Organic light-emitting diodes and organic light-emitting devices including the same

Abstract

This invention relates to an organic light-emitting diode (OLED), comprising a first electrode; a second electrode facing the first electrode; and a light-emitting material layer comprising a first compound and a second compound and located between the first and second electrodes. The energy levels of the first compound and the second compound satisfy predetermined conditions. Furthermore, an organic light-emitting device may include the aforementioned OLED. Additionally, this invention relates to an organic light-emitting device that may include the aforementioned OLED.

Description

[Technical Field]

[0001] This invention relates to an organic light-emitting diode (OLED), and more specifically, to an organic light-emitting diode with excellent light-emitting characteristics and an organic light-emitting display device including the same. [Background Technology]

[0002] Recently, there has been an increasing demand for flat panel display devices with a small footprint. Among flat panel display devices, organic light-emitting diode (OLED) and organic electroluminescent devices (OLEDs) technologies have developed rapidly.

[0003] OLEDs emit light by injecting electrons from the cathode (electron injection electrode) and holes from the anode (hole injection electrode) into the light-emitting material layer (EML). This combination of electrons and holes generates excitons, which then transition from an excited state to the ground state. In fluorescent materials, only singlet excitons participate in emission, resulting in low emission efficiency in existing fluorescent materials. In phosphorescent materials, both singlet and triplet excitons participate in emission, leading to higher emission efficiency than fluorescent materials. However, metal complexes, typical of phosphorescent materials, have short luminescence lifetimes, limiting their commercialization. [Summary of the Invention]

[0004] [Technical Issues]

[0005] Therefore, the present invention aims to provide an OLED and organic light-emitting device that substantially eliminates one or more problems caused by the limitations and disadvantages of the prior art.

[0006] One object of the present invention is to provide an OLED with improved light-emitting properties such as luminous efficiency and lifetime.

[0007] Another object of the present invention is to provide an organic light-emitting display device including the above-described OLED, which has improved light-emitting characteristics, such as luminous efficiency and lifetime.

[0008] Additional features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practice of the invention. The objects and other advantages of the invention will be realized and obtained through the written description and its claims, as well as the structures particularly pointed out in the drawings.

[0009] [Technical Solution]

[0010] According to one aspect, the present invention provides an organic light-emitting diode (OLED) comprising: a first electrode; a second electrode facing the first electrode; and a first light-emitting material layer comprising a first compound and a second compound and located between the first and second electrodes, wherein the first compound is represented by Formula 1, wherein Z1 and Z2 are each independently selected from oxygen, sulfur, and selenium, and R is selected from hydrogen, deuterium, C1 to C20 alkyl, C6 to C30 aryl, C5 to C30 heteroaryl, and C1 to C20 amino, and wherein the second compound is represented by Formula 2-1 or Formula 2-2, wherein in Formula 2-1, X is selected from single bonds. CR3R4, O, S and NR5, Y is selected from CN, halogen and C1 to C20 haloalkyl, wherein n1 and n2 are each independently an integer from 0 to 4, wherein, in formula 2-2, X1 is selected from CR6 and N, X2 to X4 are each independently selected from single bond, CR7R8, O, S and NR9, wherein L is selected from C6 to C30 arylene and C5 to C30 heteroarylene, m is an integer from 1 to 3, wherein R1 to R9 are each independently selected from H, D, C1 to C20 alkyl, C6 to C30 aryl, C5 to C30 heteroaryl and C1 to C20 amino.

[0011]

[0012]

[0013] According to another aspect, the present invention provides an organic light-emitting display device, comprising: a substrate; the aforementioned organic light-emitting diode located above the substrate; and an encapsulation film covering the organic light-emitting diode.

[0014] It should be understood that the foregoing general description and the following detailed description are illustrative and explanatory, and are intended to provide further explanation of the claimed invention.

[0015] [Beneficial Effects]

[0016] In OLEDs and organic light-emitting devices, the emissive layer comprises a host and a delayed fluorescence compound, with the energy levels of the host matched to those of the delayed fluorescence compound. This prevents the exciplex from reducing luminous efficiency and lifetime, thus enabling OLEDs and organic light-emitting devices to exhibit excellent luminous properties and efficiency.

[0017] Furthermore, the luminescent layer further includes a fluorescent compound, thereby providing the high quantum efficiency of the delayed fluorescence compound and the narrow full width at half maximum (FWHM) of the fluorescence compound. Therefore, OLEDs and organic light-emitting devices exhibit further improved luminescent characteristics and luminescent efficiency.

[0018] [Attached Image Description]

[0019] The accompanying drawings, which are included and form part of this specification to provide a further understanding of the invention, illustrate embodiments of the invention and, together with the specification, serve to explain the principles of these embodiments.

[0020] Figure 1 This is a circuit diagram of the organic light-emitting display device of the present invention.

[0021] Figure 2 This is a cross-sectional schematic diagram of the organic light-emitting display device according to the first embodiment of the present invention.

[0022] Figure 3 This is a cross-sectional schematic diagram of the OLED according to the second embodiment of the present invention.

[0023] Figure 4 This is a schematic diagram illustrating the light emission mechanism of the OLED using a delayed fluorescence compound according to the present invention.

[0024] Figure 5 This is a schematic diagram showing the energy level relationship between the first and second compounds in an OLED.

[0025] Figure 6 This is a cross-sectional schematic diagram of the OLED according to the third embodiment of the present invention.

[0026] Figure 7 This is a cross-sectional schematic diagram of the OLED according to the fourth embodiment of the present invention.

[0027] Figure 8 This is a cross-sectional schematic diagram of the OLED according to the fifth embodiment of the present invention.

[0028] Figure 9 This is a cross-sectional schematic diagram of the organic light-emitting display device according to the sixth embodiment of the present invention.

[0029] Figure 10 This is a cross-sectional schematic diagram of the OLED according to the seventh embodiment of the present invention.

[0030] Figure 11 This is a cross-sectional schematic diagram of the organic light-emitting display device according to the eighth embodiment of the present invention.

[0031] Figure 12 This is a cross-sectional schematic diagram of the OLED according to the ninth embodiment of the present invention.

[0032] Figure 13 This is a cross-sectional schematic diagram of the OLED according to the tenth embodiment of the present invention.

Detailed Implementation Methods

[0033] Reference will now be made in detail to various aspects of the invention, examples of which are shown in the accompanying drawings.

[0034] This invention relates to an OLED and an organic light-emitting device including the OLED, wherein a host and a delayed fluorescence compound having matched energy levels are provided in a single light-emitting material layer or adjacent light-emitting material layers. For example, the organic light-emitting device can be an organic light-emitting display device or an organic lighting device. As an example, an organic light-emitting display device comprising the OLED of this invention will be primarily described.

[0035] Figure 1 This is a circuit diagram of the organic light-emitting display device of the present invention.

[0036] like Figure 1 As shown, the organic light-emitting display device includes a gate line GL, a data line DL, a power line PL, a switching thin-film transistor (TFT) Ts, a driving TFT Td, a storage capacitor Cst, and an OLED D. The gate line GL and the data line DL intersect to define a pixel region P. The pixel region P may include a red pixel region, a green pixel region, and a blue pixel region.

[0037] The switching TFT Ts is connected to the gate line GL and the data line DL, while the driving TFT Td and the storage capacitor Cst are connected to the switching TFT Ts and the power line PL. The OLED D is connected to the driving TFT Td.

[0038] In an organic light-emitting display device, when the switching TFT Ts is turned on by the gate signal applied through the gate line GL, the data signal from the data line DL is applied to the gate electrode of the driving TFT Td and the electrode of the storage capacitor Cst.

[0039] When the driving TFT Td is turned on by a data signal, current is supplied from the power line PL to the OLED D. As a result, the OLED D emits light. In this case, when the driving TFT Td is turned on, the current level applied from the power line PL to the OLED D is determined so that the OLED D can produce grayscale.

[0040] When the switching TFT Ts is turned off, the storage capacitor Cst is used to maintain the voltage of the gate electrode of the driving TFT Td. Therefore, even when the switching TFT Ts is turned off, the current level applied to the OLED D from the power line PL is maintained until the next frame.

[0041] As a result, the organic light-emitting display device displays the desired image.

[0042] Figure 2 This is a cross-sectional schematic diagram of the organic light-emitting display device according to the first embodiment of the present invention.

[0043] like Figure 2 As shown, the organic light-emitting display device 100 includes a substrate 110, a TFT Tr, and an OLEDD connected to the TFT Tr.

[0044] The substrate 110 can be a glass substrate or a flexible substrate. For example, the flexible substrate can be a polyimide (PI) substrate, a polyethersulfone (PES) substrate, a polyethylene naphthalate (PEN) substrate, a polyethylene terephthalate (PET) substrate, or a polycarbonate (PC) substrate.

[0045] A buffer layer 122 is formed on the substrate, and a TFT Tr is formed on the buffer layer 122. The buffer layer 122 can be omitted.

[0046] A semiconductor layer 120 is formed on the buffer layer 122. The semiconductor layer 120 may include an oxide semiconductor material or polysilicon.

[0047] When the semiconductor layer 120 comprises an oxide semiconductor material, a light-shielding pattern (not shown) can be formed beneath the semiconductor layer 120. Light reaching the semiconductor layer 120 is shielded or blocked by the light-shielding pattern, thereby preventing thermal degradation of the semiconductor layer 120. On the other hand, when the semiconductor layer 120 comprises polysilicon, impurities can be doped onto both sides of the semiconductor layer 120.

[0048] A gate insulating layer 124 is formed on the semiconductor layer 120. The gate insulating layer 124 may be formed of an inorganic insulating material such as silicon oxide or silicon nitride.

[0049] A gate electrode 130, formed of a conductive material such as a metal, is formed on the gate insulating layer 124 corresponding to the center of the semiconductor layer 120. Figure 2 In this case, the gate insulating layer 124 is formed over the entire surface of the substrate 110. Alternatively, the gate insulating layer 124 may be patterned to have the same shape as the gate electrode 130.

[0050] An interlayer insulating layer 132, formed of an insulating material, is formed on the gate electrode 130. The interlayer insulating layer 132 may be formed of an inorganic insulating material (e.g., silicon oxide or silicon nitride) or an organic insulating material (e.g., benzocyclobutene or photo-acryl).

[0051] The interlayer insulating layer 132 includes a first contact hole 134 and a second contact hole 136 exposing both sides of the semiconductor layer 120. The first contact hole 134 and the second contact hole 136 are located on both sides of the gate electrode 130 and spaced apart from the gate electrode 130.

[0052] The first contact hole 134 and the second contact hole 136 are formed through the gate insulating layer 124. Alternatively, when the gate insulating layer 124 is patterned to have the same shape as the gate electrode 130, the first contact hole 134 and the second contact hole 136 are formed only through the interlayer insulating layer 132.

[0053] Source electrode 144 and drain electrode 146, formed of conductive materials such as metal, are formed on interlayer insulating layer 132.

