Reflective electrode protective layer compound and back light emitting element comprising the same

Abstract

The present application provides a compound for a reflective electrode protective layer of a back light emitting element represented by the following Chemical Formula 1. <Chemical Formula 1>

Description

TECHNICAL FIELD

[0001] The present application relates to a compound for a reflective electrode protective layer and a back light emitting element comprising the same. BACKGROUND

[0002] Materials used as an organic layer in an organic light emitting element can be broadly classified into a light emitting material, a hole injecting material, a hole transporting material, an electron transporting material, and an electron injecting material, etc. according to their functions.

[0003] Further, the light emitting material can be classified into a fluorescent material derived from a singlet excited state of an electron, a phosphorescent material derived from a triplet excited state of an electron, and a delayed fluorescent material derived from electron movement from a triplet excited state to a singlet excited state according to a light emitting mechanism, and into a blue, green, red, yellow, and orange light emitting material according to a light emitting color.

[0004] A general organic light emitting element can adopt a structure in which an anode is formed on a substrate, and a hole transporting layer, a light emitting layer, an electron transporting layer, and a cathode are sequentially formed on the anode. Among them, the hole transporting layer, the light emitting layer, and the electron transporting layer are organic thin films composed of organic compounds.

[0005] The driving principle of an organic light emitting element having the above structure is as follows.

[0006] When a voltage is applied between the anode and the cathode, holes injected from the anode move to the light emitting layer through the hole transporting layer, and electrons injected from the cathode move to the light emitting layer through the electron transporting layer. The holes and the electrons recombine in the light emitting layer and generate an exciton. Light is generated in the process in which the exciton is converted from an excited state to a ground state.

[0007] Further, the efficiency of an organic light emitting element can be generally classified into internal light emitting efficiency and external light emitting efficiency. The internal light emitting efficiency is related to the efficiency of generating an exciton in an organic layer between a first electrode and a second electrode such as a hole transporting layer, a light emitting layer, and an electron transporting layer, and realizing light conversion, and the internal light emitting efficiency of fluorescence is 25% in theory, and that of phosphorescence is 100%.

[0008] For a front light emitting element as described above, efforts have been made to develop a cover layer material having a high refractive index for light extraction.

[0009] On the other hand, for the back light emitting element, light reflected by the reflective cathode is radiated toward the direction of the driving thin film transistor, i.e., the transparent anode side. At this time, the protective film formed for the protection of the reflective electrode which is susceptible to corrosion of the organic light emitting element generally uses Alq3 which has excellent thermal stability, but since ash is generated at the time of deposition, a non-uniform protective film is formed, and thus a gap is formed between the electrode and the protective film and penetration of moisture or oxygen occurs, resulting in a short service life. In order to compensate for the above-mentioned disadvantages, an organic protective film compound is used as the material of the protective film, but in order to improve the service life of the back light emitting element which is gradually becoming larger, there has been an ongoing effort to develop a reflective electrode protective film compound which can form a more uniform thin film, has a low deposition temperature, and has excellent thermal stability. SUMMARY

[0010] Accordingly, an object of the present application is to provide a back light emitting element which further improves the service life by providing a protective layer which can protect the reflective electrode and the inside of the back light emitting element from moisture, oxygen, and external contamination, forms a uniform thin film, and has excellent thermal stability.

[0011] Next, the problems and additional problems as described above will be described in detail.

[0012] As a means to solve the above-mentioned problems,

[0013] As an embodiment of the present application, there is provided a reflective electrode protective layer compound for a back light emitting element represented by the following Chemical Formula 1:

[0014] <Chemical Formula 1>

[0015]

[0016] In the Chemical Formula 1,

[0017] Ar1 to Ar3 are each independently a substituted or unsubstituted C6 to C50 aryl group, or a substituted or unsubstituted C2 to C50 heteroaryl group,

[0018] L1 to L3 are each independently a direct bond, a substituted or unsubstituted C6 to C50 arylene group, or a substituted or unsubstituted C2 to C50 heteroarylene group.

