Patent Publication Number: US-2023142329-A1

Title: Organic light emitting element

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority from Korean Patent Application No. 10-2021-0154313, filed on Nov. 10, 2021, which is hereby incorporated by reference for all purposes as if fully set forth herein. 
     BACKGROUND 
     Technical Field 
     Embodiments of the disclosure relate to an organic light emitting element. 
     Discussion of the Related Art 
     In general, organic light emission refers to a phenomenon in which electric energy is converted into light energy by an organic material. The organic light emitting element refers to a light emitting element using the organic light emission phenomenon. The organic light emitting element has a structure including an anode, a cathode, and an organic material layer disposed therebetween. 
     The organic material layer may have a multilayer structure composed of different materials to increase the efficiency and stability of the organic light emitting element and may include a light emitting layer (also referred to as an emission material layer (EML)). 
     The lifespan and efficiency are the most important issues with organic light emitting elements. The efficiency, lifespan, and driving voltage are related to each other. If the efficiency is increased, the driving voltage is relatively decreased, so that the crystallization of the organic material by the Joule heating during driving is reduced, leading to an increase in lifespan. 
     The role of the light emitting layer EML is important to enhance the light emitting properties of the organic light emitting element and increase the lifespan. In particular, to have high-efficiency characteristics, the host material of the light emitting layer is required to have a high triplet level, and the stability of the material is needed. 
     SUMMARY 
     Accordingly, embodiments of the present disclosure are directed to an organic light emitting element that substantially obviates one or more of the problems due to limitations and disadvantages of the related art. 
     In order for the organic light emitting element to sufficiently exhibit its excellent characteristics, the materials constituting the organic material layer should be stable and have excellent efficiency. Since the phosphorescent organic light emitting element has a greater hole mobility than electron mobility in the light emitting layer and a long triplet state lifespan, excitons formed in the light emitting layer are distributed over a wide area, so that the light emission may be reduced. Accordingly, the inventors of the disclosure have invented an organic light emitting element that may have excellent efficiency or long lifespan. 
     An aspect of the present disclosure is to provide an organic light emitting element having high efficiency or long lifespan. 
     Additional features and aspects will be set forth in the description that follows, and in part will be apparent from the description, or may be learned by practice of the inventive concepts provided herein. Other features and aspects of the inventive concepts may be realized and attained by the structure particularly pointed out in the written description, or derivable therefrom, and the claims hereof as well as the appended drawings. 
     To achieve these and other aspects of the inventive concepts, as embodied and broadly described herein, an organic light emitting element comprises a first electrode, a second electrode, and an organic material layer positioned between the first electrode and the second electrode. 
     The organic material layer includes a compound represented by chemical formula 1 below: 
     
       
         
         
             
             
         
       
     
     According to embodiments of the disclosure, there may be provided an organic light emitting element having high efficiency or long lifespan. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this application, illustrate embodiments of the disclosure and together with the description serve to explain various principles. In the drawings: 
         FIGS.  1  and  2    are views schematically illustrating an organic light emitting element according to embodiments of the disclosure; 
         FIG.  3    is a view schematically illustrating an organic light emitting element according to embodiments of the disclosure; and 
         FIG.  4    is a view schematically illustrating an organic light emitting element according to embodiments of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description of examples or embodiments of the disclosure, reference will be made to the accompanying drawings in which it is shown by way of illustration specific examples or embodiments that can be implemented, and in which the same reference numerals and signs can be used to designate the same or like components even when they are shown in different accompanying drawings from one another. Further, in the following description of examples or embodiments of the disclosure, detailed descriptions of well-known functions and components incorporated herein will be omitted when it is determined that the description may make the subject matter in some embodiments of the disclosure rather unclear. The terms such as “including”, “having”, “containing”, “constituting” “make up of”, and “formed of” used herein are generally intended to allow other components to be added unless the terms are used with the term “only”. As used herein, singular forms are intended to include plural forms unless the context clearly indicates otherwise. 
     Terms, such as “first”, “second”, “A”, “B”, “(A)”, or “(B)” may be used herein to describe elements of the disclosure. Each of these terms is not used to define essence, order, sequence, or number of elements etc., but is used merely to distinguish the corresponding element from other elements. 
     When it is mentioned that a first element “is connected or coupled to”, “contacts or overlaps” etc. a second element, it should be interpreted that, not only can the first element “be directly connected or coupled to” or “directly contact or overlap” the second element, but a third element can also be “interposed” between the first and second elements, or the first and second elements can “be connected or coupled to”, “contact or overlap”, etc. each other via a fourth element. Here, the second element may be included in at least one of two or more elements that “are connected or coupled to”, “contact or overlap”, etc. each other. 
     When time relative terms, such as “after,” “subsequent to,” “next,” “before,” and the like, are used to describe processes or operations of elements or configurations, or flows or steps in operating, processing, manufacturing methods, these terms may be used to describe non-consecutive or non-sequential processes or operations unless the term “directly” or “immediately” is used together. 
     In addition, when any dimensions, relative sizes etc. are mentioned, it should be considered that numerical values for an elements or features, or corresponding information (e.g., level, range, etc.) include a tolerance or error range that may be caused by various factors (e.g., process factors, internal or external impact, noise, etc.) even when a relevant description is not specified. Further, the term “may” fully encompasses all the meanings of the term “can”. 
     Hereinafter, various embodiments of the disclosure are described in detail with reference to the accompanying drawings. 
     As used herein, the term “halo” or “halogen” includes fluorine (F), chlorine (Cl), bromine (Br), and iodine (I), and the like, unless otherwise specified. 
     As used herein, the term “alkyl” or “alkyl group” may mean a radical of a saturated aliphatic functional group having 1 to 60 carbon atoms linked by a single bond and including a straight chain alkyl group, branched chain alkyl group, cycloalkyl (alicyclic) group, alkyl-substituted cycloalkyl group, or cycloalkyl-substituted alkyl group, unless otherwise specified. 
     As used herein, the term “haloalkyl group” or “halogenalkyl group” may mean a halogen-substituted alkyl group unless otherwise specified. 
     As used herein, the term “alkenyl” or “alkynyl” may have a double bond or a triple bond, respectively, and may include a straight or branched chain group and may have 2 to 60 carbon atoms unless otherwise specified. 
     As used herein, the term “cycloalkyl” may refer to an alkyl forming a ring having 3 to 60 carbon atoms, unless otherwise specified. 
     As used herein, the term “alkoxy group” or “alkyloxy group” refers to an alkyl group to which an oxygen radical is bonded, and may have 1 to 60 carbon atoms unless otherwise specified. 
     As used herein, the term “alkenoxyl group”, “alkenoxy group”, “alkenyloxyl group”, or “alkenyloxy group” refers to an alkenyl group to which an oxygen radical is attached, and may have 2 to 60 carbon atoms unless otherwise specified. 
     As used herein, the terms “aryl group” and “arylene group” each may have 6 to 60 carbon atoms unless otherwise specified, but are not limited thereto. In the disclosure, the aryl group or the arylene group may include a monocyclic type, a ring assembly, a fused polycyclic system, a spiro compound, and the like. For example, the aryl group includes, but is not limited to, phenyl, biphenyl, naphthyl, anthryl, indenyl, phenanthryl, triphenylenyl, pyrenyl, peryleneyl, chrysenyl, naphthacenyl, or fluoranthenyl. The naphthyl may include 1-naphthyl and 2-naphthyl, and the anthryl may include 1-anthryl, 2-anthryl and 9-anthryl. 
     In the disclosure, the term “fluorenyl group” or “fluorenylene group” may refer to a monovalent or divalent functional group, respectively, of fluorene, unless otherwise specified. The “fluorenyl group” or “fluorenylene group” may mean a substituted fluorenyl group or a substituted fluorenylene group. “Substituted fluorenyl group” or “substituted fluorenylene group” may refer to a monovalent or divalent functional group of substituted fluorene. “Substituted fluorene” may mean that at least one of the following substituents R, R′, R″ and R′″ is a functional group other than hydrogen. It may include a case where R and R′ are bonded to each other to form a spiro compound together with the carbon to which they are bonded. 
     