[0054] The source electrode 144 and the drain electrode 146 are spaced apart from each other relative to the gate electrode 130 and contact the two sides of the semiconductor layer 120 through the first contact hole 134 and the second contact hole 136, respectively.

[0055] Semiconductor layer 120, gate electrode 130, source electrode 144, and drain electrode 146 constitute TFT Tr. TFT Tr serves as a driving element. That is, TFT Tr drives TFT Td (… Figure 1 ).

[0056] In the TFT Tr, the gate electrode 130, the source electrode 144, and the drain electrode 146 are located above the semiconductor layer 120. That is, the TFT Tr has a coplanar structure.

[0057] Alternatively, in the TFT Tr, the gate electrode can be located below the semiconductor layer, and the source and drain electrodes can be located above the semiconductor layer, allowing the TFT Tr to have an anti-interlaced structure. In this case, the semiconductor layer may include amorphous silicon.

[0058] Although not shown, the gate line and data line intersect each other to define a pixel area, and a switching TFT is formed to connect to the gate line and the data line. The switching TFT is connected to the TFT Tr, which serves as a driving element. Furthermore, a power line, which can be formed parallel to and spaced apart from one of the gate line and the data line, and a storage capacitor for maintaining the gate voltage of the TFT Tr within a frame can be further formed.

[0059] A leveling layer 150 is formed on the entire surface of the substrate 110 to cover the source electrode 144 and the drain electrode 146. The leveling layer 150 provides a flat top surface and has a drain contact hole 152 that exposes the drain electrode 146 of the TFT Tr.

[0060] The OLED D is disposed on the planarization layer 150 and includes a first electrode 210 connected to the drain 146 of the TFT Tr, an emissive layer 220, and a second electrode 230. The emissive layer 220 and the second electrode 230 are stacked sequentially on the first electrode 210. The OLED D is located in each of the red, green, and blue pixel regions and emits red light, green light, and blue light, respectively.

[0061] First electrodes 210 are formed in each pixel region. The first electrode 210 can be an anode and can be formed of a conductive material with a relatively high work function (e.g., transparent conductive oxide (TCO)). For example, the first electrode 210 can be formed of indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), tin oxide (SnO), zinc oxide (ZnO), indium copper oxide (ICO), or aluminum zinc oxide (Al:ZnO, AZO).

[0062] When the organic light-emitting display device 100 operates in a bottom-emitting mode, the first electrode 210 may have a single-layer structure with a transparent conductive material layer. When the organic light-emitting display device 100 operates in a top-emitting mode, a reflective electrode or reflective layer may be formed below the first electrode 210. For example, the reflective electrode or reflective layer may be formed of silver (Ag) or an aluminum palladium copper (APC) alloy. In this case, the first electrode 210 may have a three-layer structure of ITO / Ag / ITO or ITO / APC / ITO.

[0063] Furthermore, a dam layer 160 is formed on the leveling layer 150 to cover the edge of the first electrode 210. That is, the dam layer 160 is located at the boundary of the pixel area and exposes the center of the first electrode 210 in the pixel area.

[0064] The light-emitting layer 220, serving as a light-emitting unit, is formed on the first electrode 210. The light-emitting layer 220 may have a single-layer structure comprising a light-emitting material layer (EML). Alternatively, the light-emitting layer 220 may have a multilayer structure. For example, the light-emitting layer 220 may further include at least one of a hole injection layer (HIL), a hole transport layer (HTL), an electron blocking layer (EBL), a hole blocking layer (HBL), an electron transport layer (ETL), and an electron injection layer (EIL). The HIL, HTL, and EBL are sequentially disposed between the first electrode 210 and the EML, and the HBL, ETL, and EIL are sequentially disposed between the EML and the second electrode 230. Furthermore, the EML may have a single-layer structure or a multilayer structure. Additionally, the light-emitting layer 220 may include at least two EMLs spaced apart from each other, allowing the OLED to have a series structure.

[0065] The second electrode 230 is formed above the substrate 110 on which the light-emitting layer 220 is formed. The second electrode 230 covers the entire surface of the display area and can be formed of a conductive material with a relatively low work function to serve as a cathode. For example, the second electrode 230 can be formed of aluminum (Al), magnesium (Mg), calcium (Ca), silver (Ag), or alloys or combinations thereof. In the top-emitting organic light-emitting display device 100, the second electrode 230 can have a thin profile (small thickness) to provide light-transmitting properties (or semi-transmitting properties).

[0066] Although not shown, the organic light-emitting display device 100 may include color filters corresponding to the red, green, and blue pixel areas. For example, when an OLED D having a series structure and emitting white light is formed to all red, green, and blue pixel areas, a red color filter pattern, a green color filter pattern, and a blue color filter pattern may be formed in the red, green, and blue pixel areas respectively, thereby providing full-color display.

[0067] When the organic light-emitting display device 100 operates in a bottom-emitting mode, the color filter can be disposed between the OLED D and the substrate 110, for example, between the interlayer insulating layer 132 and the leveling layer 150. Alternatively, when the organic light-emitting display device 100 operates in a top-emitting mode, the color filter can be disposed above the OLED D, for example, above the second electrode 230.

[0068] An encapsulation film 170 is formed on the second electrode 230 to prevent moisture from penetrating into the OLED D. The encapsulation film 170 includes, but is not limited to, a first inorganic insulating layer 172, an organic insulating layer 174, and a second inorganic insulating layer 176 stacked in sequence.

[0069] The organic light-emitting display device 100 may further include a polarizing plate (not shown) for reducing ambient light reflection. For example, the polarizing plate may be a circular polarizing plate. In a bottom-emitting organic light-emitting display device 100, the polarizing plate may be disposed below the substrate 110. In a top-emitting organic light-emitting display device 100, the polarizing plate may be disposed on or above the encapsulation film 170.

[0070] Furthermore, in the top-emitting organic light-emitting display device 100, a cover window (not shown) can be attached to the encapsulation film 170 or a polarizing plate. In this case, the substrate 110 and the cover window have flexible properties, thereby providing a flexible organic light-emitting display device.

[0071] Figure 3 This is a cross-sectional schematic diagram of the OLED according to the second embodiment of the present invention.

[0072] like Figure 3 As shown, OLED D1 includes a first electrode 210 and a second electrode 230 facing each other, and a light-emitting layer 220 between them. The light-emitting layer 220 includes a light-emitting material layer (EML) 240. Figure 2 The organic light-emitting display device 100 may include a red pixel area, a green pixel area and a blue pixel area, and the OLED D1 may be located in the green pixel area.

[0073] The first electrode 210 can be an anode, and the second electrode 230 can be a cathode.

[0074] The light-emitting layer 220 further includes at least one of a hole transport layer (HTL) 260 between the first electrode 210 and the EML 240 and an electron transport layer (ETL) 270 between the second electrode 230 and the EML 240.

[0075] Furthermore, the light-emitting layer 220 may further include at least one of a hole injection layer (HIL) 250 between the first electrode 210 and HTL 260 and an electron injection layer (EIL) 280 between the second electrode 230 and ETL 270.

[0076] Furthermore, the light-emitting layer 220 may further include at least one of an electron blocking layer (EBL) 265 between HTL 260 and EML 240 and a hole blocking layer (HBL) 275 between EML 240 and ETL 270.

[0077] For example, HIL 250 may include at least one compound selected from the group consisting of: 4,4',4”-tris(3-methylphenylamino)triphenylamine (MTDATA), 4,4',4”-tris(N,N-diphenyl-amino)triphenylamine (NATA), 4,4',4”-tris(N-(naphthyl-1-yl)-N-phenyl-amino)triphenylamine (1T-NATA), 4,4',4”-tris(N-(naphthyl-2-yl)-N-phenyl-amino)triphenylamine (2T-NATA), copper phthalocyanine (CuPc), tris(4-carbazole-9-ylphenyl)amine (TCTA), and N,N'-diphenyl-N,N'-bis(1-naphthyl) -1,1'-biphenyl-4,4”-diamine (NPB; NPD), 1,4,5,8,9,11-hexaazatriphenylhexacarbonitrile (dipyrazine[2,3-f:2'3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile; HAT-CN), 1,3,5-tris[4-(diphenylamino)phenyl]benzene (TDAPB), poly(3,4-ethylenedioxythiophene)polystyrene sulfonate (PEDOT / PSS), and N-(biphenyl-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluorene-2-amine, but not limited thereto.

[0078] HTL 260 may include at least one compound selected from the group consisting of: N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine; TPD), NPB (NPD), 4,4'-bis(N-carbazolyl)-1,1'-biphenyl (CBP), poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (poly-TPD), poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)] (poly-TPD), (poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)] (poly-TPD) (poly- ... Diphenylamine (TFB), di-[4-(N,N-di-p-tolyl-amino)-phenyl]cyclohexane (TAPC), 3,5-bis(9H-carbazole-9-yl)-N,N-diphenylaniline (DCDPA), N-(biphenyl-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazole-3-yl)phenyl)-9H-fluorene-2-amine, and N-(biphenyl-4-yl)-N-(4-(9-phenyl-9H-carbazole-3-yl)phenyl)biphenyl-4-amine, but not limited thereto.

[0079] ETL 270 may include at least one of the following: oxadiazole-based compounds, triazole-based compounds, phenanthroline-based compounds, benzoxazole-based compounds, benzothiazole-based compounds, benzimidazole-based compounds, and triazine-based compounds. For example, ETL... 270 may include at least one compound selected from the group consisting of: tri-(8-hydroxyquinoline)aluminum (Alq3), 2-biphenyl-4-yl-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD), spiro-PBD, lithium quinoline (Liq), 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene (TPBi), bis(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum (BAlq), 4,7-diphenyl-1,10-phenanthroline (Bphen), 2,9-bis(naphthyl-2-yl)4,7-diphenyl-1,10-phenanthroline (NBphen), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 3-(4 The following are not limited to the following: 4-(naphthyl-1-yl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ), 4-(naphthyl-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (NTAZ), 1,3,5-tris(p-pyridin-3-yl-phenyl)benzene (TpPyPB), 2,4,6-tris(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]-alt-2,7-(9,9-dioctylfluorene)] (PFNBr), tris(phenylquinoxaline) (TPQ), and diphenyl-4-triphenylsilyl-phenylphosphine oxide (TSPO1).

[0080] EIL 280 may include, but is not limited to, at least one of alkali metal halide compounds (such as LiF, CsF, NaF or BaF2) and organometallic compounds (such as Liq, lithium benzoate or sodium stearate).

[0081] The EBL 265 is located between the HTL 260 and the EML 240 to prevent electrons from transferring from the EML 240 to the HTL. In 260, it may include at least one compound selected from the group consisting of: TCTA, tris[4-(diethylamino)phenyl]amine, N-(biphenyl-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazole-3-yl)phenyl)-9H-fluorene-2-amine, TAPC, MTDATA, 1,3-bis(carbazole-9-yl)phenyl (mCP), 3,3'-bis(N-carbazole)-1,1'-biphenyl (mCBP), CuPc, N,N'-bis[4-[bis(3-methylphenyl)amino]phenyl]-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (DNTPD), TDAPB, DCDPA, and 2,8-bis(9-phenyl-9H-carbazole-3-yl)dibenzo[b,d]thiophene, but not limited thereto.