[0019] Further, as an embodiment of the present application,

[0020] A back light emitting element is provided, including: a first electrode and a second reflective electrode; one or more organic layers interposed between the first electrode and the second reflective electrode; and a reflective electrode protective layer disposed outside the second reflective electrode, containing a compound for the reflective electrode protective layer.

[0021] The compound for the reflective electrode protective layer according to the present application is a compound containing an arylamine group, which can effectively improve the stability of the element under oxygen, moisture and external contamination because of excellent intermolecular thin film arrangement, and which can inhibit the generation of foreign matter during deposition because of easy guarantee of high purity of the compound. In addition, in the case where the arylamine group contains an extended aryl group, a fused aryl group, a heteroaryl group or a fused heteroaryl group, it can have a high glass transition temperature (Tg) and a high decomposition temperature (Td), and thus can prevent recrystallization between molecules and maintain a stable state of the thin film when heat is generated during driving of the back light emitting element, thereby achieving a low deposition temperature.

[0022] Next, the effects and additional effects as described above will be described in detail. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a schematic cross-sectional view illustrating the configuration of a back light emitting element according to an embodiment of the present application.

[0024] Figure 2 is an electron microscope photograph (SEM) for measuring the uniformity of a thin film.

[0025] SYMBOL DESCRIPTION

[0026] 200: hole injection layer

[0027] 300: hole transport layer

[0028] 400: light emitting layer

[0029] 500: electron transport layer

[0030] 600: electron injection layer

[0031] 1000: first electrode (anode, transparent electrode)

[0032] 2000: second electrode (cathode, reflective electrode)

[0033] 3000: reflective electrode protective layer DETAILED DESCRIPTION

[0034] Before any embodiments of the application are explained in detail, it is to be understood that the application is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. Rather, the application is capable of other embodiments and of being practiced or being carried out in various ways.

[0035] Throughout this specification and the claims, unless otherwise indicated, the terms "comprise", "comprises" and "comprising" are used on an inclusive basis, that is terms are to be construed to mean "including but not limited to".

[0036] Throughout this specification and the claims, the term "aryl" can mean a C5-50 aromatic hydrocarbon ring group such as a phenyl group, a benzyl group, a naphthyl group, a biphenyl group, a terphenyl group, a fluorenyl group, a phenanthryl group, a triphenylenyl group, a phenylene group, a fluoranthenyl group, a benzofluorenyl group, a benzophenanthryl group, an anthryl group, a stilbenyl group, and a pyrenyl group, and the term "heteroaryl" means a C2-50 aromatic ring group containing one or more hetero elements such as a pyrrolyl group, a pyrazinyl group, a pyridyl group, an indolyl group, an isoindolyl group, a furanyl group, a benzofuranyl group, an isobenzofuranyl group, a dibenzofuranyl group, a benzothiophenyl group, a dibenzothiophenyl group, a quinolyl group, an isoquinolyl group, a quinoxalyl group, a carbazolyl group, a phenanthridyl group, an acridyl group, a phenanthrolinyl group, a thiophenyl group, a pyrrolidinyl group, a piperidinyl group, a morpholinyl group, a piperazinyl group, a carbazolyl group, a furanyl group, a thiophenyl group, an oxazolyl group, an oxadiazolyl group, a benzofuranyl group, a thiazolyl group, a thiadiazolyl group, a benzothiophenyl group, a triazolyl group, an imidazolyl group, a benzimidazolyl group, a pyranyl group, a dibenzofuranyl group, and the like.

[0037] In addition, Ar x (wherein x is an integer) means a substituted or unsubstituted C6-C50 aryl group, or a substituted or unsubstituted C2-C50 heteroaryl group, unless otherwise specified, L x (wherein x is an integer) means a directly bonded, substituted or unsubstituted C6-C50 arylene group, or a substituted or unsubstituted C2-C50 heteroarylene group, unless otherwise specified, R x ​​​​​(wherein x is an integer) represents hydrogen, deuterium, halogen, nitro, nitrile, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C1-C30 thioalkyl, substituted or unsubstituted C6-C50 aryl, or substituted or unsubstituted C2-C50 heteroaryl, unless explicitly defined otherwise.