       
         
         
             
             
         
       
     
     As used herein, the term “spiro compound” has a ‘spiro union’, and the spiro union means a union formed as two rings share only one atom. In this case, the atom shared by the two rings may be referred to as a ‘spiro atom’. 
     As used herein, the term “heterocyclic group” may include not only an aromatic ring, such as a “heteroaryl group” or “heteroarylene group” but also a non-aromatic ring and, unless otherwise specified, means a ring with 2 to 50 carbon atoms and one or more heteroatoms, but is not limited thereto. As used herein, the term “heteroatom” refers to N, O, S, P or Si unless otherwise specified, and the heterocyclic group may mean a monocyclic group containing a heteroatom, a ring assembly, a fused polycyclic system, or a spyro compound. 
     The “heterocyclic group” may include a ring containing SO2 instead of carbon forming the ring. For example, the “heterocyclic group” may include the following compounds. 
     
       
         
         
             
             
         
       
     
     As used herein, the term “ring” may include monocycles and polycycles, may include hydrocarbon rings as well as heterocycles containing at least one heteroatom, or may include aromatic and non-aromatic rings. 
     As used herein, the term “polycycle” may include ring assemblies, fused polycyclic systems, and spiro compounds, may include aromatic as well as non-aromatic compounds, or may include heterocycles containing at least one heteroatom as well as hydrocarbon rings. 
     As used herein, the term “aliphatic ring group” refers to a cyclic hydrocarbon other than the aromatic hydrocarbon, may include a monocyclic type, a ring assembly, a fused polycyclic system, and a spiro compound and, unless otherwise specified, may mean a ring having 3 to 60 carbon atoms. For example, a fusion of benzene, which is an aromatic ring, and cyclohexane, which is a non-aromatic ring, also corresponds to an aliphatic ring. 
     As used herein, the term “alkylsilyl group” may refer to a monovalent substituent in which three alkyl groups are bonded to a Si atom. 
     As used herein, the term “arylsilyl group” may refer to a monovalent substituent in which three aryl groups are bonded to a Si atom. 
     As used herein, the term “alkylarylsilyl group” may refer to a monovalent substituent in which one alkyl group and two aryl groups are bonded to a Si atom or two alkyl groups and one aryl group are bonded to the Si atom. 
     As used herein, the term “ring assembly” means that two or more ring systems (single or fused ring systems) are directly connected to each other through single or double bonds. For example, in the case of an aryl group, a biphenyl group or a terphenyl group may be a ring assembly but is not limited thereto. 
     As used herein, the term “fused polycyclic system” refers to a type of fused rings sharing at least two atoms. For example, in the case of an aryl group, a naphthalenyl group, a phenanthrenyl group, or a fluorenyl group may be a fused polycyclic system, but is not limited thereto. 
     When prefixes are named successively, it may mean that the substituents are listed in the order specified first. For example, an arylalkoxy group may mean an alkoxy group substituted with an aryl group, an alkoxycarbonyl group may mean a carbonyl group substituted with an alkoxy group, and an arylcarbonylalkenyl group may mean an alkenyl group substituted with an arylcarbonyl group. The arylcarbonyl group may be a carbonyl group substituted with an aryl group. 
     Unless otherwise explicitly stated, in the term “substituted” or “unsubstituted” as used herein, “substituted” may mean being substituted with one or more substitutents selected from the group consisting of halogen, an amino group, a nitrile group, a nitro group, a C 1 -C 20  alkyl group, a C 1 -C 20  alkoxy group, a C 1 -C 20  alkylamine group, a C 1 -C 20  alkylthiophene group, a C 6 -C 20  arylthiophene group, a C 2 -C 20  alkenyl group, a C 2 -C 20  alkynyl group, a C 3 -C 20  cycloalkyl group, a C 6 -C 20  aryl group, a C 8 -C 20  arylalkenyl group, a silane group, a boron group, a germanium group, and a C 2 -C 20  heterocyclic group including at least one heteroatom selected from the group consisting of O, N, S, Si and P, but is not limited to the substitutents. 
     In the disclosure, the ‘functional group names’ corresponding to the aryl group, arylene group, and heterocyclic group provided as examples of the symbols and their substituents may be described with ‘the names of the functional groups reflecting the valence’, but may also be described with ‘the names of the parent compounds.’ For example, in the case of ‘phenanthrene’, which is a type of aryl group, its name may be specified with its group identified, such as ‘phenanthryl (group)’ for the monovalent group, and ‘phenanthrylene (group)’ as the divalent groui, but may also be specified as ‘phenanthrene’, which is the name of the parent compound, regardless of the valence. Similarly, pyrimidine may be specified as ‘pyrimidine’ regardless of the valence or may also be specified as pyrimidinyl (group) for the monovalence and as pyrimidylene (group) for the divalence. Therefore, in the disclosure, when the type of the substituent is specified with the name of the parent compound, it may mean an n-valent ‘group’ formed by detachment of the hydrogen atom bonded to a carbon atom and/or a heteroatom of the parent compound. 
     Further, unless explicitly stated, the formulas used in the disclosure may be applied in the same manner as the definition of the substituent by the following formulas. 
     
       
         
         
             
             
         
       
     
     When a is 0, it means that the substituent R 1  does not exist, meaning that hydrogen is bonded to each of the carbon atoms forming the benzene ring. In this case, the chemical formula or chemical compound may be specified without expressing the hydrogen bonded to the carbon. Further, when a is 1, one substituent R 1  is bonded to any one of the carbon atoms forming the benzene ring, and when a is 2 or 3, it may be bonded as follows. When a is an integer of 4 to 6, it is bonded to the carbon of the benzene ring in a similar manner, and when a is an integer of 2 or more, R 1  may be identical or different. 
     