[0082] HBL 275 is located between EML 240 and ETL 270 to prevent holes from transferring from EML 240 to ETL 270, and it may include the aforementioned material of ETL 270. For example, the material of HBL 275 has a lower HOMO energy level than the material of EML 240 and may be at least one compound selected from the group consisting of: BCP, BAlq, Alq3, PBD, spiro-PBD, Liq, bis-4,6-(3,5-di-3-pyridylphenyl)-2-methylpyrimidine (B3PYMPM), bis[2-(diphenylphosphino)phenyl]dentate oxide (DPEPO), 9-(6-9H-carbazole-9-yl)pyridin-3-yl)-9H-3,9'-bicarbazole, and TSPO1, but is not limited thereto.

[0083] EML 240 comprises a first compound as the main component and a second compound as a delayed fluorescence material (compound). The second compound as the delayed fluorescence material can be used as a dopant (emissor).

[0084] The first compound, which is the main component, is represented by Formula 1.

[0085] [Formula 1]

[0086]

[0087] In Formula 1, Z1 and Z2 are each independently selected from oxygen (O), sulfur (S) and selenium (Se), and R is selected from hydrogen (H), deuterium (D), C1 to C20 alkyl, C6 to C30 aryl, C5 to C30 heteroaryl and C1 to C20 amino (e.g. alkylamine or arylamine).

[0088] For example, Z1 and Z2 can be independently selected from O and S, and Z1 and Z2 can be different. R can be a C6 to C30 aryl group, such as phenyl or naphthyl.

[0089] The second compound, which serves as a delayed fluorescence material, is represented by formula 2-1 or 2-2.

[0090] [Equation 2-1]

[0091]

[0092] [Equation 2-2]

[0093]

[0094] In Formula 2-1, X is selected from single bonds, CR3R4, O, S, and NR5, and Y is selected from CN, halogens, and C1 to C20 haloalkyl groups. Each of n1 and n2 is an integer from 0 to 4.

[0095] In Formula 2-2, X1 is selected from CR6 and N, and X2 to X4 are each independently selected from single bonds, CR7R8, O, S, and NR9. L is selected from C6 to C30 arylene and C5 to C30 heteroarylene, and m is an integer from 1 to 3. L may be substituted with at least one of D, CN, CF3, and halogens (e.g., F).

[0096] In formulas 2-1 and 2-2, R1 to R9 are each independently selected from H, D, C1 to C20 alkyl, C6 to C30 aryl, C5 to C30 heteroaryl, and C1 to C20 amino.

[0097] In Formula 2-1, X can be a single bond, and Y can be CN. That is, the second compound of Formula 2-1 can be represented by Formula 2-3. Furthermore, in Formula 2-2, X3 and X4 can each be a single bond, L can be cyanophenylene, and m can be 1. That is, the second compound of Formula 2-2 can be represented by Formula 2-4.

[0098] [Equation 2-3]

[0099]

[0100] [Equation 2-4]

[0101]

[0102] For example, in formulas 2-3, at least one of n1 and n2 can be 2 or more. Preferably, n1 can be 2 and n2 can be 4. In formula 4, X1 can be N, X2 can be NR9, and R1 and R2 can each be an unsubstituted or substituted C6 to C30 aryl group, for example, phenyl.

[0103] For example, the first compound can be one of the compounds in Formula 3.

[0104] [Formula 3]

[0105]

[0106]

[0107] For example, the second compound could be one of the compounds in Formula 4.

[0108] [Formula 4]

[0109]

[0110]

[0111]

[0112] In the OLED D1 of the present invention, EML 240 includes a second compound of formula 2-1 or 2-2 as a delayed fluorescence material. Since singlet and triplet excitons of the delayed fluorescence material participate in emission, the quantum efficiency (luminous efficiency) of the OLED D1 is improved.

[0113] That is, referring to the schematic diagram of the light emission mechanism of the OLED using a delayed fluorescence compound as described in this invention. Figure 4 In delayed fluorescence compounds, when triplet excitons are activated by a field or heat, both the triplet and singlet excitons transform into the intermediate state "I1" and then into the ground state "S0," emitting light. In other words, the singlet state "S1" and the triplet state "T1" participate in luminescence, thereby improving the luminescence efficiency. Delayed fluorescence materials can be called field-activated delayed fluorescence (FADF) materials or thermally activated delayed fluorescence (TADF) materials.

[0114] However, when a conventional host is used with a delayed fluorescent material having a deep highest occupied molecular orbital (HOMO) energy level, an excitocomplex is formed between the delayed fluorescent material and the host, resulting in problems such as reduced emission efficiency, increased full width at half maximum (FWHM), and / or emission wavelength shift.

[0115] In the OLED D1 of the present invention, a first compound of Formula 1 is used as the host and a second compound of Formula 2-1 or 2-2 is used as the delayed fluorescence material, and no exciton complex is generated between the first and second compounds. Therefore, quantum efficiency is improved by converting the triplet energy of the second compound into the singlet energy of the second compound, i.e., RISC, without problems such as reduced emission efficiency, increased FWHM, and / or emission wavelength shift.

[0116] Referencing a schematic diagram illustrating the energy level relationship between the first and second compounds in an OLED. Figure 5 The HOMO level "H1" of the first compound is equal to or lower than the HOMO level "H2" of the second compound, and the difference "ΔH" between the HOMO levels "H1" and "H2" of the first and second compounds can be less than about 0.2 eV. As a result, no exciton complex is generated between the first and second compounds, thus improving the luminescence characteristics and luminous efficiency of OLED D1. Furthermore, the band gap of the second compound can be equal to or less than 2.5 eV.

[0117] Furthermore, the lowest unoccupied molecular orbital (LUMO) level "L1" of the first compound is higher than the LUMO level "L2" of the second compound, and the difference "ΔL" between the LUMO level "L1" of the first compound and the LUMO level "L2" of the second compound can be approximately 0.8 to 1.0 eV.

[0118] In EML 240, the weight percentage of the first compound can be equal to or greater than the weight percentage of the second compound. For example, in EML 240, the first compound can be about 50% to 70% by weight, and the second compound can be 30% to 50% by weight. However, it is not limited to this.

[0119] As described above, in the OLED D1 of the present invention, EML 240 comprises a first compound of formula 1 as the main body and a second compound of formula 2-1 or 2-2 as a delayed fluorescence material, such that the OLED D1 and the organic light-emitting display device 100 comprising the OLED D1 ( Figure 2 The luminescence characteristics and luminescence efficiency of the light are improved.

[0120] [OLED]

[0121] On the anode (ITO, 50 nm), HIL (compound of formula 5-1, 7 nm), HTL (compound of formula 5-2, 78 nm), EBL (compound of formula 5-3, 15 nm), EML (35 nm), HBL (compound of formula 5-4, 10 nm), ETL (compound of formula 5-5, 25 nm), EIL (LiF) and cathode (Al) are stacked sequentially to form an OLED.

[0122] (1) Comparative Example 1 (Ref 1)

[0123] The compound of Formula 6-1 (60 wt%) was used as the host and the compound of Formula 4 (40 wt%) was used to form the EML.

[0124] (2) Comparative Example 2 (Ref 2)

[0125] The compound of Formula 6-2 (60 wt%) was used as the host and the compound of Formula 4, 2-1 (40 wt%), was used to form the EML.

[0126] (3) Comparative Example 3 (Ref 3)

[0127] The compound of Formula 6-3 (60 wt%) was used as the host and the compound of Formula 4, 2-1 (40 wt%), was used to form the EML.

[0128] (4) Comparative Example 4 (Ref 4)

[0129] The compound of Formula 6-4 (60 wt%) was used as the host and the compound of Formula 4, 2-1 (40 wt%), was used to form the EML.

[0130] (5) Comparative Example 5 (Ref 5)

[0131] Compounds of Formula 6-5 (60 wt%) were used as the host and compound 2-1 of Formula 4 (40 wt%) were used to form EML.

[0132] (6) Comparative Example 6 (Ref 6)

[0133] Compound of Formula 6-6 (60 wt%) was used as the host and compound 2-1 of Formula 4 (40 wt%) was used to form EML.

[0134] (7) Example 1 (Ex1)

[0135] Compound 1-1 (60 wt%) of Formula 3 was used as the host and compound 2-1 (40 wt%) of Formula 4 was used to form EML.

[0136] (8) Example 2 (Ex2)

[0137] Compounds 1-2 (60 wt%) of Formula 3 were used as the host and compound 2-1 (40 wt%) of Formula 4 were used to form EML.

[0138] (9) Example 3 (Ex3)

[0139] Compounds 1-3 (60 wt%) of Formula 3 were used as the host and compound 2-1 (40 wt%) of Formula 4 were used to form EML.

[0140] (10) Example 4 (Ex4)

[0141] Compounds 1-4 of Formula 3 (60 wt%) were used as the main body and compound 2-1 of Formula 4 (40 wt%) were used to form EML.

[0142] (11) Comparative Example 7 (Ref 7)

[0143] The compound of Formula 6-1 (50 wt%) was used as the host and the compound of Formula 4 (3-1, 50 wt%) was used to form the EML.

[0144] (12) Comparative Example 8 (Ref 8)

[0145] The compound of Formula 6-2 (50 wt%) was used as the host and the compound of Formula 4 (50 wt%) was used to form the EML.

[0146] (13) Comparative Example 9 (Ref 9)

[0147] The compound of Formula 6-3 (50 wt%) was used as the host and the compound of Formula 4 (50 wt%) was used to form the EML.

[0148] (14) Comparative Example 19 (Ref 10)

[0149] Compound of Formula 6-4 (50 wt%) was used as the host and compound 3-1 of Formula 4 (50 wt%) was used to form EML.

[0150] (15) Comparative Example 11 (Ref 11)

[0151] Compounds of Formula 6-5 (50 wt%) were used as the host and compound 3-1 of Formula 4 (50 wt%) were used to form EML.

[0152] (16) Comparative Example 12 (Ref 12)

[0153] Compound of Formula 6-6 (50 wt%) was used as the host and compound of Formula 4 (50 wt%) was used to form EML.

[0154] (17) Example 5 (Ex5)

[0155] Compound 1-1 (50 wt%) of Formula 3 was used as the host and compound 3-1 (50 wt%) of Formula 4 was used to form EML.

[0156] (18) Example 6 (Ex6)

[0157] Compounds 1-2 (50 wt%) of Formula 3 were used as the host and compound 3-1 (50 wt%) of Formula 4 were used to form EML.

[0158] (19) Example 7 (Ex7)

[0159] Compounds 1-3 (50 wt%) of Formula 3 were used as the host and compound 3-1 (50 wt%) of Formula 4 were used to form EML.