[0038] Throughout the present specification and the claims, the term "substituted or unsubstituted" means substituted or unsubstituted with any one or more selected from the group consisting of deuterium, halogen, amino, cyano, nitrile, nitro, nitroso, sulfonamide, isothiocyanate, thiocyanate, carboxyl, or C1-C30 alkyl, C1-C30 alkylsulfinyl, C1-C30 alkylsulfonyl, C1-C30 alkylsulfanyl, C1-C12 fluoroalkyl, C2-C30 alkenyl, C1-C30 alkoxy, C1-C12 N-alkylamino, C2-C20 N,N-dialkylamino, substituted or unsubstituted C1-C30 thioalkyl, C1-C6 N-alkylsulfonamide, C2-C12 N,N-dialkylsulfonamide, C3-C30 silyl, C3-C20 cycloalkyl, C3-C20 heterocycloalkyl, C6-C50 aryl, and C2-C50 heteroaryl, but is not particularly limited thereto. In addition, the same symbols have the same meanings throughout the present specification, unless explicitly stated otherwise.

[0039] In addition, unless explicitly stated to the contrary, the embodiments of the present application can be combined with other certain embodiments. Next, the embodiments of the present application and their effects will be described.

[0040] Next, the present application will be described in detail.

[0041] The compound for the reflective electrode protective layer of the back light emitting element according to the present application can be represented by the following Chemical Formula 1:

[0042] <Chemical Formula 1>

[0043]

[0044] In the Chemical Formula 1,

[0045] Ar1 to Ar3 are each independently substituted or unsubstituted C6-C50 aryl, or substituted or unsubstituted C2-C50 heteroaryl,

[0046] L1 to L3 are each independently a direct bond, substituted or unsubstituted C6-C50 arylene, or substituted or unsubstituted C2-C50 heteroarylene.

[0047] Specifically, in the chemical formula 1, two or three of Ar1to Ar3may be the same or all different from each other. In the case where Ar1to Ar3are all the same structure, it is advantageous to form a uniform thin film.

[0048] More specifically, Ar1to Ar3may each independently be an aryl group of C12or more, a condensed aryl group of C10or more, a heteroaryl group of C5or more, or a condensed heteroaryl group of C7or more. In the case where Ar1to Ar3are a heteroaryl group or a condensed heteroaryl group, one hetero element can be included.

[0049] Further, in the chemical formula 1, Ar1to Ar3may each independently be an aryl group of 3 rings or less, or a heteroaryl group of 3 rings or less. Thereby, the thermal stability of the compound at the time of deposition can be improved by lowering the deposition temperature.

[0050] As a specific example, Ar1to Ar3may each independently be a phenanthryl group, a carbazolyl group, a phenyl group, a biphenyl group, a pyridyl group, or a combination thereof. In the case as described above, even with a smaller molecular weight, a higher glass transition temperature (Tg) can be obtained, and thus the thermal stability at the time of deposition and driving is excellent.

[0051] Further, one or more of Ar1to Ar3of the chemical formula 1 can each independently be a 1-ring or 2-ring N-containing heteroaryl group. More specifically, Ar1to Ar3may each independently be a 1-ring or 2-ring N-containing heteroaryl group. Since excellent intermolecular arrangement can be ensured by means of a nitrogen atom, the service life of the element can be effectively improved when used as a protective layer of a backside light emitting element.

[0052] In the chemical formula 1, one or more of L1to L3, specifically L1to L3may each independently be a phenylene group, a biphthalene group, or a pyridyl group. In the case as described above, the twisting of the compound can be more effectively prevented and a lower deposition temperature can be achieved.

[0053] The deposition temperature of the compound of the chemical formula 1 can be 320°C or less. The glass transition temperature (Tg) of the compound of the chemical formula 1 can be 85°C or more.

[0054] The glass transition temperature (Tg) of the compound of the chemical formula 1 can be 85°C or more.

[0055] The following compounds are specific examples of the compound of the chemical formula 1 according to the present application. The following examples are merely illustrative for explaining the present application, and the present application is not limited thereto.

[0056]

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065]

[0066]

[0067]

[0068] The synthetic reaction formula of the compound according to an embodiment of the present application is shown below, but is not limited thereto.

[0069] <Reaction Formula 1>

[0070]

[0071] <Reaction Formula 2>

[0072]

[0073] In another embodiment of the present application, there is provided a back light emitting element containing a reflective electrode protective layer compound according to the present application in a reflective electrode protective layer.

[0074] Next, the back light emitting element according to the present application will be described in more detail.

[0075] The present application provides a back light emitting element including: a first electrode and a second reflective electrode; one or more organic layers interposed between the first electrode and the second reflective electrode; and a reflective electrode protective layer disposed outside the second reflective electrode, containing the reflective electrode protective layer compound. The back light emitting element can be specifically an organic light emitting element that emits light from the back.

[0076] The reflective electrode refers to an opaque electrode that reflects light transmitted from a light emitting layer interposed inside the electrode.

[0077] The organic layer can have a structure in which two or more light emitting layers are stacked, and a second protective layer can be further provided outside the reflective electrode protective layer. Specifically, the second protective layer can be an inorganic substance, such as silicon nitride or silicon oxide.

[0078] The thickness of the reflective electrode protective layer can be 2500 to 5000 A. Specifically, it can be 4000 to 5000 A. In the above-described case, the service life of the reflective electrode can be further improved.

[0079] In addition, the organic layer can include a hole transport layer, a light emitting layer, and an electron transport layer, which are generally included in a light emitting portion, but is not limited thereto.

[0080] Specifically, the back light emitting element according to an embodiment of the present application can include one or more organic layers constituting a light emitting portion such as a hole injection layer (HIL), a hole transport layer (HTL), a light emitting layer (EML), an electron transport layer (ETL), and an electron injection layer (EIL) between a first electrode (anode, transparent electrode) and a second electrode (cathode, reflective electrode). The first electrode can be a transparent electrode, and the second electrode can be a reflective electrode.

[0081] Figure 1 is a cross-sectional view schematically illustrating a configuration of a back light emitting element according to an embodiment of the present application. The back light emitting element according to an embodiment of the present application can be manufactured in a structure as shown in Figure 1 .

[0082] As shown in Figure 1 , the back light emitting element can have a structure in which a first electrode 1000, a hole injection layer 200, a hole transport layer 300, a light emitting layer 400, an electron transport layer 500, an electron injection layer 600, a second electrode 2000, and a reflective electrode protective layer 3000 are sequentially stacked from bottom to top. The first electrode can be a transparent electrode, and the second electrode can be a reflective electrode. When light is emitted to the outside through the first electrode to perform back light emission, the second electrode, as a reflective electrode, can reflect light generated inside in the direction of the first electrode.

[0083] The first electrode 1000 is used as a hole injection electrode for injecting holes in the back light emitting element. The first electrode 1000 is manufactured using a substance having a work function as low as possible to achieve injection of holes, and can be formed using a transparent material such as indium tin oxide (ITO), indium zinc oxide (IZO), and graphene.

[0084] Meanwhile, the hole injection layer 200 can be formed by depositing a hole injection layer material on the upper portion of the first electrode 1000 using methods such as vacuum deposition, spin coating, casting, and Langmuir-Blodgett (LB) methods. When forming the hole injection layer 200 by vacuum deposition, the deposition conditions vary depending on the compound used as the material of the hole injection layer 200, the desired structure of the hole injection layer 200, and the thermal properties. Generally, the deposition temperature can be 50 to 500°C, 10 -8 to 10 -3 Torr vacuum degree, 0.01 to / s deposition rate and The thickness can be appropriately selected within the range of 1 to 5 μm. In addition, a charge generation layer can be additionally deposited on the surface of the hole injection layer 200 as needed. As the charge generation layer material, a general material can be used, for example, hexacyano-hexaazatriphenylene (HATCN) can be used.

[0085] In addition, the hole transport layer 300 can be formed by depositing a hole transport layer material on the upper part of the hole injection layer 200 using a method such as vacuum deposition, spin coating, casting, Langmuir-Brøgeta (LB) method, etc. When the hole transport layer 300 is formed by the vacuum deposition method, its deposition conditions will vary depending on the compound used, but it is generally appropriate to select conditions within a range that is almost the same as the conditions for forming the hole injection layer 200. The hole transport layer 300 can be formed using well-known compounds. The hole transport layer 300 as described above can be more than one layer, and although in Figure 1 Although not shown in the figure, a luminescence auxiliary layer may be additionally formed on the hole transport layer 300 .

[0086] Meanwhile, the light-emitting layer 400 can be formed by depositing a light-emitting layer material on top of the hole transport layer 300 or the light-emitting auxiliary layer using methods such as vacuum deposition, spin coating, casting, and the Langmuir-Brötten (LB) method. When forming the light-emitting layer 400 by the vacuum deposition method, the deposition conditions will vary depending on the compound used, but are generally preferably selected within a range of conditions that are substantially the same as those used for forming the hole injection layer 200. As the light-emitting layer material, known compounds can be used as a main agent or a dopant.

[0087] When a phosphorescent dopant is used in the light-emitting layer material, in order to prevent triplet excitons or holes from diffusing to the electron transport layer 500, a stacked hole blocking material (HBL) can be added on the upper part of the light-emitting layer 400 by vacuum deposition or spin coating. The hole blocking material that can be used is not particularly limited, and any known material can be used. For example, Examples of hole-blocking materials include oxadiazole derivatives, benzotriazole derivatives, o-phenanthroline derivatives, and those described in Japanese Patent Application Laid-Open No. 11-329734(A1). Representative examples include Balq (bis(8-hydroxy-2-methylquinolinol)-(4-phenylphenoxy)aluminum) and phenanthroline compounds (e.g., BCP (bathocuproine) from UDC). The light-emitting layer 400 of the present invention may include one or more blue light-emitting layers, or two or more blue light-emitting layers.

[0088] Furthermore, the electron transport layer 500 is formed on the upper portion of the light-emitting layer 400 and can be formed by methods such as vacuum deposition, spin coating, and casting. The deposition conditions of the electron transport layer 500 vary depending on the compound used, but are generally preferably selected within a range of conditions that are substantially the same as those used for forming the hole injection layer 200.

[0089] Furthermore, the electron injection layer 600 can be formed by depositing an electron injection layer material on the electron transport layer 500 , and can be formed by methods such as vacuum deposition, spin coating, and casting.

[0090] Furthermore, the second electrode 2000 serves as an electron injection electrode, reflecting light generated in the light-emitting layer within the electrode. It can be formed on top of the electron injection layer 600 by vacuum deposition or spin coating. The second electrode 2000 can be made of various reflective metals, such as aluminum (Al) and silver (Ag), but is not limited thereto.

[0091] The back-light emitting device of the present invention may further include various layers in addition to the above-mentioned layers as needed.

[0092] Furthermore, the thickness of each organic layer formed by the present invention can be adjusted as needed, and specifically can be 10 to 1000 nm, more specifically 20 to 150 nm.

[0093] The reflective electrode protection layer 3000 is as follows Figure 1 As shown, the reflective electrode is protected by being formed on the outer side surface of the second electrode 2000 .

[0094] Next, the present application will be described in more detail by a synthesis example of a compound according to an embodiment of the present application and a manufacturing example of a back light emitting element. The following synthesis example and example are only for exemplifying the present application, and the scope of the present application is not limited to the following examples.

[0095] Synthesis Example 1: Synthesis of Compound 3

[0096]

[0097] In a round bottom flask, 5.0 g of tris(4-bromophenyl)amine, 6.2 g of [l,l'-biphenyl]-4-ylboronic acid, 16 g of K2CO3(2M), 0.4 g of Pd(pph3)4were dissolved in 150 ml of 1,4-dioxane and then stirred with reflux. The reaction was confirmed by thin layer chromatography (TLC) and ended after adding water. The organic layer was extracted with MC (Methylene chloride) and recrystallized after filtration under reduced pressure, thereby obtaining 4.6 g of compound 3. (Yield: 63%)

[0098] m / z: 701.31 (100.0%), 702.31 (59.2%), 703.31 (17.0%), 704.32 (3.2%)

[0099] Synthesis Example 2: Synthesis of Compound 15

[0100]

[0101] Compound 15 was synthesized according to the same method as in Synthesis Example 1, using phenanthren-9-ylboronic acid instead of [l,l'-biphenyl]-4-ylboronic acid. (Yield: 60%)

[0102] m / z: 773.31 (100.0%), 774.31 (65.7%), 775.31 (20.9%), 776.32 (4.4%)

[0103] Synthesis Example 3: Synthesis of Compound 57

[0104] ​

[0105] Compound 57 was synthesized according to the same method as in Synthetic Example 1, using 4-(pyridin-3-yl)phenyl)boronic acid instead of [1,1'-biphenyl]-4-ylboronic acid. (Yield 65%)

[0106] m / z: 704.29 (100.0%), 705.30 (55.6%), 706.30 (15.1%), 707.30 (2.9%), 705.29 (1.5%)

[0107] Synthetic Example 4: Synthesis of Compound 63

[0108]

[0109] Compound 63 was synthesized according to the same method as in Synthetic Example 1, using quinolin-8-ylboronic acid instead of [1,1'-biphenyl]-4-ylboronic acid. (Yield 61%)

[0110] m / z: 626.25 (100.0%), 627.25 (49.0%), 628.25 (12.3%), 629.26 (1.8%), 627.24 (1.5%)

[0111] Synthetic Example 5: Synthesis of Compound 114

[0112]

[0113] In a round bottom flask, 5.0 g of tris(4-bromophenyl)amine, 5.2 g of 9H-carbazole, 1.5 g of t-BuONa, 0.5 g of Pd2(dba)3, 1.5 ml of (t-Bu)3P were dissolved in 200 ml of toluene and then stirred with reflux. The reaction was confirmed by thin layer chromatography (TLC) and the reaction was completed after adding water. The organic layer was extracted with MC (methylene chloride) and recrystallized after filtration under reduced pressure, thereby obtaining 5.2 g of compound 114. (Yield 70%)

[0114] m / z: 740.29 (100.0%), 741.30 (58.8%), 742.30 (17.0%), 743.30 (3.4%), 741.29 (1.5%)

[0115] Synthesis Example 6: Synthesis of Compound 9

[0116]

[0117] Compound 9 was synthesized by the same method as in Synthesis Example 1, using naphthalen-2-ylboronic acid instead of [1,1'-biphenyl]-4-ylboronic acid. (Yield: 59%)

[0118] m / z: 623.26 (100.0%), 624.26 (52.3%), 625.27 (13.4%), 626.27 (2.3%)

[0119] Synthesis Example 7: Synthesis of Compound 113

[0120]

[0121] Compound 113 was synthesized using the same method as in Synthesis Example 5, using N,N-bis(4-bromophenyl)-[1,1'-biphenyl]-4-amine instead of tris(4-bromophenyl)amine. (Yield: 55%)

[0122] m / z: 651.27 (100.0%), 652.27 (52.3%), 653.27 (13.8%), 654.28 (2.2%), 652.26 (1.1%)

[0123] Manufacturing of back-emitting elements

[0124] According to Figure 1 The structure shown here produces a back-emitting element. The back-emitting element is stacked in the following order: substrate 100 / anode (hole injection electrode, transparent electrode 1000) / hole injection layer 200 / hole transport layer 300 / light-emitting layer 400 / electron transport layer 500 / electron injection layer 600 / cathode (electron injection electrode, reflective electrode 2000) / reflective electrode protective layer 3000, from bottom to top.

[0125] A compound used in the organic layer on the inside of the electrode of the back light emitting element of the present application is shown in Table 1 below.

