Patent Publication Number: US-11038113-B2

Title: Organic light-emitting device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a continuation application based on pending application Ser. No. 14/723,136 filed May 27, 2015, the entire contents of which is hereby incorporated by reference. 
     Korean Patent Application No. 10-2014-0161628, filed on Nov. 19, 2014, in the Korean Intellectual Property Office, and entitled: “Organic Light-Emitting Device,” is incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     1. Field 
     Embodiments relate to an organic light-emitting device. 
     2. Description of the Related Art 
     Organic light-emitting devices are self-emission devices that have wide viewing angles, high contrast ratios, short response times, and excellent brightness, driving voltage, and response speed characteristics, and produce full-color images. 
     The organic light-emitting device may include a first electrode disposed on a substrate, and a hole transport region, an emission layer, an electron transport region, and a second electrode, which are sequentially disposed 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, are recombined in the emission layer to produce excitons. These excitons change from an excited state to a ground state, thereby generating light. 
     SUMMARY 
     Embodiments are directed to an organic light-emitting device. 
     According to one or more exemplary embodiments, provided is an organic light-emitting device including: 
     a first electrode; 
     a second electrode facing the first electrode; 
     an emission layer disposed between the first electrode and the second electrode; and 
     an electron transport region disposed between the emission layer and the second electrode, 
     wherein the electron transport region may include a condensed cyclic compound represented by Formula 1 below: 
     
       
         
         
             
             
         
       
     
     wherein in Formulae 1 and 2 above, 
     A 1  ring and A 2  ring may be condensed with each other; 
     A 1  ring may be a substituted or unsubstituted benzene ring; 
     A 2  ring may be represented by Formula 2 above, X 1  may be selected from N-[(L 1 ) a1 -(Ar 1 ) b1 ], an oxygen atom (O) and a sulfur atom (S); 
     L 1  may be selected from a substituted or unsubstituted C 3 -C 10  cycloalkylene group, a substituted or unsubstituted C 1 -C 10  heterocycloalkylene group, a substituted or unsubstituted C 3 -C 10  cycloalkenylene group, a substituted or unsubstituted C 1 -C 10  heterocycloalkenylene group, a substituted or unsubstituted C 6 -C 60  arylene group, a substituted or unsubstituted C 1 -C 60  heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group; 
     a1 may be selected from integers of 0 to 3; 
     Ar 1  may be selected from a substituted or unsubstituted C 1 -C 10  heterocycloalkyl group, a substituted or unsubstituted C 1 -C 10  heterocycloalkenyl group, a substituted or unsubstituted C 1 -C 60  heteroaryl group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group; 
     b1 may be an integer selected from 1 to 3; 
     R 1  to R 12  may be each independently selected from a hydrogen, a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, a substituted or unsubstituted C 1 -C 60  alkyl group, a substituted or unsubstituted C 2 -C 60  alkenyl group, a substituted or unsubstituted C 2 -C 60  alkynyl group, a substituted or unsubstituted C 1 -C 60  alkoxy group, a substituted or unsubstituted C 3 -C 10  cycloalkyl group, a substituted or unsubstituted C 1 -C 10  heterocycloalkyl group, a substituted or unsubstituted C 3 -C 10  cycloalkenyl group, a substituted or unsubstituted C 1 -C 10  heterocycloalkenyl group, a substituted or unsubstituted C 6 -C 60  aryl group, a substituted or unsubstituted C 6 -C 60  aryloxy group, a substituted or unsubstituted C 6 -C 60  arylthio group, a substituted or unsubstituted C 1 -C 60  heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group and —Si(Q 1 )(Q 2 )(Q 3 ); 
     at least one substituent of the substituted benzene ring, the substituted C 3 -C 10  cycloalkylene group, substituted C 1 -C 10  heterocycloalkylene group, substituted C 3 -C 10  cycloalkenylene group, substituted C 1 -C 10  heterocycloalkenylene group, substituted C 6 -C 60  arylene group, substituted C 1 -C 60  heteroarylene group, substituted divalent non-aromatic condensed polycyclic group, substituted divalent non-aromatic condensed heteropolycyclic group, substituted C 1 -C 60  alkyl group, substituted C 2 -C 60  alkenyl group, substituted C 2 -C 60  alkynyl group, substituted C 1 -C 60  alkoxy group, substituted C 3 -C 10  cycloalkyl group, substituted C 1 -C 10  heterocycloalkyl group, substituted C 3 -C 10  cycloalkenyl group, substituted C 1 -C 10  heterocycloalkenyl group, substituted C 6 -C 60  aryl group, substituted C 6 -C 60  aryloxy group, substituted C 6 -C 60  arylthio group, substituted C 1 -C 60  heteroaryl group, substituted monovalent non-aromatic condensed polycyclic group and substituted monovalent non-aromatic condensed heteropolycyclic group may be selected from 
     a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, a C r  C 60  alkyl group, a C 2 -C 60  alkenyl group, a C 2 -C 60  alkynyl group, and a C 1 -C 60  alkoxy group; 
     a C 1 -C 60  alkyl group, a C 2 -C 60  alkenyl group, a C 2 -C 60  alkynyl group, and a C 1 -C 60  alkoxy group, each substituted with at least one selected from a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, 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 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, a C 1 -C 60  heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, and —Si(Q 11 )(Q 12 )(Q 13 ); 
     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 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, a C 1 -C 60  heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group; 
     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 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, a C 1 -C 60  heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group, each substituted with at least one selected from a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, 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 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 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, a C 1 -C 60  heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, and —Si(Q 21 )(Q 22 )(Q 23 ); and 
     —Si(Q 31 )(Q 32 )(Q 33 ), 
     wherein Q 1  to Q 3 , Q 11  to Q 13 , Q 21  to Q 23 , and Q 31  to Q 33  may be each independently selected from a hydrogen, a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, 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 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. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       Features will be apparent to those of skill in the art by describing in detail exemplary embodiments with reference to the attached drawing in which: 
         FIG. 1  illustrates a schematic view of an organic light-emitting device according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Example embodiments will now be described more fully hereinafter with reference to the accompanying drawing; however, they may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey exemplary implementations to those skilled in the art. 
     In the drawing FIGURE, the dimensions of layers and regions may be exaggerated for clarity of illustration. Like reference numerals refer to like elements throughout. 
     Expressions such as “at least one of” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. 
       FIG. 1  illustrates a schematic view of an organic light-emitting device  10  according to an embodiment. The organic light-emitting device  10  may include a first electrode  110 , an organic layer  150 , and a second electrode  190 . 
     Hereinafter, the structure of an organic light-emitting device according to an embodiment and a method of manufacturing an organic light-emitting device according to an embodiment will be described in connection with  FIG. 1 . 
     In  FIG. 1 , a substrate may be additionally disposed under the first electrode  110  or above the second electrode  190 . The substrate may be a glass substrate or transparent plastic substrate, each with excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and water resistance. 
     The first electrode  110  may be formed by depositing or sputtering a material for forming the first electrode on the substrate. When the first electrode  110  is an anode, the material for the first electrode  110  may be selected from materials with a high work function to facilitate hole injection. The first electrode  110  may be a reflective electrode or a transmissive electrode. The material for the first electrode may be a transparent and highly conductive material, and examples of such a material may include indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO 2 ), and zinc oxide (ZnO). When the first electrode  110  is a semi-transmissive electrode or a reflective electrode, as a material for forming the first electrode, at least one of magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag) may be used. 
     The first electrode  110  may have a single-layer structure, or a multi-layer structure including two or more layers. For example, the first electrode  110  may have a three-layered structure of ITO/Ag/ITO. 
     An organic layer  150  may be disposed on the first electrode  110 . The organic layer  150  may include an emission layer. 
     The organic layer  150  may further include a hole transport region disposed between the first electrode and the emission layer, and/or an electron transport region disposed between the emission layer and the second electrode. 
     The hole transport region may include at least one selected from a hole injection layer (HIL), a hole transport layer (HTL), a buffer layer, and an electron blocking layer (EBL). The electron transport region may include at least one selected from a hole blocking layer (HBL), an electron transport layer (ETL), and an electron injection layer (EIL). 
     The hole transport region may have a single-layered structure formed of a single material, a single-layered structure formed of a plurality of different materials, or a multi-layered structure having a plurality of layers formed of a plurality of different materials. 
     For example, the hole transport region may have a single-layered structure formed of a plurality of different materials, or a structure of HIL/HTL, a structure of HIL/HTL/buffer layer, a structure of HIL/buffer layer, a structure of HTL/buffer layer, or a structure of HIL/HTL/EBL, wherein layers of each structure are sequentially stacked from the first electrode  110  in this stated order, but are not limited thereto. 
     When the hole transport region includes a HIL, the HIL may be formed on the first electrode  110  by using various methods, e.g., vacuum deposition, spin coating, casting, a Langmuir-Blodgett (LB) method, ink-jet printing, laser-printing, or laser-induced thermal imaging. 
     When a HIL is formed by vacuum deposition, e.g., the vacuum deposition may be performed at a temperature of a deposition temperature of about 100 to about 500° C., at a vacuum degree of about 10 −8  to about 10 −3  torr, and/or at a deposition rate of about 0.01 to about 100 Å/sec in consideration of a compound for a HIL to be deposited, and the structure of a HIL to be formed. 
     When a HIL is formed by spin coating, the spin coating may be performed at a coating rate of about 2,000 rpm to about 5,000 rpm, and/or at a temperature of about 80° C. to 200° C. in consideration of a compound for a HIL to be deposited, and the structure of a HIL to be formed. 
     When the hole transport region includes a HTL, the HTL may be formed on the first electrode  110  or the HIL by using various methods, e.g., vacuum deposition, spin coating, casting, a LB method, ink-jet printing, laser-printing, or laser-induced thermal imaging. When the HTL is formed by vacuum deposition or spin coating, deposition and coating conditions for the HTL may be the same as the deposition and coating conditions for the HIL. 
     The hole transport region may include at least one selected from m-MTDATA, TDATA, 2-TNATA, NPB, β-NPB, TPD, Spiro-TPD, Spiro-NPB, α-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 sulfonicacid (Pani/CSA), (polyaniline)/poly(4-styrenesulfonate) (PANI/PSS), a compound represented by Formula 201 below, and a compound represented by Formula 202 below. 
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     In Formulae 201 and 202, 
     L 201  to L 205  may each independently be selected from or include, e.g., a substituted or unsubstituted C 3 -C 10  cycloalkylene group, a substituted or unsubstituted C 1 -C 10  heterocycloalkylene group, a substituted or unsubstituted C 3 -C 10  cycloalkenylene group, a substituted or unsubstituted C 1 -C 10  heterocycloalkenylene group, a substituted or unsubstituted C 6 -C 60  arylene group, a substituted or unsubstituted C 1 -C 60  heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group. 
     At least one substituent of the substituted C 3 -C 10  cycloalkylene group, substituted C 1 -C 10  heterocycloalkylene group, substituted C 1 -C 10  cycloalkenylene group, substituted C 1 -C 10  heterocycloalkenylene group, substituted C 6 -C 60  arylene group, substituted C 1 -C 60  heteroarylene group, substituted divalent non-aromatic condensed polycyclic group and substituted divalent non-aromatic condensed heteropolycyclic group may be selected from: 
     a deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group and a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, a C 1 -C 60  alkyl group, a C 2 -C 60  alkenyl group, a C 2 -C 60  alkynyl group, and a C 1 -C 60  alkoxy group; 
     a C 1 -C 60  alkyl group, a C 2 -C 60  alkenyl group, a C 2 -C 60  alkynyl group, and a C 1 -C 60  alkoxy group, each substituted with at least one selected from a deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group and a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof; 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 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, a C 1 -C 60  heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q 201 )(Q 202 ), —Si(Q 203 )(Q 204 )(Q 205 ), and —B(Q 206 )(Q 207 ); 
     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 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, a C 1 -C 60  heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group; 
     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 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, a C 1 -C 60  heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group, each substituted with at least one selected from a deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group and a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, 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 10  cycloalkyl group, a C 1 -C 10  heterocycloalkyl group, a C 3 -C 10  cycloalkenyl group, a C 1 -C 10  heterocycloalkenyl group, C 6 -C 60  aryl group, C 6 -C 60  aryloxy group, C 6 -C 60  arylthio group, C 1 -C 60  heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q 211 )(Q 212 ), —Si(Q 213 )(Q 214 )(Q 215 ) and —B(Q 216 )(Q 217 ); and 
     —N(Q 221 )(Q 222 ), —Si(Q 223 )(Q 224 )(Q 225 ), and —B(Q 226 )(Q 227 ); 
     xa1 to xa4 may each independently be selected from 0, 1, 2, and 3; 
     xa5 may be selected from 1, 2, 3, 4, and 5; and 
     R 201  to R 204  may each independently be selected from or include, e.g., a substituted or unsubstituted C 3 -C 10  cycloalkyl group, a substituted or unsubstituted C 1 -C 10  heterocycloalkyl group, a substituted or unsubstituted C 3 -C 10  cycloalkenyl group, a substituted or unsubstituted C 1 -C 10  heterocycloalkenyl group, a substituted or unsubstituted C 6 -C 60  aryl group, a substituted or unsubstituted C 6 -C 60  aryloxy group, a substituted or unsubstituted C 6 -C 60  arylthio group, a substituted or unsubstituted C 1 -C 60  heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group. 
     In some embodiments, in Formulae 201 and 202, 
     L 201  to L 205  may each independently be selected from: 
     a phenylene group, a naphthylene group, a fluorenylene group, a spiro-fluorenylene group, a benzofluorene group, a dibenzofluorene group, a phenanthrenylene group, an anthracenylene group, a pyrenylene group, a chrysenylene group, a pyridinylene group, a pyrazinylene group, a pyrimidinylene group, a pyridazinylene group, a quinolinylene group, an isoquinolinylene group, a quinoxalinylene group, a quinazolinylene group, a carbazolylene group, and a triazinylene group; and 
     a phenylene group, a naphthylene group, a fluorenylene group, a spiro-fluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenanthrenylene group, an anthracenylene group, a pyrenylene group, a chrysenylene group, a pyridinylene group, a pyrazinylene group, a pyrimidinylene group, a pyridazinylene group, a quinolinylene group, an isoquinolinylene group, a quinoxalinylene group, a quinazolinylene group, a carbazolylene group, and a triazinylene group, each substituted with at least one selected from a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, a C 1 -C 20  alkyl group, a C 1 -C 20  alkoxy group, a phenyl group, a naphthyl group, a fluorenyl group, a spiro-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a pyrenyl group, a chrysenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group and a triazinyl group; 
     xa1 to xa4 may each independently be selected from 0, 1, or 2; 
     xa5 may be 1, 2, or 3; 
     R 201  to R 204  may each independently be selected from: 
     a phenyl group, a naphthyl group, a fluorenyl group, a Spiro-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a pyrenyl group, a chrysenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, and a triazinyl group; and 
     a phenyl group, a naphthyl group, a fluorenyl group, a spiro-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a pyrenyl group, a chrysenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, and a triazinyl group, each substituted with at least one selected from a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, a C 1 -C 20  alkyl group, a C 1 -C 20  alkoxy group, a phenyl group, a naphthyl group, an azulenyl group, a fluorenyl group, a spiro-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a pyrenyl group, a chrysenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, and a triazinyl group. 
     The compound represented by Formula 201 may be represented by Formula 201A: 
     