[0160] (20) Example 8 (Ex8)

[0161] Compounds 1-4 of Formula 3 (50 wt%) were used as the main body and compound 3-1 of Formula 4 (50 wt%) were used to form EML.

[0162] [Equation 5-1]

[0163]

[0164] [Equation 5-2]

[0165]

[0166] [Equation 5-3]

[0167]

[0168] [Equation 5-4]

[0169]

[0170] [Equation 5-5]

[0171]

[0172] [Equation 6-1]

[0173]

[0174] [Equation 6-2]

[0175]

[0176] [Equation 6-3]

[0177]

[0178] [Equation 6-4]

[0179]

[0180] [Equation 6-5]

[0181]

[0182] [Equation 6-6]

[0183]

[0184] The luminescence characteristics of the OLEDs in Ref1 to Ref12 and Ex1 to Ex8, namely driving voltage “V”, external quantum efficiency “EQE”, maximum emission wavelength “λmax” and FWHM, were measured and are listed in Table 1.

[0185] Table 1

[0186] @6.3mA / cm2

[0187]

[0188] As shown in Table 1, the luminescence properties of OLEDs that include the first compound of Formula 1 and the second compound of Formula 2-1 or 2-2 in the EML are improved.

[0189] That is, in the OLEDs of Ref1 to Ref12, excitocomplexes are generated in the EML, causing the emission wavelength to shift to a longer wavelength and increasing the field of view (FWHM). Furthermore, due to the low hole mobility of the host, the driving voltage can be increased and / or the emission efficiency reduced, for example, by EQE.

[0190] However, in OLEDs comprising a first compound of Formula 1 and a second compound of Formula 2-1 or 2-2 in the EML of this invention, the generation of exciton complexes is prevented or minimized, thus preventing wavelength shift and providing a narrow field of view (FWHM). Furthermore, in the first compound of Formula 1, the first compound has a high hole content due to the association (connection or bonding) between the 3-position of the carbazole moiety and the 3-position of the adjacent heteroaryl moiety. Therefore, the driving voltage of the OLED is reduced, and the luminous efficiency of the OLED, such as EQE, is improved.

[0191] The HOMO and LUMO levels of compounds 1-1 to 1-4 of Formula 3, which are the first compounds of the present invention, and the HOMO and LUMO levels of compounds 2-1 and 3-1 of Formula 4, which are the second compounds of the present invention, were measured and are listed in Table 2. ([eV])

[0192] Table 2

[0193] Compound 1-1 -5.9 -2.4 Compounds 1-2 -5.9 -2.4 Compounds 1-3 -5.9 -2.4 Compounds 1-4 -5.8 -2.4 Compound 2-1 -5.8 -3.4 Compound 3-1 -5.7 -3.2

[0194] As shown in Table 2, the difference between the HOMO energy levels of the first compound (e.g., compounds 1-1 to 1-4) and the second compound (e.g., compounds 2-1 and 3-1) is equal to or less than 0.2 eV, and the band gap of the second compound is less than 2.5 eV. Furthermore, the difference between the LUMO energy levels of the first compound and the second compound is between 0.8 eV and 1.0 eV.

[0195] The difference between the singlet and triplet energy levels of the second compound of formula 2-1 or 2-2, which serves as a delayed fluorescence material, is very small (e.g., below about 0.3 eV). The energy of the triplet exciton in the delayed fluorescence material is converted into a singlet exciton via reverse systematic cross-linking (RISC), resulting in high quantum efficiency. However, due to the wide wide field-whole diameter (FWHM), delayed fluorescence materials suffer from limitations in color purity.

[0196] To overcome the color purity problem of delayed fluorescence materials, EML240 may further include a third compound as a fluorescent material to provide superfluorescence. In this case, the weight percentage of the second compound may be equal to or less than the weight percentage of the first compound, and may be greater than the weight percentage of the third compound. For example, in EML240, the first compound may be about 40% to 60% by weight, the second compound may be about 30% to 50% by weight, and the third compound may be about 0.1% to 10% by weight.

[0197] The third compound, which is a fluorescent material, can be represented by one of formulas 7-1 to 7-3.

[0198] [Equation 7-1]

[0199]

[0200] [Equation 7-2]

[0201]

[0202] [Equation 7-3]

[0203]

[0204] In equations 7-1 to 7-3, R 11 To R 26 Each of them, R 31 To R 34 Each of them and R 41 To R 47 Each of them is independently selected from H, D, C1 to C20 alkyl, C1 to C20 alkoxy, C1 to C20 silyl such as alkylsilyl or arylsilyl, C6 to C30 aryl, C5 to C30 heteroaryl and C1 to C20 amino.

[0205] For example, R 11 To R 26 Each can be independently selected from H, C1 to C20 alkyl, and C1 to C20 alkoxy, R 31 To R 34 Each can be independently selected from H and C1 to C20 alkyl groups. R 41 To R 47 Each can be independently selected from H, C1 to C20 alkyl and C6 to C30 aryl.

[0206] In formulas 1, 2-1 to 2-4 and 7-1 to 7-3, the aryl and / or heteroaryl groups may be unsubstituted or substituted. The substituents of the aryl and / or heteroaryl groups may be D, halogen, CN, or C1 to C20 alkyl groups.

[0207] Furthermore, in Formulas 1, 2-1 to 2-4, and 7-1 to 7-3, the C6 to C30 aryl (or arylene) groups may be selected from phenyl, biphenyl, terphenyl, naphthyl, anthraceneyl, pentanenyl, indene, indo-indene, heptaphenyl, biphenylenyl, indane, phenanthrene, benzo[a]phenanthrene, dibenzo[a]phenanthrene, azulel, pyrene, fluoranyl, triphenylene, etc. Phosphoryl, tetraphenyl, bis(tetraphenyl), picenyl, pentaphenyl, pentaphenyl, fluorenyl, indofluorenyl, and spirofluorenyl.

[0208] Furthermore, in Formulas 1, 2-1 to 2-4, and 7-1 to 7-3, the C5 to C30 heteroaryl groups can be selected from pyrroloyl, pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazinyl, tetraazinyl, imidazolyl, pyrazolyl, indoleyl, isoindoleyl, indazoleyl, indoleazinyl, pyrroloazinyl, carbazoleyl, benzo[carbazoleyl], dibenzo[carbazoleyl], indole[carbazoleyl], indo[carbazoleyl], benzofuran[carbazoleyl], benzo[thiophene[carbazoleyl], quinolinyl, isoquinolinyl, phthalazinyl, quinoxolinyl, quinazolinyl, quinozolinyl, quinolinyl, purine, phthalazinyl, quinoxolinyl, benzo[quinolinyl], benzo[isoquinolinyl] , benzoquinazolinyl, benzoquinoxolinyl, acridineyl, phenanthrene-rholinyl, pteridineyl, phenanthridineyl, pteridineyl, nephtharidinyl, naphtharidinyl, furanyl, oxazinyl, oxazolyl, oxadiazolyl, triazolyl, dioxinyl, benzofuranyl, dibenzofuranyl, thiaranyl, anthraquinoneyl, benzopyranyl, isobenzopyranyl, thioazinyl, phenylthio, benzophenylthio, dibenzophenylthio, difuran-pyrazinyl, benzofuran-dibenzofuranyl, benzothiophene-benzophenylthio, benzothiophene-dibenzophenylthio, benzothiophene-benzofuran, and benzothiophene-dibenzofuranyl.

[0209] For example, the third compound could be one of the compounds in Formula 8.

[0210] [Formula 8]

[0211]

[0212]

[0213] When the EML 240 of OLED D1 includes the first to third compounds, excitons from the second compound are transferred to the third compound, causing the third compound to provide light emission. Therefore, OLED D1 provides light emission with high quantum efficiency through the second compound and narrow FWHM through the third compound.

[0214] Figure 6 This is a cross-sectional schematic diagram of the OLED according to the third embodiment of the present invention.

[0215] like Figure 6 As shown, the OLED D2 of the third embodiment of the present invention includes a first electrode 310 and a second electrode 330 facing each other, and a light-emitting layer 320 between them. The light-emitting layer 320 includes an EML 340. Figure 2 The organic light-emitting display device 100 may include a red pixel area, a green pixel area and a blue pixel area, and the OLED D2 may be disposed in the green pixel area.

[0216] The first electrode 310 can be an anode, and the second electrode 330 can be a cathode.

[0217] The light-emitting layer 320 may further include at least one of HTL 360 between the first electrode 310 and EML 340 and ETL 370 between the second electrode 330 and EML 340.

[0218] Furthermore, the light-emitting layer 320 may further include at least one of HIL 350 between the first electrode 310 and HTL 360 and EIL 380 between the second electrode 330 and ETL 370.

[0219] Furthermore, the light-emitting layer 320 may further include at least one of EBL 365 between HTL 360 and EML 340 and HBL 375 between EML 340 and ETL 370.

[0220] EML 340 includes a first EML (first layer or lower light-emitting material layer) 342 and a second EML (second layer or upper light-emitting material layer) 344 stacked sequentially above the first electrode 310. That is, the second EML 344 is located between the first EML 342 and the second electrode 330.

[0221] In EML 340, one of the first and second EMLs 342 and 344 includes a first compound of formula 1 and a second compound of formula 2-1 or 2-2, and the other of the first and second EMLs 342 and 344 includes a third compound of one of formulas 7-1 to 7-3 and a fourth compound as the main component. For example, the fourth compound may be a compound of formula 1.

[0222] The explanation will explain that the first EML 342 includes the OLED of the first and second compounds.

[0223] The second compound, exhibiting delayed fluorescence properties, possesses high quantum efficiency. However, due to its wide free-wavelength (FWHM), it suffers from limitations in color purity. On the other hand, the third compound, possessing fluorescence properties, has a narrow FWHM. However, the triplet exciton in the third compound does not participate in light emission, resulting in limitations in luminescence efficiency.

[0224] In OLED D2, the triplet exciton energy of the second compound in the first EML 342 is converted to the singlet exciton energy of the first compound via RISC, and the singlet exciton energy of the first compound in the second EML 344 is transferred to the singlet exciton energy of the third compound. As a result, the third compound provides light emission. Therefore, both the singlet and triplet exciton energies participate in light emission, thereby improving luminous efficiency. Furthermore, since the light emission is provided by the third compound of the fluorescent material, light emission with a narrow FWHM is provided.

[0225] In the first EML 342, the weight percentage of the first compound may be equal to or greater than the weight percentage of the second compound. Furthermore, in the second EML 344, the weight percentage of the third compound may be less than that of the fourth compound. The weight percentage of the second compound in the first EML 342 may be greater than the weight percentage of the third compound in the second EML 344.

[0226] As a result, FRET energy transfer from the second compound in the first EML 342 to the third compound in the second EML 344 can be sufficiently or efficiently generated. For example, the second compound in the first EML 342 may be 30% to 50% by weight, preferably 40% to 50% by weight, and the third compound in the second EML 344 may be 0.1% to 10% by weight, preferably 0.1% to 5% by weight.