[0126] [Table 1]

[0127]

[0128] Example 1

[0129] On an indium tin oxide (ITO) substrate, a film was formed to make a hole injection layer of HIOl of HATCN, and a hole transport layer of HTOl of A light emitting layer was formed by doping and forming a film of ETOl : Liq (1 : 1) of LiF was deposited to form an electron injection layer. Further, an Al of thickness was deposited to form a reflective electrode, and on the reflective electrode (cathode), a compound 3 produced in Synthesis Example 1 was deposited to form a reflective electrode protective layer of thickness. A back light emitting element was produced by encapsulating the element in a glove box.

[0130] Examples 2 to 7

[0131] A back light emitting element was produced by forming a reflective electrode protective layer using the compounds produced in Synthesis Examples 2 to 7, respectively, in the same manner as in Example 1.

[0132] Example 8

[0133] A back light emitting element was produced by forming a reflective electrode protective layer of thickness of the compound 3 produced in Synthesis Example 1 in the same manner as in Example 1.

[0134] Example 9

[0135] A back light emitting element was produced by forming a reflective electrode protective layer of thickness of the compound 3 produced in Synthesis Example 1 in the same manner as in Example 1.

[0136] Comparative Examples 1 and 2

[0137] A back light emitting element was produced in the same manner as in the above-mentioned Embodiment 1, using Comparative Compound 1 (Ref. 1) and Comparative Compound 2 (Ref. 2) shown in Table 2 below to form a reflective electrode protective layer.

[0138] [Table 2]

[0139]

[0140] Comparative Example 3: Production of a front light emitting element

[0141] On top of an indium tin oxide (ITO) substrate on which a reflective layer containing Ag was formed, a film of HATCN was formed as a hole injection layer, followed by a film of HT01 as a hole transport layer. Next, a film of BH01:BD0 13% doped was formed as a light emitting layer. Next, a film of ET01:Liq (1:1) was formed as an electron transport layer, followed by deposition of LiF to form an electron injection layer. Next, MgAg was deposited as a transparent electrode (cathode) to a thickness of 15 nm, followed by deposition of Comparative Compound 1 (Ref. 1) as a light efficiency improving layer to a thickness of 10 nm on top of the cathode. A front light emitting element was produced by encapsulating the element in a glove box. HI01 of the above-mentioned Comparative Compound 1 (Ref. 1), HATCN of the above-mentioned Comparative Compound 2 (Ref. 2), and HT01 of the above-mentioned Comparative Compound 1 (Ref. 1), followed by a film of BH01:BD0 13% doped to form a light emitting layer. Next, a film of ET01:Liq (1:1) was formed as an electron transport layer, followed by deposition of LiF to form an electron injection layer. Next, MgAg was deposited as a transparent electrode (cathode) to a thickness of 15 nm, followed by deposition of Comparative Compound 1 (Ref. 1) as a light efficiency improving layer to a thickness of 10 nm on top of the cathode. A front light emitting element was produced by encapsulating the element in a glove box. ET01:Liq (1:1) of the above-mentioned Comparative Compound 2 (Ref. 2), followed by deposition of LiF to form an electron injection layer. Next, MgAg was deposited as a transparent electrode (cathode) to a thickness of 15 nm, followed by deposition of Comparative Compound 1 (Ref. 1) as a light efficiency improving layer to a thickness of 10 nm on top of the cathode. A front light emitting element was produced by encapsulating the element in a glove box.

[0142] Evaluation of the performance of the elements

[0143] The performance of the elements, i.e., the current density and the luminance with respect to the applied voltage, of the elements of the above-mentioned Embodiments 1 to 9 and Comparative Examples 1 to 3 were evaluated under atmospheric pressure conditions by injecting electrons and holes by loading a voltage to a Kiethley 2400 source measurement unit, and measuring the luminance when light was emitted using a Konica Minolta spectroradiometric luminance meter (CS-2000), and the results are shown in Table 3 below.

[0144] [Table 3]

[0145] Op. V mA / cm 2 ]] Cd / A LT50 Example 1 3.4 10 9.0 1130 Example 2 3.4 10 9.0 1140 Example 3 3.4 10 9.0 1190 Example 4 3.4 10 9.0 1180 Example 5 3.4 10 9.0 1110 Example 6 3.4 10 9.0 1125 Example 7 3.4 10 9.0 1070 Example 8 3.5 10 8.5 1305 Example 9 3.5 10 8.5 1300 Comparative Example 1 3.4 10 9.0 790 Comparative Example 2 3.4 10 9.0 670 Comparative Example 3 3.6 10 5.0 530

[0146] ​​​It can be found that the compound of the present application has an aromatic amine structure that minimizes the volume property compared to Comparative Example 1 and Comparative Example 2, and thus does not form bubbles and recrystallization on the surface and side of deposition, so that a thin film can be stably formed. By this, the stability of the element under oxygen, moisture and external contamination can be effectively improved, and the service life can be significantly improved. In addition, it can be found that the back light emitting structure of the present application uses The electrode protection layer of the above thickness is preferable, but in the front light emitting structure as shown in Comparative Example 3, when the light efficiency improving layer is formed by stacking a thickness of 100 nm or more, it can cause a significant decrease in efficiency and service life. That is, in the front light emitting structure, when a certain thickness or more is stacked in order to sufficiently achieve the function as an electrode protection layer, it can eventually cause the element balance to be broken and the service life to be decreased due to a significant decrease in light transmittance and a decrease in light extraction efficiency. In addition, by comparing Example 8 and Example 9, it can be found that, in particular, in the case of a thickness of 100 nm or more, the service life can be further improved, and even in the case of stacking a thickness of 100 nm or more, it does not show a service life improvement effect proportional to the thickness. By this, it can be known that, by applying a thickness range of 50 nm to 100 nm, the consumption of the protection film material can be reduced and commercialization can be more effectively achieved.

[0147] Thin film uniformity measurement

[0148] Each 3 g of Comparative Compound 1 (Ref. 1), Comparative Compound 2 (Ref. 2), Compound 57, and Compound 15 was vacuum-deposited on the glass substrate, and after heat treatment at 100°C for 30 minutes, the upper end and the side were measured using a scanning electron microscope (SEM, Hitachi, SU8010), and the results are shown in Figure 2 Referring to Figure 2 it can be found that the compound of the present application forms a uniform thin film on the upper end and the side compared to the comparative compound, indicating that a stable thin film can be effectively formed. Although not shown in the figure, other compounds proposed in the synthesis example of the present application can also form a uniform thin film.

Claims

1. A back-emitting element, characterized in that: Include: a first electrode and a second reflective electrode; One or more organic layers are interposed between the first electrode and the second reflective electrode; and The reflective electrode protection layer is arranged outside the second reflective electrode and contains a compound for the reflective electrode protection layer. The compound for the reflective electrode protective layer is represented by the following chemical formula 1: Chemical formula 1 In the chemical formula 1, Ar1 and Ar2 are each independently phenanthryl, carbazolyl, phenyl, biphenyl, terphenyl, pyridyl, naphthyl, quinolyl, or isoquinolyl, Ar3 is an aryl group having 3 or fewer rings, or a heteroaryl group having 3 or fewer rings, L1 to L3 are each independently a direct bond, a phenylene group or a biphenylene group.

2. The back-light emitting element according to claim 1, Ar1 and Ar2 are each independently pyridyl or quinolinyl, Ar3 is a monocyclic or bicyclic N-containing heteroaryl group.

3. The back-light emitting element according to claim 1, Ar1 to Ar3 all have the same structure.

4. The back-light emitting element according to claim 1, The compound of Chemical Formula 1 is any one of the compounds represented by the following chemical formulas:

5. The back-light emitting element according to claim 1, The thickness of the reflective electrode protection layer is 2500 to 6. The back-light emitting element according to claim 1, The organic layer has a structure in which two or more light-emitting layers are stacked.

7. The back-light emitting element according to claim 1, A second protective layer is further provided on the outer side of the reflective electrode protective layer.

8. The back-light emitting element according to claim 1, The second protective layer includes silicon nitride or silicon oxide.

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