       
         
         
             
             
         
       
     
     In the disclosure, when substituents are bonded to each other to form a ring, it may mean that adjacent groups are bonded to each other to form a monosycle or fused polycycle, and the monocycle or fused polycycle may include heterocycles containing at least one heteroatom as well as hydrocarbon rings and may include aromatic and non-aromatic rings. 
     In the disclosure, organic light emitting element may mean a component(s) between the anode and the cathode or an organic light emitting diode including an anode, a cathode, and component(s) positioned therebetween. 
     In some cases, in the disclosure, organic light emitting element may mean an organic light emitting diode and a panel including the same, or an electronic device including the panel and circuitry. The electronic device may include, e.g., a display device, a lighting device, a solar cell, a portable or mobile terminal (e.g., a smart phone, a tablet, a PDA, an electronic dictionary, or PMP), a navigation terminal, a game device, various TVs, and various computer monitors but, without limited thereto, may include any type of device including the component(s). 
       FIG.  1    is a view schematically illustrating an organic light emitting element according to embodiments of the disclosure. 
     The organic light emitting element  100  according to embodiments of the disclosure includes a first electrode  110 , a second electrode  120 , and an organic material layer  130  positioned between the first electrode  110  and the second electrode  120 . 
     For example, the first electrode  110  may be the anode electrode, and the second electrode  120  may be the cathode electrode. 
     For example, the first electrode  110  may be a transparent electrode, and the second electrode  130  may be a reflective electrode. In another example, the first electrode  110  may be a reflective electrode, and the second electrode  130  may be a transparent electrode. 
     The organic material layer  130  is a layer positioned between the first electrode  110  and the second electrode  120  and including an organic material and may be composed of a plurality of layers. 
     The organic material layer  130  includes a compound represented by chemical formula 1. The compound represented by chemical formula 1 is described below in detail. 
     The organic material layer  130  may include a light emitting layer. The organic layer  130  may further include at least one of a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer. 
     For example, the organic material layer  130  may include a hole injection layer positioned on the first electrode  110 , a hole transport layer positioned on the hole injection layer, a light emitting layer positioned on the hole transport layer, an electron transport layer positioned on the light emitting layer, and an electron injection layer positioned on the electron transport layer. In such an example, the first electrode  110  may be the anode electrode, and the second electrode  120  may be the cathode electrode. 
     The light emitting layer is a layer in which as holes and electrons transferred from the first electrode  110  and the second electrode  130  meet to emit light and may include, e.g., a host material and a dopant. 
     The light emitting layer may include the compound represented by chemical formula 1 described above. The compound represented by chemical formula 1 may be the host compound of the light emitting layer. For example, the compound represented by chemical formula 1 may be a phosphorescent host compound of the light emitting layer. 
     The light emitting layer may further include a host compound different from the compound represented by chemical formula 1 described above. The type of the host compound that may be additionally included is not particularly limited, and a known host compound may be used. 
       FIG.  2    is a view schematically illustrating an organic light emitting element according to embodiments of the disclosure. 
     The organic light emitting element  200  according to embodiments of the disclosure includes a first electrode  110 , a second electrode  120 , and an organic material layer  130  positioned between the first electrode  110  and the second electrode  120 . 
     For example, the first electrode  110  may be the anode electrode, and the second electrode  120  may be the cathode electrode. 
     For example, the first electrode  110  may be a transparent electrode, and the second electrode  120  may be a reflective electrode. In another example, the first electrode  110  may be a reflective electrode, and the second electrode  120  may be a transparent electrode. 
     The organic material layer  130  is a layer positioned between the first electrode  110  and the second electrode  120  and including an organic material and may be composed of a plurality of layers. 
     The organic material layer  130  includes a compound represented by chemical formula 1. The compound represented by chemical formula 1 is described below in detail. 
     The organic material layer  130  may include a hole injection layer  231  positioned on the first electrode  110 , a hole transport layer  232  positioned on the hole injection layer  231 , a light emitting layer  233  positioned on the hole transport layer  232 , an electron transport layer  234  positioned on the light emitting layer  233 , and an electron injection layer  235  positioned on the electron transport layer  234 . In such an example, the first electrode  110  may be the anode electrode, and the second electrode  120  may be the cathode electrode. The organic material layer  130  may not include some of the layers shown in  FIG.  2    or may include an additional functional layer, such as a light emitting assist layer. 
     The light emitting layer  233  may include the compound represented by chemical formula 1 described above. 
     The light emitting layer  233  may include a host compound  2331  and a dopant  2332 . The host compound  2331  may be a compound represented by chemical formula 1 described above. The host compound  2331  may further include another compound different from the compound represented by chemical formula 1 described above. For example, the host compound  2331  may include a compound represented by chemical formula 1 and a biscarbazole-based compound. 
     The type of the dopant  2332  is not particularly limited. For example, the dopant  2332  may be a green phosphorescent dopant. For example, the dopant  2332  may be a metal complex, such as of iridium. 
       FIG.  3    is a view schematically illustrating an organic light emitting element according to embodiments of the disclosure. 
     Referring to  FIG.  3   , the organic material layer  130  includes a first stack  331 , a second stack  332 , and a charge generation layer  333  positioned between the first stack  331  and the second stack  332 . 
     The organic light emitting element  300  may be a tandem-type organic light emitting element including a plurality of stacks each including a light emitting layer. The plurality of light emitting layers may be formed of the same material or different materials. The first stack  331  may include a first light emitting layer  3313 . The second stack  332  may include a second light emitting layer  3323 . The first light emitting layer  3313  and the second light emitting layer  3323  may be formed of the same material or different materials. 
     The first stack  331  may include a first light emitting layer  3313 . The first light emitting layer  3313  may include, e.g., a first host compound  33131  and a first dopant  33132 . 
     The first stack  231  may further include at least one of a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer. 
     For example, the first stack  331  may include a first hole injection layer  3311  positioned on the first electrode  110 , a first hole transport layer  3312  positioned on the first hole injection layer  3311 , a first light emitting layer  3313  positioned on the first hole transport layer  3312 , a first electron transport layer  3314  positioned on the first light emitting layer  3313 , and a first electron injection layer  3315  positioned on the first electron transport layer  3314 . In such an example, the first electrode  110  may be the anode electrode, and the second electrode  120  may be the cathode electrode. The first stack  331  may not include some of the layers shown in FIG.  3  or may include an additional functional layer, such as a light emitting assist layer. 
     The first light emitting layer  3313  may include the compound represented by chemical formula 1 described above. 
     The first light emitting layer  3313  may include a first host compound  33131  and a first dopant  33132 . The first host compound  33131  may be a compound represented by chemical formula 1 described above. The first host compound  33131  may further include another compound different from the compound represented by chemical formula 1 described above. For example, the first host compound  33131  may include a compound represented by chemical formula 1 and a biscarbazole-based compound. 
     The type of the first dopant  33132  is not particularly limited. For example, the first dopant  33132  may be a green phosphorescent dopant. For example, the first dopant  33132  may be a metal complex, such as of iridium. 
     The second stack  332  may include a second light emitting layer  3323 . The second light emitting layer  3323  may include, e.g., a second host compound and a second dopant. 
     The second stack  332  may further include at least one of a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer. 
     For example, the second stack  332  may include a second hole injection layer  3321  positioned on the second electrode  110 , a second hole transport layer  3322  positioned on the second hole injection layer  3321 , a second light emitting layer  3323  positioned on the second hole transport layer  3322 , a second electron transport layer  3324  positioned on the second light emitting layer  3323 , and a second electron injection layer  3325  positioned on the second electron transport layer  3324 . In such an example, the first electrode  110  may be the anode electrode, and the second electrode  120  may be the cathode electrode. The second stack  332  may not include some of the layers shown in  FIG.  3    or may include an additional functional layer, such as a light emitting assist layer. 
     The second light emitting layer  3323  may emit light of the same color as, or a different color from, the light emitted by the first light emitting layer  3313 . In the disclosure, that the light emitting layers emit light of the same color means that the light emitting layers emit not only light of colors with the same color coordinates but also light of colors similar to each other to be classified as pixels representing the same color in the technical field of the disclosure. 
     The second light emitting layer  3323  may include a second host compound and a second dopant. 
     The type of the second host compound is not particularly limited. The second host compound may be the same as, or different from, the first host compound  33131 . 
     The type of the second dopant is not particularly limited. The second dopant may be the same as, or different from, the first dopant  33132 . 
     In embodiments of the disclosure, the second light emitting layer  3323  may emit light of the same color as the light emitted by the first light emitting layer  3313 . In the above-described embodiments, the first light emitting layer  3323  may include the compound represented by chemical formula 2 described above. 
     In embodiments in which the first light emitting layer  3313  and the second light emitting layer  3323  emit light of the same color, the second host compound may be a compound represented by chemical formula 1 described above. The second host compound may further include another compound different from the compound represented by chemical formula 1 described above. For example, the second host compound may include a compound represented by chemical formula 1 and a biscarbazole-based compound. 
     In embodiments in which the first light emitting layer  3313  and the second light emitting layer  3323  emit light of the same color, the type of the second dopant is not particularly limited and may be the same as the first dopant  33132 . For example, the second dopant may be a green phosphorescent dopant. For example, the second dopant may be a metal complex, such as of iridium. 
     The charge generation layer  333  may be formed between the plurality of light emitting layers to smoothly distribute charges, thereby increasing the current efficiency of the light emitting layer. Accordingly, the charge generation layer  333  is positioned between the first stack  331  including the first light emitting layer  3313  and the second stack  332  including the second light emitting layer  3323 . 