[0227] The fourth compound, which forms the main component of the second EML 344, can be the same material as HBL 375. In this case, the second EML 344 can have both hole-blocking and emission functions. That is, the second EML 344 can be used as a buffer layer for blocking holes. When HBL 375 is omitted, the second EML 344 can be used as both a light-emitting material layer and a hole-blocking layer.

[0228] When a third compound, serving as a fluorescent material, is included in the first EML 342 and a second compound is included in the second EML 344, the fourth compound, which is the main component of the first EML 342, can be the same material as the EBL 365. In this case, the first EML 342 can have both electron blocking and emission functions. That is, the first EML 342 can be used as a buffer layer that blocks electrons. When EBL 365 is omitted, the first EML 342 can be used as both a luminescent material layer and an electron blocking layer.

[0229] Figure 7 This is a cross-sectional schematic diagram of the OLED according to the fourth embodiment of the present invention.

[0230] like Figure 7 As shown, the OLED D3 of the fourth embodiment of the present invention includes a first electrode 410 and a second electrode 430 facing each other, and a light-emitting layer 420 between them. The light-emitting layer 420 includes an EML 440. Figure 2 The organic light-emitting display device 100 may include a red pixel area, a green pixel area and a blue pixel area, and the OLED D3 may be located in the green pixel area.

[0231] The first electrode 410 can be an anode, and the second electrode 430 can be a cathode.

[0232] The light-emitting layer 420 may further include at least one of HTL 460 between the first electrode 410 and EML 440 and ETL 470 between the second electrode 430 and EML 440.

[0233] Furthermore, the light-emitting layer 420 may further include at least one of HIL 450 between the first electrode 410 and HTL 460 and EIL 480 between the second electrode 430 and ETL 470.

[0234] Furthermore, the light-emitting layer 420 may further include at least one of EBL 465 between HTL 460 and EML 440 and HBL 475 between EML 440 and ETL 470.

[0235] EML 440 includes a first EML (first layer, intermediate light-emitting material layer) 442, a second EML (second layer, lower light-emitting material layer) 444 between the first EML 442 and the first electrode 410, and a third EML (third layer, upper light-emitting material layer) 446 between the first EML 442 and the second electrode 430. That is, EML 440 has a three-layer structure of the second EML 444, the first EML 442 and the third EML 446 stacked sequentially.

[0236] For example, the first EML 442 can be located between EBL 465 and HBL 475, the second EML 444 can be located between EBL 465 and the first EML 442, and the third EML 446 can be located between HBL 475 and the first EML 442.

[0237] The first EML 442 comprises a first compound of Formula 1 and a second compound of Formula 2-1 or 2-2, and each of the second and third EMLs 444 and 446 comprises a third compound of one of Formulas 7-1 to 7-3 and a fourth compound as the main component. The third compound in the second EML 444 and the third compound in the third EML 446 may be the same or different, and the fourth compound in the second EML 444 and the fourth compound in the third EML 446 may be the same or different. For example, each of the fourth compounds in the second EML 444 and the fourth compounds in the third EML 446 may be a compound of Formula 1.

[0238] In OLED D3, the triplet exciton energy of the second compound in the first EML 442 is converted to the singlet exciton energy of the second compound via RISC, and this singlet exciton energy is then transferred to the singlet exciton energy of the third compound in the second EML 444 and the third EML 446. As a result, the third compound in the second and third EMLs 444 and 446 provides light emission. Therefore, both singlet and triplet exciton energies participate in light emission, thereby improving luminous efficiency. Furthermore, since the light emission is provided by the third compound as a fluorescent material, light emission with a narrow FWHM is provided.

[0239] In the first EML 442, the weight ratio of the first compound may be equal to or greater than the weight ratio of the second compound. In the second EML 444, the weight ratio of the third compound may be less than the weight ratio of the fourth compound. In the third EML 446, the weight ratio of the third compound may be less than the weight ratio of the fourth compound.

[0240] As a result, energy is transferred sufficiently and / or efficiently from the second compound in the first EML 442 to the third compounds in the second EML 444 and the third EML 446 via FRET. For example, the second compound may be about 30% to 50% by weight in the first EML 442, preferably about 40% to 50% by weight. The third compound may be about 0.1% to 10% by weight in each of the second EML 444 and the third EML 446, preferably about 0.1% to 5% by weight.

[0241] The fourth compound, which forms the core of the second EML 444, can be the same material as the EBL 465. In this case, the second EML 444 can have both electron blocking and emission functions. That is, the second EML 444 can be used as a buffer layer that blocks electrons. When EBL 465 is omitted, the second EML 444 can be used as both a light-emitting layer and an electron-blocking layer.

[0242] The fourth compound, which forms the core of the third EML 446, can be made of the same material as HBL 475. In this case, the third EML 446 can have both hole-blocking and emission functions. That is, the third EML 446 can be used as a buffer layer for blocking holes. When HBL 475 is omitted, the third EML 446 can be used as both a light-emitting layer and a hole-blocking layer.

[0243] The fourth compound, which is the main component of the second EML 444, can be the same material as EBL 465, and the fourth compound, which is the main component of the third EML 446, can be the same material as HBL 475. In this case, the second EML 444 can have both electron blocking and emission functions, and the third EML 446 can have both hole blocking and emission functions. That is, the second EML 444 can be used as a buffer layer that blocks electrons, and the third EML 446 can be used as a buffer layer that blocks holes. When EBL 465 and HBL 475 are omitted, the second EML 444 can be used as both a luminescent material layer and an electron blocking layer, while the third EML 446 can be used as both a luminescent material layer and a hole blocking layer.

[0244] Figure 8 This is a cross-sectional schematic diagram of the OLED according to the fifth embodiment of the present invention.

[0245] like Figure 8 As shown, OLED D4 includes a first electrode 510 and a second electrode 530 facing each other, and a light-emitting layer 520 between them. Figure 2 The organic light-emitting display device 100 may include a red pixel area, a green pixel area and a blue pixel area, and the OLED D4 may be located in the green pixel area.

[0246] The first electrode 510 can be an anode, and the second electrode 530 can be a cathode.

[0247] The light-emitting layer 520 includes a first emitting portion 540 containing a first EML 550 and a second emitting portion 560 containing a second EML 570. Furthermore, the light-emitting layer 520 may further include a charge generation layer (CGL) 580 between the first and second emitting portions 540 and 560.

[0248] CGL 580 is located between the first and second transmitters 540 and 560, such that the first transmitter 540, CGL 580 and the second transmitter 560 are stacked sequentially on the first electrode 510. That is, the first transmitter 540 is located between the first electrode 510 and CGL 580, and the second transmitter 560 is located between the second electrode 530 and CGL 580.

[0249] The first launch unit 540 includes a first EML 550.

[0250] Furthermore, the first transmitting unit 540 may further include at least one of the following: a first HTL 540b between the first electrode 510 and the first EML 550, a HIL 540a between the first electrode 510 and the first HTL 540b, and a first ETL 540e between the first EML 550 and the CGL 580.

[0251] Furthermore, the first transmitter 540 may further include at least one of a first EBL 540c between the first HTL 540b and the first EML 550 and a first HBL 540d between the first EML 550 and the first ETL 540e.

[0252] The second launcher 560 includes a second EML 570.

[0253] Furthermore, the second transmitter 560 may further include at least one of the following: a second HTL 560a between the CGL 580 and the second EML 570; a second ETL 560d between the second EML 570 and the second electrode 530; and an EIL 560e between the second ETL 560d and the second electrode 530.

[0254] Furthermore, the second transmitter 560 may further include at least one of the second EBL 560b between the second HTL 560a and the second EML 570 and the second HBL 560c between the second EML 570 and the second ETL 560d.

[0255] CGL 580 is located between the first and second emitters 540 and 560. That is, the first and second emitters 540 and 560 are connected to each other via CGL 580. CGL 580 can be a PN junction type CGL, such as N-type CGL 582 or P-type CGL 584.

[0256] The N-type CGL 582 is located between the first ETL 540e and the second HTL 560a, and the P-type CGL 584 is located between the N-type CGL 582 and the second HTL 560a. The N-type CGL 582 provides electrons to the first EML 550 of the first emitter 540, and the P-type CGL 584 provides holes to the second EML 570 of the second emitter 560.

[0257] Each of the first and second EMLs 550 and 570 is a green EML. At least one of the first and second EMLs 550 and 570 comprises a first compound of formula 1 and a second compound of formula 2-1 or 2-2.

[0258] For example, the first EML 550 may include a first compound of Formula 1 and a second compound of Formula 2-1 or 2-2. In this case, luminescence is provided by the second compound. In the first EML 550, the weight percentage of the first compound may be equal to or greater than the weight percentage of the second compound. For example, in the first EML 550, the first compound may be about 50% to 70% by weight, and the second compound may be about 30% to 50% by weight.

[0259] The first EML 550 may further include a third compound of one of formulas 7-1 to 7-3 as a fluorescent material. In this case, luminescence is provided by the third compound. The weight percentage of the second compound may be equal to or less than that of the first compound and may be greater than that of the third compound. For example, in the first EML 550, the first compound may be about 40% to 60% by weight, the second compound may be about 30% to 50% by weight, and the third compound may be about 0.1% to 10% by weight. When the weight percentage of the second compound is greater than that of the third compound, the energy of the second compound is sufficiently transferred to the third compound.

[0260] The second EML 570 may include a first compound of formula 1 and a second compound of formula 2-1 or 2-2. Furthermore, the second EML 570 may further include a third compound of one of formulas 7-1 to 7-3.

[0261] Alternatively, the second EML 570 may include a compound different from the first and second compounds in the first EML 550 or at least one of the first to third compounds in the first EML 550, such that the first and second EMLs 550 and 570 are different in terms of emission wavelength or luminous efficiency.

[0262] In the OLED D4 of the present invention, the luminescence characteristics and luminescence efficiency of the OLED D4 are improved by using a first compound as the main component and a second compound as a delayed fluorescence material. Furthermore, when a third compound as a fluorescent material is further included, the color purity of the OLED D4 is further improved.

[0263] Figure 9 This is a cross-sectional schematic diagram of the organic light-emitting display device according to the sixth embodiment of the present invention.

[0264] like Figure 9 As shown, the organic light-emitting display device 1000 includes a substrate 1010, which defines first to third pixel regions P1, P2, and P3, and a TFT Tr and an OLED D5 above the substrate 1010. The OLED D5 is disposed above and connected to the TFT Tr. For example, the first to third pixel regions P1, P2, and P3 can be a green pixel region, a red pixel region, and a blue pixel region, respectively.

[0265] The substrate 1010 can be a glass substrate or a flexible substrate. For example, the flexible substrate can be a polyimide (PI) substrate, a polyethersulfone (PES) substrate, a polyethylene naphthalate (PEN) substrate, a polyethylene terephthalate (PET) substrate, or a polycarbonate (PC) substrate.