       
         
         
             
             
         
       
     
     For example, the compound represented by Formula 201 may be represented by Formula 201A-1 below, but is not limited thereto: 
     
       
         
         
             
             
         
       
     
     For example, the compound represented by Formula 202 may be represented by Formula 202A below, but is not limited thereto: 
     
       
         
         
             
             
         
       
     
     In Formulae 201A, 201A-1, and 202A above, L 201  to L 203 , xa1 to xa3, xa5 and R 202  to R 204  may be described in connection with the descriptions herein, R 211  may be described in connection with the description of R 203 , R 213  to R 216  may be each independently selected from a hydrogen, a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, 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 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 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, a C 1 -C 60  heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group. 
     The compound represented by Formula 201, and the compound represented by Formula 202 may each include one of compounds HT1 to HT20 illustrated below. 
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     A thickness of the hole transport region may be in a range of about 100 Å to about 10,000 Å, e.g., about 100 Å to about 1000 Å. When the hole transport region includes both a hole injection layer and a hole transport layer, a thickness of the hole injection layer may be in a range of about 100 Å to about 10,000 Å, e.g., 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, e.g., about 100 Å to about 1,500 Å. When the thicknesses of the hole transport region, the HIL, and the HTL are within these ranges, satisfactory hole transporting characteristics may be obtained without a substantial increase in driving voltage. 
     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 homogeneously or unhomogeneously dispersed in the hole transport region. 
     The charge-generation material may be, e.g., a p-dopant. The p-dopant may be one of a quinone derivative, a metal oxide, and a cyano group-containing compound, but it is not limited thereto. Examples of the p-dopant may include a quinone derivative such as tetracyanoquinone dimethane (TCNQ) and 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinone dimethane (F4-TCNQ); a metal oxide such as tungsten oxide and molybdenum oxide; and Compound HT-D1. 
     