     The charge generation layer  333  may include a p-type charge generation layer and an n-type charge generation layer to smoothly distribute charges. When the first electrode  110  is the anode electrode, and the second electrode  120  is the cathode electrode, the p-type charge generation layer may be positioned on the side of the cathode electrode, and the n-type charge generation layer may be positioned on the side of the anode electrode. 
     Although  FIG.  3    illustrates a tandem-type organic light emitting element including two stacks, embodiments of the disclosure are not limited thereto but may include tandem-type organic light emitting elements including two or more stacks. When the organic light emitting element  300  includes an additional stack, an additional charge generation layer may be positioned between the additional stack and the first stack  331  or second stack  332  adjacent thereto. 
       FIG.  4    is a view schematically illustrating an organic light emitting element according to embodiments of the disclosure. 
     Referring to  FIG.  4   , the organic material layer  130  includes a first stack  431 , a second stack  432 , a third stack  433 , a first charge generation layer  434  positioned between the first stack  431  and the second stack  432 , and a second charge generation layer  435  positioned between the first stack  431  and the third stack  433 . In the embodiments illustrated in  FIG.  4   , the first stack  431  is positioned between the second stack  432  and the third stack  433 , but embodiments of the disclosure including three stacks are limited to this structure, and the positions of the first stack  431 , the second stack  432 , and the third stack  433  may be exchanged with each other. 
     The organic light emitting element  400  may be a tandem-type organic light emitting element including a plurality of stacks each including a light emitting layer. The plurality of light emitting layers may be formed of the same material or different materials. 
     The first stack  431  may include a first light emitting layer  4313 . The first light emitting layer  4313  may include, e.g., a first host compound  43131  and a first dopant  43132 . 
     The first stack  431  may further include at least one of a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer. 
     For example, the first stack  431  may include a first hole injection layer  4311  positioned on the first electrode  110 , a first hole transport layer  4312  positioned on the first hole injection layer  4311 , a first light emitting layer  4313  positioned on the first hole transport layer  4312 , a first electron transport layer  4314  positioned on the first light emitting layer  4313 , and a first electron injection layer  4315  positioned on the first electron transport layer  4314 . In such an example, the first electrode  110  may be the anode electrode, and the second electrode  120  may be the cathode electrode. The first stack  431  may not include some of the layers shown in  FIG.  4    or may include an additional functional layer, such as a light emitting assist layer. 
     The first light emitting layer  4313  may include the compound represented by chemical formula 1 described above. 
     The first light emitting layer  4313  may include a first host compound  43131  and a first dopant  43132 . The first host compound  43131  may be a compound represented by chemical formula 1 described above. The first host compound  43131  may further include another compound different from the compound represented by chemical formula 1 described above. For example, the first host compound  43131  may include a compound represented by chemical formula 1 and a biscarbazole-based compound. 
     The type of the first dopant  43132  is not particularly limited. For example, the first dopant  43132  may be a green phosphorescent dopant. For example, the first dopant  43132  may be a metal complex, such as of iridium. 
     The second stack  432  may include a second light emitting layer  4323 . The second light emitting layer  4323  may include, e.g., a second host compound  43231  and a second dopant  43232 . 
     The second stack  432  may further include at least one of a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer. 
     For example, the second stack  432  may include a second hole injection layer  4321  positioned on the second electrode  110 , a second hole transport layer  4322  positioned on the second hole injection layer  4321 , a second light emitting layer  4323  positioned on the second hole transport layer  4322 , a second electron transport layer  4324  positioned on the second light emitting layer  4323 , and a second electron injection layer  4325  positioned on the second electron transport layer  4324 . In such an example, the first electrode  110  may be the anode electrode, and the second electrode  120  may be the cathode electrode. The second stack  432  may not include some of the layers shown in  FIG.  4    or may include an additional functional layer, such as a light emitting assist layer. 
     The second light emitting layer  4323  may emit light of the same color as or a different color from, the light emitted by the first light emitting layer  4313 . 
     The second light emitting layer  4323  may include a second host compound and a second dopant. 
     The type of the second host compound is not particularly limited. The second host compound may be the same as, or different from, the first host compound  43131 . 
     The type of the second dopant is not particularly limited. The second dopant may be the same as, or different from, the first dopant  43132 . 
     In embodiments of the disclosure, the second light emitting layer  4323  may emit light of the same color as the light emitted by the first light emitting layer  4313 . In the above-described embodiments, the first light emitting layer  4323  may include the compound represented by chemical formula 2 described above. 
     In embodiments in which the first light emitting layer  4313  and the second light emitting layer  4323  emit light of the same color, the second host compound may be a compound represented by chemical formula 1 described above. The second host compound may further include another compound different from the compound represented by chemical formula 1 described above. For example, the second host compound may include a compound represented by chemical formula 1 and a biscarbazole-based compound. 
     In embodiments in which the first light emitting layer  4313  and the second light emitting layer  4323  emit light of the same color, the type of the second dopant is not particularly limited and may be the same as the first dopant  43132 . For example, the second dopant may be a green phosphorescent dopant. For example, the second dopant may be a metal complex, such as of iridium. 
     The third stack  433  may include a third light emitting layer  4333 . The third light emitting layer  4333  may include, e.g., a third host compound and a third dopant. 
     The third stack  432  may further include at least one of a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer. 
     For example, the third stack  432  may include a third hole injection layer  4331  positioned on the third electrode  110 , a third hole transport layer  4332  positioned on the third hole injection layer  4331 , a third light emitting layer  4333  positioned on the third hole transport layer  4332 , a third electron transport layer  4334  positioned on the third light emitting layer  4333 , and a third electron injection layer  4335  positioned on the third electron transport layer  4334 . In such an example, the first electrode  110  may be the anode electrode, and the second electrode  120  may be the cathode electrode. The third stack  433  may not include some of the layers shown in  FIG.  4    or may include an additional functional layer, such as a light emitting assist layer. 
     The third light emitting layer  4333  may emit light of the same color as or a different color from, the light emitted by the first light emitting layer  4313 . 
     The third light emitting layer  4333  may include a third host compound and a third dopant. 
     The type of the third host compound is not particularly limited. The third host compound may be the same as, or different from, the first host compound  43131 . 
     The type of the third dopant is not particularly limited. The third dopant may be the same as, or different from, the first dopant  43132 . 
     In embodiments of the disclosure, the third light emitting layer  4333  may emit light of the same color as the light emitted by the first light emitting layer  4313 . In the above-described embodiments, the first light emitting layer  4333  may include the compound represented by chemical formula 3 described above. 
     In embodiments in which the first light emitting layer  4313  and the third light emitting layer  4333  emit light of the same color, the third host compound may be a compound represented by chemical formula 1 described above. The third host compound may further include another compound different from the compound represented by chemical formula 1 described above. For example, the third host compound may include a compound represented by chemical formula 1 and a biscarbazole-based compound. 
     In embodiments in which the first light emitting layer  4313  and the third light emitting layer  4333  emit light of the same color, the type of the second dopant is not particularly limited and may be the same as the first dopant  43132 . For example, the second dopant may be a green phosphorescent dopant. For example, the second dopant may be a metal complex, such as of iridium. 
     The first host compound  43131 , the second host compound, and the third host compound may be the same as or different from each other. One or more of the first host compound  43131 , the second host compound, and the third host compound may be a compound represented by chemical formula 1 described above. Accordingly, one of the first host compound  43131 , the second host compound, and the third host compound may include a compound represented by chemical formula 1 described above. Two of the first host compound  43131 , the second host compound, and the third host compound may include a compound represented by chemical formula 1 described above. All of the first host compound  43131 , the second host compound, and the third host compound may include a compound represented by chemical formula 1 described above. When there are two or more light emitting layers containing a host compound including the compound represented by chemical formula 1, the two or more light emitting layers may emit light of the same color. 
     The first dopant  33132 , the second dopant, and the third dopant may be the same as or different from each other. 
     As the first stack  431 , the second stack  432 , and the third stack  433  are configured as described above, the holes and electrons transferred from the first electrode  110  and the second electrode  120  meet at the first light emitting layer  4313 , the second light emitting layer  4323 , and the third light emitting layer  4333 , emitting light. 
     The first charge generation layer  434  and second charge generation layer  435  may be formed between the plurality of light emitting layers to smoothly distribute charges, thereby increasing the current efficiency of the light emitting layer. Accordingly, the first charge generation layer  434  may be positioned between the first stack  431  including the first light emitting layer  4313  and the second stack  432  including the second light emitting layer  4323 , and the second charge generation layer  435  may be positioned between the second stack  432  including the second light emitting layer  433  and the third stack  433  including the third light emitting layer  4333 . 
     The first charge generation layer  434  and second charge generation layer  435  may include a p-type charge generation layer and an n-type charge generation layer to smoothly distribute charges. When the first electrode  110  is the anode electrode, and the second electrode  120  is the cathode electrode, the p-type charge generation layer may be positioned on the side of the cathode electrode, and the n-type charge generation layer may be positioned on the side of the anode electrode. 
     The first charge generation layer  434  and the second charge generation layer  435  may be the same as or different from each other. The first charge generation layer  434  and the second charge generation layer  435  may be formed of the same material or different materials. 
     The compound represented by chemical formula 1 described above is described below. 
     The compound represented by chemical formula 1 described above may be represented by chemical formula 1 as follows. 
     