[0266] A buffer layer 1012 is formed on the substrate 1010, and a TFT Tr is formed on the buffer layer 1012. The buffer layer 1012 can be omitted.

[0267] like Figure 2 As explained, a TFT Tr can include a semiconductor layer, a gate electrode, a source electrode, and a drain electrode, and can be used as a driving element.

[0268] A leveling layer (or passivation layer) 1050 is formed on the TFT Tr. The leveling layer 1050 has a flat top surface and includes a drain contact hole 1052 that exposes the drain of the TFT Tr.

[0269] OLED D5 is disposed on planarization layer 1050 and includes a first electrode 1060, an emissive layer 1062, and a second electrode 1064. The first electrode 1060 is connected to the drain of TFT Tr, and the emissive layer 1062 and the second electrode 1064 are sequentially stacked on the first electrode 1060. OLED D5 is disposed in each of the first to third pixel regions P1 to P3, and emits light of different colors in each of the first to third pixel regions P1 to P3. For example, OLED D5 in the first pixel region P1 can emit green light, OLED D5 in the second pixel region P2 can emit red light, and OLED D5 in the third pixel region P3 can emit blue light.

[0270] The first electrode 1060 is formed separately in the first to third pixel areas P1 to P3, and the second electrode 1064 is formed integrally to cover the first to third pixel areas P1 to P3.

[0271] The first electrode 1060 is one of the anode and the cathode, and the second electrode 1064 is the other of the anode and the cathode. In addition, one of the first electrode 1060 and the second electrode 1064 can be a light-transmitting electrode (or a semi-light-transmitting electrode), while the other of the first electrode 1060 and the second electrode 1064 can be a reflective electrode.

[0272] For example, the first electrode 1060 may be an anode and may include a transparent conductive oxide material layer formed of a transparent conductive oxide (TCO) material having a relatively high work function. The second electrode 1064 may be a cathode and may include a metallic material layer formed of a low-resistance metallic material having a relatively low work function. For example, the transparent conductive oxide material layer of the first electrode 1060 may include at least one of indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), tin oxide (SnO), zinc oxide (ZnO), indium copper oxide (ICO), and aluminum zinc oxide alloy (Al:ZnO), and the second electrode 1064 may include Al, Mg, Ca, Ag, alloys thereof, such as Mg-Ag alloys, or combinations thereof.

[0273] In the bottom-emitting organic light-emitting display device 1000, the first electrode 1060 may have a single-layer structure with a transparent conductive oxide material layer.

[0274] On the other hand, in the top-emitting organic light-emitting display device 1000, a reflective electrode or reflective layer can be formed below the first electrode 1060. For example, the reflective electrode or reflective layer can be formed of Ag or an aluminum-palladium-copper (APC) alloy. In this case, the first electrode 1060 can have a three-layer structure of ITO / Ag / ITO or ITO / APC / ITO. Furthermore, the second electrode 1064 can have a thin profile (small thickness) to provide light transmission characteristics (or semi-transparency characteristics).

[0275] A dam layer 1066 is formed on the leveling layer 1050 to cover the edge of the first electrode 1060. That is, the dam layer 1066 is located at the boundary of the first to third pixel regions P1 to P3 and exposes the center of the first electrode 1060 in the first to third pixel regions P1 to P3.

[0276] The light-emitting layer 1062, serving as a light-emitting unit, is formed on the first electrode 1060. The light-emitting layer 1062 may have a single-layer EML structure. Alternatively, the light-emitting layer 1062 may further include at least one of HIL, HTL, and EBL sequentially stacked between the first electrode 1060 and the EML, and HBL, ETL, and EIL sequentially stacked between the EML and the second electrode 1064.

[0277] In the first pixel region P1, which is the green pixel region, the EML of the emissive layer 1062 includes a first compound of formula 1 and a second compound of formula 2-1 or 2-2. Furthermore, the EML of the emissive layer 1062 in the first pixel region P1, which is the green pixel region, may further include a third compound of one of formulas 7-1 to 7-3.

[0278] An encapsulation film 1070 is formed on the second electrode 1064 to prevent moisture from penetrating into the OLED D5. The encapsulation film 1070 may have a three-layer structure including a first inorganic insulating layer, an organic insulating layer, and a second inorganic insulating layer, but is not limited thereto.

[0279] The organic light-emitting display device 1000 may further include a polarizing plate (not shown) for reducing ambient light reflection. For example, the polarizing plate may be a circular polarizing plate. In the bottom-emitting organic light-emitting display device 1000, the polarizing plate may be disposed below the substrate 1010. In the top-emitting organic light-emitting display device 1000, the polarizing plate may be disposed on or above the encapsulation film 1070.

[0280] Figure 10 This is a cross-sectional schematic diagram of the OLED according to the seventh embodiment of the present invention.

[0281] refer to Figure 10 and Figure 9 The OLED D5 is located in each of the first to third pixel regions P1 to P3, and includes a first electrode 1060 and a second electrode 1064 facing each other and an emissive layer 1062 between them. The emissive layer 1062 includes an EML 1090.

[0282] The first electrode 1060 can be an anode, and the second electrode 1064 can be a cathode. For example, the first electrode 1060 can be a reflective electrode, and the second electrode 1064 can be a transmissive electrode (or a semi-transmissive electrode).

[0283] The light-emitting layer 1062 may further include an HTL 1082 between the first electrode 1060 and the EML 1090 and an ETL 1094 between the EML 1090 and the second electrode 1064.

[0284] Furthermore, the light-emitting layer 1062 may further include HIL 1080 between the first electrode 1060 and HTL 1082 and EIL 1096 between ETL 1094 and the second electrode 1064.

[0285] Furthermore, the light-emitting layer 1062 may further include an EBL 1086 between EML 1090 and HTL 1082 and an HBL 1092 between EML 1090 and ETL 1094.

[0286] Furthermore, the light-emitting layer 1062 may further include an auxiliary HTL 1084 between HTL 1082 and EBL 1086. The auxiliary HTL 1084 may include a first auxiliary HTL 1084a in the first pixel region P1, a second auxiliary HTL 1084b in the second pixel region P2, and a third auxiliary HTL 1084c in the third pixel region P3.

[0287] The first auxiliary HTL 1084a has a first thickness, the second auxiliary HTL 1084b has a second thickness, and the third auxiliary HTL 1084c has a third thickness. The first thickness is less than the second thickness and greater than the third thickness, enabling the OLED D5 to provide a microcavity structure.

[0288] That is, through the first to third auxiliary HTLs 1084a, 1084b, and 1084c with thickness differences, the distance between the first electrode 1060 and the second electrode 1064 in the first pixel region P1 (where light in the first wavelength range, e.g., green light is emitted) is smaller than the distance between the first electrode 1060 and the second electrode 1064 in the second pixel region P2 (where light in the second wavelength range, greater than the first wavelength range, e.g., red light is emitted), and larger than the distance between the first electrode 1060 and the second electrode 1064 in the third pixel region P3 (where light in the third wavelength range, less than the first wavelength range, e.g., blue light is emitted). Therefore, the luminous efficiency of the OLED D5 is improved.

[0289] exist Figure 10 In this configuration, the third auxiliary HTL 1084c is formed in the third pixel region P3. Alternatively, a microcavity structure can be provided without the third auxiliary HTL 1084c.

[0290] A capping layer (not shown) for improving light extraction characteristics can be further formed on the second electrode 1084.

[0291] EML 1090 includes a first EML 1090a in the first pixel area P1, a second EML 1090b in the second pixel area P2, and a third EML 1090c in the third pixel area P3. The first to third EMLs 1090a, 1090b, and 1090c can be green EML, red EML, and blue EML, respectively.

[0292] The first EML 1090a in the first pixel region P1 includes a first compound of Formula 1 and a second compound of Formula 2-1 or 2-2. In this case, the emission is provided by the second compound. In the first EML 1090a in the first pixel region P1, the weight ratio of the first compound can be equal to or greater than the weight ratio of the second compound. For example, in the first EML 1090a in the first pixel region P1, the first compound can be about 50% to 70% by weight, and the second compound can be about 30% to 50% by weight.

[0293] The first EML 1090a in the first pixel region P1 may further include a third compound as one of formulas 7-1 to 7-3, which is a fluorescent material. In this case, luminescence is provided by the third compound. The weight percentage of the second compound may be equal to or less than that of the first compound and may be greater than that of the third compound. For example, in the first EML 1090a, the first compound may be about 40% to 60% by weight, the second compound may be about 30% to 50% by weight, and the third compound may be about 0.1% to 10% by weight. When the weight percentage of the second compound is greater than that of the third compound, the energy of the second compound is sufficiently transferred to the third compound.

[0294] Each of the second EML 1090b in the second pixel region P2 and the third EML 1090c in the third pixel region P3 may include a host and a dopant. For example, in each of the second EML 1090b in the second pixel region P2 and the third EML 1090c in the third pixel region P3, the dopant may include at least one of a phosphorescent compound, a fluorescent compound, and a delayed fluorescence compound.

[0295] Figure 10 The OLED D5 emits green, red, and blue light in the first to third pixel regions P1 to P3, respectively, so that ( Figure 9 The organic light-emitting display device 1000 can provide full-color images.

[0296] The organic light-emitting display device 1000 may further include color filter layers corresponding to the first to third pixel regions P1 to P3 to improve color purity. For example, the color filter layers may include a first color filter layer corresponding to the first pixel region P1, such as a green color filter layer; a second color filter layer corresponding to the second pixel region P2, such as a red color filter layer; and a third color filter layer corresponding to the third pixel region P3, such as a blue color filter layer.

[0297] In the bottom-emitting organic light-emitting display device 1000, a color filter layer can be disposed between the OLED D5 and the substrate 1010. On the other hand, in the top-emitting organic light-emitting display device 1000, the color filter layer can be disposed on or above the OLED D5.

[0298] Figure 11 This is a cross-sectional schematic diagram of the organic light-emitting display device according to the eighth embodiment of the present invention.

[0299] like Figure 11 As shown, the organic light-emitting display device 1100 includes a substrate 1110 defining first to third pixel regions P1, P2, and P3, a TFT Tr above the substrate 1110, an OLED D disposed above and connected to the TFT Tr, and color filter layers 1120 corresponding to the first to third pixel regions P1 to P3. For example, the first to third pixel regions P1, P2, and P3 can be green pixel regions, red pixel regions, and blue pixel regions, respectively.

[0300] The substrate 1110 can be a glass substrate or a flexible substrate. For example, the flexible substrate can be a polyimide (PI) substrate, a polyethersulfone (PES) substrate, a polyethylene naphthalate (PEN) substrate, a polyethylene terephthalate (PET) substrate, or a polycarbonate (PC) substrate.

[0301] TFT Tr is formed on substrate 1110. Alternatively, a buffer layer (not shown) may be formed on substrate 1110, and TFT Tr may be formed on the buffer layer.

[0302] like Figure 2 As explained, a TFT Tr can include a semiconductor layer, a gate electrode, a source electrode, and a drain electrode, and can be used as a driving element.

[0303] Furthermore, a color filter layer 1120 is disposed on the substrate 1110. For example, the color filter layer 1120 may include a first color filter layer 1122 corresponding to a first pixel region P1, a second color filter layer 1124 corresponding to a second pixel region P2, and a third color filter layer 1126 corresponding to a third pixel region P3. The first to third color filter layers 1122, 1124, and 1126 may be a green color filter layer, a red color filter layer, and a blue color filter layer, respectively. For example, the first color filter layer 1122 may include at least one of a green dye and a green pigment, while the second color filter layer 1124 may include at least one of a red dye and a red pigment. The third color filter layer 1126 may include at least one of a blue dye and a blue pigment.

[0304] A leveling layer (or passivation layer) 1150 is formed on the TFT Tr and the color filter layer 1120. The leveling layer 1150 has a flat top surface and includes a drain contact hole 1152 that exposes the drain of the TFT Tr.

[0305] OLED D is disposed on planarization layer 1150 and corresponds to color filter layer 1120. OLED D includes a first electrode 1160, an emissive layer 1162, and a second electrode 1164. The first electrode 1160 is connected to the drain electrode of TFT Tr, and the emissive layer 1162 and the second electrode 1164 are sequentially stacked on the first electrode 1160. OLED D emits white light in each of the first to third pixel regions P1 to P3.

[0306] The first electrode 1160 is formed separately in the first to third pixel areas P1 to P3, and the second electrode 1164 is formed integrally to cover the first to third pixel areas P1 to P3.

[0307] The first electrode 1160 is one of the anode and the cathode, and the second electrode 1164 is the other of the anode and the cathode. Furthermore, the first electrode 1160 can be a light-transmitting electrode (or a semi-transmitting electrode), and the second electrode 1164 can be a reflective electrode.

[0308] For example, the first electrode 1160 may be an anode and may include a transparent conductive oxide material layer formed of a transparent conductive oxide (TCO) material having a relatively high work function. The second electrode 1164 may be a cathode and may include a metallic material layer formed of a low-resistance metallic material having a relatively low work function. For example, the transparent conductive oxide material layer of the first electrode 1160 may include at least one of indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), tin oxide (SnO), zinc oxide (ZnO), indium copper oxide (ICO), and aluminum zinc oxide alloy (Al:ZnO), and the second electrode 1164 may include Al, Mg, Ca, Ag, alloys thereof, such as Mg-Ag alloys, or combinations thereof.

[0309] A light-emitting layer 1162, serving as a light-emitting unit, is formed on the first electrode 1160. The light-emitting layer 1162 includes at least two emitting portions that emit light of different colors. Each emitting portion may have a single-layer EML structure. Alternatively, each emitting portion may further include at least one of HIL, HTL, EBL, HBL, ETL, and EIL. Furthermore, the light-emitting layer 1162 may further include a charge-generating layer (CGL) between the emitting portions.

[0310] One of the emitting portions, the EML, comprises a first compound of formula 1 and a second compound of formula 2-1 or 2-2. The EML of one of the emitting portions may further comprise a third compound of formula 7-1 to 7-3 as a fluorescent material.

[0311] A dam layer is formed on the leveling layer 1150 to cover the edge of the first electrode 1160. That is, the dam layer is located at the boundary of the first to third pixel regions P1 to P3 and exposes the center of the first electrode in the first to third pixel regions P1 to P3. As described above, since the OLED D emits white light in the first to third pixel regions P1 to P3, the light-emitting layer 1162 can be formed as a common layer in the first to third pixel regions P1 to P3, without being separated in the first to third pixel regions P1 to P3. The dam layer can be formed to prevent current leakage at the edge of the first electrode 1160 and can be omitted.

[0312] Although not shown, the organic light-emitting display device 1100 may also include an encapsulation film formed on the second electrode 1164 to prevent moisture from penetrating into the OLED D. Furthermore, the organic light-emitting display device 1100 may further include a polarizer under the substrate 1110 to reduce ambient light reflection.

[0313] exist( Figure 11 In the organic light-emitting display device 1100, the first electrode 1160 is a transparent electrode (transparent electrode), and the second electrode 1164 is a reflective electrode. Furthermore, a color filter layer 1120 is located between the substrate 1110 and the OLED D. That is, the organic light-emitting display device 1100 is a bottom-emitting type.

[0314] Alternatively, in the organic light-emitting display device 1100, the first electrode 1160 can be a reflective electrode, and the second electrode 1154 can be a transparent electrode (or a semi-transparent electrode). In this case, the color filter layer 1120 is located on or above the OLED D.

[0315] In the organic light-emitting display device 1100, the OLEDs D in the first to third pixel regions P1 to P3 emit white light, and the white light passes through the first to third color filter layers 1122, 1124, and 1126. Therefore, green light, red light, and blue light are displayed in the first to third pixel regions P1 to P3, respectively.

[0316] Although not shown, a color conversion layer can be formed between the OLED D and the color filter layer 1120. The color conversion layer may include a green conversion layer, a red conversion layer, and a blue conversion layer corresponding to the first to third pixel regions P1 to P3, respectively, and the white light emitted by the OLED D can be converted into green, red, and blue light. The color conversion layer may include quantum dots. Therefore, the color purity of the OLED D can be further improved.

[0317] A color conversion layer may be included to replace the color filter layer 1120.

[0318] Figure 12 This is a cross-sectional schematic diagram of the OLED according to the ninth embodiment of the present invention.

[0319] like Figure 12 As shown, the OLED D6 includes a first electrode 1160 and a second electrode 1164 facing each other, and a light-emitting layer 1162 between them.

[0320] The first electrode 1160 can be an anode, and the second electrode 1164 can be a cathode. The first electrode 1160 is a transparent electrode (transparent electrode), and the second electrode 1164 is a reflective electrode.

[0321] The light-emitting layer 1162 includes a first emitting portion 1210 containing a first EML 1220, a second emitting portion 1230 containing a second EML 1240, and a third emitting portion 1250 containing a third EML 1260. Furthermore, the light-emitting layer 1162 may further include a first CGL 1270 between the first and second emitting portions 1210 and 1230, and a second CGL 1280 between the first emitting portion 1210 and the third emitting portion 1250.

[0322] The first CGL 1270 is located between the first and second emitters 1210 and 1230, and the second CGL 1280 is located between the first and third emitters 1210 and 1250. That is, the third emitter 1250, the second CGL 1280, the first emitter 1210, the first CGL 1270, and the second emitter 1230 are sequentially stacked on the first electrode 1160. In other words, the first emitter 1210 is located between the first and second CGLs 1270 and 1280, and the second emitter 1230 is located between the first CGL 1270 and the second electrode 1164. The third emitter 1250 is located between the second CGL 1280 and the first electrode 1160.

[0323] The first transmitter 1210 may further include a first HTL 1210a below the first EML 1220 and a first ETL 1210b above the first EML 1220. That is, the first HTL 1210a may be located between the first EML 1220 and the second CGL 1280, and the first ETL 1210b may be located between the first EML 1220 and the first CGL 1270.

[0324] Furthermore, the first transmitter 1210 may further include an EBL (not shown) between the first HTL 1210a and the first EML 1220 and an HBL (not shown) between the first ETL 1210b and the first EML 1220.

[0325] The second transmitter 1230 may further include a second HTL 1230a below the second EML 1240, a second ETL 1230b above the second EML 1240, and an EIL 1230c on the second ETL 1230b. That is, the second HTL 1230a may be located between the second EML 1240 and the first CGL 1270, and the second ETL 1230b and EIL 1230c may be located between the second EML 1240 and the second electrode 1164.

[0326] Furthermore, the second transmitter 1230 may further include an EBL (not shown) between the second HTL 1230a and the second EML 1240, and an HBL (not shown) between the second ETL 1230b and the second EML 1240.

[0327] The third transmitter 1250 may further include a third HTL 1250b below the third EML 1260, a HIL 1250a below the third HTL 1250b, and a third ETL 1250c above the third EML 1260. That is, HIL 1250a and the third HTL 1250b may be located between the first electrode 1160 and the third EML 1260, and the third ETL 1250c may be located between the third EML 1260 and the second CGL 1280.

[0328] Furthermore, the third transmitter 1250 may further include an EBL (not shown) between the third HTL 1250b and the third EML 1260 and an HBL (not shown) between the third ETL 1250c and the third EML 1260.

[0329] One of the first through third EMLs 1220, 1240, and 1260 is a green EML. Another of the first through third EMLs 1220, 1240, and 1260 can be a blue EML, and another of the first through third EMLs 1220, 1240, and 1260 can be a red EML.

[0330] For example, the first EML 1220 can be a green EML, the second EML 1240 can be a blue EML, and the third EML 1260 can be a red EML. Alternatively, the first EML 1220 can be a green EML, the second EML 1240 can be a red EML, and the third EML 1260 can be a blue EML.

[0331] The first EML 1220 comprises a first compound of formula 1 and a second compound of formula 2-1 or 2-2. In this case, luminescence is provided by the second compound. In the first EML 1220, the weight ratio of the first compound may be equal to or greater than the weight ratio of the second compound. For example, in the first EML 1220, the first compound may be about 50% to 70% by weight, and the second compound may be about 30% to 50% by weight.

[0332] The first EML 1220 may further include a third compound of formula 7-1 to 7-3 as a fluorescent material. In this case, luminescence is provided by the third compound. The weight percentage of the second compound may be equal to or less than that of the first compound and may be greater than that of the third compound. For example, in the first EML 1220, the first compound may be about 40% to 60% by weight, the second compound may be about 30% to 50% by weight, and the third compound may be about 0.1% to 10% by weight. When the weight percentage of the second compound is greater than that of the third compound, the energy of the second compound is sufficiently transferred to the third compound.

[0333] The second EML 1240 includes a body and a blue dopant (or a red dopant), and the third EML 1260 includes a body and a red dopant (or a blue dopant). For example, in each of the second and third EMLs 1240 and 1260, the dopant may include at least one of a phosphorescent compound, a fluorescent compound, and a delayed fluorescence compound.

[0334] ( Figure 11 The OLED D6 in the first to third pixel areas P1 to P3 emits white light, and the white light passes through the first to third pixel areas P1 to P3. Figure 11 The color filter layer 1120. Therefore, ( Figure 11 The organic light-emitting display device 1100 can provide full-color images.

[0335] Figure 13 This is a cross-sectional schematic diagram of the OLED according to the tenth embodiment of the present invention.

[0336] like Figure 13 As shown, the OLED D7 includes a first electrode 1360 and a second electrode 1364 facing each other, and a light-emitting layer 1362 between them.

[0337] The first electrode 1360 can be an anode, and the second electrode 1364 can be a cathode. The first electrode 1360 is a transparent electrode (transparent electrode), and the second electrode 1364 is a reflective electrode.