       
         
         
             
             
         
       
     
     The hole transport region may further include, in addition to the HIL and the HTL, at least one of a buffer layer and an EBL. The buffer layer may compensate for an optical resonance distance according to a wavelength of light emitted from the emission layer, and light-emission efficiency of a formed organic light-emitting device may be improved. For use as a material included in the buffer layer, materials that are included in the hole transport region may be used. The EBL may help prevent electron injection from the electron transport region. 
     For example, a material for the EBL may be mCP. 
     
       
         
         
             
             
         
       
     
     An emission layer may be formed on the first electrode  110  or the hole transport region by using various methods, e.g., vacuum deposition, spin coating, casting, a LB method, ink-jet printing, laser-printing, or laser-induced thermal imaging. When an emission layer is formed by vacuum deposition or spin coating, deposition and coating conditions for the emission may be the same as those for the HIL. 
     When the organic light-emitting device  10  is a full color organic light-emitting device, the emission layer may be patterned into a red emission layer, a green emission layer, or a blue emission layer, according to a sub pixel. In some embodiments, the emission layer may have a stacked structure of a red emission layer, a green emission layer, and a blue emission layer, or may include a red-light emission material, a green-light emission material, and a blue-light emission material, which are mixed with each other in a single layer, to emit white light. 
     In an implementation, the emission layer may include a condensed cyclic compound represented by Formula 1, below. 
     The emission layer may include a host and a dopant. For example, the host may include the condensed cyclic compound represented by Formula 1, below. 
     The dopant may be at least one selected from a fluorescent dopant and a phosphorescent dopant. The phosphorescent dopant may include an organometallic complex represented by Formula 401 below. 
     
       
         
         
             
             
         
       
     
     In Formula 401, 
     M may be selected from iridium (Ir), platinum (Pt), osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), and thulium (Tm); 
     X 401  to X 404  may each independently be nitrogen or carbon; 
     ring A 401  and ring A 402  may each independently be selected from or include, e.g., a substituted or unsubstituted benzene, a substituted or unsubstituted naphthalene, a substituted or unsubstituted fluorene, a substituted or unsubstituted spiro-fluorene, a substituted or unsubstituted indene, a substituted or unsubstituted pyrrole, a substituted or unsubstituted thiophene, a substituted or unsubstituted furan, a substituted or unsubstituted imidazole, a substituted or unsubstituted pyrazole, a substituted or unsubstituted thiazole, a substituted or unsubstituted isothiazole, a substituted or unsubstituted oxazole, a substituted or unsubstituted isoxazole, a substituted or unsubstituted pyridine, a substituted or unsubstituted pyrazine, a substituted or unsubstituted pyrimidine, a substituted or unsubstituted pyridazine, a substituted or unsubstituted quinoline, a substituted or unsubstituted isoquinoline, a substituted or unsubstituted benzoquinoline, a substituted or unsubstituted quinoxaline, a substituted or unsubstituted quinazoline, a substituted or unsubstituted carbazole, a substituted or unsubstituted benzoimidazole, a substituted or unsubstituted benzofuran, a substituted or unsubstituted benzothiophene, a substituted or unsubstituted isobenzothiophene, a substituted or unsubstituted benzoxazole, a substituted or unsubstituted isobenzoxazole, a substituted or unsubstituted triazole, a substituted or unsubstituted oxadiazole, a substituted or unsubstituted triazine, a substituted or unsubstituted dibenzofuran, and a substituted or unsubstituted dibenzothiophene. 
     At least one substituent of the substituted benzene, substituted naphthalene, substituted fluorene, substituted spiro-fluorene, substituted indene, substituted pyrrole, substituted thiophene, substituted furan, substituted imidazole, substituted pyrazole, substituted thiazole, substituted isothiazole, substituted oxazole, substituted isoxazole, substituted pyridine, substituted pyrazine, substituted pyrimidine, substituted pyridazine, substituted quinoline, substituted isoquinoline, substituted benzoquinoline, substituted quinoxaline, substituted quinazoline, substituted carbazole, substituted benzoimidazole, substituted benzofuran, substituted benzothiophene, substituted isobenzothiophene, substituted benzoxazole, substituted isobenzoxazole, substituted triazole, substituted oxadiazole, substituted triazine, substituted dibenzofuran, and substituted dibenzothiophene may be selected from: 
     a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, a C 1 -C 60  alkyl group, a C 2 -C 60  alkenyl group, a C 2 -C 60  alkynyl group, and a C 1 -C 60  alkoxy group; 
     a C 1 -C 60  alkyl group, a C 2 -C 60  alkenyl group, a C 2 -C 60  alkynyl group, and a C 1 -C 60  alkoxy group, each substituted with at least one selected from a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, a C 3 -C 10  cycloalkyl group, a C 1 -C 10  heterocycloalkyl group, a C 3 -C 0  cycloalkenyl group, a C 1 -C 10  heterocycloalkenyl group, a C 6 -C 60  aryl group, a C 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, a C 1 -C 60  heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q 401 )(Q 402 ), —Si(Q 403 )(Q 404 )(Q 405 ), and —B(Q 406 )(Q 407 ); 
     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 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, a C 1 -C 60  heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic heterocondensed polycyclic group; 
     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 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, a C 1 -C 60  heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group, each substituted with at least one selected from a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, 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 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 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, a C 1 -C 60  heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q 411 )(Q 412 ), —Si(Q 413 )(Q 414 )(Q 415 ), and —B(Q 416 )(Q 417 ); and 
     —N(Q 421 )(Q 422 ), —Si(Q 423 )(Q 424 )(Q 425 ), and —B(Q 426 )(Q 427 ); 
     L 401  may be an organic ligand; 
     xc1 may be 1, 2, or 3; and 
     xc2 may be 0, 1, 2, or 3. 
     wherein each of Q 401  to Q 407 , Q 411  to Q 417  and Q 421  to Q 427  may be described in connection with the description of Q 1 . 
     L 401  may be a monovalent, divalent, or trivalent organic ligand. For example, L 401  may be selected from a halogen ligand (for example, Cl and F), a diketone ligand (for example, acetylacetonate, 1,3-diphenyl-1,3-propanedionate, 2,2,6,6-tetramethyl-3,5-heptanedionate, and hexafluoroacetonate), a carboxylic acid ligand (for example, picolinate, dimethyl-3-a pyrazolecarboxylate, and benzoate), a carbon monoxide ligand, an isonitrile ligand, a cyano group ligand, and a phosphorus ligand (for example, phosphine, phosphite). 
     When A 401  in Formula 401 has two or more substituents, the substituents of A 402  may bind to each other to form a saturated or unsaturated ring. 
     When A 402  in Formula 401 has two or more substituents, the substituents of A 402  may bind to each other to form a saturated or unsaturated ring. 
     When xc1 in Formula 401 is two or higher, a plurality of ligands 
     
       
         
         
             
             
         
       
     
     in Formula 401 may be identical or different. In Formula 401 above, when xc1 is 2 or higher, A 401  and A 402  may be each independently connected to A 401  and A 402  of another ligand directly or via a linking group (for example, a C 1 -C 5  alkylene group, —N(R′)— (wherein, R′ may be a C 1 -C 10  alkyl group or a C 6 -C 20  aryl group) or —C(═O)—) therebetween. 
     The phosphorescent dopant may include at least one of Compounds PD1 to PD74 below. 
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     In an implementation, the phosphorescent dopant may include PtOEP. 
     
       
         
         
             
             
         
       
     
     The fluorescent dopant may include at least one selected from DPAVBi, BDAVBi, TBPe, DCM, DCJTB, Coumarin 6, and C545T. 
     
       
         
         
             
             
         
       
     
     In an implementation, the fluorescent dopant may include a compound represented by Formula 501 below. 
     
       
         
         
             
             
         
       
     
     In Formula 501, 
     Ar 501  may be selected from, e.g., a naphthalene, a heptalene, a fluorene, a spiro-fluorene, a benzofluorene, a dibenzofluorene, a phenalene, a phenanthrene, an anthracene, a fluoranthene, a triphenylene, a pyrene, a chrysene, naphthacene, a picene(picene), a perylene, a pentaphene, and an indenoanthracene; and a naphthalene, a heptalene, a fluorene, a spiro-fluorene, a benzofluorene, a dibenzofluorene, a phenalene, a phenanthrene, an anthracene, a fluoranthene, a triphenylene, a pyrene, a chrysene, naphthacene, a picene, a perylene, a pentaphene, and an indenoanthracene, each substituted with at least one selected from a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, 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 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 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, a C 1 -C 60  heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group and —Si(Q 501 )(Q 502 )(Q 503 ) (wherein Q 501  to Q 503  may be each independently selected from a hydrogen, a C 1 -C 60  alkyl group, a C 2 -C 60  alkenyl group, a C 6 -C 60  aryl group, and a C 2 -C 60  heteroaryl group); 
     L 501  to L 503  may be described in connection with the description of L 201  herein; 
     R 501  and R 502  may each independently be selected from: 
     a phenyl group, a naphthyl group, a fluorenyl group, a spiro-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a pyrenyl group, a chrysenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, a triazinyl group, a dibenzofuranyl group, and a dibenzothiophenyl group; and 
     a phenyl group, a naphthyl group, a fluorenyl group, a spiro-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a pyrenyl group, a chrysenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, a triazinyl group and a dibenzofuranyl group, and a dibenzothiophenyl group, each substituted with at least one selected from a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, a C 1 -C 20  alkyl group, a C 1 -C 20  alkoxy group, a phenyl group, a naphthyl group, a fluorenyl group, a spiro-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a pyrenyl group, a chrysenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, a triazinyl group, a dibenzofuranyl group, and a dibenzothiophenyl group; 
     xd1 to xd3 may each independently be selected from 0, 1, 2, and 3; and 
     xd4 may be selected from 1, 2, 3, and 4. 
     An amount of the dopant in the emission layer may be, e.g., in a range of about 0.01 to about 15 parts by weight, based on 100 parts by weight of the host, but is not limited thereto. 
     A thickness of the emission layer may be in a range of about 100 Å to about 1,000 Å, e.g., about 200 Å to about 600 Å. When the thickness of the emission layer is within this range, excellent light-emission characteristics may be obtained without a substantial increase in driving voltage. 
     Then, an electron transport region may be disposed on the emission layer. 
     The electron transport region may include at least one selected from a hole blocking layer, an ETL, and an EIL. 
     For example, the electron transport region may have a structure of ETL/EIL or a structure of HBL/ETL/EIL, wherein layers of each structure are sequentially stacked from the emission layer in the stated order. 
     According to an embodiment, the organic layer  150  of the organic light-emitting device may include an electron transport region between the emission layer and the second electrode  190 . 
     The electron transport region may include a condensed cyclic compound represented by Formula 1. 
     
       
         
         
             
             
         
       
     
     In Formulae 1 and 2 above, ring A 1  and ring A 2  may be condensed with each other, 
     ring A 1  may be, e.g., a substituted or unsubstituted benzene ring, 
     ring A 2  may be, e.g., represented by Formula 2 above. X 1  may be selected from, e.g., N-[(L 1 ) a1 -(Ar 1 ) b1 ], O, and S. In an implementation, X 1  may be, e.g., N-[(L 1 ) a1 -(Ar 1 ) b1 ]. Herein, L 1 , Ar 1 , a1, and b1 may be understood by referring to the description below. 
     In an implementation, the condensed cyclic compound represented by Formula 1 above may be, e.g., represented by one of the following Formulae 1A and 1B. 
     
       
         
         
             
             
         
       
     
     In Formulae 1A and 1B above, C 1  to C 4  represent carbon atoms in respective locations. 
     In an implementation, ring A 1  may be a moiety represented by one of the following Formulae 3-1 and 3-2. 
     
       
         
         
             
             
         
       
     