       
         
         
             
             
         
       
     
     In chemical formula 1, either X or Y is N, and the other is S or 0. 
     a is an integer from 0 to 5. 
     R 1  is each independently selected from the group consisting of a C 1 -C 20  alkyl group; a C 3 -C 30  cycloalkyl group; an aryloxy group; an arylthioxy group; a fluorenyl group; and a C 6 -C 60  aryl group. 
     When R 1  is an aryl group, the aryl group may be each independently a C 6 -C 30  aryl group, a C 6 -C 20  aryl group, or a C 6 -C 12  aryl group. 
     R 2  is selected from the group consisting of a C 3 -C 30  cycloalkyl group; an aryloxy group; an arylthioxy group; a fluorenyl group; and a C 6 -C 60  aryl group. 
     When R 2  is an aryl group, the aryl group may be each independently a C 6 -C 30  aryl group, a C 6 -C 20  aryl group, or a C 6 -C 12  aryl group. 
     R 3  and R 4  may be each independently selected from the group consisting of i) a C 1 -C 20  alkyl group; and a C 6 -C 60  aryl group; or may be bonded to each other to form a ring. 
     When one or more of R 3  and R 4  are aryl groups, the aryl groups each may independently be a C 6 -C 30  aryl group, a C 6 -C 20  aryl group, or a C 6 -C 12  aryl group. 
     b is an integer from 0 to 3. 
     R 5  is each independently a C 6 -C 60  aryl group. 
     When R 5  is an aryl group, the aryl group may be each independently a C 6 -C 30  aryl group, a C 6 -C 20  aryl group, or a C 6 -C 12  aryl group. 
     the alkyl group, cycloalkyl group, aryloxy group, arylthioxy group, fluorenyl group and aryl group each are further substituted with one or more substituents selected from the group consisting of a halogen group; a C 1 -C 20  alkyl group; a C 2 -C 20  alkenyl group; a C 2 -C 20  alkynyl group; a fluorenyl group; a C 6 -C 20  aryl group; and a C 2 -C 20  heterocyclic group. 
     One or more of the hydrogen atoms contained in the compound represented by chemical formula 1 may be substituted with deuterium or tritium. 
     By including the compound represented by chemical formula 1 described above, the organic light emitting elements  100  and  200  may have high efficiency or long lifespan. 
     The compound represented by chemical formula 1 may be represented by any one of chemical formulas 1a and 1b below. 
     
       
         
         
             
             
         
       
     
     In chemical formula 1a and chemical formula 1b, X and Y are each S or 0. 
     R 1 , R 2 , R 3 , R 4 , R 5 , a and b are the same as those defined above in chemical formula 1. 
     One or more of the hydrogen atoms contained in the compound represented by chemical formula 1a and chemical formula 1b may be substituted with deuterium or tritium. 
     The compound represented by chemical formula 1 described above may be one or more of the above-described compounds. 
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     One or more of the hydrogen atoms contained in the AZ1 to AK160 may be substituted with deuterium or tritium. 
     The above description has been presented to enable any person skilled in the art to make and use the technical idea of the disclosure, and has been provided in the context of a particular application and its requirements. Various modifications, additions and substitutions to the described embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the disclosure. The above description and the accompanying drawings provide an example of the technical idea of the disclosure for illustrative purposes only. That is, the disclosed embodiments are intended to illustrate the scope of the technical idea of the disclosure. Thus, the scope of the disclosure is not limited to the embodiments shown, but is to be accorded the widest scope consistent with the claims. The scope of protection of the disclosure should be construed based on the following claims, and all technical ideas within the scope of equivalents thereof should be construed as being included within the scope of the disclosure. 
     An example of manufacturing an organic light emitting element according to embodiments of the disclosure are described below in detail with reference to embodiments thereof, but embodiments of the disclosure are not limited to the following embodiments. 
     Example of Preparing the Compound 
     Synthesis Method for AZ3 
     
       
         
         
             
             
         
       
     