[0338] The light-emitting layer 1362 includes a first emitting portion 1410 containing a first EML 1420, a second emitting portion 1430 containing a second EML 1440, and a third emitting portion 1450 containing a third EML 1460. Furthermore, the light-emitting layer 1362 may further include a first CGL 1470 between the first and second emitting portions 1410 and 1430, and a second CGL 1480 between the first emitting portion 1410 and the third emitting portion 1450.

[0339] The first transmitting section 1420 includes a lower EML 1420a and an upper EML 1420b. That is, the lower EML 1420a is located closer to the first electrode 1360, and the upper EML 1420b is located closer to the second electrode 1364.

[0340] The first CGL 1470 is located between the first and second emitters 1410 and 1430, and the second CGL 1480 is located between the first and third emitters 1410 and 1450. That is, the third emitter 1450, the second CGL 1480, the first emitter 1410, the first CGL 1470, and the second emitter 1430 are sequentially stacked on the first electrode 1360. In other words, the first emitter 1410 is located between the first and second CGLs 1470 and 1480, and the second emitter 1430 is located between the first CGL 1470 and the second electrode 1364. The third emitter 1450 is located between the second CGL 1480 and the first electrode 1360.

[0341] The first transmitter 1410 may further include a first HTL 1410a below the first EML 1420 and a first ETL 1410b above the first EML 1420.

[0342] Furthermore, the first transmitter 1410 may further include an EBL (not shown) between the first HTL 1410a and the first EML 1420 and an HBL (not shown) between the first ETL 1410b and the first EML 1420.

[0343] The second transmitter 1430 may further include a second HTL 1430a below the second EML 1440, a second ETL 1430b above the second EML 1440, and an EIL 1430c on the second ETL 1430b. That is, the second HTL 1430a may be located between the second EML 1440 and the first CGL 1470, and the second ETL 1430b and EIL 1430c may be located between the second EML 1440 and the second electrode 1364.

[0344] Furthermore, the second transmitter 1430 may further include an EBL (not shown) between the second HTL 1430a and the second EML 1440, and an HBL (not shown) between the second ETL 1430b and the second EML 1440.

[0345] The third transmitter 1450 may further include a third HTL 1450b below the third EML 1460, a HIL 1450a below the third HTL 1450b, and a third ETL 1450c above the third EML 1460. That is, HIL 1450a and the third HTL 1450b may be located between the first electrode 1360 and the third EML 1460, and the third ETL 1450c may be located between the third EML 1460 and the second CGL 1480.

[0346] Furthermore, the third transmitter 1450 may further include an EBL (not shown) between the third HTL 1450b and the third EML 1460 and an HBL (not shown) between the third ETL 1450c and the third EML 1460.

[0347] One of the lower EML 1420a and the upper EML 1420b of the first EML 1420 is a green EML, and the other of the lower EML 1420a and the upper EML 1420b of the first EML 1420 can be a red EML. That is, the green EML (or red EML) and the red EML (or green EML) are stacked in sequence to form the first EML 1420.

[0348] For example, the upper EML 1420b, as a green EML, comprises a first compound of formula 1 and a second compound of formula 2-1 or 2-2. In this case, luminescence is provided by the second compound. In the upper EML 1420b, the weight ratio of the first compound can be equal to or greater than the weight ratio of the second compound. For example, in the upper EML 1420b, the first compound can be about 50% to 70% by weight, and the second compound can be about 30% to 50% by weight.

[0349] EML 1420b may further include a third compound of formula 7-1 to 7-3 as a fluorescent material. In this case, luminescence is provided by the third compound. The weight percentage of the second compound may be equal to or less than that of the first compound and may be greater than that of the third compound. For example, in EML 1420b, the first compound may be about 40% to 60% by weight, the second compound may be about 30% to 50% by weight, and the third compound may be about 0.1% to 10% by weight. When the weight percentage of the second compound is greater than that of the third compound, the energy of the second compound is sufficiently transferred to the third compound.

[0350] The lower EML 1420a, which is a red EML, may include a host and a red dopant.

[0351] Each of the second and third EMLs 1440 and 1460 can be a blue EML. Each of the second and third EMLs 1440 and 1460 can include a host and a blue dopant. The host and dopant of the second EML 1440 can be the same as those of the third EML 1460. Alternatively, the host and dopant of the second EML 1440 can be different from those of the third EML 1460. For example, the emission efficiency and / or emission wavelength of the dopant in the second EML 1440 can be different from those of the dopant in the third EML 1460.

[0352] In each of the lower EML 1420a, the second EML 1440 and the third EML 1460, the dopant may include at least one of a phosphorescent compound, a fluorescent compound and a delayed fluorescence compound.

[0353] ( Figure 11 The OLED D7 in the first to third pixel areas P1 to P3 emits white light, and the white light passes through the first to third pixel areas P1 to P3. Figure 11 The color filter layer 1120. Therefore, ( Figure 11 The organic light-emitting display device 1100 can provide full-color images.

[0354] exist Figure 13 In the OLED D7, a triple-layer (triple-overlapping) structure is used, including second and third EMLs 1440 and 1460 as the blue EML, and a first EML 1420. Alternatively, one of the second and third EMLs 1440 and 1460 can be omitted, allowing the OLED D7 to have a double-layer (double-overlapping) structure.

[0355] like Figure 8 , 12 As shown in Figure 13, the OLED in each pixel region includes a first EML containing the organic compound of the present invention, such as a green EML, one or more second EMLs, and a CGL, such that the OLED has a tandem structure. In this case, the one or more second EMLs are at least one of a red EML, a green EML, and a blue EML, such that the OLED provides green emission or white emission.

[0356] Although the invention has been described with reference to exemplary embodiments and examples, these embodiments and examples are not intended to limit the scope of the invention. Rather, it will be apparent to those skilled in the art that various modifications and variations can be made to the invention without departing from the spirit or scope thereof. Therefore, the invention is intended to cover modifications and variations thereof that fall within the scope of the appended claims and their equivalents.

[0357] The various embodiments described above can be combined to provide other embodiments. All patents, patent application publications, patent applications, foreign patents, foreign patent applications and non-patent publications mentioned in and / or listed in the application data sheets are incorporated herein by reference in their entirety. If necessary, various aspects of the embodiments can be modified to incorporate the concepts of various patents, applications and publications to provide even more alternative embodiments.

[0358] These and other changes can be made to the embodiments based on the detailed description above. Generally, the terminology used in the following claims should not be construed as limiting the claims to the specific embodiments disclosed in the specification and claims, but should be interpreted to include all possible embodiments and the full scope of the equivalents enjoyed by these claims. Therefore, the claims are not limited to the disclosure of the invention.

Claims

1. An organic light-emitting diode, comprising: First electrode; The second electrode facing the first electrode; and A first luminescent material layer, comprising a first compound and a second compound, is located between the first electrode and the second electrode. The first compound is represented by formula 1: [Formula 1] , Z1 and Z2 are each independently selected from oxygen, sulfur, and selenium, and R is selected from C6 to C30 aryl groups. The second compound is represented by formula 2-1 or formula 2-2: [Equation 2-1] ,and [Equation 2-2] ， In Equation 2-1, X is a single bond, and Y is a CN bond. Where n1 and n2 are each independent integers from 0 to 4. In Equation 2-2, X1 is selected from CR6 and N. One of X2 and X3 is selected from CR7R8, O, S, and NR9, and the other of X2 and X3, along with X4, is a single bond. Where L is selected from C6 to C 30 Aromatic and C5 to C 30 Heteroaryl, m is 1, and Among them, R6 to R9 are each independently selected from H, D, C1 to C 20 Alkyl, C6 to C 30 Aryl, C5 to C 30 heteroaryl and C1 to C 20 amino group Among them, R1 to R2 are each independently selected from C6 to C6. 30 Aryl, and Wherein, the difference between the highest occupied molecular orbital energy level of the first compound and the highest occupied molecular orbital energy level of the second compound is equal to or less than 0.2 eV.

2. The organic light-emitting diode as described in claim 1, wherein, The first compound is one of the compounds of Formula 3: [Formula 3] 。 3. The organic light-emitting diode as described in claim 1, wherein, The second compound is one of the compounds of Formula 4: [Formula 4] 。 4. The organic light-emitting diode as described in claim 1, wherein, The overlap between the absorption spectrum of the first compound and the emission spectrum of the second compound is equal to or greater than 35%.

5. The organic light-emitting diode as described in claim 1, wherein, The weight percentage of the first compound is equal to or greater than the weight percentage of the second compound.

6. The organic light-emitting diode as described in claim 4, wherein, The first luminescent material layer further comprises a third compound represented by one of formulas 5-1 to 5-3: [Equation 5-1] ， [Equation 5-2] ,and [Equation 5-3] ， Among them, R 11 To R 26 Each of them, R 31 To R 34 Each of them and R 41 To R 47 Each of them is independently selected from hydrogen, deuterium, C1 to C20 alkyl, C1 to C20 alkoxy, C1 to C20 silyl, C6 to C30 aryl, C5 to C30 heteroaryl and C1 to C20 amino.

7. The organic light-emitting diode as claimed in claim 6, wherein, The third compound is one of the compounds of Formula 6: [Formula 6] 。 8. The organic light-emitting diode as claimed in claim 6, wherein, The first luminescent material layer includes a first layer and a second layer, wherein the second layer is located between the first layer and the second electrode, and The second layer includes the first compound and the second compound, and the first layer includes the third compound and the first host.

9. The organic light-emitting diode as claimed in claim 8, wherein, The first luminescent material layer further includes a third layer, which includes the third compound and the second host, and is located between the second layer and the second electrode.

10. The organic light-emitting diode of claim 9, further comprising: Hole-blocking layer between the second electrode and the third layer The second main body is made of the same material as the hole-blocking layer.

11. The organic light-emitting diode of claim 8, further comprising: An electron blocking layer between the first electrode and the first layer The first main body is made of the same material as the electron blocking layer.

12. The organic light-emitting diode as claimed in claim 6, wherein, The first luminescent material layer includes a first layer and a second layer, wherein the second layer is located between the first layer and the second electrode, and The first layer includes the first compound and the second compound, and the second layer includes the third compound and the first host.

13. The organic light-emitting diode of claim 12, further comprising: A hole-blocking layer between the second electrode and the second layer The first main body is made of the same material as the hole blocking layer.

14. The organic light-emitting diode of claim 1, further comprising: A second luminescent material layer between the first electrode and the first luminescent material layer; and A charge generation layer between the first luminescent material layer and the second luminescent material layer. The second luminescent material layer is one of a red luminescent material layer, a green luminescent material layer, and a third luminescent material layer.

15. The organic light-emitting diode as claimed in claim 1, wherein, In Equation 1, Z1 is one of oxygen, sulfur, and selenium, and Z2 is another of oxygen, sulfur, and selenium.

16. An organic light-emitting display device, comprising: substrate; An organic light-emitting diode located above the substrate according to any one of claims 1 to 15; and The encapsulation film covering the organic light-emitting diode.

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