Organic compound, organic light-emitting diode and device containing the same

Abstract

The present disclosure relates to an organic compound, an organic light emitting diode and a device comprising the compound, in particular an organic compound having the following structure, and an organic light emitting diode (OLED) and an organic light emitting display device comprising the organic compound. The organic compound includes an electron donor portion separated from an electron acceptor portion, and thus has a delayed fluorescence property. The organic compound is applied to an emission layer so that the OLED and the organic light emitting display device allow the OLED and the organic light emitting display device to improve their luminous efficiency.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Korean Patent Application No. 10-2019-0155567 filed in Korea on November 28, 2019, which is hereby incorporated by reference into this application in its entirety. Technical Field

[0003] The present disclosure relates to an organic compound, and more particularly, to an organic compound having excellent light-emitting properties, and an organic light-emitting diode and an organic light-emitting device including the compound. Background Art

[0004] As display devices become larger and larger, a flat display device with lower space requirements is needed. Among the currently widely used flat panel display devices, organic light emitting diodes (OLEDs) are rapidly replacing liquid crystal displays (LCDs).

[0005] OLEDs can be formed with a thickness less than The OLED can be formed on a flexible transparent substrate (e.g., a plastic substrate), so that the OLED can easily realize a flexible or foldable display. In addition, the OLED can be driven at a lower voltage of less than 10V. In addition, compared with the plasma display panel and the inorganic electroluminescent device, the OLED has relatively low driving power consumption, and the color purity of the OLED is very high. In particular, the OLED can realize red, green, and blue, so it has attracted a lot of attention as a light-emitting device.

[0006] In OLED, when charge is injected into the emission material layer between the electron injection electrode (i.e. cathode) and the hole injection electrode (i.e. anode), the charge recombination forms excitons, which then emit light as the recombined excitons are converted to a stable ground state. Conventional fluorescent materials have low luminous efficiency because only singlet excitons participate in the luminescence process. On the other hand, compared with fluorescent materials, phosphorescent materials in which triplet excitons and singlet excitons participate in the luminescence process have relatively high luminous efficiency. However, the luminescence lifetime of metal complexes as typical phosphorescent materials is too short to be used in commercial devices. Summary of the invention

[0007] Accordingly, embodiments of the present disclosure are directed to an organic compound that substantially alleviates one or more problems due to limitations and disadvantages of the related art, and an OLED and an organic light-emitting device including the same.

[0008] An object of the present disclosure is to provide an organic compound having excellent luminous efficiency and color purity, and an OLED and an organic light-emitting device applying the organic compound.

[0009] Additional features and aspects will be described in the following description, and some will be apparent from the description, or can be learned by practicing the inventive concepts provided herein. Other features and aspects of the inventive concepts can be realized and obtained by the structures specifically pointed out in the specification and its claims and the drawings or by the structures derived therefrom.

[0010] To achieve these and other aspects of the inventive concept as embodied and broadly described, the present disclosure provides an organic compound having the structure of the following Chemical Formula 1:

[0011] [Chemical formula 1]

[0012]

[0013] Where R 1 and R 2 are each independently selected from hydrogen, an unsubstituted or substituted C 1 -C 20 Alkyl, unsubstituted or substituted C 1 -C 20 Alkoxy, unsubstituted or substituted C 1 -C 20 Alkylamino, unsubstituted or substituted C 6 -C 30 Aryl and unsubstituted or substituted C 3 -C 30 A group consisting of heteroaryl groups; R 3 To R 14 are each independently selected from hydrogen, an unsubstituted or substituted C 1 -C 20 Alkyl, unsubstituted or substituted C 1 -C 20 Alkoxy, unsubstituted or substituted C 1 -C 20 Alkylamino, unsubstituted or substituted C 6 -C 30 Aryl and unsubstituted or substituted C 3 -C 30 A group consisting of heteroaryl groups, or R 3 To R 14 The two adjacent groups in the form a C with no substituent or with a substituent 6 -C 20Aromatic ring or unsubstituted or substituted C 3 -C 20 Heteroaromatic ring; X 1 To X 4 Each is independently halogen; L 1 To L 3 Each independently is C having no substituent or having a substituent 6 -C 30 Arylene or unsubstituted or substituted C 3 -C 30 o is an integer of 1 or 2; p and q are each an integer of 0 to 2.

[0014] In another aspect, the present disclosure provides an OLED including: a first electrode; a second electrode facing the first electrode; and an emission material layer disposed between the first electrode and the second electrode, wherein the first emission material layer includes the organic compound.

[0015] In another aspect, the present disclosure provides an organic light-emitting device including a substrate and an OLED disposed on the substrate as described above.

[0016] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the inventive concepts as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings 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 the principle of the disclosure.

[0018] Figure 1 is a schematic diagram showing the light emission mechanism of the organic compound of the present disclosure.

[0019] Figure 2 is a schematic cross-sectional view showing an organic light emitting display device of the present disclosure.

[0020] Figure 3 is a schematic cross-sectional view showing an OLED according to an exemplary aspect of the present disclosure.

[0021] Figure 4 is a schematic diagram illustrating a light emitting mechanism caused by an energy level band gap between light emitting materials according to an exemplary aspect of the present disclosure.

[0022] Figure 5 is a schematic cross-sectional view illustrating an OLED according to another exemplary aspect of the present disclosure.

[0023] Figure 6is a schematic diagram illustrating a light emitting mechanism caused by an energy level band gap between light emitting materials according to another exemplary aspect of the present disclosure.

[0024] Figure 7 is a schematic cross-sectional view illustrating an OLED diode according to another exemplary aspect of the present disclosure.

[0025] Figure 8 is a schematic diagram illustrating a light emitting mechanism caused by an energy level band gap between light emitting materials according to another exemplary aspect of the present disclosure.

[0026] Fig. 9 is a schematic cross-sectional view illustrating an OLED according to another exemplary aspect of the present disclosure.

[0027] Fig.10 is a schematic diagram illustrating a light emitting mechanism caused by an energy level band gap between light emitting materials according to another exemplary aspect of the present disclosure. DETAILED DESCRIPTION

[0028] Reference will now be made in detail hereinafter to various aspects of the present disclosure, examples of which are illustrated in the accompanying drawings.

[0029] [Organic compounds]

[0030] Organic compounds applied to organic light emitting diodes (OLEDs) should have excellent charge affinity and maintain stable properties during driving of OLEDs. In particular, the luminescent material is the most important factor in determining the luminous efficiency of OLEDs. The luminescent material should have high luminous efficiency and high charge mobility, and should have appropriate energy levels for other materials applied to the same emission layer and adjacent emission layers. The organic compound of the present disclosure comprises two boron-dipyrromethene (BODIPY) moieties connected via an amino moiety. The organic compound of the present disclosure may have the structure of the following chemical formula 1:

[0031] [Chemical formula 1]

[0032]

[0033] In Chemical Formula 1, R 1 and R 2 are each independently selected from hydrogen, an unsubstituted or substituted C 1 -C 20 Alkyl, unsubstituted or substituted C 1 -C 20 Alkoxy, unsubstituted or substituted C 1 -C 20 Alkylamino, unsubstituted or substituted C 6 -C 30Aryl and unsubstituted or substituted C 3 -C 30 A group consisting of heteroaryl groups; R 3 To R 14 are each independently selected from hydrogen, an unsubstituted or substituted C 1 -C 20 Alkyl, unsubstituted or substituted C 1 -C 20 Alkoxy, unsubstituted or substituted C 1 -C 20 Alkylamino, unsubstituted or substituted C 6 -C 30 Aryl and unsubstituted or substituted C 3 -C 30 A group consisting of heteroaryl groups, or R 3 To R 14 The two adjacent groups in the form a C with no substituent or with a substituent 6 -C 20 Aromatic ring or unsubstituted or substituted C 3 -C 20 Heteroaromatic ring; X 1 To X 4 Each is independently halogen; L 1 To L 3 Each independently is C having no substituent or having a substituent 6 -C 30 Arylene or unsubstituted or substituted C 3 -C 30 o is an integer of 1 or 2; p and q are each an integer of 0 to 2.

[0034] As used herein, the term "having no substituent" refers to attachment to hydrogen, which in this case includes protium, deuterium, and tritium.

[0035] As used herein, the term "having a substituent" means that the substituent includes, but is not limited to, a C 1 -C 20 Alkyl, unsubstituted or halogen-substituted C 1 -C 20 Alkoxy, halogen, cyano, -CF 3 , hydroxyl, carboxyl, carbonyl, amino, C 1 -C 10 Alkylamino, C 6 -C 30 Arylamino, C 3 -C 30 Heteroarylamino, C6 -C 30 Aryl, C 3 -C 30 Heteroaryl, nitro, hydrazide, sulfonate, C 1 -C 20 Alkylsilyl, C 6 -C 30 Arylsilyl and C 3 -C 30 Heteroarylsilyl.

[0036] As used herein, the term "hetero" in "heteroaromatic ring", "heterocycloalkylene", "heteroarylene", "heteroarylalkylene", "heteroaryloxy", "heterocycloalkyl", "heteroaryl", "heteroarylalkyl", "heteroaryloxy", "heteroarylamino" means that at least one carbon atom (e.g., 1 to 5 carbon atoms) constituting the aromatic ring or alicyclic ring is substituted by at least one heteroatom selected from the group consisting of N, O, S, P and combinations thereof.

[0037] In Chemical Formula 1, each BODIPY moiety acts as an electron acceptor and the amino moiety acts as an electron donor. The BODIPY moiety as an electron acceptor and the amino moiety as an electron donor are connected by two linking groups L 1 and L 2 The organic compound having the structure of Chemical Formula 1 may have a delayed fluorescence property.

[0038] In one exemplary aspect, R 1 To R 14 C in each 6 -C 30 The aryl group may include C 6 -C 30 Aryl, C 7 -C 30 Aralkyl, C 6 -C 30 Aryloxy and C 6 -C 30 Arylamino. 1 To R 14 The respective C 3 -C 30 Heteroaryl groups may include C 3 -C 30 Heteroaryl, C 4 -C 30 Heteroarylalkyl, C 3 -C 30 Heteroaryloxy and C 3 -C 30 Heteroarylamino.

[0039] In one exemplary aspect, R 1To R 14 C in each 6 -C 30 Aryl or substituted to R 1 To R 14 C 6 -C 30 The aryl group may independently include, but is not limited to, non-fused or fused aryl groups such as phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, pentalenyl, indenyl, indenoindenyl, heptalenyl, biphenylene, indacenyl, phenalenyl, phenanthrenyl, triphenylene, diphenylene, azulenyl, pyrenyl, fluoranthenyl, triphenylene, fluorenyl, indenofluorenyl, tetraphenyl, tetraphenyl, tetracenyl, septaphenyl, pyrofluorenyl, pentaphenyl, pentacenyl, fluorenyl, indenofluorenyl and spirofluorenyl.

[0040] In one exemplary aspect, R 1 To R 14 Each in or substituted to R 1 To R 14 C 6 -C 30 The heteroaryl groups may independently include, but are not limited to, fused or fused heteroaryl groups such as pyrrolyl, azophenyl, pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazinyl, tetrazinyl, imidazolyl, pyrazolyl, indolyl, isoindolyl, indazolyl, indolizinyl, pyrrolizinyl, carbazolyl, benzocarbazolyl, dibenzocarbazolyl, indolocarbazolyl, indenocarbazolyl, benzofuranocarbazolyl, benzothiophenocarbazolyl, carbolyl, quinolyl, isoquinolyl, phthalazinyl, quinoxalinyl, cinnolinyl, quinazolinyl, quinozolinyl, purinyl, benzoquinolyl, benzoisoquinolyl, benzoquinaz ... quinolinyl, benzoquinoxalinyl, acridinyl, phenazinyl, phenoxazinyl, phenothiazinyl, phenanthrolinyl, perylene diazaphenyl, phenanthridinyl, pteridinyl, naphthyridinyl, furanyl, pyranyl, oxazinyl, oxazolyl, oxadiazolyl, triazolyl, dioxinyl, benzofuranyl, dibenzofuranyl, thiopyranyl, xanthenyl, chromenyl, isochromenyl, thiazinyl, thienyl, benzothienyl, dibenzothienyl, difuranopyrazinyl, benzofuranodibenzofuranyl, benzothienobenzothienyl, benzothienodibenzofuranyl, benzothienobenzofuranyl, benzothienodibenzofuranyl, xanthine-linked spiroacridinyl, substituted with at least one C 1 -C 10 Alkyl dihydroacridinyl and N-substituted spirofluorenyl.

[0041] For example, when R 3 To R 14When two adjacent groups in form an aromatic ring or a heteroaromatic ring, the new aromatic ring or heteroaromatic ring may include, but is not limited to, a benzene ring, a furan ring, a thiophene ring, a pyridine ring, an indene ring and / or an indole ring. In this case, the aromatic ring and the heteroaromatic ring may each independently have no substituent, or may be substituted with a substituent selected from C 1 -C 10 Alkyl, C 6 -C 30 Aryl and C 3 -C 30 At least one of the group consisting of heteroaryl groups.

[0042] As an example, R 1 To R 14 C 6 -C 30 Aryl and C 3 -C 30 Each heteroaromatic ring may independently have no substituent or may be substituted with a substituent selected from C 1 -C 10 Alkyl, C 6 -C 30 Aryl and C 3 -C 30 At least one of the group consisting of heteroaryl groups.

[0043] In addition, L 1 To L 3 Each may be C without or with a substituent. 6 -C 30 Arylene and unsubstituted or substituted C 3 -C 30 The arylene and heteroarylene groups are each respectively corresponding to the above-mentioned aryl and heteroaryl groups. For example, the arylene and heteroarylene groups may each have no substituent, or may be substituted with a substituent selected from C 1 -C 10 Alkyl, C 6 -C 30 Aryl and C 3 -C 30 At least one of the group consisting of heteroaryl groups.

[0044] In one exemplary aspect, R 1 To R 14 The aryl or heteroaryl in each of them is substituted to R 1 To R 14 The aryl or heteroaryl group and L 1 To L 3 The arylene or heteroarylene groups in each of the above groups may independently include 1 to 3 aromatic or heteroaromatic rings. 1 To R 14 The aromatic ring or heteroaromatic ring in each of them is substituted to R 1 To R14 The aromatic ring or heteroaromatic ring and L 1 To L 3 When the number of aromatic rings or heteroaromatic rings in each becomes larger, the conjugated structure between the entire molecules is too long, and thus the energy band gap of the organic compound may be significantly reduced.

[0045] As an example, R 1 To R 14 The aryl or heteroaryl in each of them is substituted to R 1 To R 14 The aryl or heteroaryl groups may include, but are not limited to, phenyl, naphthyl, anthracenyl, pyridyl, benzofuranyl, dibenzofuranyl, benzothienyl, dibenzothienyl, carbazolyl, acridinyl, phenazinyl, phenoxazinyl and / or phenothiazinyl. 1 To L 3 The arylene or heteroarylene group in each may include, but is not limited to, phenylene, biphenylene, naphthylene, anthracene, benzofuranylene, dibenzofuranylene, benzothiophenylene, dibenzothiophenylene, carbazolylene, acridinylene, phenazinylene, phenoxazinylene and / or phenothiazinylene.

[0046] The organic compound having the structure of Chemical Formula 1 can be used as a dopant in the emission layer and may have delayed fluorescence properties. The OLED includes a hole injection layer (anode), an electron injection layer (cathode), and an emission layer disposed between the anode and the cathode. In order to improve the luminous efficiency, the emission layer may include a hole injection layer (HIL), a hole transport layer (HTL) disposed on the hole injection layer in sequence, an emission material layer (EML), an electron transport layer (ETL), and an electron injection layer (EIL). When the holes injected from the anode and the electrons injected from the cathode recombine to form excited excitons, the OLED emits light due to the transfer of unstable excitons to a stable ground state. The external quantum efficiency (EQE, η) of the luminescent material is ext ) can be determined by four factors, namely, the exciton generation efficiency (singlet / triplet ratio), the charge balance factor, the radiation efficiency and the output coupling efficiency.

[0047] When holes and electrons meet to form excitons, theoretically, singlet excitons with paired spins and triplet excitons with unpaired spins are generated at a ratio of 1:3. Since only singlet excitons in fluorescent materials participate in luminescence, the remaining 75% of triplet excitons cannot participate in luminescence, so the singlet / triplet ratio in conventional fluorescent materials is 0.25. Therefore, considering all four factors, the maximum luminous efficiency of OLEDs using conventional fluorescent materials is only about 5%.

[0048] On the other hand, phosphorescent materials have different luminescence mechanisms that convert both singlet excitons and triplet excitons into light. Phosphorescent materials convert singlet excitons into triplet excitons by intersystem crossing (ISC). Therefore, when using phosphorescent materials that utilize singlet excitons and triplet excitons simultaneously, the low luminous efficiency of fluorescent materials can be improved. However, when the conjugated structure or condensed ring structure of organic aromatic compounds increases, the excited triplet energy level of the compound is significantly reduced, so the organic molecules that can be used as phosphorescent hosts are greatly restricted. In addition, phosphorescent hosts with wide energy band gaps cause delays in charge injection and transport, so OLEDs containing the hosts show an increase in driving voltage and degradation of luminescent life.

[0049] Delayed fluorescence materials have been developed that can solve the problems associated with conventional fluorescent and / or phosphorescent materials. Representative delayed fluorescence materials are thermally activated delayed fluorescence (TADF) materials. Figure 1 Explain the luminescence mechanism of delayed fluorescent materials, Figure 1 Schematic diagram showing the light emission mechanism of the organic compound of the present disclosure. Figure 1 As shown, the singlet energy level S in the delayed fluorescent material DF 1 DF The exciton and triplet energy level T 1 DF The excitons can be transferred to the intermediate energy state, namely the ICT (intramolecular charge transfer) state, and then the intermediate state excitons can be transferred to the ground state (S 0 DF ; S 1 DF →ICT←T 1 DF ).

[0050] Since there is almost no orbital overlap between HOMO and LUMO in compounds that can be in the ICT state, there is almost no interaction between the HOMO state and the LUMO state. As a result, the change in the electron spin state has no effect on other electrons, and a new charge transfer band (CT band) that does not follow the selection rule is formed in the delayed fluorescent material. In the case of driving an OLED including a delayed fluorescent material, 25% of the singlet excitons and 75% of the triplet excitons are converted to the ICT state by heat or an electric field, and then the converted excitons transition to the ground state S 0 Therefore, the delayed fluorescent material can theoretically have an internal quantum efficiency of 100%.

[0051] The excited singlet energy level S of the delayed fluorescent material DF 1 DF and the excited triplet state energy level T 1 DF The energy gap between the two levels is ΔE STDF Must be equal to or less than about 0.3 eV, for example, about 0.05 to about 0.3 eV. The singlet energy level S 1 DF and the triplet energy level T 1 DF The energy gap between the two levels is ΔE ST DF Small materials can exhibit ordinary fluorescence using ground state crossing (ISC) (where the singlet energy level S 1 DF The excitons can transition to the ground state) and delayed fluorescence using reverse intersystem crossing (RISC) (where the triplet energy level T 1 DF The exciton can transition upward to the singlet energy level S 1 DF The exciton then has a triplet energy level T 1 DF The singlet energy level S 1 DF The exciton can transition to the ground state S 0 DF ).

[0052] As shown in Chemical Formula 1, the organic compound is a dimer compound including two BODIPY moieties. The BODIPY moiety of the electron acceptor is connected via two linking groups L 1 and L 2 The organic compound having the structure of Chemical Formula 1 has almost no orbital overlap between the HOMO (highest occupied molecular orbital) state and the LUMO (lowest unoccupied molecular orbital) state as the distance between the electron acceptor and the electron donor increases.

[0053] In addition, since the steric hindrance between the BODIPY part of the electron acceptor and the amino part of the electron donor becomes large, the conjugated structure between these parts is limited. Since the molecule is easily separated into the HOMO energy state and the LUMO energy state and a dipole is formed between the BODIPY part and the amino part, the dipole moment in the molecule increases and the luminescence efficiency of the organic compound is improved. As the distance between the electron acceptor and the electron donor increases, there is almost no overlap between the HOMO state and the LUMO state in the molecule of the organic compound, so the excited singlet energy level S can be reduced. 1 DF and the excited triplet state energy level T 1 DF The energy gap between the two levels is ΔE ST DFSince the two BODIPY parts as electron acceptors include rigid fused and heteroaromatic rings, respectively, the organic compound has a restricted three-dimensional conformation. When the organic compound emits light, there is no energy loss due to the change in the three-dimensional conformation of the entire molecule, and the photoluminescence spectrum can be confined to a specific range, so high color purity can be achieved.

[0054] In addition, the excited triplet energy level of the organic compound having the structure of Chemical Formula 1 may be lower than the excited triplet energy level of the conventional phosphorescent material, and the energy band gap is narrower than that of the phosphorescent material. Unlike conventional phosphorescent materials, an organic compound having a high triplet energy level and a wide energy band gap does not need to be used as a host. In addition, the charge injection and transport delay problems caused by the use of a wide energy band gap host can be prevented.

[0055] In one exemplary aspect, R can be substituted to the BODIPY core. 3 To R 8 At least four groups and R 9 To R 14 The at least four groups in the formula may be independently C without or with a substituent. 1 -C 10 In this case, the organic compound having the structure of Chemical Formula 1 may emit green light, for example, may have a maximum photoluminescence wavelength (PLλ) of, but not limited to, about 530 nm to about 580 nm. max ) and a maximum absorption wavelength (Abs.λ) of about 510 nm to about 570 nm max ). In addition, L 1 To L 3 Each of them may be independently C without or with a substituent. 6 -C 30 An arylene group, and p and q may be independently an integer of 1 or 2. For example, the organic compound emitting green light may include any one of the structures of the following Chemical Formula 2:

[0056] [Chemical formula 2]

[0057]

[0058]

[0059] In another exemplary aspect, R can be substituted to the BODIPY core. 3 , R 5 , R 7 and R 8 At least two groups and R 9 , R 11 , R 12 and R 14At least two groups in the formula may be independently C without or with substituents. 6 -C 20 Aryl or unsubstituted or substituted C 3 -C 20 In this case, the organic compound having the structure of Chemical Formula 1 may emit red light, for example, may have a PLλ of, but not limited to, about greater than 580 nm to about 620 nm. max and Abs.λ from about 550nm to about 580nm max In addition, L 1 To L 3 Each of them may be independently C without or with a substituent. 6 -C 30 An arylene group, and p and q may be independently an integer of 1 or 2. For example, the organic compound emitting red light may include any one of the structures of the following Chemical Formula 3:

[0060] [Chemical formula 3]

[0061]

[0062]

[0063] [Organic Light Emitting Devices and OLEDs]

[0064] The organic compound having the structure of Chemical Formulas 1 to 3 may be applied to the EML of the OLED so that it can reduce the driving voltage, enhance the color purity and improve the luminous efficiency of the OLED. The OLED disclosed herein may be applied to an organic light-emitting device such as an organic light-emitting display device or an organic light-emitting lighting device. An organic light-emitting display device including the OLED will be described. Figure 2 is a schematic cross-sectional view of an organic light emitting display device of the present disclosure.

[0065] like Figure 2 As shown, the organic light emitting display device 100 includes a substrate 110, a thin film transistor Tr on the substrate 110, and an organic light emitting diode (OLED) D connected to the thin film transistor Tr.

[0066] The substrate 110 may include, but is not limited to, glass, a thin flexible material, and / or a polymer plastic. For example, the flexible material may be selected from the group consisting of polyimide (PI), polyethersulfone (PES), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polycarbonate (PC), and combinations thereof, but is not limited thereto. The substrate 110 on which the thin film transistor Tr and the OLED D are disposed forms an array substrate.

[0067] The buffer layer 122 may be disposed on the substrate 110, and the thin film transistor Tr is disposed on the buffer layer 122. The buffer layer 122 may be omitted.

[0068] The semiconductor layer 120 is disposed on the buffer layer 122. In one exemplary aspect, the semiconductor layer 120 may include, but is not limited to, an oxide semiconductor material. In this case, a light shielding pattern may be disposed under the semiconductor layer 120, and the light shielding pattern may prevent light from being incident on the semiconductor layer 120, thereby preventing the semiconductor layer 120 from being degraded by light. Alternatively, the semiconductor layer 120 may include, but is not limited to, polycrystalline silicon. In this case, the opposite edges of the semiconductor layer 120 may be doped with impurities.

[0069] The gate insulating layer 124 formed of an insulating material is disposed on the semiconductor layer 120. The gate insulating layer 124 may include, but is not limited to, an inorganic insulating material, such as silicon oxide (SiO x ) or silicon nitride (SiN x ).

[0070] The gate electrode 130 made of a conductive material such as metal is disposed on the gate insulating layer 124 so as to correspond to the center of the semiconductor layer 120. Figure 2 The gate insulating layer 124 is disposed on the entire area of ​​the substrate 110 , but the gate insulating layer 124 may be patterned identically to the gate electrode 130 .

[0071] An interlayer insulating layer 132 formed of an insulating material is disposed on the gate electrode 130 and covers the entire surface of the substrate 110. The interlayer insulating layer 132 may include, but is not limited to, an inorganic insulating material such as silicon oxide (SiO x ) or silicon nitride (SiN x ), or an organic insulating material such as benzocyclobutene or photo-acryl.

[0072] The interlayer insulating layer 132 has a first semiconductor layer contact hole 134 and a second semiconductor layer contact hole 136 exposing both sides of the semiconductor layer 120. The first semiconductor layer contact hole 134 and the second semiconductor layer contact hole 136 are disposed on both sides of the gate electrode 130 and are spaced apart from the gate electrode 130. Figure 2 In the embodiment, the first semiconductor layer contact hole 134 and the second semiconductor layer contact hole 136 are formed in the gate insulating layer 124. Alternatively, when the gate insulating layer 124 is patterned identically to the gate electrode 130, the first semiconductor layer contact hole 134 and the second semiconductor layer contact hole 136 are formed only in the interlayer insulating layer 132.

[0073] Source electrode 144 and drain electrode 146 made of a conductive material such as metal are disposed on interlayer insulating layer 132. Source electrode 144 and drain electrode 146 are spaced apart from each other relative to gate electrode 130 and contact both sides of semiconductor layer 120 through first semiconductor layer contact hole 134 and second semiconductor layer contact hole 136, respectively.

[0074] The semiconductor layer 120 , the gate electrode 130 , the source electrode 144 , and the drain electrode 146 constitute a thin film transistor Tr, which functions as a driving element. Figure 2 The thin film transistor Tr in the embodiment has a coplanar structure in which a gate electrode 130, a source electrode 144 and a drain electrode 146 are arranged on the semiconductor layer 120. Alternatively, the thin film transistor Tr may have an inversely overlapped structure in which a gate electrode is arranged under the semiconductor layer and a source electrode and a drain electrode are arranged on the semiconductor layer. In this case, the semiconductor layer may include, but is not limited to, amorphous silicon.

[0075] The gate lines and the data lines intersect each other to define a pixel area, and Figure 2 A switching element connected to the gate line and the data line may be further formed in the pixel region. The switching element is connected to a thin film transistor Tr as a driving element. In addition, the power line is spaced apart in parallel with the gate line or the data line, and the thin film transistor Tr may further include a storage capacitor configured to constantly maintain the voltage of the gate electrode during one frame.

[0076] In addition, the organic light emitting display device 100 may include a color filter containing a dye or pigment for transmitting light of a specific wavelength emitted from the OLED D. For example, the color filter may transmit light of a specific wavelength, such as red (R), green (G), and / or blue (B). Each of the red, green, and blue color filters may be formed in each pixel region, respectively. In this case, the organic light emitting display device 100 may realize full color through the color filter.

[0077] For example, when the organic light-emitting display device 100 is a bottom emission type, a color filter may be disposed on the interlayer insulating layer 132 corresponding to the OLED D. Alternatively, when the organic light-emitting display device 100 is a top emission type, a color filter may be disposed on the OLED D (ie, the second electrode 230 ).

[0078] In addition, the organic light emitting device 100 may include a color conversion layer (not shown) that converts light of a specific wavelength in the light emitted from the OLED D into light in a long wavelength range. The color conversion layer may include inorganic light emitting particles such as quantum dots or quantum rods. For example, the color conversion layer may be disposed above or below the OLED D.

[0079] The passivation layer 150 is disposed on the source electrode 144 and the drain electrode 146 on the entire substrate 110. The passivation layer 150 has a flat top surface and a drain electrode contact hole 152 exposing the drain electrode 146 of the thin film transistor Tr. Although the drain electrode contact hole 152 is disposed on the second semiconductor layer contact hole 136, it may be spaced apart from the second semiconductor layer contact hole 136.

[0080] The passivation layer 150 is disposed on the source electrode 144 and the drain electrode 146 on the entire substrate 110. The passivation layer 150 has a flat top surface and a drain electrode contact hole 152 exposing the drain electrode 146 of the thin film transistor Tr. Although the drain electrode contact hole 152 is disposed on the second semiconductor layer contact hole 136, it may be spaced apart from the second semiconductor layer contact hole 136.

[0081] The OLED D includes a first electrode 210 disposed on the passivation layer 150 and connected to the drain electrode 146 of the thin film transistor Tr. The OLED D also includes an emission layer 220 and a second electrode 230 each disposed on the first electrode 210 in sequence.

[0082] The first electrode 210 is disposed in each pixel region. The first electrode 210 may be an anode and include a conductive material having a relatively high work function value. For example, the first electrode 210 may include, but is not limited to, a transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), tin oxide (SnO), zinc oxide (ZnO), indium cerium oxide (ICO), and aluminum-doped zinc oxide (AZO).

[0083] In one exemplary aspect, when the organic light-emitting display device 100 is a top emission type, a reflective electrode or a reflective layer may be provided under the first electrode 210. For example, the reflective electrode or the reflective layer may include, but is not limited to, an aluminum-palladium-copper (APC) alloy. In addition, a bank layer 160 is provided on the passivation layer 150 to cover the edge of the first electrode 210. The bank layer 160 exposes the center of the first electrode 210.

[0084] The emission layer 220 is disposed on the first electrode 210. In one exemplary aspect, the emission layer 220 may have a single-layer structure of a light-emitting material layer (EML). Alternatively, the emission layer may have a multilayer structure of a hole injection layer (HIL), a hole transport layer (HTL), an electron blocking layer (EBL), an EML, a hole blocking layer (HBL), an electron transport layer (ETL), and / or an electron injection layer (EIL) (see Figure 3 , 5 , 7 and 9). In one aspect, the emission layer 220 may have one emission unit. Alternatively, the emission layer 220 may have multiple emission units to form a series structure.

[0085] The emission layer 220 includes any one of the structures of Chemical Formulae 1 to 3. As an example, the organic compound having the structures of Chemical Formulae 1 to 3 may be applied to a dopant in the EML, in which case the EML may further include a host and optionally at least one other light emitting material.

[0086] The second electrode 230 is disposed on the substrate 110 provided with the emission layer 220. The second electrode 230 may be disposed on the entire display area, and may include a conductive material having a relatively low work function value compared to the first electrode 210. The second electrode 230 may be a cathode. For example, the second electrode 230 may include, but is not limited to, aluminum (Al), magnesium (Mg), calcium (Ca), silver (Ag), alloys thereof, or combinations thereof, such as aluminum-magnesium alloy (Al-Mg).

[0087] In addition, the encapsulation film 170 may be disposed on the second electrode 230 to prevent external moisture from penetrating into the OLED D. The encapsulation film 170 may have, but is not limited to, a stacked structure of a first inorganic insulating film 172 , an organic insulating film 174 , and a second inorganic insulating film 176 .

[0088] In addition, a polarizer may be attached to the packaging film 170 to reduce external light reflection. For example, the polarizer may be a circular polarizer. In addition, a cover window may be attached to the packaging film 170 or the polarizer. In this case, the substrate 110 and the cover window may have flexibility, so the organic light-emitting display device 100 may be a flexible display device.

[0089] We will now describe OLEDs in more detail. Figure 3 is a schematic cross-sectional view showing an OLED according to an exemplary aspect of the present disclosure. Figure 3 As shown, the OLED D1 includes a first electrode 210 and a second electrode 230 facing each other, and an emission layer 220 having a single emission unit is disposed between the first electrode 210 and the second electrode 230. In an exemplary aspect, the emission layer 220 includes an EML 240 disposed between the first electrode 210 and the second electrode 230. In addition, the emission layer 220 also includes a HIL 250 and an HTL 260 sequentially disposed between the first electrode 210 and the EML 240, and an ETL 270 and an EIL 280 sequentially disposed between the EML 240 and the second electrode 230. Alternatively, the emission layer 220 may further include a first exciton blocking layer (i.e., an EBL 265 disposed between the HTL 260 and the EML 240) and / or a second exciton blocking layer (i.e., an HBL 275 disposed between the EML 240 and the ETL 270).

[0090] The first electrode 210 may be an anode that provides holes to the EML 240. The first electrode 210 may include, but is not limited to, a conductive material having a relatively high work function value, for example, a transparent conductive oxide (TCO). In an exemplary aspect, the first electrode 210 may include, but is not limited to, ITO, IZO, ITZO, SnO, ZnO, ICO, AZO, and the like.

[0091] The second electrode 230 may be a cathode that provides electrons to the EML 240. The second electrode 230 may include, but is not limited to, a conductive material having a relatively low work function value, ie, a highly reflective material such as Al, Mg, Ca, Ag, alloys thereof, and combinations thereof.

[0092] The EML 240 may include a first compound H and a second compound DF. The first compound H may be a host, and the second compound DF may be a delayed fluorescent material (dopant). For example, an organic compound having a structure of Chemical Formulas 1 to 3 may be used as the second compound in the EML 240 .

[0093] For example, the first compound H of the host in the EML 240 may include, but is not limited to, 9-(3-(9H-carbazol-9-yl)phenyl)-9H-carbazole-3-carbonitrile (mCP-CN), 4,4'-di(N-carbazolyl)-1,1'-biphenyl (CBP), 3,3'-di(N-carbazolyl)-1,1'-biphenyl (mCBP), 1,3-di(carbazol-9-yl)benzene (mCP), bis[2-(diphenylphosphino)phenyl]ether oxide (DPE), PO), 2,8-bis(diphenylphosphoryl)dibenzothiophene (PPT), 1,3,5-tris[(3-pyridyl)-phenyl-3-yl]benzene (TmPyPB), 2,6-bis(9H-carbazole-9-yl)pyridine (PYD-2Cz), 2,8-bis(9H-carbazole-9-yl)dibenzothiophene (DCzDBT), 3',5'-bis(carbazole-9-yl)-[1,1'-diphenyl]-3,5-dicarbonitrile (DCzT PA), 4'-(9H-carbazole-9-yl)diphenyl-3,5-dicarbonitrile (4'-(9H-carbazole-9-yl)diphenyl-3,5-dicarbonitrile (pCzB-2CN), 3'-(9H-carbazole-9-yl)diphenyl-3,5-dicarbonitrile (mCzB-2CN), diphenyl-4-triphenylsilylphenyl-phosphine oxide (TSPO1), 9-(9-phenyl-9H-carbazole-6-yl)-9H-carbazole (CCP ), 4-(3-(triphenylene-2-yl)phenyl)dibenzo[b,d]thiophene, 9-(4-(9H-carbazole-9-yl)phenyl)-9H-3,9'-bicarbazole, 9-(3-(9H-carbazole-9-yl)phenyl)-9H-3,9'-bicarbazole, 9-(6-(9H-carbazole-9-yl)pyridin-3-yl)-9H-3,9'-bicarbazole and / or 4-(3-(2-triphenylene-2-yl)phenyl)-dibenzothiophene.

[0094] As described above, the organic compounds having the structures of Chemical Formulae 1 to 3 include a BODIPY moiety of an electron acceptor separated from an amino moiety of an electron donor, and the conjugated conformation between these moieties is limited, thus having delayed fluorescence properties. Figure 1 As shown, when an organic compound having a delayed fluorescence property is introduced into the EML 240 as the second compound DF, 25% of the excited singlet energy level S 1 DF The excitons and 75% of the excited triplet energy level T 1 DF The excitons are transferred to the ICT state, and then the excitons drop to the stable ground state S0, thereby improving its internal quantum efficiency.

[0095] The excited singlet energy level S of the second compound DF having delayed fluorescence property 1 DF and the excited triplet state energy level T1 DF The energy gap between the two levels is ΔE ST DF It should be about 0.3 eV or less, for example, about 0.05 eV to about 0.3 eV, so that both singlet excitons and triplet excitons can be transferred. Since the energy level band gap between the singlet state and the triplet state of the organic compound having the structure of Chemical Formulae 1 to 3 is small, when the energy of the original singlet exciton is reduced to the ground state to show fluorescence, the organic compound can exhibit fluorescence, and when the triplet exciton is up-converted to its singlet state through RISC and the converted exciton is then transferred to the ground state, the organic compound can exhibit delayed fluorescence.

[0096] Still refer to Figure 3 , the HIL 250 and the HTL 260 may be sequentially disposed between the first electrode 210 and the EML 240. The HIL 250 is disposed between the first electrode 210 and the HTL 260 and improves the interface properties between the inorganic first electrode 210 and the organic HTL 260. In one exemplary aspect, the HIL 250 may include, but is not limited to, 4,4',4"-tris(3-methylphenylamino)triphenylamine (MTDATA), 4,4',4"-tris(N,N-biphenyl-amino)triphenylamine (NATA), 4,4',4"-tris(N-(naphthalene-1-yl)-N-phenyl-amino)triphenylamine (1T-NATA), 4,4',4"-tris(N-(naphthalene-2-yl)-N-phenyl-amino)triphenylamine (2T-NATA), copper phthalocyanine (CuPc), tris(4-carbazolyl-9-yl-phenyl)amine (TCTA), N,N'-biphenyl-N,N'-di(1-naphthyl)-1,1' -biphenyl-4,4″-diamine (NPB; NPD), 1,4,5,8,9,11-hexaazatriphenylene hexacarbonitrile (dipyrazine [2,3-f:2′3′-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HAT-CN), 1,3,5-tris[4-(biphenylamino)phenyl]benzene (TDAPB), poly(3,4-ethylenedioxythiophene) polystyrenesulfonic acid (PEDOT / PSS) and / or N-(biphenyl-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine. HIL 250 may be omitted depending on the structure of OLED D1.

[0097] The HTL 260 is disposed adjacent to the EML 240 between the first electrode 210 and the EML 240. In an exemplary aspect, the HTL 260 may include, but is not limited to, N,N'-biphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD), NPB, CBP, poly[N,N'-di(4-butylphenyl)-N,N'-di(phenyl)-benzidine] (poly-TPD), poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)-1,1'-biphenyl-4,4'-diamine) ... )diphenylamine))] (TFB), bis[4-(N,N-di-p-tolyl-amino)-phenyl]cyclohexane (TAPC), N-(biphenyl-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazole-3-yl)phenyl)-9H-fluoren-2-amine and / or N-(biphenyl-4-yl)-N-(4-(9-phenyl-9H-carbazole-3-yl)phenyl)biphenyl-4-amine.

[0098] The ETL 270 and the EIL 280 may be sequentially disposed between the EML 240 and the second electrode 230. The ETL 270 includes a material having high electron mobility to stably provide electrons to the EML 240 through rapid electron transport. In an exemplary aspect, the ETL 270 may include, but is not limited to, oxadiazole compounds, triazole compounds, phenanthroline compounds, benzoxazole compounds, benzothiazole compounds, benzimidazole compounds, triazine compounds, and the like.

[0099] As an example, ETL 270 may include, but is not limited to: tris-(8-hydroxyquinoline aluminum) (Alq 3), 2-biphenyl-4-yl-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD), spiro-PBD, lithium quinolate (Liq), 1,3,5-tri(N-phenylbenzimidazol-2-yl)benzene (TPBi), bis(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum (BAlq), 4,7-biphenyl-1,10-phenanthroline (Bphen), 2,9-di(naphthalene-2-yl)-4,7-biphenyl-1,10-phenanthroline (NBphen), 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline (BCP), 3-(4-biphenyl)- 4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ), 4-(naphthalen-1-yl)-3,5-biphenyl-4H-1,2,4-triazole (NTAZ), 1,3,5-tri(p-pyridin-3-yl-phenyl)benzene (TpPyPB), 2,4,6-tri(3'-(pyridin-3-yl)biphenyl-3-yl)1,3,5-triazine (TmPPPyTz), poly[9,9-bis(3'-((N,N-dimethyl)-N-ethylammonium)-propyl)-2,7-fluorene]-cross-2,7-(9,9-dioctylfluorene)] (PFNBr), tris(phenylquinoxaline) (TPQ) and / or TSPO1.

[0100] The EIL 280 is disposed between the second electrode 230 and the ETL 270, and can improve the physical properties of the second electrode 230, and thus can increase the life span of the OLED D1. In an exemplary aspect, the EIL 280 may include, but is not limited to, alkali metal halides (e.g., LiF, CsF, NaF, and BaF 2 etc.) and / or organometallic compounds (e.g., lithium quinoline, lithium benzoate, sodium stearate, etc.).

[0101] When holes are transferred to the second electrode 230 and / or electrons are transferred to the first electrode 210 via the EML 240, the lifetime of the OLED D1 may be short and the light emission efficiency may be reduced. To prevent these phenomena, the OLED D1 according to this aspect of the present invention may have at least one exciton blocking layer adjacent to the EML 240.

[0102] For example, the OLED D1 of this exemplary aspect includes an EBL 265 between the HTL 260 and the EML 240 to control and prevent electron transfer. In one exemplary aspect, the EBL 265 may include, but is not limited to, TCTA, tris[4-(diethylamino)phenyl]amine, N-(biphenyl-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazole-3-yl)phenyl)-9H-fluoren-2-amine, TAPC, MTDATA, mCP, mCBP, CuPc, N,N'-bis[4-(bis(3-methylphenyl)amino)phenyl]-N,N'-biphenyl-[1,1'-biphenyl]-4,4'-diamine (DNTPD), TDAPB, 3,5-bis(9H-carbazole-9-yl)-N,N-diphenylamine (DCDPA), and / or 3,6-bis(N-carbazole)-N-phenyl-carbazole.

[0103] In addition, the OLED D1 may further include an HBL 275 as a second exciton blocking layer between the EML 240 and the ETL 270 so that holes cannot be transferred from the EML 240 to the ETL 270. In an exemplary aspect, the HBL 275 may include, but is not limited to, oxadiazole compounds, triazole compounds, phenanthroline compounds, benzoxazole compounds, benzothiazole compounds, benzimidazole compounds, and triazine compounds, all of which may be used for the ETL 270.

[0104] For example, the HBL 275 may include a compound having a relatively low HOMO energy level compared to the light emitting material in the EML 240. The HBL 275 may include, but is not limited to, BCP, BAlq, Alq 3 , PBD, spiro-PBD, Liq, di-4,5-(3,5-di-3-pyridylphenyl)-2-methylpyrimidine (B3PYMPM), DPEPO, 9-(6-(9H-carbazol-9-yl)pyridin-3-yl)-9H-3,9'-bicarbazole, and combinations thereof.

[0105] When the EML 240 includes the first compound H of the host and the second compound DF of the organic compound having the structure of Chemical Formulas 1 to 3, it is necessary to adjust the energy level between the first compound H of the host and the second compound DF of the delayed fluorescence material. Figure 4 is a schematic diagram illustrating a light emitting mechanism caused by an energy level band gap between light emitting materials according to an exemplary aspect of the present disclosure.

[0106] like Figure 4 As shown, the excited singlet energy level S of the first compound H of the host in the EML 240 is 1 H and the excited triplet state energy level T 1 Hshould be higher than the excited singlet energy level S of the second compound DF of the delayed fluorescent material. 1 DF and the excited triplet state energy level T 1 DF As an example, the excited triplet energy level T of the first compound 1 H1 It can be higher than the excited triplet energy level T of the second compound DF 1 DF At least about 0.5 eV, such as at least about 0.2 eV.

[0107] When the excited singlet energy level S of the first compound 1 H and the excited triplet state energy level T 1 H Each is not sufficiently higher than the singlet energy level S of the second compound DF 1 DF and the excited triplet state energy level T 1 DF When the excited triplet energy level T of the second compound DF 1 DF The exciton at can be reversely transferred to the excited triplet energy level T of the first compound H 1 H In this case, the triplet excitons of the first compound H that are back-transferred to the triplet excitons that cannot emit are quenched to not emit, so the triplet exciton energy of the second compound DF having delayed fluorescence properties cannot contribute to luminescence. As an example, the excited singlet energy level S of the second compound DF is 1 DF and the excited triplet state energy level T 1 DF The energy gap between the two levels is ΔE ST DF The wavelength may be equal to or less than about 0.3 eV, for example, about 0.05 eV to about 0.3 eV, thereby achieving delayed fluorescence.

[0108] In addition, the LUMO energy level and the HOMO energy level of the first compound H and the second compound DF need to be adjusted so that holes and electrons are quickly injected into the EML 240 so that the excitons are effectively recombined. For example, it is preferred that the HOMO energy level (HOMO H ) and the HOMO energy level of the second compound DF (HOMO DF ) between the energy levels (|HOMO H -HOMO DF |) or the LUMO energy level of the first compound H (LUMO H ) and the LUMO energy level (LUMO DF) between the energy levels (|LUMO H -LUMO DF |) may be equal to or less than about 0.5 eV, for example, about 0.1 eV to about 0.5 eV.

[0109] When the EML 240 includes the first compound H of the host and the second compound DF of the delayed fluorescent material having the structure of Chemical Formulas 1 to 3, the exciton energy can be transferred to the second compound DF without energy loss during the light emission process. In particular, the exciton quenching caused by the interaction between the excitons of the first compound H of the host and the peripheral polarons can be minimized, so that the light emission lifetime of the OLED D1 can be prevented from being deteriorated due to electro-oxidation and photo-oxidation.

[0110] When EML 240 includes the first compound H of the host and the second compound DF of the delayed fluorescent material, the content of the second compound DF in EML 240 may be about 1 wt % to about 50 wt %, preferably about 10 wt % to about 50 wt %, more preferably about 20 wt % to about 40 wt %, but is not limited thereto.

[0111] Figure 5 is a schematic cross-sectional view showing an OLED according to another exemplary aspect of the present disclosure. Figure 5 As shown, the OLED D2 includes a first electrode 210, a second electrode 230 facing the first electrode 210, and an emission layer 220A disposed between the first electrode 210 and the second electrode 230. The emission layer 220A having a single emission unit includes an EML 240A. In addition, the emission layer 220A includes a HIL 250 and an HTL 260 disposed in sequence between the first electrode 210 and the EML 240A, respectively, and an ETL 270 and an EIL 280 disposed in sequence between the EML 240A and the second electrode 230, respectively. Alternatively, the emission layer 220A further includes an EBL 265 disposed between the HTL 260 and the EML 240A, and / or an HBL 275 disposed between the EML 240A and the ETL 270. The configurations of the first electrode 210, the second electrode 230, and the other layers of the emission layer 220A except the EML 240A may be substantially the same as the corresponding electrodes and layers in the OLED D1.

[0112] In this regard, EML 240A includes a first compound, a second compound, and a third compound. The first compound H may be a host, the second compound may be a delayed fluorescent material (a first dopant), and the third compound FD may be a fluorescent material (a second dopant). The second compound DF may include any organic compound having a structure of chemical formulas 1 to 3. When EML 240A further includes a fluorescent material and a delayed fluorescent material, an OLED D2 having significantly enhanced luminous efficiency may be realized by adjusting the energy level between the host and the dopant.

[0113] EML 240 (see Figure 3 ) contains only a first compound H of a host and a second compound DF having a delayed fluorescence property, and the second compound DF theoretically exhibits an internal quantum efficiency of up to 100%, which is equivalent to conventional phosphorescent materials such as metal complexes. However, due to the bond formation between the electron acceptor and the electron donor and the conformational distortion within the delayed fluorescent material, additional charge transfer transitions (CT transitions) within the delayed fluorescent material are caused, and the delayed fluorescent material has various geometric configurations. As a result, the delayed fluorescent material exhibits a spectrum with a very wide FWHM (full width at half maximum) during the light emission process, which leads to poor color purity. In addition, the delayed fluorescent material utilizes triplet exciton energy as well as singlet exciton energy during the light emission process, while rotating each part in its molecular structure, resulting in a twisted internal charge transfer (TICT). As a result, the luminescence lifetime of an OLED containing only a delayed fluorescent material may be reduced due to the weakening of the molecular bonding force between the delayed fluorescent materials.

[0114] The EML 240A of this aspect further includes a three-compound FD of a fluorescent or phosphorescent material in order to prevent the color purity and light emission life of the OLED D2 from being deteriorated when the EML includes only a delayed fluorescent material as a dopant. Figure 6 , the triplet exciton energy of the second compound DF having delayed fluorescence properties is converted upward into singlet exciton energy, and then the converted singlet exciton energy of the second compound DF can be transferred to the third compound FD in the same EML 240 through a FRET (Forster resonance energy transfer) mechanism, thereby achieving superfluorescence.

[0115] When the EML 240A includes the first compound H of a host, the second compound DF having a delayed fluorescence property, and the third compound FD of a fluorescent or phosphorescent material, it is necessary to adjust the energy level properties between these light emitting materials. Figure 6 is a schematic diagram illustrating a light emitting mechanism caused by an energy level band gap between light emitting materials according to another exemplary aspect of the present disclosure.

[0116] like Figure 6 As shown, the excited singlet energy level S of the second compound DF1 DF and the excited triplet state energy level T 1 DF The energy gap between the two levels is ΔE ST DF It may be equal to or less than about 0.3 eV in order to achieve delayed fluorescence. The exciton energy generated at the first compound H should be mainly transferred to the second compound DF. To this end, the excited singlet energy level S of the first compound H of the host in the EML 240 1 H and the excited triplet state energy level T 1 H Each is higher than the excited singlet energy level S of the second compound 1 DF and the excited triplet state energy level T 1 DF As an example, the excited triplet energy level T of the first compound H1 is 1 H1 It can be higher than the excited triplet energy level T of the second compound DF 1 DF At least about 0.2 eV, preferably at least about 0.3 eV, more preferably at least about 0.5 eV.

[0117] In addition, the EML 240A needs to achieve high luminous efficiency and color purity, and efficiently transfer the exciton energy from the second compound DF (which is converted to the ICT complex state in the EML 240A through the RISC mechanism) to the third compound FD of the fluorescent or phosphorescent material in the EML 240A. To this end, the excited triplet energy level T of the second compound DF is 1 DF Higher than the excited triplet energy level T of the third compound FD 1 FD Optionally, the excited singlet energy level S of the second compound DF 1 DF can be higher than the excited singlet energy level S of the third compound FD 1 FD The first compound H and the second compound DF may be the compounds described in the above aspects, respectively.

[0118] In addition, the exciton energy should be effectively transferred from the second compound DF of the delayed fluorescence material to the third compound FD of the fluorescent or phosphorescent material to achieve superfluorescence. As an example, a fluorescent or phosphorescent material having an absorption (Abs.) spectrum with a large overlapping region with the photoluminescence (PL) spectrum of the second compound DF having delayed fluorescence properties can be used as the third compound FD.

[0119] The third compound FD may include a fluorescent or phosphorescent material that emits green or red light. In an exemplary aspect, the third compound FD of the fluorescent material emitting green light may include a BODIPY core and / or a quinoline acridine core, but is not limited thereto. As an example, the third compound may include, but is not limited to, 5,12-dimethylquinoline [2,3-b] acridine-7,14 (5H, 12H) dione, 5,12-diethylquinoline [2,3-b] acridine-7,14 (5H, 12H) dione, 5,12-dibutyl-3,10-difluoroquinoline [2,3-b] acridine-7,14 (5H, 12H) dione, 5,12-dibutyl-3,10-bis (trifluoroquinoline) ... 1H,5H-benzo[i,j]quinazolin-9-yl)vinyl]-4H-pyran-4-ylidene}malononitrile (DCJTB).

[0120] Alternatively, the third compound FD of the phosphorescent material emitting green light may include, but is not limited to, [bis(2-phenylpyridine)](pyridyl-2-benzofurano[2,3-b]pyridine)iridium), fac-tris(2-phenylpyridine)iridium(III) (fac-Ir(ppy) 3 ), bis(2-phenylpyridine)(acetylacetonate)iridium(III) (Ir(ppy) 2 (acac)), tris[2-(p-tolyl)pyridine]iridium(III) (Ir(mppy) 3 ), bis(2-(naphthalene-2-yl)pyridine)(acetylacetonate)iridium(III)(Ir(npy) 2 acac), tris(2-phenyl-3-methyl-pyridine)iridium(Ir(3mppy) 3 ) and fac-tri(2-(3-p-xylyl)phenyl)pyridineiridium(III) (TEG).

[0121] In addition, the third compound FD of the fluorescent material emitting red light may include a perylene core. Alternatively, the third compound FD of the fluorescent material emitting red light may include, but is not limited to, [bis(2-(4,6-dimethyl)phenylquinoline)](2,2,6,6-tetramethylheptyl-3,5-diketonate)iridium(III), (bis[2-(4-n-hexylphenyl)quinoline](acetylacetonate)iridium(III) (Hex-Ir(phq) 2 (acac)), tris[2-(4-n-hexylphenyl)quinolinol]iridium(III) (Hex-Ir(phq) 3 )、Tris[2-phenyl-4-methylquinoline]iridium(III) (Ir(Mphq)3 ), bis(2-phenylquinoline)(2,2,6,6-tetramethylheptyl-3,5-dionato)iridium(III)(Ir(dpm)PQ 2 ), bis(phenylisoquinoline)(2,2,6,6-tetramethylheptyl-3,5-dionato)iridium(III)(Ir(dpm)(piq) 2 ), bis[(4-hexylphenyl)isoquinoline](acetylacetonate)iridium(III) (Hex-Ir(piq) 2 (acac)), tris[2-(4-n-hexylphenyl)quinolinol]iridium(III) (Hex-Ir(piq) 3 ), tris(2-(3-methylphenyl)-7-methyl-quinolinol)iridium (Ir(dmpq) 3 ), bis[2-(2-methylphenyl)-7-methyl-quinoline](acetylacetonate)iridium(III) (Ir(dmpq) 2 (acac)) and bis[2-(3,5-dimethylphenyl)-4-methyl-quinolinyl](acetylacetonate)iridium(III) (Ir(mphmq) 2 (acac)).

[0122] In one exemplary aspect, the content of the first compound H in the EML 240A may be greater than the content of the second compound DF, and the content of the second compound DF may be greater than the content of the third compound FD. In this case, the exciton energy can be effectively transferred from the second compound DF to the third compound FD. For example, the EML 240A may include, but is not limited to, about 55 wt % to about 75 wt % of the first compound H, about 20 wt % to about 40 wt % of the second compound DF, and about 0.1 wt % to about 5 wt % of the third compound FD.

[0123] The OLED according to the aforementioned aspect has a single-layer EML. Alternatively, the OLED of the present disclosure may include a multi-layer EML. Figure 7 is a schematic cross-sectional view illustrating an OLED diode according to another exemplary aspect of the present disclosure. Figure 8 is a schematic diagram illustrating a light emitting mechanism caused by an energy level band gap between light emitting materials according to another exemplary aspect of the present disclosure.

[0124] like Figure 7As shown, the OLED D3 according to this aspect includes a first electrode 310 and a second electrode 330 facing each other, and an emission layer 320 having a single emission unit disposed between the first electrode 310 and the second electrode 330. In an exemplary aspect, the emission layer 320 includes an EML 340. In addition, the emission layer 320 includes a HIL 350 and a HTL 360 disposed sequentially between the first electrode 310 and the EML 340, respectively, and an ETL 370 and an EIL 380 disposed sequentially between the EML 340 and the second electrode 330, respectively. Alternatively, the emission layer 320 may further include an EBL 365 disposed between the HTL 360 and the EML 340, and / or an HBL 375 disposed between the EML 340 and the ETL 370. The configurations of the first electrode 310, the second electrode 330, and the other layers of the emission layer 320 except the EML 340 may be substantially the same as the corresponding electrodes and layers in the OLEDs D1 and D2.

[0125] The EML 340 includes a first EML (EML1) 342 and a second EML (EML2) 344. The EML1 342 is disposed between the EBL 365 and the HBL 375, and the EML2 344 is disposed between the EML1 342 and the HBL 375. One of the EML1 342 and the EML2 344 includes a second compound DF (first dopant) of a delayed fluorescent material, and the other of the EML1 342 and the EML2 344 includes a fifth compound FD (second dopant) of a fluorescent or phosphorescent material. Hereinafter, the EML 340 in which the EML1 342 includes the second compound DF and the EML2 344 includes the fifth compound FD will be described.

[0126] EML1 342 includes a first compound H1 of a first host and a second compound DF of a delayed fluorescent material. EML2 344 includes a fourth compound H2 of a second host and a fifth compound FD of a fluorescent or phosphorescent material.

[0127] The second compound DF in EML1 342 includes any organic compound of Chemical Formulas 1 to 3 and has delayed fluorescence. Therefore, the triplet exciton energy of the second compound DF in EML1 342 can be upwardly transitioned to its own singlet exciton energy through the RISC mechanism. Although the second compound DF has a high internal quantum efficiency, it has poor color purity due to its wide FWHM. In contrast, the fifth compound FD of the fluorescent or phosphorescent material in EML2 344 has an advantage in color purity due to its narrow FWHM, but has low internal quantum efficiency because its triplet exciton cannot participate in the light emitting process.

[0128] However, in this exemplary aspect, the singlet exciton energy and triplet exciton energy of the second compound DF having a delayed fluorescence property in EML1 342 can be transferred to the fifth compound FD in EML2 344 disposed adjacent to EML1 342 through a FRET mechanism, and the final light emission occurs in the fifth compound FD within EML2 344. In other words, the triplet exciton energy of the second compound DF is up-converted into its own singlet exciton energy through a RISC mechanism in EML1 342. Then, the converted singlet exciton energy of the second compound DF is transferred to the singlet exciton energy of the fifth compound FD in EML2 344.

[0129] The fifth compound FD in EML2 344 can emit light using triplet exciton energy and singlet exciton energy. Since the singlet exciton energy generated at the second compound DF of the delayed fluorescent material in EML1 342 is effectively transferred to the fifth compound FD of the fluorescent or phosphorescent material in EML2 344, OLED D3 can achieve super fluorescence. In this case, although the second compound DF compound with delayed fluorescence properties is only used to transfer exciton energy to the fifth compound FD, significant light emission occurs in the EML2 344 containing the fifth compound FD of the fluorescent or phosphorescent material. Therefore, OLED D3 can improve quantum efficiency and color purity and have a narrow FWHM. The fifth compound can be a fluorescent or phosphorescent material that emits red light or green light. For example, the fifth compound can be the same as the third compound in the second aspect.

[0130] EML1 342 and EML2 344 each include a first compound H1 of a first host and a fourth compound H2 of a second host. The exciton energy generated at the first compound H1 and the fourth compound H2 should be mainly transferred to the second compound DF of the delayed fluorescent material. To this end, the excited singlet energy level S of the first compound H1 and the fourth compound H2 is 1 H1 and S 1 H2 and the excited triplet state energy level T 1 H1 and T 1 H2 Each is higher than the excited singlet energy level S of the second compound DF having delayed fluorescence property. 1 DF and the excited triplet state energy level T 1 DF As an example, the excited triplet energy levels T of the first compound H1 and the fourth compound H2 are 1 H1 and T 1 H2Each of them can be higher than the excited triplet energy level T of the second compound DF 1 DF At least about 0.2 eV, such as at least about 0.3 eV, preferably at least about 0.5 eV.

[0131] In addition, the excited singlet energy level S of the fourth compound H2 in EML2 344 1 H2 Higher than the excited singlet energy level S of the fifth compound FD 1 FD Alternatively, the excited triplet energy level T of the fourth compound H2 1 H2 Higher than the excited triplet energy level T of the fifth compound FD 1 FD In this case, the singlet exciton energy generated at the fourth compound H2 may be transferred to the singlet energy of the fifth compound FD.

[0132] In addition, the exciton energy should be efficiently transferred from the second compound DF (which is converted into the ICT complex in EML1 342 by RISC) to the fifth compound FD of the fluorescent or phosphorescent material in EML2 344. To this end, the excited singlet energy level S of the second compound DF in EML1 342 is 1 DF Higher than the excited singlet energy level S of the fifth compound FD in EML2 344 1 FD Alternatively, the excited triplet energy level T of the second compound DF in EML1 342 is 1 DF Higher than the excited triplet energy level T of the fifth compound FD in EML2 344 1 FD .

[0133] In addition, the HOMO energy level (HOMO H ) and the HOMO energy level of the second compound DF (HOMO DF ) between the energy levels (|HOMO H -HOMO DF |) or the LUMO energy level (LUMO H ) and the LUMO energy level (LUMO DF ) between the energy levels (|LUMO H -LUMO DF|) may be equal to or less than about 0.5 eV. When the light emitting material does not meet the above requirements, the excitons may be non-radiatively quenched at each second compound DF, or the exciton energy may not be transferred from the host to the dopant, resulting in reduced light emission efficiency in the OLED D3.

[0134] The first compound H1 and the fourth compound H2 may be the same as or different from each other. In an exemplary aspect, the first compound H1 and the fourth compound H2 may be the same as the first compound H in the above aspect. The second compound DF of the delayed fluorescent material may be any organic compound having the structure of Chemical Formulas 1 to 3. The fifth compound FD may be the same as the third compound FD described in the second aspect.

[0135] In one exemplary aspect, the content of each of the first compound H1 and the fourth compound H2 in EML 342 and EML 344 may be greater than or equal to the content of the second compound DF and the fifth compound FD in the same layer. In addition, the content of the second compound DF in EML1 342 may be greater than the content of the fifth compound FD in EML2 344. In this case, the exciton energy can be effectively transferred from the second compound DF to the fifth compound FD through the FRET mechanism. As an example, the content of the second compound DF in EML1 342 may be about 1 wt % to about 50 wt %, preferably about 10 wt % to about 50 wt %, more preferably about 20 wt % to about 40 wt %, but is not limited thereto. In contrast, EML2 344 may include about 90 wt % to about 99 wt %, preferably about 95 wt % to about 99 wt % of the fourth compound H2, and about 1 wt % to about 10 wt %, preferably about 1 wt % to about 5 wt % of the fifth compound FD.

[0136] In another exemplary aspect, when EML2 344 is disposed adjacent to HBL 375, the fourth compound H2 included in EML2 344 together with the fifth compound FD may be the same material as HBL 375. In this case, EML1 344 may have a hole blocking function as well as an emission function. In other words, EML2 344 may be used as a buffer layer for blocking holes. In one aspect, when EML2 344 may be a hole blocking layer as well as an emission material layer, HBL 375 may be omitted.

[0137] On the other hand, when EML2 344 is disposed adjacent to EBL 365, the fourth compound H2 in EML2 344 may be the same as EBL 365. In this case, EML2 344 may have an electron blocking function as well as an emission function. In other words, EML2 344 may be used as a buffer layer for blocking electrons. On the one hand, when EML2 344 may be an electron blocking layer as well as an emission material layer, EBL 365 may be omitted.

[0138] An OLED having three layers of EML will be described. Fig. 9 is a schematic cross-sectional view illustrating an OLED according to another exemplary aspect of the present disclosure. Fig.10 is a schematic diagram illustrating a light emitting mechanism caused by an energy level band gap between light emitting materials according to another exemplary aspect of the present disclosure.

[0139] like Fig. 9 As shown, the OLED D4 of this aspect includes a first electrode 410 and a second electrode 430 facing each other, and an emission layer 420 having a single emission unit disposed between the first electrode 410 and the second electrode 430. In an exemplary aspect, the emission layer 420 having a single emission unit includes three layers of EML 440. The emission layer 420 includes a HIL 450 and a HTL 460 disposed sequentially between the first electrode 410 and the EML 440, respectively, and an ETL 470 and an EIL 480 disposed sequentially between the EML 440 and the second electrode 430, respectively. Alternatively, the emission layer 420 may further include an EBL 465 disposed between the HTL 460 and the EML 440, and / or an HBL 475 disposed between the EML 440 and the ETL 470. The configurations of the first electrode 410, the second electrode 430, and the other layers of the emission layer 420 except the EML 440 may be substantially the same as the corresponding electrodes and layers in the OLEDs D1, D2, and D3.

[0140] The EML 440 includes a first EML (EML1) 442, a second EML (EML2) 444, and a third EML (EML3) 446. The EML1 442 is disposed between the EBL 465 and the HBL 475, the EML2 444 is disposed between the EBL 465 and the EML1 442, and the EML3 446 is disposed between the EML1 442 and the HBL 475.

[0141] EML1 442 includes a second compound DF of a delayed fluorescent material, and EML2 444 and EML3 446 each include a fifth compound FD1 (second dopant) and a seventh compound FD2 (third dopant) which may be fluorescent or phosphorescent materials, respectively. In addition, each of EML1 442, EML2 444 and EML3 446 may further include a first compound H1, a fourth compound H2 and a sixth compound H3, which may each be a first to third host, respectively.

[0142] According to this aspect, the singlet energy and triplet energy of the second compound DF (i.e., delayed fluorescence material) in the EML 442 may be transferred to the fifth compound FD1 and the seventh compound FD2 (i.e., fluorescent or phosphorescent material) respectively contained in EML2 444 and EML3 446 disposed adjacent to the EML1 442 through the FRET energy transfer mechanism. Therefore, the final light emission occurs in the fifth compound FD1 and the seventh compound FD2 within the EML2 444 and EML3 446.

[0143] In other words, the triplet exciton energy of the second compound DF having delayed fluorescence property in EML1 442 is up-converted into its own singlet exciton energy through the RISC mechanism, and then the singlet exciton energy of the second compound DF is transferred to the fifth compound FD1 and the seventh compound FD2 in EML2 444 and EML3 446 because the excited singlet energy level S of the second compound DF is 1 DF Higher than the excited singlet energy level S of the fifth compound FD1 and the seventh compound FD2 1 FD1 and S 1 FD2 (See Fig.10 ).

[0144] Since the fifth compound FD1 and the seventh compound FD2 in EML2 444 and EML3 446 can emit light using the singlet exciton energy and triplet exciton energy derived from the second compound DF, the OLED D4 can improve its luminous efficiency. In addition, since the fifth compound FD1 and the seventh compound FD2 have relatively narrow FWHM compared with the second compound DF, respectively, the OLED D4 can enhance its color purity. In particular, in the case of using the fifth compound FD1 and the seventh compound FD2 whose Abs. spectrum has a large overlapping area with the PL spectrum of the second compound DF, the exciton energy can be effectively transferred from the second compound DF to the fifth compound FD1 and the seventh compound FD2. In this case, although the second compound DF is only used to transfer the exciton energy to the fifth compound FD1 and the seventh compound FD2, a large amount of luminescence occurs in the EML2 444 and EML3 446 containing the fifth compound FD1 and the seventh compound FD2.

[0145] In addition, the luminescent materials introduced into EML1 442, EML2 444, and EML3 446 need to be adjusted in order to implement efficient luminescence. Fig.10 , the excited singlet energy levels S of the first compound H1, the fourth compound H2 and the sixth compound H3 as the first to third hosts, respectively 1 H1 , S1 H1 and S 1 H3 and the excited triplet energy level T 1 H1 , T 1 H2 and T 1 H3 Each is higher than the excited singlet energy level S of the second compound DF 1 DF and the excited triplet state energy level T 1 DF .

[0146] In addition, the exciton energy should be efficiently transferred from the second compound DF in EML1 442 (which is converted to the ICT complex state by RISC) to the fifth compound FD1 and the seventh compound FD2, which are fluorescent or phosphorescent materials in EML2 444 and EML3 446, respectively. To this end, the excited singlet energy level S of the second compound DF in EML1 442 is 1 DF Higher than the excited singlet energy level S of each of the fifth compound FD1 and the seventh compound FD2 in EML2 444 and EML3 446 1 FD1 and S 1 FD2 Alternatively, the excited triplet energy level T of the second compound DF in EML1 442 is 1 DF Higher than the excited triplet energy level T of each of the fifth compound FD1 and the seventh compound FD2 in EML2 444 and EML3 446 1 FD1 and T 1 FD2 .

[0147] In addition, the exciton energy transferred from the second compound DF of the delayed fluorescent material to the fifth compound FD1 and the seventh compound FD2 of the fluorescent or phosphorescent material should not be transferred to the fourth compound H2 and the sixth compound H3 in order to achieve efficient luminescence. For this reason, the excited singlet energy level S of the fourth compound H2 and the sixth compound H3, each serving as the second and third hosts, is 1 H2 and S 1 H3 higher than the excited singlet energy level S of the fifth compound FD1 and the seventh compound FD2, each of which is a fluorescent or phosphorescent material. 1 FD1 and S 1 FD2 Alternatively, the excited triplet energy levels T1 H2 and T 1 H3 can be higher than the excited triplet energy level T of the fifth compound FD1 and the seventh compound FD2, respectively. 1 FD1 and T 1 FD2 .

[0148] As described above, EML1 442, EML2 444, and EML3 446 each include a first compound H1, a fourth compound H2, and a sixth compound H3 as first to third hosts, respectively. The first compound H1, the fourth compound H2, and the sixth compound H3 may be the same as or different from each other. In an exemplary aspect, the first compound H1 and the fourth compound H2 may be the same as the first compound H in the above aspect, respectively. The second compound DF of the delayed fluorescent material may be any organic compound having a structure of Chemical Formulas 1 to 3. The fifth compound FD1 and the seventh compound FD2 may be the same as the third compound described in the second aspect, respectively.

[0149] In one exemplary aspect, the content of the second compound DF in EML1 442 may be greater than the content of each of the fifth compound FD1 and the seventh compound FD2 in EML2 444 and EML3 446. In this case, the exciton energy is effectively transferred from the second compound DF to the fifth compound FD1 and the seventh compound FD2 through the FRET mechanism. As an example, the content of the second compound DF in EML1 442 may be about 1 wt % to about 50 wt %, preferably about 10 wt % to about 50 wt %, more preferably about 20 wt % to about 40 wt %, but is not limited thereto. In contrast, EML2 444 and EML3 446 may include about 90 wt % to about 99 wt %, preferably about 95 wt % to about 99 wt % of the fourth compound H2 or the sixth compound H3, and about 1 wt % to about 10 wt %, preferably about 1 wt % to about 5 wt % of the fifth compound FD1 or the seventh compound FD2, respectively.

[0150] In one exemplary aspect, when EML2 444 is disposed adjacent to EBL 465, the fourth compound H2 in EML2 444 may be the same material as EBL 465. In this case, EML2 444 may have an electron blocking function as well as an emission function. In other words, EML2 444 may be used as a buffer layer for blocking electron holes. In one aspect, when EML2 444 may be an electron blocking layer as well as an emission material layer, EBL 465 may be omitted.

[0151] When EML3 446 is disposed adjacent to HBL 475, the sixth compound H3 in EML3 446 may be the same material as HBL 475. In this case, EML3 446 may have a hole blocking function as well as an emission function. In other words, EML3 446 may be used as a buffer layer for blocking holes. In one aspect, when EML3 446 may be a hole blocking layer as well as an emission material layer, HBL 475 may be omitted.

[0152] In another exemplary aspect, the fourth compound H2 in EML2 444 may be the same material as EBL 455, and the sixth compound H3 in EML3 446 may be the same material as HBL 475. In this aspect, EML2 444 may have an electron blocking function as well as an emission function, and EML3 446 may have a hole blocking function as well as an emission function. In other words, each of EML2 444 and EML3 446 may be used as a buffer layer for blocking electrons or holes, respectively. In one aspect, when EML2 444 may be an electron blocking layer as well as an emission material layer and EML3 446 may be a hole blocking layer as well as an emission material layer, EBL 465 and HBL 475 may be omitted.

[0153] Synthesis Example 1: Synthesis of Compound 1-4

[0154]

[0155] 4,4'-([1,1'-biphenyl]-4,4'-diylbis(phenylazadiyl)benzaldehyde (1.00 g, 1 eq.) and 3-ethyl-2,4-dimethyl-1H-pyrrole (0.68 g, 3 eq.) were dissolved in dichloromethane under a nitrogen atmosphere, and the solution was stirred. Trifluoroacetic acid was added to the solution, and the solution was stirred at room temperature overnight. p-Chloroaniline (0.50 g, 1.1 eq.) was added to the solution, and the solution was stirred for more than 30 minutes. Triethylamine (1.54 mL, 6 eq.) was slowly added to the solution, and the solution was stirred at room temperature for more than 30 minutes. Boron trifluoride etherate (BF 3 OE 2 , 2.04 mL, 9 equivalents) was added to the solution, and the mixture was then reacted at room temperature for more than 4 hours. After the reaction was completed, the solution was extracted three times with dichloromethane and DI water, and then washed with Na 2 SO 4 The water was removed. The extracted organic layer was filtered through lamination using diatomaceous earth and silica gel, and the crude product was purified by column chromatography, wherein hexane: dichloromethane (MC), hexane: ethyl acetate (EA) and hexane: toluene were used as eluents in each purification step. The purified product was recrystallized to obtain red solid compound 1-4.

[0156] Synthesis Example 2: Synthesis of Compound 1-8

[0157]

[0158] 4,4'-([1,1'-biphenyl]-4,4'-diyldi(tolylazadiyl)benzaldehyde (1.00 g, 1 eq.) and 3-ethyl-2,4-dimethyl-1H-pyrrole (0.65 g, 3 eq.) were dissolved in dichloromethane under a nitrogen atmosphere, and the solution was stirred. Trifluoroacetic acid was added to the solution, and the solution was stirred at room temperature overnight. p-Chloroaniline (0.47 g, 1.1 eq.) was added to the solution, and the solution was stirred for more than 30 minutes. Triethylamine (1.46 mL, 6 eq.) was slowly added to the solution, and the solution was stirred at room temperature for more than 30 minutes. Boron trifluoride etherate (BF 3 OE 2 , 1.94 mL, 9 equivalents) was added to the solution, and the mixture was then reacted at room temperature for more than 4 hours. After the reaction was completed, the solution was extracted three times with dichloromethane and DI water, and then washed with Na 2 SO 4 The water was removed. The extracted organic layer was filtered through lamination using diatomaceous earth and silica gel, and the crude product was purified by column chromatography, wherein hexane: dichloromethane (MC), hexane: ethyl acetate (EA) and hexane: toluene were used as eluents in each purification step. The purified product was recrystallized to obtain an orange solid compound 1-8.

[0159] Synthesis Example 3: Synthesis of Compound 1-11

[0160]

[0161] The same synthesis procedure as in Synthesis Example 1 was performed, except that 4,4'-([1,1'-biphenyl]-3,3'-diylbis(phenylazadiyl)benzaldehyde (1.00 g, 1 equivalent) was used instead of 4,4'-([1,1'-biphenyl]-4,4'-diylbis(phenylazadiyl)benzaldehyde as the starting material to obtain an orange solid compound 1-11.

[0162] Synthesis Example 4: Synthesis of Compound 2-1

[0163]

[0164] The same synthesis procedure as in Synthesis Example 1 was performed except that 2,4-diphenyl-1H-pyrrole was used as the starting material instead of 3-ethyl-2,4-dimethyl-1H-pyrrole to obtain a red solid compound 2-1.

[0165] Experimental Example 1: Measurement of Energy Levels

[0166] Compounds 1-4, 1-8 and 1-11 synthesized in Synthesis Examples 1 to 3 were respectively reacted at 10 -5 After the concentration of M was dissolved in toluene, the physical properties of the compound, such as photoluminescence spectrum (PLλ) and photoluminescence quantum yield (PLQY), were measured. For comparison, the PLλ and PLQY of the Ref.1 compound and the Ref.2 compound shown below were also measured using the same procedure. The following Table 1 shows the measurement results.

[0167] [Comparative Compounds]

[0168]

[0169] Table 1: Physical properties of organic compounds

[0170] Compound PLλ(nm) PLQY(%) 1-4 540 94 1-8 542 90 1-11 540 80 Ref.1 526 57 Ref.2 516 74

[0171] As shown in Table 1, the organic compound synthesized in Synthesis Example shows a PL peak in the green wavelength range and has an improved PLQY compared to the compounds of Ref. 1 and Ref. 2.

[0172] Example 1: Fabrication of OLED

[0173] OLEDs were fabricated in which compounds 1-4 were applied as dopants in the EML. An ITO (50 nm) attached glass substrate was washed with ozone and loaded into a vacuum system and then transferred to a vacuum deposition chamber for deposition of other layers on the substrate. -7 Support, and set the deposition rate to The organic layers were deposited by evaporation from a heated boat in the following order.

[0174] ITO (50nm); HIL (HAT-CN; 5nm); HTL (NPB, 50nm); EBL (mCBP, 10nm); EML (4-(3-(2-triphenyl-2-yl)phenyl)-dibenzothiophene (host): compound 1-4 (dopant) = 70:30 (by weight), 30nm); HBL (B3PYMPM, 10nm); ETL (TPBi, 30nm); EIL (LiF; 1.0nm); and cathode (Al; 100nm).

[0175] Then, a capping layer (CPL) is deposited on the cathode and the device is encapsulated with glass. After deposition of the emissive layer and cathode, the OLED is transferred from the deposition chamber to a dry box for film formation and then encapsulated using a UV-curable epoxy resin and a moisture absorber.

[0176] Examples 2 to 3 (Ex. 2 to Ex. 3): Fabrication of OLED

[0177] An OLED was fabricated using the same materials as in Example 1, except that Compound 1-8 (Ex. 2) or Compound 1-11 (Ex. 3) was applied to the EML as a dopant instead of Compound 1-4.

[0178] Comparative Examples 1 to 3 (Com.1 to Com.3): Production of OLED

[0179] An OLED was fabricated using the same materials as in Example 1, except that Ref. 1 compound (Com. 1), Ref. 2 compound (Com. 2), or Ref. 3 compound (Com. 3) was applied to the EML as a dopant instead of Compounds 1-4.

[0180] Experimental Example 2: Measurement of OLED light emission properties

[0181] The light emitting area is 9mm 2 Each OLED manufactured by Ex.1 to Ex.3 and Ref.1 to Ref.3 was connected to an external power supply, and then the luminescence properties of all diodes were evaluated at room temperature using a constant current source (KEITHLEY) and a photometer PR650. In particular, 6.3 mA / cm 2 The driving voltage (V) and the maximum electroluminescence wavelength (EL max The results are shown in Table 2.

[0182] Table 2: Light-emitting properties of OLEDs

[0183] sample Dopant V <![CDATA[EL max (nm)]]> FWHM(nm) EQE(%) CIE(x,y) Ref.1 Ref.1 4.27 538 105.0 6.75 (0.406,0.555) Ref.2 Ref.2 4.68 544 90.6 9.23 (0.388,0.578) Ref.3 Ref.3 4.61 539 85.0 6.21 (0.360,0.567) Ex.1 1-4 4.82 544 78.3 12.75 (0.393,0.575) Ex.2 1-8 4.50 544 77.8 12.06 (0.391,0.577) Ex.3 1-11 4.43 543 80.8 10.10 (0.370,0.579)

[0184] As shown in Table 2, compared with the OLED in Ref.1 in which the conventional triazine-based delayed fluorescent material is applied to the EML, the FWHM of the OLEDs in Ex.1 to Ex.3 is reduced by up to 25.9% (up to 27.2 nm), and its EQE is increased by up to 88.9%. Compared with the OLED in Ref.2 in which the compound containing the BODIPY core connected to the aryl amino group is applied to the EML, the OLEDs in Ex.1 to Ex.3 show that the driving voltage is approximately equal or slightly reduced, the FWHM is reduced by up to 14.1% (up to 12.8 nm), and its EQE is increased by up to 38.1%. In addition, compared with the OLED in Ref.3 in which the organic compound having two BODIPY parts interconnected by the phenyl amino group is applied to the EML, the OLEDs in Ex.1 to Ex.3 show that the driving voltage is approximately equal or slightly reduced, the FWHM is reduced by up to 8.5% (up to 7.2 nm), and its EQE is increased by up to 105.3%.

[0185] Those skilled in the art will appreciate that various modifications and changes can be made in the present disclosure without departing from the technical concept or scope of the present disclosure. Therefore, the present disclosure is intended to cover modifications and changes of the present disclosure as long as they fall within the scope of the attached claims and their equivalents.

Claims

1. An organic compound having the structure of the following chemical formula 1: [Chemical formula 1] in, R1 and R2 are each independently C6-C 30 Aryl; R3 to R 14 Each independently selected from hydrogen and C1-C 20 alkyl; X1 to X4 are each independently halogen; L1 is each biphenylene; L2 and L3 are each independently C6-C 30 arylene group; o is an integer of 1 or 2; p and q are each an integer of 1 to 2.

2. The organic compound according to claim 1, wherein At least four groups from R3 to R8 and R9 to R 14 At least four groups in the 10 Alkyl, L2 and L3 are each independently C6-C 30 In the arylene group, p and q are each independently an integer of 1 or 2.

3. The organic compound according to claim 1, wherein The organic compound includes any one of the structures of the following Chemical Formula 2: [Chemical formula 2] 4. An organic light emitting diode, comprising: a first electrode; a second electrode facing the first electrode; and an emitting material layer disposed between the first electrode and the second electrode, The emission material layer comprises an organic compound having the structure of the following chemical formula 1: [Chemical formula 1] Wherein R1 and R2 are each independently C6-C 30 Aryl; R3 to R 14 Each independently selected from hydrogen and C1-C 20 alkyl; X1 to X4 are each independently halogen; L1 is each biphenylene; L2 and L3 are each independently C6-C 30 arylene group; o is an integer of 1 or 2; p and q are each an integer of 1 to 2.

5. The organic light emitting diode according to claim 4, wherein: At least four groups from R3 to R8 and R9 to R 14 At least four groups in the 10 Alkyl, L2 and L3 are each independently C6-C 30 In the arylene group, p and q are each independently an integer of 1 or 2.

6. The organic light emitting diode according to claim 4, wherein: The emission material layer includes a first compound and a second compound, and wherein the second compound includes the organic compound.

7. The organic light emitting diode according to claim 6, wherein: An excited singlet energy level and an excited triplet energy level of the first compound are each higher than each of an excited singlet energy level and an excited triplet energy level of the second compound, respectively. The organic light emitting diode as claimed in claim 6 , wherein the emission material layer further comprises a third compound.

9. The organic light emitting diode according to claim 8, wherein: An excited singlet energy level of the second compound is higher than an excited singlet energy level of the third compound.

10. The organic light emitting diode according to claim 4, wherein: The emission material layer includes a first emission material layer and a second emission material layer, wherein the first emission material layer is arranged between the first electrode and the second electrode, and the second emission material layer is arranged between the first electrode and the first emission material layer or between the first emission material layer and the second electrode.

11. The organic light emitting diode according to claim 10, wherein: The first emission material layer includes a first compound and a second compound, and the second emission material layer includes a fourth compound and a fifth compound, and wherein the second compound includes the organic compound.

12. The organic light emitting diode according to claim 11, wherein: The excited singlet energy level and the excited triplet energy level of the first compound and the fourth compound are each higher than the excited singlet energy level and the excited triplet energy level of the second compound, respectively.

13. The organic light emitting diode according to claim 11, wherein: An excited singlet energy level of the second compound is higher than an excited singlet energy level of the fifth compound.

14. The organic light emitting diode according to claim 11, wherein: The emission material layer further includes a third emission material layer, which is disposed opposite to the second emission material layer with respect to the first emission material layer, and wherein the third emission material layer includes a sixth compound and a seventh compound.

15. The organic light emitting diode according to claim 14, wherein: The excited singlet energy level and the excited triplet energy level of the first compound, the fourth compound, and the sixth compound are each higher than the excited singlet energy level and the excited triplet energy level of the second compound, respectively.

16. The organic light emitting diode according to claim 14, wherein: The second compound has an excited singlet energy level higher than those of the fifth and seventh compounds.

17. An organic light emitting display device, comprising: substrate; and The organic light emitting diode of claim 4 is on the substrate.

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