     Synthesis of Intermediate A 
     Benzoic acid (10 g, 0.082 mol), 2-amino-4-bromophenol (33.9 g, 0.180 mol), diisopropylethylamine(37.1 ml, 0.213 mol), 4M K 2 CO 3  aqueous solution 80 ml, methylene chloride 300 ml are put in a round-bottom flask and stirred while reducing the temperature to 0° C. Deoxo-fluor reagent, 50% in THF (66.4 ml, 0.180 mol) diluted with 45 ml of MC is slowly added dropwise to the solution. After the dropwise addition is finished, the solution is stirred at 0° C. for 2 hours. After the reaction is finished by adding 150 ml of saturated aqueous sodium bicarbonate solution to the reaction solution, the solution is heated to room temperature. After the reaction solution is separated into layers to recover the organic layer, the organic layer was dried with MgSO 4  and concentrated under reduced pressure. The concentrated crude material was separated by column to obtain 19.1 g of intermediate A. 
     Synthesis of AZ3 
     An intermediate A (5 g, 0.018 mol), 2-(4-biphenylyl)amino-9,9-dimethylfluorene(7.9 g, 0.022 mol), palladium acetate (I) 0.08 g, 0,365 mmol), 2,2-Bis(diphenylphosphino)-1,1′-binaphthyl (0.23 g, 0.365 mmol), sodium-t-butoxide (2.63 g, 0.027 mol), and toluene 100 ml are put in a round-bottom flask and heated to 100° C. while b stirred for 8 hours. The reaction solution was hot-filtered through silicagel to remove impurities, and the filtrate was concentrated under reduced pressure to obtain a crude material. The obtained crude material was purified by MC/acetone to obtain 6.9 g of AZ3. 
     Synthesis Method for AZ5 
     
       
         
         
             
             
         
       
     
     The synthesis was carried out in the same way as in the synthesis method for AZ3 except that 2-(2-biphenylyl)amino-9,9-dimethylfluorene (7.9 g, 0.022 mol) was used instead of 2-(4-biphenylyl)amino-9,9-dimethylfluorene. As a result, 6.6 g of AZ5 was obtained. 
     Synthesis Method for AZ10 
     
       
         
         
             
             
         
       
     
     The synthesis was carried out in the same way as in the synthesis method for AZ3 except that 2-(3-dibenzofuranyl)amino-9,9-dimethylfluorene (8.2 g, 0.022 mol) was used instead of 2-(4-biphenylyl)amino-9,9-dimethylfluorene. As a result, 7.1 g of AZ10 was obtained. 
     Synthesis Method for AZ11 
     
       
         
         
             
             
         
       
     
     The synthesis was carried out in the same way as in the synthesis method for AZ3 except that 2-(3-dibenzothiophenyl)amino-9,9-dimethylfluorene (8.6 g, 0.022 mol) was used instead of 2-(4-biphenylyl)amino-9,9-dimethylfluorene. As a result, 7.3 g of AZ11 was obtained. 
     Synthesis Method for AZ18 
     
       
         
         
             
             
         
       
     
     The synthesis was carried out using the same reagents and the same dosage and same method as in the synthesis method for AZ3 that bis(9,9-dimethyl-9H-fluoren-2-yl)amine (8.8 g, 0.022 mol) was applied instead of 2-(4-biphenylyl)amino-9,9-dimethylfluorene and, as a result, 7.6 g of AZ18 was obtained. 
     Synthesis Method for AZ20 
     
       
         
         
             
             
         
       
     
     The synthesis was carried out in the same way as in the synthesis method for AZ3 except that (9,9-dimethylfluorene-2-yl)-9,9-spirobifluorene-2-amine(11.5 g, 0.022 mol) was used instead of 2-(4-biphenylyl)amino-9,9-dimethylfluorene. As a result, 9.0 g of AZ20 was obtained. 
     Synthesis Method for AZ23 
     
       
         
         
             
             
         
       
     
     The synthesis was carried out in the same way as in the synthesis method for AZ3 except that 2-(4-Biphenylyl)amino-9,9-diphenylfluorene (10.6 g, 0.022 mol) was used instead of 2-(4-biphenylyl)amino-9,9-dimethylfluorene. As a result, 8.8 g of AZ23 was obtained. 
     Synthesis Method for AZ43 
     
       
         
         
             
             
         
       
     
     Synthesis of Intermediate B 
     4-bromobenzoic acid(20 g, 0.099 mol), phenylboronic acid(14.6 g, 0.119 mol), tetrakis(triphenylphosphine)palladium(0) (2.3 g, 1.99 mmol), toluene 400 ml, and 4M K 2 CO 3 (potassium carbonate) 100 ml were put in a round-bottom flask and stirred under reflux for 12 hours. After completion of the reaction, the reaction solution is separated into layers, the organic layer is recovered and concentrated under reduced pressure to obtain a crude product. The filtered crude was separated by column to obtain 17.7 g of intermediate B. 
     Synthesis of Intermediate C 
     An intermediate B (15 g, 0.076 mol), 2-amino-4-bromophenol (31.3 g, 0.166 mol), diisopropylethylamine(34.3 ml, 0.197 mol), 4M K 2 CO 3  aqueous solution 75 ml, methylene chloride 350 ml are put in a round-bottom flask and stirred while reducing the temperature to 0° C. Deoxo-fluor reagent, 50% in THF (61.4 ml, 0.166 mol) diluted with 45 ml of MC is slowly added dropwise to the solution. After completion of the dropwise addition, the solution was stirred at 0° C. for 2 hours. The subsequent procedure was the same as that for the intermediate A and, as a result, 22.5 g of intermediate C was obtained. 
     Synthesis of AZ43 
     An intermediate C(5 g, 0.014 mol),  2 -(4-Biphenylyl)amino-9,9-dimethylfluorene(6.2 g, 0.017 mol), instead of the intermediate A in the synthesis method for AZ3, palladium acetate(II) 0.06 g, 0.365 mmol), 2,2′-Bis(diphenylphosphino)-1,1′-binaphthyl (0.18 g, 0.365 mmol), sodium-t-butoxide (2.06 g, 0.021 mol), and toluene 100 ml are put and heated to 100° C. while being stirred for 8 hours. The reaction solution was hot filtered through silicagel to remove impurities, and the filtrate was concentrated under reduced pressure to obtain crude. After the obtained crude was purified by MC/acetone, 6.9 g of AZ43 was obtained. 
     Synthesis Method for AZ83 
     
       
         
         
             
             
         
       
     
     Synthesis of Intermediate D 
     The same method as the synthesis method for the intermediate A except that 2-amino-4-bromobenzenethiol(36.8 g, 0.180 mol) was applied instead of 2-amino-4-bromophenol was performed and, as a result, 18.5 g of intermediate D was obtained. 
     Synthesis of AZ83 
     An intermediate D(5 g, 0.017 mol), 2-(4-Biphenylyl)amino-9,9-dimethylfluorene(7.5 g, 0.021 mol), instead of the intermediate A in the synthesis method for AZ3, palladium acetate(II) 0.08 g, 0.345 mmol), 2,2′-Bis(diphenylphosphino)-1,1′-binaphthyl (0.21 g, 0.345 mmol), sodium-t-butoxide (2.48 g, 0.026 mol), and toluene 100 ml are put and heated to 100° C. while being stirred for 8 hours. The reaction solution was hot filtered through silicagel to remove impurities, and the filtrate was concentrated under reduced pressure to obtain crude. After the obtained crude was purified by MC/acetone, 6.7 g of AZ83 was obtained. 
     Synthesis of AZ92 
     
