color conversion layer, or iii) a color filter and a color conversion layer. The color filter and/or the color conversion layer may be located in at least one traveling direction of light emitted from the light-emitting device. In an embodiment, the light emitted from the light-emitting device may be blue light or white light. The light-emitting device may be the same as described above. In an embodiment, the color conversion layer may include quantum dots. The quantum dot may be, for example, a quantum dot as described herein. 
     The electronic apparatus may include a first substrate. The first substrate may include a plurality of subpixel areas, the color filter may include a plurality of color filter areas respectively corresponding to the plurality of subpixel areas, and the color conversion layer may include a plurality of color conversion areas respectively corresponding to the plurality of subpixel areas. 
     A pixel-defining film may be located among the plurality of subpixel areas to define each of the subpixel areas. 
     The color filter may further include a plurality of color filter areas and light-shielding patterns located among the plurality of color filter areas, and the color conversion layer may include a plurality of color conversion areas and light-shielding patterns located among the plurality of color conversion areas. 
     The plurality of color filter areas (or the plurality of color conversion areas) may include a first area emitting a first color light, a second area emitting a second color light, and/or a third area emitting a third color light, and the first color light, the second color light, and/or the third color light may have different maximum emission wavelengths from one another. In an embodiment, the first color light may be red light, the second color light may be green light, and the third color light may be blue light. In an embodiment, the color filter areas (or the color conversion areas) may include quantum dots. In an embodiment, the first area may include a red quantum dot (e.g., a red-light emitting quantum dot), the second area may include a green quantum dot (e.g., a green-light emitting quantum dot), and the third area may not include a quantum dot. The quantum dot may be the same as described in the present specification. The first area, the second area, and/or the third area may each further include a scatterer. 
     In an embodiment, the light-emitting device may emit a first light, the first area may absorb the first light to emit a first first-color light, the second area may absorb the first light to emit a second first-color light, and the third area may absorb the first light to emit a third first-color light. In this regard, the first first-color light, the second first-color light, and the third first-color light may have different maximum emission wavelengths. In an embodiment, the first light may be blue light, the first first-color light may be red light, the second first-color light may be green light, and the third first-color light may be blue light. 
     The electronic apparatus may further include a thin-film transistor in addition to the light-emitting device as described above. The thin-film transistor may include a source electrode, a drain electrode, and an activation layer (e.g., an active layer), wherein the source electrode or the drain electrode may be electrically connected to the first electrode or the second electrode of the light-emitting device. 
     The thin-film transistor may further include a gate electrode, a gate insulating film, etc. 
     The activation layer may include crystalline silicon, amorphous silicon, an organic semiconductor, an oxide semiconductor, and/or the like. 
     The electronic apparatus may further include a sealing portion for sealing the light-emitting device. The sealing portion may be placed between the color filter and the light-emitting device and/or between the light-emitting device and the color conversion layer. The sealing portion allows light from the light-emitting device to be extracted to the outside, while concurrently (or simultaneously) preventing or substantially preventing ambient air and/or moisture from penetrating into the light-emitting device. The sealing portion may be a sealing substrate including a transparent glass substrate or a plastic substrate. The sealing portion may be a thin-film encapsulation layer including at least one layer of an organic layer and/or an inorganic layer. When the sealing portion is a thin film encapsulation layer, the electronic apparatus may be flexible. 
     Various suitable functional layers may be additionally located on the sealing portion, in addition to the color filter and/or the color conversion layer, according to the usage of the electronic apparatus. The functional layers may include a touch screen layer, a polarizing layer, and/or the like. The touch screen layer may be a pressure-sensitive touch screen layer, a capacitive touch screen layer, or an infrared touch screen layer. The authentication apparatus may be, for example, a biometric authentication apparatus that authenticates an individual by utilizing biometric information of a living body (for example, fingertips, pupils, etc.). 
     The authentication apparatus may further include, in addition to the light-emitting device, a biometric information collector. 
     The electronic apparatus may be applied to various suitable displays, light sources, lighting (e.g., lighting apparatuses), personal computers (for example, a mobile personal computer), mobile phones, digital cameras, electronic organizers, electronic dictionaries, electronic game machines, medical instruments (for example, electronic thermometers, sphygmomanometers, blood glucose meters, pulse measurement devices, pulse wave measurement devices, electrocardiogram displays, ultrasonic diagnostic devices, and/or endoscope displays), fish finders, various suitable measuring instruments, meters (for example, meters for a vehicle, an aircraft, and/or a vessel), projectors, and/or the like. 
     Description of FIGS.  2  and  3   
       FIG. 2  is a cross-sectional view showing a light-emitting apparatus according to an embodiment of the present disclosure. 
     The light-emitting apparatus of  FIG. 2  includes a substrate  100 , a thin-film transistor (TFT), a light-emitting device, and an encapsulation portion  300  that seals the light-emitting device. 
     The substrate  100  may be a flexible substrate, a glass substrate, or a metal substrate. A buffer layer  210  may be formed on the substrate  100 . The buffer layer  210  may prevent or reduce penetration of impurities through the substrate  100  and may provide a flat surface on the substrate  100 . 
     A TFT may be located on the buffer layer  210 . The TFT may include an activation layer  220 , a gate electrode  240 , a source electrode  260 , and a drain electrode  270 . 
     The activation layer  220  may include an inorganic semiconductor such as silicon and/or polysilicon, an organic semiconductor, and/or an oxide semiconductor, and may include a source region, a drain region and a channel region. 
     A gate insulating film  230  for insulating the activation layer  220  from the gate electrode  240  may be located on the activation layer  220 , and the gate electrode  240  may be located on the gate insulating film  230 . 
     An interlayer insulating film  250  may be located on the gate electrode  240 . The interlayer insulating film  250  may be placed between the gate electrode  240  and the source electrode  260  to insulate the gate electrode  240  from the source electrode  260  and between the gate electrode  240  and the drain electrode  270  to insulate the gate electrode  240  from the drain electrode  270 . 
     The source electrode  260  and the drain electrode  270  may be located on the interlayer insulating film  250 . The interlayer insulating film  250  and the gate insulating film  230  may be formed to expose the source region and the drain region of the activation layer  220 , and the source electrode  260  and the drain electrode  270  may be in contact with the exposed portions of the source region and the drain region of the activation layer  220 . 
     The TFT may be electrically connected to a light-emitting device to drive the light-emitting device, and may be covered by a passivation layer  280 . The passivation layer  280  may include an inorganic insulating film, an organic insulating film, or a combination thereof. A light-emitting device may be provided on the passivation layer  280 . The light-emitting device may include a first electrode  110 , an interlayer  130 , and a second electrode  150 . 
     The first electrode  110  may be formed on the passivation layer  280 . The passivation layer  280  does not completely cover the drain electrode  270  and exposes a portion of the drain electrode  270 , and the first electrode  110  is connected to the exposed portion of the drain electrode  270 . 
     A pixel defining layer  290  containing an insulating material may be located on the first electrode  110 . The pixel defining layer  290  exposes a region of the first electrode  110 , and an interlayer  130  may be formed in the exposed region of the first electrode  110 . The pixel defining layer  290  may be a polyimide or a polyacrylic organic film. In one or more embodiments, at least some layers (e.g., one or more layers) of the interlayer  130  may extend beyond the upper portion of the pixel defining layer  290  to be in the form of a common layer. 
     The second electrode  150  may be located on the interlayer  130 , and a capping layer  170  may be additionally formed on the second electrode  150 . The capping layer  170  may be formed to cover the second electrode  150 . 
     The encapsulation portion  300  may be located on the capping layer  170 . The encapsulation portion  300  may be located on a light-emitting device to protect the light-emitting device from moisture and/or oxygen. The encapsulation portion  300  may include: an inorganic film including silicon nitride (SiN x ), silicon oxide (SiOx), indium tin oxide, indium zinc oxide, or any combination thereof; an organic film including polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, polyethylene sulfonate, polyoxymethylene, polyarylate, hexamethyldisiloxane, an acrylic-based resin (for example, polymethyl methacrylate, polyacrylic acid, and/or the like), an epoxy-based resin (for example, aliphatic glycidyl ether (AGE), and/or the like), or any combination thereof; or a combination of the inorganic film and the organic film. 
       FIG. 3  shows a cross-sectional view showing a light-emitting apparatus according to an embodiment of the present disclosure. 
     The light-emitting apparatus of  FIG. 3  is the same as the light-emitting apparatus of  FIG. 2 , except that a light-shielding pattern  500  and a functional region  400  are additionally located on the encapsulation portion  300 . The functional region  400  may be i) a color filter area, ii) a color conversion area, or iii) a combination of the color filter area and the color conversion area. In an embodiment, the light-emitting device included in the light-emitting apparatus of  FIG. 3  may be a tandem light-emitting device. 
     Manufacture Method 
     Respective layers included in the hole transport region, the emission layer, and respective layers included in the electron transport region may be formed in a certain region by utilizing one or more suitable methods selected from vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) deposition, ink-jet printing, laser-printing, and laser-induced thermal imaging. 
     When layers constituting the hole transport region, the emission layer, and layers constituting the electron transport region are formed by vacuum deposition, the deposition may be performed at a deposition temperature of about 100° C. to about 500° C., a vacuum degree of about 10 −8  torr to about 10 −3  torr, and a deposition speed of about 0.01 Å/sec to about 100 Å/sec, depending on a material to be included in a layer to be formed and the structure of a layer to be formed. 
     DEFINITION OF TERMS 
     The term “C 3 -C 60  carbocyclic group” as used herein refers to a cyclic group consisting of only carbon atoms as ring-forming atoms and having three to sixty carbon atoms, and the term “C 1 -C 60  heterocyclic group” as used herein refers to a cyclic group that has, in addition to one to sixty carbon atom(s), a heteroatom as ring-forming atoms. The C 3 -C 60  carbocyclic group and the C 1 -C 60  heterocyclic group may each be a monocyclic group consisting of one ring or a polycyclic group in which two or more rings are condensed with each other. For example, the C 1 -C 60  heterocyclic group may have 3 to 61 ring-forming atoms. 
     The term “cyclic group” as used herein may include the C 3 -C 60  carbocyclic group, and the C 1 -C 60  heterocyclic group. 
     The term “π electron-rich C 3 -C 60  cyclic group” as used herein refers to a cyclic group that has three to sixty carbon atoms and does not include *—N═*′ as a ring-forming moiety, and the term “π electron-deficient nitrogen-containing C 1 -C 60  cyclic group” as used herein refers to a heterocyclic group that has one to sixty carbon atoms and includes *—N═*′ as a ring-forming moiety. 
     For example, 
     the C 3 -C 60  carbocyclic group may be i) group T1 or ii) a condensed cyclic group in which two or more groups T1 are condensed with each other (for example, the C 3 -C 60  carbocyclic group may be a cyclopentadiene group, an adamantane group, a norbornane group, a benzene group, a pentalene group, a naphthalene group, an azulene group, an indacene group, an acenaphthylene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a perylene group, a pentaphene group, a heptalene group, a naphthacene group, a picene group, a hexacene group, a pentacene group, a rubicene group, a coronene group, an ovalene group, an indene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, an indenophenanthrene group, and/or an indenoanthracene group), 
     the C 1 -C 60  heterocyclic group may be i) group T2, ii) a condensed cyclic group in which two or more groups T2 are condensed with each other, or iii) a condensed cyclic group in which at least one group T2 and at least one group T1 are condensed with each other (for example, the C 1 -C 60  heterocyclic group may be a pyrrole group, a thiophene group, a furan group, an indole group, a benzoindole group, a naphthoindole group, an isoindole group, a benzoisoindole group, a naphthoisoindole group, a benzosilole group, a benzothiophene group, a benzofuran group, a carbazole group, a dibenzosilole group, a dibenzothiophene group, a dibenzofuran group, an indenocarbazole group, an indolocarbazole group, a benzofurocarbazole group, a benzothienocarbazole group, a benzosilolocarbazole group, a benzoindolocarbazole group, a benzocarbazole group, a benzonaphthofuran group, a benzonaphthothiophene group, a benzonaphthosilole group, a benzofurodibenzofuran group, a benzofurodibenzothiophene group, a benzothienodibenzothiophene group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, an oxadiazole group, a thiazole group, an isothiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzisoxazole group, a benzothiazole group, a benzoisothiazole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a benzoisoquinoline group, a quinoxaline group, a benzoquinoxaline group, a quinazoline group, a benzoquinazoline group, a phenanthroline group, a cinnoline group, a phthalazine group, a naphthyridine group, an imidazopyridine group, an imidazopyrimidine group, an imidazotriazine group, an imidazopyrazine group, an imidazopyridazine group, an azacarbazole group, an azafluorene group, an azadibenzosilole group, an azadibenzothiophene group, an azadibenzofuran group, etc.), 
     the π electron-rich C 3 -C 60  cyclic group may be i) group T1, ii) a condensed cyclic group in which two or more groups T1 are condensed with each other, iii) group T3, iv) a condensed cyclic group in which two or more groups T3 are condensed with each other, or v) a condensed cyclic group in which at least one group T3 and at least one group T1 are condensed with each other (for example, the π electron-rich C 3 -C 60  cyclic group may be the C 3 -C 60  carbocyclic group, a 1H-pyrrole group, a silole group, a borole group, a 2H-pyrrole group, a 3H-pyrrole group, a thiophene group, a furan group, an indole group, a benzoindole group, a naphthoindole group, an isoindole group, a benzoisoindole group, a naphthoisoindole group, a benzosilole group, a benzothiophene group, a benzofuran group, a carbazole group, a dibenzosilole group, a dibenzothiophene group, a dibenzofuran group, an indenocarbazole group, an indolocarbazole group, a benzofurocarbazole group, a benzothienocarbazole group, a benzosilolocarbazole group, a benzoindolocarbazole group, a benzocarbazole group, a benzonaphthofuran group, a benzonaphthothiophene group, a benzonaphthosilole group, a benzofurodibenzofuran group, a benzofurodibenzothiophene group, a benzothienodibenzothiophene group, etc.), 
     the π electron-deficient nitrogen-containing C 1 -C 60  cyclic group may be i) group T4, ii) a condensed cyclic group in which two or more groups T4 are condensed with each other, iii) a condensed cyclic group in which at least one group T4 and at least one group T1 are condensed with each other, iv) a condensed cyclic group in which at least one group T4 and at least one group T3 are condensed with each other, or v) a condensed cyclic group in which at least one group T4, at least one group T1, and at least one group T3 are condensed with one another (for example, the π electron-deficient nitrogen-containing C 1 -C 60  cyclic group may be a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, an oxadiazole group, a thiazole group, an isothiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzisoxazole group, a benzothiazole group, a benzoisothiazole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a benzoisoquinoline group, a quinoxaline group, a benzoquinoxaline group, a quinazoline group, a benzoquinazoline group, a phenanthroline group, a cinnoline group, a phthalazine group, a naphthyridine group, an imidazopyridine group, an imidazopyrimidine group, an imidazotriazine group, an imidazopyrazine group, an imidazopyridazine group, an azacarbazole group, an azafluorene group, an azadibenzosilole group, an azadibenzothiophene group, an azadibenzofuran group, etc.), 
     group T1 may be a cyclopropane group, a cyclobutane group, a cyclopentane group, a cyclohexane group, a cycloheptane group, a cyclooctane group, a cyclobutene group, a cyclopentene group, a cyclopentadiene group, a cyclohexene group, a cyclohexadiene group, a cycloheptene group, an adamantane group, a norbornane (or a bicyclo[2.2.1]heptane) group, a norbornene group, a bicyclo[1.1.1]pentane group, a bicyclo[2.1.1]hexane group, a bicyclo[2.2.2]octane group, or a benzene group, 
     group T2 may be a furan group, a thiophene group, a 1H-pyrrole group, a silole group, a borole group, a 2H-pyrrole group, a 3H-pyrrole group, an imidazole group, a pyrazole group, a triazole group, a tetrazole group, an oxazole group, an isoxazole group, an oxadiazole group, a thiazole group, an isothiazole group, a thiadiazole group, an azasilole group, an azaborole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a tetrazine group, a pyrrolidine group, an imidazolidine group, a dihydropyrrole group, a piperidine group, a tetrahydropyridine group, a dihydropyridine group, a hexahydropyrimidine group, a tetrahydropyrimidine group, a dihydropyrimidine group, a piperazine group, a tetrahydropyrazine group, a dihydropyrazine group, a tetrahydropyridazine group, or a dihydropyridazine group, 
     group T3 may be a furan group, a thiophene group, a 1H-pyrrole group, a silole group, or a borole group, and 
     group T4 may be a 2H-pyrrole group, a 3H-pyrrole group, an imidazole group, a pyrazole group, a triazole group, a tetrazole group, an oxazole group, an isoxazole group, an oxadiazole group, a thiazole group, an isothiazole group, a thiadiazole group, an azasilole group, an azaborole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, or a tetrazine group. 
     The terms “the cyclic group,” “the C 3 -C 60  carbocyclic group,” “the C 1 -C 60  heterocyclic group,” “the π electron-rich C 3 -C 60  cyclic group,” or “the π electron-deficient nitrogen-containing C 1 -C 60  cyclic group” as used herein each refer to a group condensed to any cyclic group or a monovalent or polyvalent group (for example, a divalent group, a trivalent group, a tetravalent group, etc.), depending on the structure of a formula in connection with which the terms are used. In an embodiment, “a benzene group” may be a benzo group, a phenyl group, a phenylene group, and/or the like, which may be easily understood by one of ordinary skill in the art according to the structure of a formula including the “benzene group.” 
     Examples of the monovalent C 3 -C 60  carbocyclic group and the monovalent C 1 -C 6  heterocyclic group may include a C 3 -C 10  cycloalkyl group, a C 1 -C 10  heterocycloalkyl group, a C 3 -C 10  cycloalkenyl group, a C 1 -C 10  heterocycloalkenyl group, a C 6 -C 60  aryl group, a C 1 -C 60  heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group, and examples of the divalent C 3 -C 60  carbocyclic group and the divalent C 1 -C 60  heterocyclic group may include a C 3 -C 10  cycloalkylene group, a C 1 -C 10  heterocycloalkylene group, a C 3 -C 10  cycloalkenylene group, a C 1 -C 10  heterocycloalkenylene group, a C 6 -C 60  arylene group, a C 1 -C 60  heteroarylene group, a divalent non-aromatic condensed polycyclic group, and a divalent non-aromatic condensed heteropolycyclic group. 
     The term “C 1 -C 60  alkyl group” as used herein refers to a linear or branched aliphatic hydrocarbon monovalent group that has one to sixty carbon atoms, and examples thereof may include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, a tert-pentyl group, a neopentyl group, an isopentyl group, a sec-pentyl group, a 3-pentyl group, a sec-isopentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isooctyl group, a sec-octyl group, a tert-octyl group, an n-nonyl group, an isononyl group, a sec-nonyl group, a tert-nonyl group, an n-decyl group, an isodecyl group, a sec-decyl group, and a tert-decyl group. The term “C 1 -C 60  alkylene group” as used herein refers to a divalent group having the same structure as the C 1 -C 60  alkyl group. 
     The term “C 2 -C 60  alkenyl group” as used herein refers to a monovalent hydrocarbon group having at least one carbon-carbon double bond in the middle and/or at a terminal end (e.g., the terminus) of the C 2 -C 60  alkyl group, and examples thereof may include an ethenyl group, a propenyl group, and a butenyl group. The term “C 2 -C 60  alkenylene group” as used herein refers to a divalent group having the same structure as the C 2 -C 60  alkenyl group. 
     The term “C 2 -C 60  alkynyl group” as used herein refers to a monovalent hydrocarbon group having at least one carbon-carbon triple bond in the middle and/or at a terminal end (e.g., the terminus) of the C 2 -C 60  alkyl group, and examples thereof may include an ethynyl group and a propynyl group. The term “C 2 -C 60  alkynylene group” as used herein refers to a divalent group having the same structure as the C 2 -C 60  alkynyl group. 
     The term “C 1 -C 60  alkoxy group” as used herein refers to a monovalent group represented by —OA 101  (wherein A 101  is the C 1 -C 60  alkyl group), and examples thereof may include a methoxy group, an ethoxy group, and an isopropyloxy group. 
     The term “C 3 -C 10  cycloalkyl group” as used herein refers to a monovalent saturated hydrocarbon cyclic group having 3 to 10 carbon atoms, and examples thereof may include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group (or bicyclo[2.2.1]heptyl group), a bicyclo[1.1.1]pentyl group, a bicyclo[2.1.1]hexyl group, and a bicyclo[2.2.2]octyl group. The term “C 3 -C 10  cycloalkylene group” as used herein refers to a divalent group having the same structure as the C 3 -C 10  cycloalkyl group. 
     The term “C 1 -C 10  heterocycloalkyl group” as used herein refers to a monovalent cyclic group that further includes, in addition to a carbon atom, at least one heteroatom as a ring-forming atom and has 1 to 10 carbon atoms, and examples thereof may include a 1,2,3,4-oxatriazolidinyl group, a tetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term “C 1 -C 10  heterocycloalkylene group” as used herein refers to a divalent group having the same structure as the C 1 -C 10  heterocycloalkyl group. 
     The term “C 3 -C 10  cycloalkenyl group” as used herein refers to a monovalent cyclic group that has three to ten carbon atoms and at least one carbon-carbon double bond in the ring thereof and no aromaticity, and examples thereof may include a cyclopentenyl group, a cyclohexenyl group, and a cycloheptenyl group. The term “C 3 -C 10  cycloalkenylene group” as used herein refers to a divalent group having the same structure as the C 3 -C 10  cycloalkenyl group. 
     The term “C 1 -C 10  heterocycloalkenyl group” as used herein refers to a monovalent cyclic group that has, in addition to a carbon atom, at least one heteroatom as a ring-forming atom, 1 to 10 carbon atoms, and at least one double bond (e.g., carbon-carbon double bond) in the cyclic structure thereof. Examples of the C 1 -C 10  heterocycloalkenyl group may include a 4,5-dihydro-1,2,3,4-oxatriazolyl group, a 2,3-dihydrofuranyl group, and a 2,3-dihydrothiophenyl group. The term “C 1 -C 10  heterocycloalkenylene group” as used herein refers to a divalent group having the same structure as the C 1 -C 10  heterocycloalkenyl group. 
     The term “C 6 -C 60  aryl group” as used herein refers to a monovalent group having a carbocyclic aromatic system having six to sixty carbon atoms, and the term “C 6 -C 60  arylene group” as used herein refers to a divalent group having a carbocyclic aromatic system having six to sixty carbon atoms. Examples of the C 6 -C 60  aryl group may include a phenyl group, a pentalenyl group, a naphthyl group, an azulenyl group, an indacenyl group, an acenaphthyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a heptalenyl group, a naphthacenyl group, a picenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, a fluorenyl group, and an ovalenyl group. When the C 6 -C 60  aryl group and the C 6 -C 60  arylene group each include two or more rings, the two or more rings may be condensed with each other. 
     The term “C 1 -C 60  heteroaryl group” as used herein refers to a monovalent group having a heterocyclic aromatic system that has, in addition to a carbon atom, at least one heteroatom as a ring-forming atom, and 1 to 60 carbon atoms. The term “C 1 -C 60  heteroarylene group” as used herein refers to a divalent group having a heterocyclic aromatic system that has, in addition to a carbon atom, at least one heteroatom as a ring-forming atom, and 1 to 60 carbon atoms. Examples of the C 1 -C 60  heteroaryl group may include a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, a benzoquinolinyl group, an isoquinolinyl group, a benzoisoquinolinyl group, a quinoxalinyl group, a benzoquinoxalinyl group, a quinazolinyl group, a benzoquinazolinyl group, a cinnolinyl group, a phenanthrolinyl group, a phthalazinyl group, a carbazolyl group, a dibenzofuranyl group, a dibenzothiofuranyl group, and a naphthyridinyl group. When the C 1 -C 60  heteroaryl group and the C 1 -C 60  heteroarylene group each include two or more rings, the two or more rings may be condensed with each other. 
     The term “monovalent non-aromatic condensed polycyclic group” as used herein refers to a monovalent group having two or more rings condensed to each other, only carbon atoms (for example, having 8 to 60 carbon atoms) as ring-forming atoms, and no aromaticity in its entire molecular structure. Examples of the monovalent non-aromatic condensed polycyclic group may include an indenyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, an indenophenanthrenyl group, an adamantyl group, and an indeno anthracenyl group. The term “divalent non-aromatic condensed polycyclic group” as used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed polycyclic group. 
     The term “monovalent non-aromatic condensed heteropolycyclic group” as used herein refers to a monovalent group having two or more rings condensed to each other, at least one heteroatom other than carbon atoms (for example, having 1 to 60 carbon atoms), as a ring-forming atom, and non-aromaticity in its entire molecular structure. Examples of the monovalent non-aromatic condensed heteropolycyclic group may include a pyrrolyl group, a thiophenyl group, a furanyl group, an indolyl group, a benzoindolyl group, a naphtho indolyl group, an isoindolyl group, a benzoisoindolyl group, a naphthoisoindolyl group, a benzosilolyl group, a benzothiophenyl group, a benzofuranyl group, a carbazolyl group, a dibenzosilolyl group, a dibenzothiophenyl group, a dibenzofuranyl group, an azacarbazolyl group, an azafluorenyl group, an azadibenzosilolyl group, an azadibenzothiophenyl group, an azadibenzofuranyl group, a pyrazolyl group, an imidazolyl group, a triazolyl group, a tetrazolyl group, an oxazolyl group, an isoxazolyl group, a thiazolyl group, an isothiazolyl group, an oxadiazolyl group, a thiadiazolyl group, a benzopyrazolyl group, a benzimidazolyl group, a benzoxazolyl group, a benzothiazolyl group, a benzoxadiazolyl group, a benzothiadiazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an imidazotriazinyl group, an imidazopyrazinyl group, an imidazopyridazinyl group, an indenocarbazolyl group, an indolocarbazolyl group, a benzofurocarbazolyl group, a benzothienocarbazolyl group, a benzosilolocarbazolyl group, a benzoindolocarbazolyl group, a benzocarbazolyl group, a benzonaphthofuranyl group, a benzonaphthothiophenyl group, a benzonaphthosilolyl group, a benzofurodibenzofuranyl group, a benzofurodibenzothiophenyl group, and a benzothienodibenzothiophenyl group. The term “divalent non-aromatic condensed heteropolycyclic group” as used herein refers to a divalent group having the same structure as a monovalent non-aromatic condensed heteropolycyclic group. 
     The term “C 6 -C 60  aryloxy group” as used herein refers to a monovalent group represented by —OA 102  (wherein A 102  is the C 6 -C 60  aryl group), and the term “C 6 -C 60  arylthio group” as used herein refers to a monovalent group represented by —SA 103  (wherein A 103  is the C 6 -C 60  aryl group). 
     The term “C 7 -C 60  aryl alkyl group” as used herein refers to a monovalent group represented by -A 104 A 105  (where A 104  may be a C 1 -C 54  alkylene group, and A 105  may be a C 6 -C 59  aryl group), and the term C 2 -C 60  heteroaryl alkyl group” as used herein refers to -A 106 A 107  (where A 106  may be a C 1 -C 59  alkylene group, and A 107  may be a C 1 -C 59  heteroaryl group). 
     The term “R 10a ” as used herein refers to: 
     deuterium (-D), —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, or a nitro group; 
     a C 1 -C 60  alkyl group, a C 2 -C 60  alkenyl group, a C 2 -C 60  alkynyl group, or a C 1 -C 60  alkoxy group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C 3 -C 60  carbocyclic group, a C 1 -C 60  heterocyclic group, a C 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, a C 7 -C 60  aryl alkyl group, a C 2 -C 60  heteroaryl alkyl group, —Si(Q 11 )(Q 12 )(Q 13 ), —N(Q 11 )(Q 12 ), —B(Q 11 )(Q 12 ), —C(═O)(Q 11 ), —S(═O) 2 (Q 11 ), —P(═O)(Q 11 )(Q 12 ), or any combination thereof; 
     a C 3 -C 60  carbocyclic group, a C 1 -C 60  heterocyclic group, a C 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, a C 7 -C 60  aryl alkyl group, or a C 2 -C 60  heteroaryl alkyl group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C 1 -C 60  alkyl group, a C 2 -C 60  alkenyl group, a C 2 -C 60  alkynyl group, a C 1 -C 60  alkoxy group, a C 3 -C 60  carbocyclic group, a C 1 -C 60  heterocyclic group, a C 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, a C 7 -C 60  aryl alkyl group, a C 2 -C 60  heteroaryl alkyl group, —Si(Q 21 )(Q 22 )(Q 23 ), —N(Q 21 )(Q 22 ), —B(Q 21 )(Q 22 ), —C(═O)(Q 21 ), —S(═O) 2 (Q 21 ), —P(═O)(Q 21 )(Q 22 ), or any combination thereof; or 
     —Si(Q 31 )(Q 32 )(Q 33 ), —N(Q 31 )(Q 32 ), —B(Q 31 )(Q 32 ), —C(═O)(Q 31 ), —S(═O) 2 (Q 31 ), or —P(═O)(Q 31 )(Q 32 ). 
     Q 1  to Q 3 , Q 11  to Q 13 , Q 21  to Q 23 , and Q 31  to Q 33  as used herein may each independently be: hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; a C 1 -C 6  alkyl group; a C 2 -C 60  alkenyl group; a C 2 -C 60  alkynyl group; a C 1 -C 60  alkoxy group; a C 3 -C 60  carbocyclic group or a C 1 -C 60  heterocyclic group, each unsubstituted or substituted with deuterium, —F, a cyano group, a C 1 -C 60  alkyl group, a C 1 -C 60  alkoxy group, a phenyl group, a biphenyl group, or any combination thereof; a C 7 -C 60  aryl alkyl group; or a C 2 -C 60  heteroaryl alkyl group. 
     The term “heteroatom” as used herein refers to any atom other than a carbon atom. Examples of the heteroatom may include O, S, N, P, Si, B, Ge, Se, and any combination thereof. 
     The term “the transition metal” (e.g., a third-row transition metal) as used herein may include hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), etc. 
     The term “Ph” as used herein refers to a phenyl group, the term “Me” as used herein refers to a methyl group, the term “Et” as used herein refers to an ethyl group, the term “tert-Bu” or “Bu t ” as used herein refers to a tert-butyl group, and the term “OMe” as used herein refers to a methoxy group. 
     The term “biphenyl group” as used herein refers to “a phenyl group substituted with a phenyl group.” In other words, the “biphenyl group” is a substituted phenyl group having a C 6 -C 60  aryl group as a substituent. 
     The term “terphenyl group” as used herein refers to “a phenyl group substituted with a biphenyl group”. In other words, the “terphenyl group” is a substituted phenyl group having, as a substituent, a C 6 -C 60  aryl group substituted with a C 6 -C 60  aryl group. 
     * and *′ as used herein, unless defined otherwise, each refer to a binding site to a neighboring atom in a corresponding formula or moiety. 
     Hereinafter, a compound according to embodiments and a light-emitting device according to embodiments will be described in more detail with reference to Synthesis Examples and Examples. The expression “B was utilized instead of A” as used in describing Synthesis Examples refers to that an identical molar equivalent of B was utilized in place of A. 
     Examples 
     Synthesis Example 1: Synthesis of Compound 1 
     
       
         
         
             
             
         
       
     
     (1) Synthesis of Intermediate 1-1 
     3-(bromophenyl)triphenylsilane (1 eq) and THF (150 ml) were added to a round-bottom flask (RBF). nBuLi (2 M, 17 ml, 1.2 eq) was dissolved in hexane and was slowly added dropwise to the solution at a temperature of −78° C. The resultant mixture was stirred for 40 minutes and trimethyl borate (5.75 ml, 1.5 eq) was slowly added dropwise thereto. The mixture was slowly heated up to room temperature, stirred overnight, and the reaction was quenched with water and NH 4 Cl solution. The reaction product was washed with ethyl acetate (EA) and H 2 O, dried with MgSO 4 , and separated by methylene chloride (MC):EA column chromatography to thereby obtain Intermediate 1-1 (yield of 87%). 
     C 24 H 21 BO 2 Si [M]+: calculated: 380.33, found: 379 
     
       
         
         
             
             
         
       
     
     (2) Synthesis of Intermediate 1-2 
     Dichlorodiphenylsilane (1 eq) and THF (150 ml) were added to an RBF. nBuLi (2 M, 30 ml. 2.2 eq) was dissolved in hexane and was slowly added dropwise to the solution at a temperature of −78° C. The resultant mixture was stirred for 30 minutes and 1,3-dibromobenzene (2.3 eq, 1 M solution in THF) was slowly added dropwise thereto. The mixture was slowly heated up to room temperature, stirred overnight, and the reaction was quenched with water and NH 4 Cl solution. The reaction product was washed with ethyl acetate (EA) and H 2 O, dried with MgSO 4 , and separated by MC:EA column chromatography to thereby obtain Intermediate 1-2 (yield of 70%). 
     C 24 H 18 Br 2 Si [M]+: calculated: 491.95, found: 491 
     (3) Synthesis of Compound 1 
     Intermediate 1-2 (1 eq), Pd (PPh 3 ) 4  (0.05 eq), K 2 CO 3  (2.1 eq), THF (400 ml), and H 2 O (100 ml) were added to an RBF and stirred. The temperature was cooled to 0° C., and 1 M of solution of Intermediate 1-1 dissolved in THF was added dropwise to the solution (e.g., in the RBF). The resultant mixture was slowly heated up to room temperature and stirred overnight. EA and H 2 O were added to the reaction, stirred for 30 minutes, and only an organic layer was separated therefrom utilizing a separation funnel. The separated product was dried with MgSO 4 , put through MC silica filtration, and the resulting solid was filtered utilizing MeOH, and was dried. The dried solid was boiled in toluene (100 ml) and melted, a mixture of MC and hexane (MC:hexane=1:1, 100 ml) was added dropwise thereto, and was solidified (e.g., a solid was collected). The solid was melt in MC and separated by MC:EA column chromatography to thereby synthesize Compound 1 (yield of 61%). 
     C 72 H 56 Si 3  [M]+: calculated: 1004.4, found: 1003 
     Elemental Analysis for calcd: C, 86.01; H, 5.61; Si, 8.38 
     Synthesis Example 2: Synthesis of Compound 3 
     
       
         
         
             
             
         
       
     
     (1) Synthesis of Compound 3 
     1,3,5-tribromobenzene (1 eq), Pd(PPh 3 ) 4  (0.1 eq), K 2 CO 3  (3.2 eq), THF (200 ml), and H 2 O (50 ml) were added to an RBF and stirred. The temperature was cooled to 0° C., and 1 M of solution of Intermediate 1-1 dissolved in THF was added dropwise to the solution. The resultant mixture was slowly heated to room temperature and stirred overnight. EA and H 2 O were added to the reaction, stirred for 30 minutes, and only an organic layer was separated therefrom utilizing a separation funnel. The separated product was dried with MgSO 4 , put through MC silica filtration, and the resulting solid was filtered utilizing MeOH, and was dried. The dried solid was boiled in toluene (100 ml) and melted, a mixture of MC and hexane (MC:hexane=1:1, 100 ml) was added dropwise thereto, and was solidified (e.g., a solid was collected). The solid was melted in MC and separated by MC:EA column chromatography to thereby synthesize Compound 3 (yield of 55%). 
     C 78 H 60 Si 3  [M]+: calculated: 1080.4, found: 1079 
     Elemental Analysis for calcd: C, 86.62; H, 5.59; Si,  7 . 79   
     Synthesis Example 3: Synthesis of Compound 5 
     
       
         
         
             
             
         
       
     
     (1) Synthesis of Compound 5 
     3,3′-dibromo-1,1′-biphenyl (1 eq), Pd(PPh 3 ) 4  (0.1 eq), K 2 CO 3  (2.1 eq), THF (200 ml), and H 2 O (50 ml) were added to an RBF and stirred. The temperature was cooled to 0° C., and 1 M of solution of Intermediate 1-1 dissolved in THF was added dropwise to the solution. The resultant mixture was slowly heated to room temperature and stirred overnight. EA and H 2 O were added to the reaction, stirred for 30 minutes, and only an organic layer was separated therefrom utilizing a separation funnel. The separated product was dried with MgSO 4 , put through MC silica filtration, and the resulting solid was filtered utilizing MeOH, and was dried. The dried solid was boiled in toluene (100 ml) and melted, a mixture of MC and hexane (MC:hexane=1:1, 100 ml) was added dropwise thereto, and was solidified (e.g., a solid was collected). The solid was melted in MC and separated by CHCl 3 : hexane column chromatography to thereby synthesize Compound 5 (yield of 63%). 
     C 60 H 46 Si 2  [M]+: calculated: 822.3, found: 821 
     Elemental Analysis for calcd: C, 87.54; H, 5.63; Si, 6.82 
     Example 1 
     As an anode, a Corning 15 Ω/cm 2  (1,200 Å) ITO glass substrate was cut to a size of 50 mm×50 mm×0.5 mm, sonicated with isopropyl alcohol and pure water each for 10 minutes, and then cleaned by exposure to ultraviolet rays and ozone for 10 minutes. The ITO glass substrate was provided to a vacuum deposition apparatus. 
     m-MTDATA was vacuum-deposited on the ITO anode formed on the glass substrate to form a hole injection layer having a thickness of 4 nm. 
     NPB was vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 1 nm. 
     mCBP (host 1), H125 (host 2), and PD25 (dopant) were co-deposited on the hole transport layer to a weight ratio of 4.5:4.5:1 to form an emission layer having a thickness of 40 nm. 
     Then, Compound 1 was deposited on the emission layer to form a first buffer layer having a thickness of 2.5 nm. 
     ET46 was vacuum-deposited on the first buffer layer to form a second buffer layer having a thickness of 5 nm. 
     ET1 was vacuum-deposited on the second buffer layer to form an electron transport layer having a thickness of 30 nm, and Mg was vacuum-deposited on the electron transport layer to form a cathode having a thickness of 80 nm, thereby completing the manufacture of a light-emitting device. 
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     Example 2 to 6 and Comparative Example 1 
     Light-emitting devices were manufactured in the same manner as in Example 1 except that compounds shown in Table 1 were utilized to form first buffer layers having respective thicknesses instead of utilizing Compound 1 to form a first buffer layer having a thickness of 2.5 nm. 
     Evaluation Example 1 
     To evaluate characteristics of the light-emitting devices manufactured according to Examples 1 to 6 and Comparative Example 1, the driving voltage (V) at a current density of 1,000 cd/m 2 , emission efficiency (%), and lifespan (T 95 , hr) thereof were each measured utilizing a Keithley MU 236 and luminance meter PR650, and the results thereof are shown in Table 1. The lifespan is a measure of the time taken for the luminance to drop from the initial luminance to 95% of the initial luminance. 
     
       
         
           
               
               
               
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                   
                 Thick- 
                 Driving 
                 Emission 
                 Life- 
               
               
                   
                 First buffer 
                 ness 
                 voltage 
                 efficiency 
                 span 
               
               
                   
                 layer 
                 (nm) 
                 (V) 
                 (%) 
                 (T 95 , hr) 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 Example 1 
                 Compound 1 
                 2.5 
                 4.8 
                 10.1 
                 55 
               
               
                 Example 2 
                 Compound 1 
                 5 
                 5.0 
                 10.8 
                 59 
               
               
                 Example 3 
                 Compound 3 
                 2.5 
                 4.9 
                 10.6 
                 62 
               
               
                 Example 4 
                 Compound 3 
                 5 
                 5.1 
                 11.0 
                 70 
               
               
                 Example 5 
                 Compound 5 
                 2.5 
                 4.8 
                 10.0 
                 49 
               
               
                 Example 6 
                 Compound 5 
                 5 
                 5.0 
                 10.4 
                 50 
               
               
                 Comparative 
                 Compound A 
                 5 
                 5.2 
                 9.5 
                 35 
               
               
                 Example 1 
               
               
                   
               
            
           
         
       
     
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     Table 1 shows that the light-emitting devices of Examples 1 to 6 each have a low driving voltage, a suitable (e.g., excellent) emission efficiency, and a long lifespan. 
     It should be understood that embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments. While one or more embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various suitable changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims, and equivalents thereof.