     In Formulae 1A, 1B, 3-1 and 3-2 above, X 1 , L 1 , Ar 1 , a1, and b1 may be understood by referring to the descriptions provided in relation to Formula 1, and R 13  and R 14  may be defined the same as R 1  of Formula 1. 
     L 1  may be selected from or include, e.g., a substituted or unsubstituted C 3 -C 10  cycloalkylene group, a substituted or unsubstituted C 1 -C 10  heterocycloalkylene group, a substituted or unsubstituted C 3 -C 10  cycloalkenylene group, a substituted or unsubstituted C 1 -C 10  heterocycloalkenylene group, a substituted or unsubstituted C 6 -C 60  arylene group, a substituted or unsubstituted C 1 -C 60  heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group. 
     In an implementation, L 1  may be selected from, e.g., a phenylene group, a pentalenylene group, an indenylene group, a naphthylene group, an azulenylene group, a heptalenylene group, an indacenylene group, an acenaphthylene group, a fluorenylene group, a spiro-fluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenalenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a naphthacenylene group, a picenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a rubicenylene group, a coronenylene group, an ovalenylene group, a pyrrolylene group, a thiophenylene group, a furanylene group, an imidazolylene group, a pyrazolylene group, a thiazolylene group, an isothiazolylene group, an oxazolylene group, an isoxazolylene group, a pyridinylene group, a pyrazinylene group, a pyrimidinylene group, a pyridazinylene group, an isoindolylene group, an indolylene group, an indazolylene group, a purinylene group, a quinolinylene group, an isoquinolinylene group, a benzoquinolinylene group, a phthalazinylene group, a naphthyridinylene group, a quinoxalinylene group, a quinazolinylene group, a cinnolinylene group, a carbazolylene group, a phenanthridinylene group, an acridinylene group, a phenanthrolinylene group, a phenazinylene group, a benzoimidazolylene group, a benzofuranylene group, a benzothiophenylene group, an isobenzothiazolylene group, a benzoxazolylene group, an isobenzoxazolylene group, a triazolylene group, a tetrazolylene group, an oxadiazolylene group, a triazinylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a thiadiazolylene group, an imidazopyridinylene group, and an imidazopyrimidinylene group; and 
     a phenylene group, a pentalenylene group, an indenylene group, a naphthylene group, an azulenylene group, a heptalenylene group, an indacenylene group, an acenaphthylene group, a fluorenylene group, a spiro-fluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenalenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a naphthacenylene group, a picenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a rubicenylene group, a coronenylene group, an ovalenylene group, a pyrrolylene group, a thiophenylene group, a furanylene group, an imidazolylene group, a pyrazolylene group, a thiazolylene group, an isothiazolylene group, an oxazolylene group, an isoxazolylene group, a pyridinylene group, a pyrazinylene group, a pyrimidinylene group, a pyridazinylene group, an isoindolylene group, an indolylene group, an indazolylene group, a purinylene group, a quinolinylene group, an isoquinolinylene group, a benzoquinolinylene group, a phthalazinylene group, a naphthyridinylene group, a quinoxalinylene group, a quinazolinylene group, a cinnolinylene group, a carbazolylene group, a phenanthridinylene group, an acridinylene group, a phenanthrolinylene group, a phenazinylene group, a benzoimidazolylene group, a benzofuranylene group, a benzothiophenylene group, an isobenzothiazolylene group, a benzoxazolylene group, an isobenzoxazolylene group, a triazolylene group, a tetrazolylene group, an oxadiazolylene group, a triazinylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a thiadiazolylene group, an imidazopyridinylene group, and an imidazopyrimidinylene group, each substituted with at least one selected from a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, a C 1 -C 20  alkyl group, a C 1 -C 20  alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, a benzoxazoiyi group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinyl group, and an imidazopyrimidinyl group. 
     In an implementation, L 1  may be, e.g., a group represented by one of the following Formulae 4-1 to Formula 4-29. 
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     * and *′ in Formulae 4-1 to 4-29 indicate binding sites to a neighboring atom. 
     In an implementation, L 1  may be selected from, e.g., 
     a phenylene group, a naphthylene group, a fluorenylene group, a phenanthrenylene group, an anthracenylene group, a triphenylenylene group, a pyrenylene group, and a chrysenylene group; and 
     a phenylene group, a naphthylene group, a fluorenylene group, a phenanthrenylene group, an anthracenylene group, a triphenylenylene group, a pyrenylene group and a chrysenylene group, each substituted with at least one selected from a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, a C 1 -C 20  alkyl group, a C 1 -C 20  alkoxy group, a phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a triphenylenyl group, a pyrenyl group, and a chrysenyl group. 
     a1 indicates a number of L 1  and it may be selected from integers of 0 to 3. When a1 is 2 or more, a plurality of L 1  may be identical or different. For example, a1 may be 0 or 1. 
     Ar 1  may be selected from or include, e.g., a substituted or unsubstituted C 1 -C 10  heterocycloalkyl group, a substituted or unsubstituted C 1 -C 10  heterocycloalkenyl group, a substituted or unsubstituted C 1 -C 60  heteroaryl group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group. 
     In an implementation, Ar 1  may be selected from, e.g., a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinyl group, and an imidazopyrimidinyl group; and 
     a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinyl group, and an imidazopyrimidinyl group, each substituted with at least one selected from a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, a C 1 -C 20  alkyl group, a C 1 -C 20  alkoxy group, a phenyl group, a naphthyl group, a phenanthrenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, and a benzoxazolyl group. 
     In an implementation, Ar 1  may be, e.g., a group represented by one of the following Formulae 5-1 to 5-44. 
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     In Formulae 5-1 to 5-44, 
     Z 11  to Z 16  may each independently be selected from, e.g., a hydrogen, a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, a C 1 -C 20  alkyl group, a C 1 -C 20  alkoxy group, a phenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, phenanthridinyl, acridinyl, phenanthrolinyl, phenazinyl, a benzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, and an imidazopyrimidinyl group; and 
     * indicates a binding site to a neighboring atom. 
     In an implementation, Ar 1  may be, e.g., a group represented by one of the following Formulae 6-1 to 6-19. 
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     In Formulae 6-1 to 6-19 above, * may be a binding site to a neighboring atom. 
     b1 indicates an number of Ar 1  and may be selected from integers of 1 to 3. When b1 is 2 or higher, a plurality of Ar 1  may be identical or different. For example, b1 may be 1 or 2. 
     In Formula 1 above, R 1  to R 12  may each independently be selected from or include, e.g., a hydrogen, a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, a substituted or unsubstituted C 1 -C 60  alkyl group, a substituted or unsubstituted C 2 -C 60  alkenyl group, a substituted or unsubstituted C 2 -C 60  alkynyl group, a substituted or unsubstituted C 1 -C 60  alkoxy group, a substituted or unsubstituted C 3 -C 10  cycloalkyl group, a substituted or unsubstituted C 1 -C 10  heterocycloalkyl group, a substituted or unsubstituted C 3 -C 10  cycloalkenyl group, a substituted or unsubstituted C 1 -C 10  heterocycloalkenyl group, a substituted or unsubstituted C 6 -C 60  aryl group, a substituted or unsubstituted C 6 -C 60  aryloxy group, a substituted or unsubstituted C 6 -C 60  arylthio group, a substituted or unsubstituted C 1 -C 60  heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, and —Si(Q 1 )(Q 2 )(Q 3 ), wherein Q 1  to Q 3  may be the same as described below. 
     In an implementation, R 1  to R 12  may each independently be selected from, e.g., a hydrogen, a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, a C 1 -C 20  alkyl group, and a C 1 -C 20  alkoxy group; 
     a phenyl group, a naphthyl group, a fluorenyl group, a spiro-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, a benzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, an imidazopyridinyl group, and an imidazopyrimidinyl group; 
     a phenyl group, a naphthyl group, a fluorenyl group, a spiro-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, a benzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, an imidazopyridinyl group, and an imidazopyrimidinyl group, each substituted with at least one selected from a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, a C 1 -C 10  alkyl group, a C 1 -C 10  alkoxy group, a phenyl group, a naphthyl group, a fluorenyl group, a spiro-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, a benzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, an imidazopyridinyl group, an imidazopyrimidinyl group and —Si(Q 31 )(Q 32 )(Q 33 ); and 
     —Si(Q 1 )(Q 2 )(Q 3 ), 
     wherein Q 1  to Q 3  and Q 31  to Q 33  may be each independently selected from a C 1 -C 10  alkyl group, a C 1 -C 10  alkoxy group, a phenyl group, and a naphthyl group. 
     In an implementation, R 1  to R 12  may each independently be selected from, e.g., 
     a hydrogen, a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, a C 1 -C 10  alkyl group, and a C 1 -C 10  alkoxy group; 
     a phenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, and a triazinyl group; 
     a phenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, and a triazinyl group, each substituted with at least one selected from a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, a C 1 -C 10  alkyl group, a C 1 -C 10  alkoxy group, a phenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a triazinyl group, and —Si(Q 31 )(Q 32 )(Q 33 ); and 
     —Si(Q 1 )(Q 2 )(Q 3 ), wherein 
     Q 1  to Q 3  and Q 31  to Q 33  may be each independently selected from a C 1 -C 10  alkyl group, a C 1 -C 20  alkoxy group, a phenyl group, and a naphthyl group. 
     In an implementation, R 1  to R 12  may each independently be selected from, e.g., 
     a hydrogen, a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, a C 1 -C 20  alkyl group, a C 1 -C 20  alkoxy group, —Si(Q 1 )(Q 2 )(Q 3 ), and groups represented by Formulae 7-1 to Formula 7-18 below, wherein Q 1  to Q 3  may be each independently selected from a C 1 -C 10  alkyl group, a C 1 -C 10  alkoxy group, a phenyl group, and a naphthyl group. 
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     In Formulae 7-1 to 7-18, 
     Y 31  may be, e.g., O, S, C(Z 33 )(Z 34 ), N(Z 35 ), or Si(Z 36 )(Z 37 ); 
     Z 31  to Z 37  may each independently be selected from, e.g., a hydrogen, a deuterium, —F, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, a C 1 -C 20  alkyl group, a C 1 -C 20  alkoxy group, a phenyl group, a naphthyl group, a fluorenyl group, a spiro-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a pyrenyl group, a chrysenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, and a triazinyl group; 
     e1 may be an integer from 1 to 5, e2 may be an integer from 1 to 7, e3 may be an integer from 1 to 3, e4 may be an integer from 1 to 4, and e5 may be 1 or 2; 
     * indicates a binding site to a neighboring atom. 
     In an implementation, R 1  to R 12  may each independently be selected from, e.g., 
     a hydrogen, a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, a C 1 -C 20  alkyl group, a C 1 -C 20  alkoxy group, —Si(Q 1 )(Q 2 )(Q 3 ), and groups represented by Formulae 8-1 to 8-3 and 8-5 to 8-29 below, wherein Q 1  to Q 3  may be each independently selected from a C 1 -C 10  alkyl group, a C 1 -C 10  alkoxy group, a phenyl group, and a naphthyl group. 
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     * in Formulae 8-1 to 8-3 and 8-5 to 8-29 indicates a binding site to a neighboring atom. 
     In an implementation, the condensed cyclic compound represented by Formula 1 above may be, e.g., represented by one of the following Formulae 1A-1 to 1B-2. 
     
       
         
         
             
             
         
       
     
     In Formulae 1A-1 to 1B-2 above, X 1 , R 1  to R 14  may be the same as those described with respect to Formula 1. 
     In an implementation, the condensed cyclic compound represented by Formula 1 may be, e.g., represented by one of the following Formulae 1B-1(1) to 1B-1(4). 
     
       
         
         
             
             
         
       
     
     In Formulae 1B-1(1) to 1B-1(4), 
     X 1  may be, e.g., N—(Ar 1 ) b1 ; 
     Ar 1  may be, e.g., a group represented by one of Formulae 6-1 to 6-19, 
     b1 may be 1; 
     R 2 , R 3 , R 6 , R 7  and R 10  may each independently be, e.g., a group represented by one of Formulae 8-1 to 8-3 and 8-5 to 8-29. 
     In an implementation, the condensed cyclic compound represented by Formula 1 may be, e.g., one of the following Compounds 1 to 360. 
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     When the electron transport region includes the condensed cyclic compound represented by Formula 1, a difference in a lowest unoccupied molecular orbitals (LUMO) between compounds included in the emission layer may be small, such that electron transport occurs effectively and thus, deterioration of the compounds may be reduced at an interface between the electron transport region and the emission layer, thereby increasing a lifespan of an organic light-emitting device. 
     In an implementation, the emission layer and the electron transport region may include, e.g., may both include, the condensed cyclic compound represented by Formula 1. 
     When the emission layer and the electron transport region both include the condensed cyclic compound represented by Formula 1, a difference in LUMOs between the emission layer and the electron transport region may be smaller, such that they may not only be useful for electron transport, but also may help improve a charge balance between the electron transport and hole transport and thus, may help increase emission efficiency and the deterioration of the compound at an interface between the emission layer and the electron transport region may be reduced to help increase a lifespan of an organic light-emitting device. 
     In an implementation, the condensed cyclic compound included in the electron transport region and the condensed cyclic compound included in the emission layer may be identical to each other. In an implementation, the condensed cyclic compound included in the electron transport region and the condensed cyclic compound included in the emission layer may be different from each other. 
     When the electron transport region includes a hole blocking layer, the hole blocking layer may be formed on the emission layer by using various methods, e.g., vacuum deposition, spin coating casting, a Langmuir-Blodgett (LB) method, ink-jet printing, laser-printing, or laser-induced thermal imaging. When the hole blocking layer is formed by vacuum deposition or spin coating, deposition and coating conditions for the hole blocking layer may be determined by referring to the deposition and coating conditions for the HIL. 
     The HBL may include, e.g., at least one of BCP and Bphen. 
     
       
         
         
             
             
         
       
     
     A thickness of the hole blocking layer may be in a range of about 20 Å to about 1,000 Å, e.g., about 30 Å to about 300 Å. When the thickness of the hole blocking layer is within these ranges, the hole blocking layer may have excellent hole blocking characteristics without a substantial increase in driving voltage. 
     The electron transport region may include an electron transport layer. The ETL may be formed on the emission layer or the HBL by using various methods, e.g., vacuum deposition, spin coating casting, a LB method, ink-jet printing, laser-printing, or laser-induced thermal imaging. When an ETL is formed by vacuum deposition or spin coating, deposition and coating conditions for the ETL may be the same as the deposition and coating conditions for the HIL. 
     In an implementation, the electron transport layer may include the condensed cyclic compound represented by Formula 1. 
     A thickness of the electron transport layer may be in a range of about 100 Å to about 1,000 Å, e.g., about 150 Å to about 500 Å. When a thickness of the ETL satisfies the ranges above, satisfactory electron injection properties may be obtained without an actual increase in driving voltage. 
     In an implementation, the ETL may further include a metal-containing material, in addition to the condensed cyclic compound. 
     The metal-containing material may include, e.g., a Li complex. The Li complex may include, e.g., Compound ET-D1 (lithium quinolate, LiQ) or ET-D2. 
     
       
         
         
             
             
         
       
     
     The electron transport region may include an EIL that facilitates an electron injection from a second electrode  190 . 
     The EIL may be formed on the ETL by using various methods, e.g., vacuum deposition, spin coating casting, a LB method, ink-jet printing, laser-printing, or laser-induced thermal imaging. When an EIL is formed by vacuum deposition or spin coating, deposition and coating conditions for the EIL may be the same as those for the HIL. 
     The EIL may include, e.g., at least one selected from, LiF, NaCl, CsF, Li 2 O, BaO, and LiQ. 
     A thickness of the EIL may be in a range of about 1 Å to about 100 Å, e.g., about 3 Å to about 90 Å. When the thickness of the EIL is within the range described above, the EIL may have satisfactory electron injection characteristics without a substantial increase in driving voltage. 
     The second electrode  190  may be disposed on the organic layer  150  having such a structure. The second electrode  190  may be a cathode which is an electron injection electrode, and in this regard, a material for the second electrode  190  may be selected from metal, an alloy, an electrically conductive compound, and a mixture thereof, which have a relatively low work function. Examples of the material for the second electrode  190  may include lithium (Li), magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), or magnesium-silver (Mg—Ag). In an implementation, the material for forming the second electrode  190  may be ITO or IZO. The second electrode  190  may be a semi-transmissive electrode or a transmissive electrode. 
     Hereinbefore, the organic light-emitting device has been described with reference to  FIG. 1 . 
     A C 1 -C 60  alkyl group used herein refers to a linear or branched aliphatic hydrocarbon monovalent group having 1 to 60 carbon atoms, and detailed examples thereof are a methyl group, an ethyl group, a propyl group, an isobutyl group, a sec-butyl group, a ter-butyl group, a pentyl group, an iso-amyl group, and a hexyl group. A C 1 -C 60  alkylene group used herein refers to a divalent group having the same structure as the C 1 -C 60  alkyl group. 
     A C 1 -C 60  alkoxy group used herein refers to a monovalent group represented by —OA 101  (wherein A 101  is the C 1 -C 60  alkyl group), and detailed examples thereof are a methoxy group, an ethoxy group, and an isopropyloxy group. 
     A C 2 -C 60  alkenyl group used herein refers to a hydrocarbon group including at least one carbon-carbon double bond in the middle or terminal of the C 2 -C 60  alkyl group, and detailed examples thereof include, an ethenyl group, a propenyl group, and a butenyl group. A C 2 -C 60  alkenylene group used herein refers to a divalent group having the same structure as the C 2 -C 60  alkenyl group. 
     A C 2 -C 60  alkynyl group used herein refers to a hydrocarbon group having at least one carbon-carbon triple bond in the middle or terminal of the C 2 -C 60  alkyl group, and detailed examples thereof are an ethynyl group, and a propynyl group. A C 2 -C 60  alkynylene group used herein refers to a divalent group having the same structure as the C 2 -C 60  alkynyl group. 
     A C 3 -C 10  cycloalkyl group used herein refers to a monovalent hydrocarbon monocyclic group having 3 to 10 carbon atoms, and detailed examples thereof are a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group. A C 3 -C 10  cycloalkylene group used herein refers to a divalent group having the same structure as the C 3 -C 10  cycloalkyl group. 
     A C 1 -C 10  heterocycloalkyl group used herein refers to a monovalent monocyclic group having at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom and 1 to 10 carbon atoms, and detailed examples thereof are a tetrahydrofuranyl group, and a tetrahydrothiophenyl group. A C 1 -C 10  heterocycloalkylene group used herein refers to a divalent group having the same structure as the C 1 -C 10  heterocycloalkyl group. 
     A C 3 -C 10  cycloalkenyl group used herein refers to a monovalent monocyclic group that has 3 to 10 carbon atoms and at least one double bond in the ring thereof and does not have aromacity, and detailed examples thereof are a cyclopentenyl group, a cyclohexenyl group, and a cycloheptenyl group. A C 3 -C 10  cycloalkenylene group used herein refers to a divalent group having the same structure as the C 3 -C 10  cycloalkenyl group. 
     A C 1 -C 10  heterocycloalkenyl group used herein refers to a monovalent monocyclic group that has at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom, 1 to 10 carbon atoms, and at least one double bond in its ring. Detailed examples of the C 1 -C 10  heterocycloalkenyl group are a 2,3-hydrofuranyl group and a 2,3-hydrothiophenyl group. A C 1 -C 10  heterocycloalkenylene group used herein refers to a divalent group having the same structure as the C 1 -C 10  heterocycloalkenyl group. 
     A C 6 -C 60  aryl group used herein refers to a monovalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms, and a C 6 -C 60  arylene group used herein refers to a divalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms. Detailed examples of the C 6 -C 60  aryl group include a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, and a chrysenyl group. When the C 6 -C 60  aryl group and the C 6 -C 60  arylene group each include two or more rings, the rings may be fused to each other. 
     A C 1 -C 60  heteroaryl group used herein refers to a monovalent group having a carboncyclic aromatic system that has at least one hetero atom selected from N, O, P, and S as a ring-forming atom, and 1 to 60 carbon atoms. A C 1 -C 60  heteroarylene group used herein refers to a divalent group having a carbocyclic aromatic system that has at least one hetero atom selected from N, O, P, and S as a ring-forming atom, and 1 to 60 carbon atoms. Examples of the C 1 -C 60  heteroaryl group are a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, and an isoquinolinyl group. When the C 1 -C 60  heteroaryl group and the C 1 -C 60  heteroarylene group each include two or more rings, the rings may be fused to each other. 
     A C 6 -C 60  aryloxy group used herein indicates —OA 102  (wherein A 102  is the C 6 -C 60  aryl group), and a C 6 -C 60  arylthio group used herein indicates —SA 103  (wherein A 103  is the C 6 -C 60  aryl group). 
     A monovalent non-aromatic condensed polycyclic group used herein refers to a monovalent group (for example, having 8 to 60 carbon atoms) that has two or more rings condensed to each other, only carbon atoms as a ring forming atom, and non-aromacity in the entire molecular structure. A detailed example of the monovalent non-aromatic condensed polycyclic group is a fluorenyl group. A divalent non-aromatic condensed polycyclic group used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed polycyclic group. 
     A monovalent non-aromatic condensed heteropolycyclic group used herein refers to a monovalent group (for example, having 2 to 60 carbon atoms) that has two or more rings condensed to each other, has a heteroatom selected from N, O, Si, P, and S, other than carbon atoms, as a ring forming atom, and has non-aromacity in the entire molecular structure. An example of the monovalent non-aromatic condensed heteropolycyclic group is a carbazolyl group. A divalent non-aromatic condensed heteropolycyclic group used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed heteropolycyclic group. 
     at least one of substituents of the substituted benzene ring, the substituted C 3 -C 10  cycloalkylene group, substituted C 1 -C 10  heterocycloalkylene group, substituted C 3 -C 10  cycloalkenylene group, substituted C 1 -C 10  heterocycloalkenylene group, substituted C 6 -C 60  arylene group, substituted C 1 -C 60  heteroarylene group, substituted divalent non-aromatic condensed polycyclic group, substituted divalent non-aromatic condensed heteropolycyclic group, substituted C 1 -C 60  alkyl group, substituted C 2 -C 60  alkenyl group, substituted C 2 -C 60  alkynyl group, substituted C 1 -C 60  alkoxy group, substituted C 3 -C 10  cycloalkyl group, substituted C 1 -C 10  heterocycloalkyl group, substituted C 3 -C 10  cycloalkenyl group, substituted C 1 -C 10  heterocycloalkenyl group, substituted C 6 -C 60  aryl group, substituted C 6 -C 60  aryloxy group, substituted C 6 -C 60  arylthio group, substituted C 1 -C 60  heteroaryl group, substituted monovalent non-aromatic condensed polycyclic group, and substituted monovalent non-aromatic condensed heteropolycyclic group may be selected from 
     a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, a C 1 -C 60  alkyl group, a C 2 -C 60  alkenyl group, a C 2 -C 60  alkynyl group, and a C 1 -C 60  alkoxy group; 
     a C 1 -C 60  alkyl group, a C 2 -C 60  alkenyl group, a C 2 -C 60  alkynyl group, and a C 1 -C 60  alkoxy group, each substituted with at least one selected from a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, 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 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, a C 1 -C 60  heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, and —Si(Q 11 )(Q 12 )(Q 13 ); 
     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 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, a C 1 -C 60  heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic heterocondensed polycyclic group; 
     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 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, a C 1 -C 60  heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic heterocondensed polycyclic group, each substituted with at least one selected from a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, 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 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 6 -C 60  aryloxy group, a C 6 -C 60  arylthio group, a C 1 -C 60  heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic heterocondensed polycyclic group, and —Si(Q 21 )(Q 22 )(Q 23 ); and 
     —Si(Q 31 )(Q 32 )(Q 33 ), 
     wherein Q 1  to Q 3 , Q 11  to Q 13 , Q 21  to Q 23 , and Q 31  to Q 33  may be each independently selected from a hydrogen, a deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, 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 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. 
     “Ph” used herein refers to a phenyl group, “Me” refers to a methyl group, “Et” refers to an ethyl group, and “tert-Bu” or “Bu t ” refers to a tert-butyl group. 
     Hereinafter, an organic light-emitting device according to an embodiment will be described in detail with reference to Synthesis Examples and Examples. The wording “B was used instead of A” used in describing Synthesis Examples means that a molar equivalent of A was identical to a molar equivalent of B. 
     The following Examples and Comparative Examples are provided in order to highlight characteristics of one or more embodiments, but it will be understood that the Examples and Comparative Examples are not to be construed as limiting the scope of the embodiments, nor are the Comparative Examples to be construed as being outside the scope of the embodiments. Further, it will be understood that the embodiments are not limited to the particular details described in the Examples and Comparative Examples. 
     EXAMPLES 
     Synthesis Example 1 
     Synthesis of Intermediate 1-1 
     
       
         
         
             
             
         
       
     
     35.40 g (103.6 mmol) of 2-bromo-7-chlorotriphenylene, 3.47 g (3.0 mmol) of Pd(PPh 3 ) 4 , and 12.0 g (300.0 mmol) of NaOH were added to 300 ml of THF and 150 ml of distilled water, 29.50 g (120.0 mmol) of (5-bromo-2-nitrophenyl)boronic acid was dropped thereto under nitrogen atmosphere and then reflux-agitated for 12 hours. After the reaction was completed, extraction was performed on the resultant obtained therefrom using methylene chloride (MC) and water, and then residual moisture was removed therefrom by using MgSO 4 . Thereafter, a column chromatography was performed using MC/Hexane (MC:Hexane=4:1) to obtain 41.83 g (yield 90.4%) of 2-(5-bromo-2-nitrophenyl)-7-chlorotriphenylene (Intermediate 1-1). 
     m/z: 462.98 (100.0%), 460.98 (77.3%), 463.98 (26.4%), 464.98 (24.5%), 461.99 (20.2%), 465.98 (6.3%), 464.99 (3.3%), 462.99 (2.9%) 
       1 H NMR: 7.64-7.70 (t, 2H), 7.71 (s, 1H), 7.99-8.00 (s, 2H), 8.12 (d, 1H), 8.25-8.37 (m, 3H), 8.79 (d, 1H), 9.08 (d, 1H), 9.10 (s, 1H), 9.27 (s, 1H). 
     Synthesis of Intermediate 1-2 
     
       
         
         
             
             
         
       
     
     40 g of 2-(5-bromo-2-nitrophenyl)-7-chlorotriphenylene (Intermediate 1-1) (86.44 mmol), 50 g (190.63 mmol) of triphenylphosphine, 150 ml of 1,2-dichlorobenzene were added together and then reflux-agitated under nitrogen atmosphere for 12 hours. 
     After the reaction was completed, an extraction was performed on a resultant obtained therefrom using methylene chloride (MC) and water, and then residual moisture was removed therefrom by using MgSO 4 . Thereafter, a column chromatography was performed using MC/Hexane (MC:Hexane=1:2) to obtain 16.23 g (yield 43.6%) of 13-bromo-6-chloro-10H-phenanthro[9,10-b]carbazole (Intermediate 1-2). 
     m/z: 430.99 (100.0%), 428.99 (77.3%), 431.99 (26.3%), 432.99 (24.1%), 430.00 (20.2%), 433.99 (6.3%), 433.00 (3.3%), 431.00 (2.5%) 
       1 H NMR: 7.42-7.47 (m, 2H), 7.64-7.70 (t, 2H), 8.05 (s, 1H), 8.12 (s, 2H), 8.27 (d, 1H), 8.86 (d, 1H), 8.93 (s, 1H), 9.60 (d, 1H), 11.66 (s, 1H). 
     Synthesis of Intermediate 1-3 
     
       
         
         
             
             
         
       
     
     15 g (34.36 mmol) of 13-bromo-6-chloro-10H-phenanthro[9,10-b]carbazole (Intermediate 1-2), 5.10 g (41.23 mmol) of phenylboronic acid, 3.47 g (3.0 mmol) of Pd(PPh 3 ) 4 , and 12.0 g (300.0 mmol) of NaOH were added to 100 ml of THF and 50 ml of distilled water and then reflux-agitated under nitrogen atmosphere for 12 hours. After the reaction was completed, extraction was performed on the resultant obtained therefrom by using MC and water and then residual moisture was removed therefrom by using MgSO 4 . Thereafter, a column chromatography was performed using MC/Hexane (MC:Hexane=1:3) to obtain 12.15 g (yield 82.6%) of 6-chloro-13-phenyl-10H-phenanthro[9,10-b]carbazole (Intermediate 1-3). 
     m/z: 427.11 (100.0%), 428.12 (32.7%), 429.11 (32.1%), 430.11 (10.5%), 429.12 (5.2%), 431.12 (1.6%) 
       1 H NMR: 7.41-7.49 (m, 3H), 7.64-7.77 (m, 5H), 7.89 (s, 2H), 7.99 (d, 1H), 8.12 (s, 2H), 8.27 (d, 1H), 8.86 (d, 1H), 8.93 (s, 1H), 9.60 (d, 1H), 11.66 (s, 1H). 
     Synthesis of Compound 1 
     
       
         
         
             
             
         
       
     
     12 g (18.26 mmol) of 6-chloro-10-(2,6-diphenylpyridine-4-yl)-13-phenyl-10H-phenanthro[9,10-b]carbazole (Intermediate 1-3), 4.76 g (20.00 mmol) of (9,9-dimethyl-9H-fluoren-2-yl)boronic acid, 0.26 g (2.0 mmol) NICl 2 (dppf), 0.38 g (6.0 mmol) of n-BuLi, and 8.50 g (60.0 mmol) of K 3 PO 4  were added to 100 ml of dioxane, and then reflux-agitated at a temperature of 80° C. under nitrogen atmosphere for 24 hours. After the reaction was completed, extraction was performed on the resultant obtained therefrom by using MC and water, and then residual moisture was removed therefrom by using MgSO 4 . Thereafter, a column chromatography was performed using MC/Hexane (MC:Hexane=1:6) to obtain 9.48 g (yield 63.7%) of Compound 1. 
     m/z: 814.33 (100.0%), 815.34 (67.5%), 816.34 (22.9%), 817.34 (5.0%) 
       1 H NMR: 1.69 (s, 2H), 7.26 (m, 3H), 7.38-7.55 (m, 11H), 7.64-7.77 (m, 5H), 7.89 (m, 3H), 7.99 (d, 1H), 8.12 (m, 2H), 8.33 (d, 4H), 8.45 (m, 2H), 8.79 (d, 1H), 8.93 (s, 1H), 9.11 (d, 1H), 9.60 (d, 1H). 
     Synthesis Examples 2 to 13 
     Syntheses of Compounds 21, 48, 63, 79, 102, 138, 173, 194, 211, 237, 264, 285, and 328 were performed with reference to the synthesis of Compound 1. 
     Example 1 
     A 15 Ω/cm 2  (500 Å) ITO glass substrate (product of Corning) was cut into a size of 50 mm×50 mm×0.7 mm, ultrasonically cleaned by using isopropyl alcohol and pure water for 5 minutes each, irradiated with UV light for 30 minutes, and then exposed to ozone to clean the same. Then, a product obtained therefrom was loaded into a vacuum deposition apparatus. 
     4,4′,4″-tris(N-(2-naphthyl)-N-phenyl-amino)-triphenylamine (2-TNATA) was vacuum deposited on the glass substrate into a thickness of 600 Å to form a hole injection layer (HIL). N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)-benzidine (NPB) was vacuum deposited on the HIL into a thickness of 300 Å to form a hole transport layer (HTL), to form a hole transport region. 
     On the hole transport region, Compound 1, which is a host, and Ir(ppy) 3 (PD1), which is a dopant, were co-deposited in a weight ratio of 92:8 to form an emission layer having a thickness of 300 Å. 
     On the emission layer, Compound 1 was vacuum deposited to form an ETL having a thickness of 300 Å, and then on the ETL, LiF was deposited to form an EIL having a thickness of 10 Å, to form an electron transport region. 
     Al was vacuum deposited on the electron transport region to form a cathode having a thickness of 2,000 Å, to manufacture an organic light-emitting device. 
     
       
         
         
             
             
         
       
     
     Example 2 
     An organic light-emitting device was manufactured in the same manner as in Example 1, except that in forming the ETL, Compound 21 was used instead of Compound 1. 
     Example 3 
     An organic light-emitting device was manufactured in the same manner as in Example 1, except that in forming the ETL, Compound 48 was used instead of Compound 1. 
     Example 4 
     An organic light-emitting device was manufactured in the same manner as in Example 1, except that in forming the ETL, Compound 63 was used instead of Compound 1. 
     Example 5 
     An organic light-emitting device was manufactured in the same manner as in Example 1, except that in forming the ETL, Compound 79 was used instead of Compound 1. 
     Example 6 
     An organic light-emitting device was manufactured in the same manner as in Example 1, except that in forming the ETL, Compound 102 was used instead of Compound 1. 
     Example 7 
     An organic light-emitting device was manufactured in the same manner as in Example 1, except that in forming the ETL, Compound 138 was used instead of Compound 1. 
     Example 8 
     An organic light-emitting device was manufactured in the same manner as in Example 1, except that in forming the ETL, Compound 173 was used instead of Compound 1. 
     Example 9 
     An organic light-emitting device was manufactured in the same manner as in Example 1, except that in forming the ETL, Compound 194 was used instead of Compound 1. 
     Example 10 
     An organic light-emitting device was manufactured in the same manner as in Example 1, except that in forming the ETL, Compound 211 was used instead of Compound 1. 
     Example 11 
     An organic light-emitting device was manufactured in the same manner as in Example 1, except that in forming the ETL, Compound 237 was used instead of Compound 1. 
     Example 12 
     An organic light-emitting device was manufactured in the same manner as in Example 1, except that in forming the ETL, Compound 264 was used instead of Compound 1. 
     Example 13 
     An organic light-emitting device was manufactured in the same manner as in Example 1, except that in forming the ETL, Compound 285 was used instead of Compound 1. 
     Example 14 
     An organic light-emitting device was manufactured in the same manner as in Example 1, except that in forming the ETL, Compound 328 was used instead of Compound 1. 
     Comparative Example 1 
     An organic light-emitting device was manufactured in the same manner as in Example 1, except that in forming the ETL, Compound A was used instead of Compound 1. 
     
       
         
         
             
             
         
       
     
     Comparative Example 2 
     An organic light-emitting device was manufactured in the same manner as in Example 1, except that in forming the emission layer, Compound B was used instead of Compound 1 as a host and Alq 3  was used instead of Compound 1 in forming the ETL. 
     
       
         
         
             
             
         
       
     
     Evaluation Example 1 
     The driving voltage, current density, efficiency, and half-lifespan of the organic light-emitting devices manufactured according to Examples 1 to 14, and Comparative Examples 1 and 2 were measured by using Kethley SMU 236 and a brightness photometer PR650, and results thereof are shown in Table 1. The half-lifespan is a period of time that lapses until the brightness of the organic light-emitting device was 80% of initial brightness. 
     
       
         
           
               
               
               
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 Emission layer 
                   
                 Driving 
                 Efficiency 
                 Half lifespan 
               
               
                   
                 Host 
                 ETL 
                 Voltage (V) 
                 (cd/A) 
                 (hr@100 mA/cm 2 ) 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 Example 1 
                 Compound 1 
                 Compound 1 
                 5.1 
                 5.1 
                 432 
               
               
                 Example 2 
                 Compound 1 
                 Compound 21 
                 5.2 
                 5.2 
                 361 
               
               
                 Example 3 
                 Compound 1 
                 Compound 48 
                 4 5 
                 5.4 
                 462 
               
               
                 Example 4 
                 Compound 1 
                 Compound 63 
                 4.9 
                 4.9 
                 462 
               
               
                 Example 5 
                 Compound 1 
                 Compound 79 
                 5.3 
                 5.2 
                 370 
               
               
                 Example 6 
                 Compound 1 
                 Compound 102 
                 4.8 
                 5.6 
                 351 
               
               
                 Example 7 
                 Compound 1 
                 Compound 138 
                 4.5 
                 5.4 
                 512 
               
               
                 Example 8 
                 Compound 1 
                 Compound 173 
                 5.0 
                 5.2 
                 438 
               
               
                 Example 9 
                 Compound 1 
                 Compound 194 
                 4.6 
                 5.3 
                 321 
               
               
                 Example 10 
                 Compound 1 
                 Compound 211 
                 4.7 
                 5.3 
                 467 
               
               
                 Example 11 
                 Compound 1 
                 Compound 237 
                 5.4 
                 5.6 
                 419 
               
               
                 Example 12 
                 Compound 1 
                 Compound 264 
                 4.9 
                 5.4 
                 351 
               
               
                 Example 13 
                 Compound 1 
                 Compound 285 
                 5.6 
                 5.5 
                 473 
               
               
                 Example 14 
                 Compound 1 
                 Compound 328 
                 5.1 
                 5.3 
                 305 
               
               
                 Comparative 
                 Compound 1 
                 Compound A 
                 6.4 
                 4.8 
                 243 
               
               
                 Example 1 
               
               
                 Comparative 
                 Compound B 
                 Alq 3   
                 7.1 
                 3.7 
                 179 
               
               
                 Example 2 
               
               
                   
               
            
           
         
       
     
     From Table 1, it may be seen that the driving voltage of the organic light-emitting devices manufactured according to Examples 1 to 14 was lower, and efficiency and half-lifespan of the organic light-emitting devices manufactured according to Examples 1 to 14 were higher than those of the organic light-emitting devices manufactured according to Comparative Examples 1 and 2. 
     The embodiments may provide an organic light-emitting device with high efficiency. 
     An organic light-emitting device according to an embodiment may have a low driving voltage, high efficiency, high brightness, and long lifespan. 
     Example embodiments have been disclosed herein, and although specific terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purpose of limitation. In some instances, as would be apparent to one of ordinary skill in the art as of the filing of the present application, features, characteristics, and/or elements described in connection with a particular embodiment may be used singly or in combination with features, characteristics, and/or elements described in connection with other embodiments unless otherwise specifically indicated. Accordingly, it will be understood by those of skill in the art that various changes in form and details may be made without departing from the spirit and scope of the present invention as set forth in the following claims.