       
         
         
             
             
         
       
     
     The synthesis was carried out in the same way as in the synthesis method for AZ3 except that 2-(4-dibenzofuranyl)amino-9,9-dimethylfluorene (7.8 g, 0.021 mol) was used instead of 2-(4-biphenylyl)amino-9,9-dimethylfluorene. As a result, 6.9 g of AZ92 was obtained. 
     Synthesis of AZ98 
     
       
         
         
             
             
         
       
     
     The synthesis was carried out using the same reagents and the same dosage and same method as in the synthesis method for AZ83 that bis(9,9-dimethyl-9H-fluoren-2-yl)amine (8.8 g, 0.022 mol) was applied instead of 2-(4-biphenylyl)amino-9,9-dimethylfluorene and, as a result, 7.8 g of AZ98 was obtained. 
     Synthesis of AZ103 
     
       
         
         
             
             
         
       
     
     The synthesis was carried out in the same way as in the synthesis method for AZ83 except that 2-(4-Biphenylyl)amino-9,9-diphenylfluorene (10.6 g, 0.022 mol) was used instead of 2-(4-biphenylyl)amino-9,9-dimethylfluorene. As a result, 9.0 g of AZ103 was obtained. 
     Synthesis Method for AK3 
     
       
         
         
             
             
         
       
     
     Synthesis of Intermediate A 
     Benzoic acid (10 g, 0.082 mol), 2-amino-5-bromophenol (33.9 g, 0.180 mol), diisopropylethylamine(37.1 ml, 0.213 mol), 4M K 2 CO 3  aqueous solution 80 ml, methylene chloride 300 ml are put in a round-bottom flask and stirred while reducing the temperature to 0° C. Deoxo-fluor reagent, 50% in THF (66.4 ml, 0.180 mol) diluted with 45 ml of MC is slowly added dropwise to the solution. After the dropwise addition is finished, the solution is stirred at 0° C. for 2 hours. After the reaction is finished by adding 150 ml of saturated aqueous sodium bicarbonate solution to the reaction solution, the solution is heated to room temperature. After the reaction solution is separated into layers to recover the organic layer, the organic layer was dried with MgSO4 and concentrated under reduced pressure. The concentrated crude was separated by column to obtain 18.4 g of intermediate A. 
     Synthesis of AK3 
     An intermediate A (5 g, 0.018 mol), 2-(4-biphenylyl)amino-9,9-dimethylfluorene(7.9 g, 0.022 mol), palladium acetate(II) 0.08 g, 0.365 mmol), 2,2′-Bis(diphenylphosphino)-1,1′-binaphthyl (0.23 g, 0.365 mmol), sodium-t-butoxide (2.63 g, 0.027 mol), and toluene 100 ml are put in a round-bottom flask and heated to 100° C. while being stirred for 8 hours. The reaction solution was hot filtered through silicagel to remove impurities, and the filtrate was concentrated under reduced pressure to obtain crude. After the obtained crude was purified by MC/acetone, 6.7 g of AK3 was obtained. 
     Synthesis of AK5 
     
       
         
         
             
             
         
       
     
     The synthesis was carried out in the same way as in the synthesis method for AK3 except that 2-(2-biphenylyl)amino-9,9-dimethylfluorene (7.9 g, 0.022 mol) was used instead of 2-(4-biphenylyl)amino-9,9-dimethylfluorene. As a result, 6.6 g of AK5 was obtained. 
     Synthesis of AK10 
     
       
         
         
             
             
         
       
     
     The synthesis was carried out in the same way as in the synthesis method for AK3 except that 2-(3-dibenzofuranyl)amino-9,9-dimethylfluorene (8.2 g, 0.022 mol) was used instead of 2-(4-biphenylyl)amino-9,9-dimethylfluorene. As a result, 6.9 g of AK10 was obtained. 
     Synthesis of AK11 
     
       
         
         
             
             
         
       
     
     The synthesis was carried out in the same way as in the synthesis method for AK3 except that 2-(3-dibenzothiophenyl)amino-9,9-dimethylfluorene (8.6 g, 0.022 mol) was used instead of 2-(4-biphenylyl)amino-9,9-dimethylfluorene. As a result, 7.3 g of AK11 was obtained. 
     Synthesis of AK18 
     
       
         
         
             
             
         
       
     
     The synthesis was carried out using the same reagents and the same dosage and same method as in the synthesis method for AK3 that bis(9,9-dimethyl-9H-fluoren-2-yl)amine (8.8 g, 0.022 mol) was applied instead of 2-(4-biphenylyl)amino-9,9-dimethylfluorene and, as a result, 7.5 g of AK18 was obtained. 
     Synthesis of AK20 
     
       
         
         
             
             
         
       
     
     The synthesis was carried out in the same way as in the synthesis method for AK3 except that (9,9-dimethylfluorene-2-yl)-9,9-spirobifluorene-2-amine(11.5 g, 0.022 mol) was used instead of 2-(4-biphenylyl)amino-9,9-dimethylfluorene. As a result, 9.1 g of AK20 was obtained. 
     Synthesis of AK23 
     
       
         
         
             
             
         
       
     
     The synthesis was carried out in the same way as in the synthesis method for AK3 except that 2-(4-Biphenylyl)amino-9,9-diphenylfluorene (10.6 g, 0.022 mol) was used instead of 2-(4-biphenylyl)amino-9,9-dimethylfluorene. As a result, 8.7 g of AK23 was obtained. 
     Synthesis Method for AK43 
     
       
         
         
             
             
         
       
     
     Synthesis of Intermediate B 
     4-bromobenzoic acid(20 g, 0.099 mol), phenylboronic acid(14.6 g, 0.119 mol), tetrakis(triphenylphosphine)palladium(0) (2.3 g, 1.99 mmol), toluene 400 ml, and 4M K 2 CO 3 (potassium carbonate) 100 ml were put in a round-bottom flask and stirred under reflux for 12 hours. After completion of the reaction, the reaction solution is separated into layers, the organic layer is recovered and concentrated under reduced pressure to obtain a crude product. The filtered crude was separated by column to obtain 17.7 g of intermediate B. 
     Synthesis of Intermediate C 
     An intermediate B (15 g, 0.076 mol), 2-amino-5-bromophenol (31.3 g, 0.166 mol), diisopropylethylamine(34.3 ml, 0.197 mol), 4M K2CO3 aqueous solution 75 ml, methylene chloride 350 ml are put in a round-bottom flask and stirred while reducing the temperature to 0° C. Deoxo-fluor reagent, 50% in THF (61.4 ml, 0.166 mol) diluted with 45 ml of MC is slowly added dropwise to the solution. After completion of the dropwise addition, the solution was stirred at 0° C. for 2 hours. The subsequent procedure was the same as that for the intermediate A and, as a result, 22.2 g of intermediate C was obtained. 
     Synthesis of AK43 
     An intermediate C(5 g, 0.014 mol),  2 -(4-Biphenylyl)amino-9,9-dimethylfluorene(6.2 g, 0.017 mol), instead of the intermediate A in the synthesis method for AK3, palladium acetate(II) 0.06 g, 0.365 mmol), 2,2′-Bis(diphenylphosphino)-1,1′-binaphthyl (0.18 g, 0.365 mmol), sodium-t-butoxide (2.06 g, 0.021 mol), and toluene 100 ml are put and heated to 100° C. while being stirred for 8 hours. The reaction solution was hot filtered through silicagel to remove impurities, and the filtrate was concentrated under reduced pressure to obtain crude. After the obtained crude was purified by MC/acetone, 6.7 g of AK43 was obtained. 
     Synthesis Method for AK83 
     
       
         
         
             
             
         
       
     
     Synthesis of Intermediate D 
     The same method as the synthesis method for the intermediate A except that 2-amino-4-bromobenzenethiol(36.8 g, 0.180 mol) was applied instead of 2-amino-4-bromophenol was performed and, as a result, 18.5 g of intermediate D was obtained. 
     Synthesis of AK83 
     An intermediate D(5 g, 0.017 mol), 2-(4-Biphenylyl)amino-9,9-dimethylfluorene(7.5 g, 0.021 mol), instead of the intermediate A in the synthesis method for AK3, palladium acetate(II) 0.08 g, 0.345 mmol), 2,2′-Bis(diphenylphosphino)-1,1′-binaphthyl (0.21 g, 0.345 mmol), sodium-t-butoxide (2.48 g, 0.026 mol), and toluene 100 ml are put and heated to 100° C. while being stirred for 8 hours. 
     The reaction solution was hot filtered through silicagel to remove impurities, and the filtrate was concentrated under reduced pressure to obtain crude. After the obtained crude was purified by MC/acetone, 6.7 g of AK83 was obtained. 
     Synthesis of AK92 
     
       
         
         
             
             
         
       
     
     The synthesis was carried out in the same way as in the synthesis method for AK83 except that 2-(4-dibenzofuranyl)amino-9,9-dimethylfluorene (7.8 g, 0.021 mol) was used instead of 2-(4-biphenylyl)amino-9,9-dimethylfluorene. As a result, 7.0 g of AK92 was obtained. 
     Synthesis of AK98 
     
       
         
         
             
             
         
       
     
     The synthesis was carried out using the same reagents and the same dosage and same method as in the synthesis method for AK83 that bis(9,9-dimethyl-9H-fluoren-2-yl)amine (8.8 g, 0.022 mol) was applied instead of 2-(4-biphenylyl)amino-9,9-dimethylfluorene and, as a result, 7.8 g of AK98 was obtained. 
     Synthesis of AK103 
     
       
         
         
             
             
         
       
     
     The synthesis was carried out in the same way as in the synthesis method for AK83 except that 2-(4-Biphenylyl)amino-9,9-diphenylfluorene (10.6 g, 0.022 mol) was used instead of 2-(4-biphenylyl)amino-9,9-dimethylfluorene. As a result, 9.0 g of AK103 was obtained. 
     Manufacturing Evaluation of Organic Light Emitting Element 
     Comparison Example 1 
     An anode, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and a cathode were formed on a substrate to manufacture an organic light emitting element having a mono structure as shown in Table 1 below. All the properties of the organic light emitting element manufactured in the disclosure were evaluated at room temperature using a constant current source and a photometer. 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 Components 
                 Materials 
               
               
                   
                   
               
             
            
               
                   
                 anode 
                 ITO (Indium tin oxide) 
               
               
                   
                 hole injection layer 
                 HI1 
               
               
                   
                 hole transport layer 
                 HT1 
               
               
                   
                 light emitting layer 
                 EM1, EM2, EM3 
               
               
                   
                 electron transport layer 
                 ET1 
               
               
                   
                 electron injection layer 
                 LiF 
               
               
                   
                 cathode 
                 Al 
               
               
                   
                   
               
            
           
         
       
     
     The compounds used in the comparative examples are as follows. 
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     Comparative Example 2 and Embodiments 1 to 16 
     The organic light emitting element was manufactured in the same manner as in comparative example 1 except that the materials shown in Table 2 below were used instead of EM2 of the light emitting layer. The compound used in comparative example 2 is as follows. 
     
       
         
         
             
             
         
       
     
     
       
         
           
               
               
               
               
               
             
               
                 TABLE 2 
               
               
                   
               
               
                   
                 light 
                   
                 efficiency 
                 lifespan 
               
               
                   
                 emitting 
                   
                 (embodiment/ 
                 (embodiment/ 
               
               
                   
                 layer 
                 voltage 
                 comparative  
                 comparative  
               
               
                   
                 material 
                 difference 
                 example 1, %) 
                 example 1, %) 
               
               
                   
               
             
            
               
                 Comparison 
                 EM2 
                 — 
                 — 
                 — 
               
               
                 example 1 
                   
                   
                   
                   
               
               
                 comparison 
                 CF1 
                 0.18 
                  98% 
                  98% 
               
               
                 example 2 
                   
                   
                   
                   
               
               
                 embodiment 
                 AZ3 
                 −0.14 
                 112% 
                 105% 
               
               
                 1 
                   
                   
                   
                   
               
               
                 embodiment 
                 AZ5 
                 −0.12 
                 112% 
                 108% 
               
               
                 2 
                   
                   
                   
                   
               
               
                 embodiment 
                 AZ10 
                 −0.23 
                 116% 
                 110% 
               
               
                 3 
                   
                   
                   
                   
               
               
                 embodiment 
                 AZ11 
                 −0.20 
                 118% 
                 108% 
               
               
                 4 
                   
                   
                   
                   
               
               
                 embodiment 
                 AZ18 
                 −0.32 
                 104% 
                 102% 
               
               
                 5 
                   
                   
                   
                   
               
               
                 embodiment 
                 AZ2 0 
                 −0.20 
                 104% 
                 105% 
               
               
                 6 
                   
                   
                   
                   
               
               
                 embodiment 
                 AZ23 
                 −0.18 
                 113% 
                 110% 
               
               
                 7 
                   
                   
                   
                   
               
               
                 embodiment 
                 AZ4 3 
                 −0.12 
                 111% 
                 108% 
               
               
                 8 
                   
                   
                   
                   
               
               
                 embodiment 
                 AZ83 
                 −0.10 
                 112% 
                 105% 
               
               
                 9 
                   
                   
                   
                   
               
               
                 embodiment  
                 AZ92 
                 −0.14 
                 115% 
                 106% 
               
               
                 10 
                   
                   
                   
                   
               
               
                 embodiment 
                 AZ98 
                 −0.28 
                 104% 
                 101% 
               
               
                 11 
                   
                   
                   
                   
               
               
                 embodiment 
                 AZ103 
                 −0.16 
                 113% 
                 107% 
               
               
                 12 
               
               
                   
               
            
           
         
       
     
     Referring to Table 2, it may be seen that the organic light emitting element according to embodiments of the disclosure has better efficiency or lifespan than the organic light emitting elements of the comparative examples. 
     In comparative example 1, EM2 was used as the light emitting layer host compound. It may be seen that the embodiments using compounds including a core represented by chemical formula 1 have better efficiency and lifespan than comparative example 1. 
     In comparative example 2, CF1 was used as the light emitting layer host compound. CF1 differs from the compound represented by chemical formula 1 in that benzoxazole is linked to the nitrogen of the amine through a phenylene group. It may be seen that the embodiments using compounds represented by chemical formula 1, in which benzoxazole is directly bonded to the nitrogen of the amine, have better efficiency and lifespan than comparative example 2. 
     It will be apparent to those skilled in the art that various modifications and variations can be made in the organic light emitting element of the present disclosure without departing from the technical idea or scope of the disclosure. Thus, it is intended that the present disclosure cover the modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalents.