Organic light emitting diode and organic light emitting device including the same

Abstract

The present disclosure relates to an organic light-emitting diode, which includes: a first electrode; a second electrode facing the first electrode; a first p-type doped layer located between the first electrode and the second electrode; a second p-type doped layer located between the first p-type doped layer and the second electrode; a third p-type doped layer located between the second p-type doped layer and the second electrode; a first emission material layer located between the first p-type doped layer and the second p-type doped layer; a second emission material layer located between the second p-type doped layer and the third p-type doped layer; and a third emission material layer located between the third p-type doped layer and the second electrode; wherein the conductivity of the third p-type doped layer is greater than the conductivity of the first p-type doped layer and is equal to or less than the conductivity of the second p-type doped layer.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Korean Patent Application No. 10-2020-0179675, filed in Korea on December 21, 2020, which is hereby incorporated by reference in its entirety. Technical Field

[0003] The present disclosure relates to an organic light emitting diode (OLED), and more particularly, to an OLED having a low driving voltage and high luminous efficiency and lifespan, and an organic light emitting device including the OLED. Background Art

[0004] Currently, the demand for flat panel display devices with a small footprint is increasing. Among flat panel display devices, the technology of organic light emitting display devices including OLEDs is developing rapidly.

[0005] OLEDs emit light by injecting electrons from a cathode serving as an electron injection electrode and holes from an anode serving as a hole injection electrode into an organic emission layer, combining electrons with holes to generate excitons, and converting the excitons from an excited state to a ground state. Flexible transparent substrates, such as plastic substrates, can be used as base substrates for forming elements thereon. In addition, OLEDs can operate at a lower voltage (e.g., 10V or lower) than that required to operate other display devices and have lower power consumption. In addition, the light from OLEDs has excellent color purity.

[0006] The OLED may include a first electrode as an anode, a second electrode facing the first electrode as a cathode, and an organic light emitting layer between the first and second electrodes.

[0007] To improve the light emission efficiency of OLEDs, the organic emission layer may include a hole injection layer (HIL), a hole transport layer (HTL), an emission material layer (EML), an electron transport layer (ETL), and an electron injection layer (EIL) sequentially stacked on a first electrode.

[0008] In an OLED, holes from the first electrode (anode) are transported into the EML through the HIL and HTL, while electrons from the second electrode (cathode) are transported into the EML through the EIL and ETL. The holes and electrons combine in the EML to form excitons, which then transition from an excited state to a ground state, emitting light.

[0009] In order to provide a low driving voltage of an OLED and sufficient luminous efficiency and lifespan, sufficient hole injection efficiency and sufficient hole transport efficiency are required. Summary of the Invention

[0010] Embodiments of the present disclosure are directed to OLEDs and organic light-emitting devices that substantially obviate one or more problems associated with limitations and disadvantages of related conventional technologies.

[0011] Other features and advantages of the present disclosure are set forth in the following description and will be apparent from the description or will be clearly seen through the practice of the present disclosure. The objects and other advantages of the present disclosure are realized and obtained through the features described herein and in the accompanying drawings.

[0012] To achieve these and other advantages for the purposes of embodiments according to the present disclosure, as described herein, one aspect of the present disclosure is an organic light emitting diode, comprising: a first electrode; a second electrode facing the first electrode; a first p-type doped layer located between the first electrode and the second electrode; a second p-type doped layer located between the first p-type doped layer and the second electrode; a third p-type doped layer located between the second p-type doped layer and the second electrode; a first emission material layer located between the first p-type doped layer and the second p-type doped layer; a second emission material layer located between the second p-type doped layer and the third p-type doped layer; and a third emission material layer located between the third p-type doped layer and the second electrode, wherein the conductivity of the third p-type doped layer is greater than the conductivity of the first p-type doped layer and is equal to or less than the conductivity of the second p-type doped layer.

[0013] Another aspect of the present disclosure is an organic light-emitting device, comprising: a substrate; an organic light-emitting diode, which is located on the substrate and includes: a first electrode; a second electrode facing the first electrode; a first p-type doped layer, which is located between the first electrode and the second electrode; a second p-type doped layer, which is located between the first p-type doped layer and the second electrode; a third p-type doped layer, which is located between the second p-type doped layer and the second electrode; a first emission material layer, which is located between the first p-type doped layer and the second p-type doped layer; a second emission material layer, which is located between the second p-type doped layer and the third p-type doped layer; a third emission material layer, which is located between the third p-type doped layer and the second electrode; and an encapsulation film covering the organic light-emitting diode, wherein the conductivity of the third p-type doped layer is greater than the conductivity of the first p-type doped layer and is equal to or less than the conductivity of the second p-type doped layer.

[0014] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the disclosure as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the disclosure and together with the description serve to explain the principles of the disclosure.

[0016] Figure 1 is a schematic circuit diagram of an organic light emitting display device disclosed herein.

[0017] Figure 2 is a schematic cross-sectional view of an organic light-emitting device according to a first embodiment of the present disclosure.

[0018] Figure 3 is a schematic cross-sectional view of an OLED according to a second embodiment of the present disclosure.

[0019] Figure 4 is a schematic cross-sectional view of an organic light-emitting device according to a third embodiment of the present disclosure.

[0020] Figure 5 is a schematic cross-sectional view of an OLED according to a fourth embodiment of the present disclosure. DETAILED DESCRIPTION

[0021] Reference will now be made in detail to some examples and preferred embodiments illustrated in the accompanying drawings.

[0022] The present disclosure relates to OLEDs and organic light-emitting devices including the OLEDs. For example, the organic light-emitting device may be an organic light-emitting display device or an organic light-emitting device. As an example, the organic light-emitting display device will be mainly described, which is a display device including the OLED of the present disclosure.

[0023] Figure 1 is a schematic circuit diagram of an organic light emitting display device disclosed herein.

[0024] like Figure 1 As shown, gate lines GL, data lines DL, and power lines PL are formed in an organic light-emitting display device. The gate lines GL and data lines DL intersect with each other to define pixels (pixels) P. A switching thin film transistor (TFT) Ts, a driving TFT Td, a storage capacitor Cst, and an OLED D are formed in the pixel P. The pixel P may include a red pixel, a green pixel, and a blue pixel. In addition, the pixel P may also include a white pixel.

[0025] A switching thin film transistor Ts is connected to a gate line GL and a data line DL, and a driving thin film transistor Td and a storage capacitor Cst are connected between the switching thin film transistor Ts and a power line PL. An OLED D is connected to a driving thin film transistor TD. When a gate signal applied via the gate line GL turns on the switching thin film transistor Ts, a data signal applied via the data line DL is applied to the gate electrode of the driving thin film transistor Td and one electrode of the storage capacitor Cst via the switching thin film transistor Ts.

[0026] The driving thin-film transistor Td is turned on by a data signal applied to its gate electrode, allowing a current proportional to the data signal to flow from the power line PL to the OLED D through the driving thin-film transistor Tr. The OLED D emits light with a brightness proportional to the current flowing through the driving thin-film transistor Td. In this state, the storage capacitor Cst is charged with a voltage proportional to the data signal, maintaining a constant voltage across the gate electrode of the driving thin-film transistor Td during one frame. As a result, the organic light-emitting display device can display the desired image.

[0027] Figure 2 is a schematic cross-sectional view of an organic light emitting display device according to a first embodiment of the present disclosure.

[0028] like Figure 2 As shown. The organic light-emitting display device 100 includes a substrate 110, a TFT Tr, and an OLED D. The OLED D is disposed on a planarization layer 150 and connected to the TFT Tr. For example, the organic light-emitting display device 100 may include a red pixel, a green pixel, and a blue pixel, and the OLED D may be formed in each of the red, green, and blue pixels. That is, an OLED D emitting red light, green light, and blue light may be disposed in the red, green, and blue pixels, respectively. Alternatively, the OLED D in the red pixel, the green pixel, and the blue pixel may emit light of the same color, such as white light.

[0029] The substrate 110 may be a glass substrate or a flexible substrate. For example, the flexible substrate may be a polyimide (PI) substrate, a polyethersulfone (PES) substrate, a polyethylene naphthalate (PEN) substrate, a polyethylene terephthalate (PET) substrate, or a polycarbonate (PC) substrate.

[0030] A buffer layer 120 is formed on the substrate, and a TFT Tr is formed on the buffer layer 120. The buffer layer 120 may be omitted.

[0031] A semiconductor layer 122 is formed on the buffer layer 120. The semiconductor layer 122 may include an oxide semiconductor material or polysilicon.

[0032] When the semiconductor layer 122 includes an oxide semiconductor material, a light shielding pattern (not shown) may be formed below the semiconductor layer 122. The light shielding pattern shields or blocks light from reaching the semiconductor layer 122, thereby preventing thermal degradation of the semiconductor layer 122. On the other hand, when the semiconductor layer 122 includes polycrystalline silicon, impurities may be doped into both sides of the semiconductor layer 122.

[0033] A gate insulating layer 124 is formed on the semiconductor layer 122. The gate insulating layer 124 may be formed of an inorganic insulating material such as silicon oxide or silicon nitride.

[0034] A gate electrode 130 formed of a conductive material (eg, metal) is formed on the gate insulating layer 124 to correspond to the center of the semiconductor layer 122 .

[0035] exist Figure 2 In the embodiment, the gate insulating layer 124 is formed on 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.

[0036] 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 such as silicon oxide or silicon nitride or an organic insulating material such as benzocyclobutene or photo-acryl.

[0037] The interlayer insulating layer 132 includes a first contact hole 134 and a second contact hole 136 exposing both sides of the semiconductor layer 122. The first contact hole 134 and the second contact hole 136 are located on both sides of the gate electrode 130 to be spaced apart from the gate electrode 130.

[0038] The first and second contact holes 134 and 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 and second contact holes 134 and 136 are formed only through the interlayer insulating layer 132.

[0039] A source electrode 140 and a drain electrode 142 formed of a conductive material (eg, metal) are formed on the interlayer insulating layer 132 .

[0040] The source electrode 140 and the drain electrode 142 are spaced apart from each other with respect to the gate electrode 130 and contact both sides of the semiconductor layer 122 through the first and second contact holes 134 and 136 , respectively.

[0041] The semiconductor layer 122, the gate electrode 130, the source electrode 140, and the drain electrode 142 constitute a TFT Tr. The TFT Tr serves as a driving element. That is, the TFT Tr may correspond to the driving TFT Td ( Figure 1 ).

[0042] In the TFT Tr, the gate electrode 130, the source electrode 140, and the drain electrode 142 are located on the semiconductor layer 122. That is, the TFT Tr has a coplanar structure.

[0043] Alternatively, in the TFT Tr, the gate electrode may be located below the semiconductor layer, and the source electrode and the drain electrode may be located above the semiconductor layer, so that the TFT Tr may have an inverted staggered structure. In this case, the semiconductor layer may include amorphous silicon.

[0044] Although not shown, gate lines and data lines cross each other to define pixels, and a switching TFT is formed to be connected to the gate lines and the data lines. The switching TFT is connected to a TFT Tr as a driving element.

[0045] In addition, a power supply line parallel to and spaced apart from one of the gate line and the data line, and a storage capacitor for maintaining a voltage of the gate electrode of the TFT Tr in one frame may be further formed.

[0046] A planarization layer 150 is formed to cover the TFT Tr, and includes a drain contact hole 152 exposing the drain electrode 142 of the TFT Tr.

[0047] A first electrode 160 connected to the drain electrode 142 of the TFT Tr through the drain contact hole 152 is formed in each pixel and on the planarization layer 150. The first electrode 160 may be an anode and may be formed of a conductive material having a relatively high work function, such as a transparent conductive oxide (TCO). For example, the first electrode 160 may 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).

[0048] When the organic light-emitting display device 100 operates in a bottom-emission mode, the first electrode 160 may have a single-layer structure of a transparent conductive oxide. When the organic light-emitting display device 100 operates in a top-emission mode, a reflective electrode or reflective layer may be formed below the first electrode 160. 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 160 may have a three-layer structure of ITO / Ag / ITO or ITO / APC / ITO.

[0049] The bank layer 166 is formed on the planarization layer 150 to cover the edge of the first electrode 160. That is, the bank layer 166 is located at the boundary of the pixel and exposes the center of the first electrode 160 in the pixel.

[0050] An organic emission layer 162 is formed on the first electrode 160, and a second electrode 164 is formed on the substrate 110 on which the organic emission layer 162 is formed. The second electrode 164 covers the entire surface of the display area and can be formed of a conductive material having a relatively low work function to serve as a cathode. For example, the second electrode 164 can be formed of aluminum (Al), magnesium (Mg), silver (Ag), or alloys thereof (e.g., Al-Mg alloy (AlMg) or Ag-Mg alloy (MgAg)). In the top-emission organic light-emitting display device 100, the second electrode 164 can have a thin profile (small thickness) to provide light transmission characteristics (or semi-transmission characteristics).

[0051] That is, one of the first electrode 160 and the second electrode 164 is a transparent (or semi-transparent) electrode, and the other of the first electrode 160 and the second electrode 164 is a reflective electrode.

[0052] Although not shown, organic emission layer 162 includes a first p-type doping layer located between first electrode 160 and second electrode 164, a second p-type doping layer located between the first p-type doping layer and second electrode 164, and a third p-type doping layer located between the first and second p-type doping layers. The third p-type doping layer has a conductivity greater than that of the first p-type doping layer and equal to or less than that of the second p-type doping layer. Therefore, in OLED D and organic light-emitting display device 100, driving voltage is reduced, and emission efficiency and lifetime are improved.

[0053] The first electrode 160 , the organic emission layer 162 , and the second electrode 164 constitute an OLED D.

[0054] An encapsulation film 170 is formed on the second electrode 164 to prevent moisture from penetrating into the OLED D. The encapsulation film 170 includes a first inorganic insulating layer 172, an organic insulating layer 174, and a second inorganic insulating layer 176 stacked in sequence, but is not limited thereto. The encapsulation film 170 may be omitted.

[0055] The organic light-emitting display device 100 may further include a color filter layer (not shown). The color filter layer may include a red filter, a green filter, and a blue filter corresponding to red pixels, green pixels, and blue pixels, respectively. The color filter layer may improve the color purity of the organic light-emitting display device 100.

[0056] The organic light-emitting display device 100 may further include a polarizing plate (not shown) to reduce 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.

[0057] In addition, in the top-emission organic light-emitting display device 100, a cover window (not shown) may be connected to the packaging film 170 or the polarizing plate. In this case, the substrate 110 and the cover window have flexible properties, thereby providing a flexible organic light-emitting display device.

[0058] Figure 3 is a schematic cross-sectional view of an OLED according to a second embodiment.

[0059] like Figure 3As shown, the OLED D includes a first electrode 160 and a second electrode 164 facing each other, and an organic emission layer 162 located between the first electrode 160 and the second electrode 164. The organic emission layer 162 includes a first emission portion 240, an m-th emission portion 250, an n-th emission portion 260, a first p-type doping layer 210 located between the first emission portion 240 and the first electrode 160, an m-th p-type doping layer 220 located between the first emission portion 240 and the m-th emission portion 250, and an n-th p-type doping layer 230 located between the m-th emission portion 250 and the n-th emission portion 260.

[0060] That is, the OLED D of the present disclosure includes at least three emission parts and at least three p-type doping layers.

[0061] The first electrode 160 is an anode, and the second electrode 164 is a cathode. One of the first electrode 160 and the second electrode 164 is a transparent electrode (or a semi-transparent electrode), and the other of the first electrode 160 and the second electrode 164 is a reflective electrode.

[0062] The first emitting portion 240 includes a first emitting material layer (EML) 242 .

[0063] In addition, the first emission portion 240 may further include at least one of a first hole assisting layer 244 disposed below the first EML 242 and a first electron assisting layer 246 disposed above the first EML 242. That is, the first hole assisting layer 244 may be located between the first p-type doping layer 210 and the first EML 242, and the first electron assisting layer 246 may be located between the first EML 242 and the m-th p-type doping layer 220. For example, the first hole assisting layer 244 may be a hole transport layer (HTL), and the first electron assisting layer 246 may be an electron transport layer (ETL).

[0064] Although not shown, the first emission portion 240 may further include at least one of an electron blocking layer (EBL) between the first hole assisting layer 244 and the first EML 242 and a hole blocking layer (HBL) between the first EML 242 and the first electron assisting layer 246 .

[0065] The m-th transmitting section 250 includes an m-th EML 252 .

[0066] In addition, the m-th emission portion 250 may further include at least one of an m-th hole assisting layer 254 disposed below the m-th EML 252 and an m-th electron assisting layer 256 disposed above the m-th EML 252. That is, the m-th hole assisting layer 254 may be located between the m-th p-type doping layer 220 and the m-th EML 252, and the m-th electron assisting layer 256 may be located between the m-th EML 252 and the n-th p-type doping layer 230. For example, the m-th hole assisting layer 254 may be a HTL, and the m-th electron assisting layer 256 may be an ETL.

[0067] The nth transmitting section 260 includes an nth EML 262 .

[0068] In addition, the nth emission portion 260 may further include at least one of an nth hole assisting layer 264 disposed below the nth EML 262 and an nth electron assisting layer 266 disposed above the nth EML 262. That is, the nth hole assisting layer 264 may be located between the nth p-type doping layer 230 and the nth EML 262, and the nth electron assisting layer 266 may be located between the nth EML 262 and the second electrode 164. For example, the nth hole assisting layer 264 may be a hole transport layer (HTL), and the nth electron assisting layer 266 may include at least one of an ETL and an electron injection layer (EIL).

[0069] Although not shown, the nth emission portion 260 may further include at least one of an EBL between the nth hole assist layer 264 and the nth EML 262 and an HBL between the nth EML 262 and the nth electron assist layer 266 .

[0070] The HTL may include at least one compound selected from the following group: N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD), N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4"-diamine (NPD), 4,4'-bis(N-carbazolyl)-1,1'-biphenyl (CBP), poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)-benzidine] (polyTPD), (poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-( The present invention also includes, but is not limited to, 4,4'-(N-(4-sec-butylphenyl)diphenylamine))] (TFB), bis-[4-(N,N-di-p-tolylamino)-phenyl]cyclohexane (TAPC), 3,5-bis(9H-carbazol-9-yl)-N,N-diphenylaniline (DCDPA), N-(biphenyl-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine and N-(biphenyl-4-yl)-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)biphenyl-4-amine.

[0071] For example, the HTL may include NPD and may have a thickness of 5-150 nm, preferably 10-120 nm. Preferably, the first HTL of the first hole assisting layer 244, the mth HTL of the mth hole assisting layer 254, and the nth HTL of the nth hole assisting layer 264 may include the same material, such as NPD. In addition, the thickness of the nth HTL of the nth hole assisting layer 264 may be less than the thickness of the first HTL of the first hole assisting layer 244, and may be greater than the thickness of the mth HTL of the mth hole assisting layer 254.

[0072] The EBL may include at least one compound selected from the group consisting of tris(4-carbazolyl-9-yl-phenyl)amine (TCTA), tris[4-(diethylamino)phenyl]amine, N-(biphenyl-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine, TAPC, 4,4',4"-tris(3-methylphenylamino)triphenylamine (MTDATA), 1,3-bis(carbazol-9-yl)benzene (mCP), 3,3'-bis(N-carbazolyl)-1, 1'-biphenyl (mCBP), copper phthalocyanine (CuPc), N,N'-bis[4-[bis(3-methylphenyl)amino]phenyl]-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (DNTPD), 1,3,5-tris[4-(diphenylamino)phenyl]benzene (TDAPB), DCDPA, and 2,8-bis(9-phenyl-9H-carbazol-3-yl)dibenzo[b,d]thiophene, but are not limited thereto. The thickness of the EBL can be 1-35 nm, preferably 10-20 nm.

[0073] The HBL may include at least one compound selected from the group consisting of tris-(8-hydroxyquinolinolato)aluminum (Alq3), 2-biphenyl-4-yl-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD), spiro-PBD, lithium hydroxyquinolinolato (Liq), 2,2',2"-(1,3,5-phenyltriyl)-tris(1-phenyl-1-H benzimidazole) (TPBi), bis(2-methyl-8-hydroxyquinolinolato-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum (BAlq), 4,7-diphenyl-1,10-phenanthroline (Bphen), 2,9-bis(naphthalen-2-yl)4,7-diphenyl-1,10-phenanthroline (NBphen), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 3-(4-biphenyl)-4-phenyl The HBL may be, but is not limited to, 5-tert-butylphenyl-1,2,4-triazole (TAZ), 4-(naphthalene-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). For example, the thickness of the HBL may be 1-35 nm, preferably 10-20 nm.

[0074] The ETL may include at least one compound selected from the group consisting of 1,3,5-tris(m-pyridin-3-ylphenyl)benzene (TmPyPB), 2,2',2"-(1,3,5-phenyltriyl)-tris(1-phenyl-1-H benzimidazole) (TPBi), tris(8-hydroxyquinolinolato)aluminum (Alq3), 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD), 3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl Butylphenyl-1,2,4-triazole (TAZ), 2-biphenyl-4-yl-4,6-bis-(4'-pyridin-2-yl-biphenyl-4-yl)-[1,3,5]triazine (DPT) and bis(2-methyl-8-hydroxyquinolinolato)-4-(phenylphenol)aluminum (BAlq), but are not limited thereto. For example, the ETL may include an azine-based compound such as TmPyPB, or an imidazole-based compound such as TPBi, and may have a carbonyl group of 50 to 100 carbon atoms. The thickness is preferably 10-40nm.

[0075] For example, each of the first ETL of the first electron assisting layer 246 and the nth ETL of the nth electron assisting layer 266 may include an azine-based compound, for example, TmPyPB, and the mth ETL of the mth electron assisting layer 256 may include an imidazole-based compound, for example, TPBi. Each of the first ETL of the first electron assisting layer 246 and the mth ETL of the mth electron assisting layer 256 may have the same thickness, and the thickness of the nth ETL of the nth electron assisting layer 266 may be greater than the thickness of each of the first ETL of the first electron assisting layer 246 and the mth ETL of the mth electron assisting layer 256.

[0076] The EIL that may be included in the nth electron assist layer 266 may include at least one of an alkali metal (e.g., Li), an alkali halide compound (e.g., LiF, CsF, NaF, or BaF2), and an organometallic compound (e.g., Liq, lithium benzoate, or sodium stearate), but is not limited thereto. For example, the EIL may have a thickness of 1-10 nm, preferably 1-5 nm.

[0077] The first EML 242, the m-th EML 252, and the n-th EML 262 may emit light of the same color or different colors. Alternatively, two of the first EML 242, the m-th EML 252, and the n-th EML 262 may emit a first color, that is, the same color, and the other of the first EML 242, the m-th EML 252, and the n-th EML 262 may emit a second color different from the first color.

[0078] When one of the first EML 242, the m-th EML 252, and the n-th EML 262 is a red EML, the red EML includes a host and a red dopant. When one of the first EML 242, the m-th EML 252, and the n-th EML 262 is a green EML, the green EML includes a host and a green dopant. When one of the first EML 242, the m-th EML 252, and the n-th EML 262 is a blue EML, the blue EML includes a host and a blue dopant. Each of the red dopant, the green dopant, and the blue dopant may be a fluorescent compound, a phosphorescent compound, or a delayed fluorescent compound.

[0079] For example, in a red EML, the host can be 4,4'-bis(carbazol-9-yl)-biphenyl (CBP), and the red dopant can be selected from bis(1-phenylisoquinolinolato)iridium acetylacetonate (PIQIr(acac)), bis(1-phenylquinolinolato)iridium acetylacetonate (PQIr(acac)), tris(1-phenylquinolinolato)iridium (PQIr), and platinum octaethylporphyrin (PtOEP). The EML in the red pixel can provide light having a wavelength range (e.g., emission wavelength range) of approximately 600 to 650 nm.

[0080] In the green EML, the host may be CBP, and the green dopant may be face-tris(2-phenylpyridinium)iridium (Ir(ppy)3) or tris(8-hydroxyquinolinato)aluminum (Alq3). The EML in the green pixel may provide light having a wavelength range of approximately 510 to 570 nm.

[0081] In the blue EML, the host may be an anthracene derivative, and the blue dopant may be a pyrene derivative. For example, the host may be 9,10-di(naphthalene-2-yl)anthracene, and the blue dopant may be 1,6-bis(diphenylamino)pyrene. In the blue EML, the blue dopant may have a weight content of 0.1-20%, preferably 1-10%. The blue EML thickness may be Preferred And light having a wavelength range of approximately 440 to 480 nm can be provided.

[0082] The first p-type doped layer 210 provides holes into the first emission portion 240 , the mth p-type doped layer 220 provides holes into the mth emission portion 250 , and the nth p-type doped layer 230 provides holes into the nth emission portion 260 .

[0083] For example, holes are provided from the first p-type doping layer 210 to the first EML 242 through the first hole auxiliary layer 244, and holes are provided from the m-th p-type doping layer 220 to the m-th EML 252 through the m-th hole auxiliary layer 254. In addition, holes are provided from the n-th p-type doping layer 230 to the n-th EML 262 through the n-th hole auxiliary layer 264.

[0084] The first p-type doping layer 210 may contact the first electrode 160 and may be a hole injection layer. Alternatively, an n-type charge generation layer (not shown) may be provided below the first p-type doping layer 210, and the first p-type doping layer 210 may be a p-type charge generation layer. In this case, the first p-type doping layer 210 and the n-type charge generation layer below the first p-type doping layer 210 constitute a charge generation layer (CGL).

[0085] An n-type CGL 226 is disposed below the m-th p-type doping layer 220 , and the m-th p-type doping layer 220 may be a p-type CGL. In this case, the m-th p-type doping layer 220 and the n-type CGL 226 below the m-th p-type doping layer 220 form a CGL 228 .

[0086] An n-type CGL 236 is disposed below the n-th p-type doping layer 230 , and the n-th p-type doping layer 230 may be a p-type CGL. In this case, the n-th p-type doping layer 230 and the n-type CGL 226 below the n-th p-type doping layer 230 form a CGL 238 .

[0087] The n-type CGLs 226 and 236 provide electrons to the electron assisting layers 246 and 256, and the electrons are provided to the first emission portion 240 and the m-th emission portion 250 through the electron assisting layers 246 and 256. Therefore, the driving voltage of the OLED D having the multiple series structure is reduced, and the emission efficiency of the OLED D is improved.

[0088] Each of the n-type CGLs 226 and 236 includes an n-type charge generation material and may have a thickness of 10-20 nm. For example, the n-type charge generating material may be selected from the group consisting of tris-(8-hydroxyquinoline)aluminum (Alq3), 2-biphenyl-4-yl-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD), spiro-PBD, hydroxyquinoline lithium (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(naphthalene-2-yl)4,7-diphenyl-1,10-phenanthroline (NBphen), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2 ,4-triazole (TAZ), 4-(naphthalene-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). In one embodiment of the present disclosure, the n-type charge generating material may be a phenanthroline derivative, for example, bathophenanthroline (Bphen).

[0089] In addition, each of the n-type CGLs 226 and 236 may further include an auxiliary n-type charge generation material. For example, the auxiliary n-type charge generation material may be an alkali metal such as Li, Cs, K, Rb, Na, or Fr, or an alkaline earth metal such as Be, Mg, Ca, Sr, Ba, or Ra. The auxiliary n-type charge generation material may comprise approximately 0.1 to 20 wt%, preferably approximately 1 to 10 wt%, of each of the n-type CGLs 226 and 236.

[0090] The first p-type doped layer 210 has a first conductivity, the m-th p-type doped layer 220 has a second conductivity, and the n-th p-type doped layer 230 has a third conductivity. Each of the second conductivity and the third conductivity is greater than the first conductivity, and the second conductivity is equal to or greater than the third conductivity. Preferably, the second conductivity may be greater than the third conductivity.

[0091] That is, the electrical conductivity of the first p-type doping layer 210 closer to the first electrode 160 serving as the anode is smaller than the electrical conductivity of each of the m-th p-type doping layer 220 and the n-th p-type doping layer 230 which are farther from the first electrode 160. In addition, the electrical conductivity of the n-th p-type doping layer 230 closer to the second electrode 164 serving as the cathode is equal to or smaller than the electrical conductivity of the m-th p-type doping layer 220 located between the first p-type doping layer 210 and the n-th p-type doping layer 230.

[0092] In other words, the nth p-type doping layer 230 has a conductivity greater than that of the first p-type doping layer 210 and equal to or less than that of the mth p-type doping layer 220 .

[0093] For example, the conductivity of the first p-type doped layer 210 may be 1*10 -5 -1*10 -4 The conductivity of the mth p-type doped layer 220 can be within the range of 1*10 -4 -1*10 -3 S / cm, and the conductivity of the nth p-type doped layer 230 can be within the range of 3*10 -5 -6*10 -4 Within the range of S / ㎝.

[0094] Each of the first p-type doping layer 210, the m-th p-type doping layer 220, and the n-th p-type doping layer 230 includes a p-type dopant 212, 222, and 232 and a body 214, 224, and 234. In each of the first p-type doping layer 210, the m-th p-type doping layer 220, and the n-th p-type doping layer 230, the weight percentage of the p-type dopant 212, 222, and 232 is less than the weight percentage of the body 214, 224, and 234.

[0095] The p-type dopants 212, 222, and 232 of each of the first p-type doping layer 210, the m-th p-type doping layer 220, and the n-th p-type doping layer 230 may be a first organic compound that is an indacene derivative (e.g., an indacene compound) substituted with a malononitrile group. The first organic compound may be represented by Formula 1-1.

[0096] [Formula 1-1]

[0097]

[0098] In Formula 1-1, R1 and R2 are each independently selected from hydrogen (H), deuterium (D), halogen, and cyano. Each of R3 to R6 is independently selected from halogen, cyano, malononitrile, C1-C10 haloalkyl, and C1-C10 haloalkoxy, and at least one of R3 and R4 and at least one of R5 and R6 is malononitrile. X and Y are each independently phenyl substituted with at least one of C1-C10 alkyl, halogen, cyano, malononitrile, C1-C10 haloalkyl, and C1-C10 haloalkoxy.

[0099] For example, the C1-C10 haloalkyl group may be a trifluoromethyl group, and the C1-C10 haloalkoxy group may be a trifluoromethoxy group. In addition, the halogen group may be one of F, Cl, Br, and I.

[0100] In Formula 1-1, one of R3 and R4 and one of R5 and R6 may be malononitrile, and the other of R3 and R4 and the other of R5 and R6 may be a cyano group.

[0101] For example, in Formula 1-1, R3 and R6 may be malononitrile. Alternatively, in Formula 1-1, R4 and R6 may be malononitrile. That is, the organic compound in Formula 1-1 may be represented by Formula 1-2 or 1-3.

[0102] [Formula 1-2]

[0103]

[0104] In Formula 1-1, a substituent at a first side of the indode nucleus may be the same as a substituent at a second side of the indode nucleus, so that the first organic compound in Formula 1-1 may have a symmetrical structure.

[0105] Alternatively, in Formula 1-1, a substituent at a first side of the indode nucleus may be different from a substituent at a second side of the indode nucleus, so that the organic compound in Formula 1-1 may have an asymmetric structure.

[0106] For example, each of X and Y may independently be a phenyl group substituted with at least one of a C1-C10 alkyl group, a halogen group, a cyano group, a malononitrile group, a C1-C10 haloalkyl group, and a C1-C10 haloalkoxy group, and X and Y may differ in at least one of the substituents and the position of the substituent. That is, the phenyl moiety that is X and the phenyl moiety that is Y may have different substituents and / or may have the same substituent or different substituents at different positions.

[0107] For example, the organic compound in Formula 1-1 can be represented by Formula 1-4.

[0108] [Formula 1-4]

[0109]

[0110] In Formulas 1-4, each of X1 to X3 and each of Y1 to Y3 is independently selected from H, C1-C10 alkyl, halogen, cyano, malononitrile, C1-C10 haloalkyl and C1-C10 haloalkoxy, and satisfies at least one of the following conditions: i) X1 and Y1 are different, ii) X2 is different from Y2 and Y3, or X3 is different from Y2 and Y3.

[0111] The first organic compound, which is the p-type dopant 212 , 222 , and 232 , has excellent hole injection, transport, and / or generation properties, thereby improving hole injection and / or transport efficiency to the first to third emission portions 240 , 250 , and 260 .

[0112] The main body 214, 224, and 234 of each of the first p-type doping layer 210, the m-th p-type doping layer 220, and the n-th p-type doping layer 230 may be a second organic compound that is a fluorene derivative (eg, a spirofluorene derivative). The second organic compound may be represented by Formula 2-1.

[0113] [Formula 2-1]

[0114]

[0115] In Formula 2-1, X and Y are each independently selected from a C6-C30 aryl group and a C5-C30 heteroaryl group, L is selected from a C6-C30 arylene group and a C5-C30 heteroarylene group, and a is 0 or 1. Each of R1 to R14 is independently selected from H, D, a C1-C10 alkyl group, a C6-C30 aryl group, and a C5-C30 heteroaryl group, or adjacent two of R1 to R14 are connected (bound or joined) to each other to form a fused ring.

[0116] In Formula 2-1, the C6 to C30 aryl (or arylene) group may be selected from the group consisting of phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, pentanenyl, indenyl, indenoindenyl, heptalenyl, biphenylenyl, indacenyl, phenanthrenyl, triphenylenyl, dibenzophenanthrenyl, azulenyl, pyrenyl, fluoranthenyl, triphenylenyl, phenyl, tetraphenyl, tetrasenyl, fluorenyl, pentaphenyl, pentacenyl, fluorenyl, indenofluorenyl and spirofluorenyl.

[0117] In formula 2-1, the C5-C30 heteroaryl (or heteroarylene) can be selected from: pyrrolyl, pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazinyl, tetrazinyl, imidazolyl, pyrazolyl, indolyl, isoindolyl, indazolyl, indolizinyl, pyrrolizinyl, carbazolyl, benzocarbazolyl, dibenzocarbazolyl, indolecarbazolyl, indenocarbazolyl, benzofurancarbazolyl, benzothiophenecarbazolyl, quinolyl, isoquinolyl, phthalazinyl, quinoxalinyl, cinnolinyl, quinazolinyl, quinozolinyl, quinolyl, purinyl, phthalazinyl, quinoxalinyl, benzoquinolyl, benzoisoquinolyl, benzoquinazolinyl, benzoquinoxalinyl, acridinyl, phenanthrolinyl, perimidinyl, phenanthridinyl, pteridinyl, cinnolinyl, naphthyridinyl, furanyl, oxazinyl, oxazolyl, oxadiazolyl, triazolyl, dioxynyl, benzofuranyl, dibenzofuranyl, thiopyranyl, xantenyl, chromanyl, isochromanyl, thioazinyl, thiophenyl, benzothiophenyl, dibenzothiophenyl, difuryrazinyl, benzofurandibenzofuranyl, benzothiophenebenzothiophenyl, benzothiophenedibenzothiophenyl, benzothiophenebenzofuranyl, and benzothiophenedibenzofuranyl.

[0118] In Formula 2-1, each of the C6-C30 aryl group and the C5-C30 heteroaryl group may include substituted and unsubstituted groups. That is, each of the C6-C30 aryl group and the C5-C30 heteroaryl group may be unsubstituted or substituted with a C1-C10 alkyl group (e.g., a methyl group, an ethyl group, or a tert-butyl group).

[0119] In Formula 2-1, X and Y may be the same or different. Each of X and Y may be selected from fluorenyl, spirofluorenyl, phenyl, biphenyl, tert-butylphenyl, fluorenylphenyl, carbazolyl, and carbazolylphenyl, and L may be a phenylene group. Each of R1 to R14 may be selected from H, D, a C1-C10 alkyl group (e.g., a tert-butyl group), and a C6-C30 aryl group (e.g., a phenyl group), and two adjacent ones of R1 to R14 (e.g., R1 and R6) may be connected to form a condensed ring. The condensed ring may be one of an aromatic ring, an alicyclic ring, and a heteroaromatic ring.

[0120] The second organic compound in Formula 2-1 may be represented by Formula 2-2 or 2-3.

[0121] [Formula 2-2]

[0122]

[0123] [Formula 2-3]

[0124]

[0125] The second organic compound in Formula 2-2 and the second organic compound in Formula 2-3 differ in the position of the amino group (or linker L1). That is, in the second organic compound in Formula 2-2, the amino group (or linker L1) is connected to the second position of the fluorene moiety or the spirofluorene moiety, while in the second organic compound in Formula 2-3, the amino group (or linker L1) is connected to the third position of the fluorene moiety or the spirofluorene moiety.

[0126] The first organic compound in Formula 1-1 may be one of the compounds in Formula 3.

[0127] [Formula 3]

[0128]

[0129]

[0130]

[0131]

[0132]

[0133]

[0134]

[0135] The second organic compound in Formula 2-1 may be one of the compounds in Formula 4.

[0136] [Formula 4]

[0137]

[0138]

[0139] [synthesis]

[0140] 1. Synthesis of Compound A04

[0141] (1) Compound 4-A

[0142] [Reaction formula 1-1]

[0143]

[0144] 2,2'-(4,6-dibromo-1,3-phenylene)diacetonitrile (180g, 573mmol), toluene (6L), copper iodide (CuI, 44mmol), tetrakis(triphenylphosphine)palladium (44mmol), diisopropylamine (2885mmol) and 1-ethynyl-4-(trifluoromethyl)benzene (637mmol) were mixed and heated to 100°C. After the reaction, the solvent (5L) was distilled off. The mixture was cooled to room temperature and filtered to obtain a solid. After the solid was dissolved in chloroform and extracted with water, magnesium sulfate and acidic clay were added and stirred for 1 hour. The mixture was filtered and the solvent was distilled again. The mixture was recrystallized from ethanol to obtain compound 4-A (104g). (Yield 45%, MS [M+H] + = 403)

[0145] (2) Compound 4-B

[0146] [Reaction formula 1-2]

[0147]

[0148] Compound 4-A (104 g, 258 mmol), toluene (3 L), CuI (21 mmol), tetrakis(triphenylphosphine)palladium (21 mmol), diisopropylamine (1290 mmol), and 1-ethynyl-4-(trifluoromethoxy)benzene (258 mmol) were mixed, heated to 100°C, and stirred for 2 hours. After the reaction, the solvent (2 L) was distilled off. The mixture was cooled to room temperature and filtered to obtain a solid. The solid was dissolved in chloroform and extracted with water, followed by addition of magnesium sulfate and acidic clay and stirring for 1 hour. After filtering the mixture, the solvent was distilled again. The mixture was recrystallized from tetrahydrofuran and ethanol to obtain compound 4-B (39.3 g). (Yield 30%, MS [M+H] + = 509).

[0149] (3) Compound 4-C

[0150] [Reaction formula 1-3]

[0151]

[0152] Compound 4-B (39 g, 77 mmol), 1,4-dioxane (520 mL), diphenyl sulfoxide (462 mmol), copper (II) bromide (CuBr (II), 15 mmol), and palladium acetate (15 mmol) were mixed, heated to 100°C, and stirred for 5 hours. After the reaction, the solvent was distilled off. The mixture was dissolved in chloroform, acidic clay was added and stirred for 1 hour. After filtering the mixture, the solvent was distilled again. The mixture was reverse precipitated with hexane to obtain a solid. The solid was recrystallized with tetrahydrofuran and hexane, and filtered to obtain compound 4-C (7 g). (Yield 17%, MS [M+H] + = 537)

[0153] (4) Compound A04

[0154] [Reaction formula 1-4]

[0155]

[0156] Compound 4-C (7 g, 13 mmol), dichloromethane (220 mL) and malononitrile (96 mmol) were added and cooled to 0 ° C. Titanium (IV) chloride (65 mmol) was slowly added and stirred at 0 ° C for 1 hour. Pyridine (97.5 mmol) dissolved in dichloromethane (75 mL) was slowly added to the mixture at 0 ° C and stirred for 1 hour. After the reaction was completed, acetic acid (130 mmol) was added and stirred for another 30 minutes. After the reaction solution was extracted with water, the organic layer was reversely precipitated in hexane to obtain a solid. After the solid was filtered through acetonitrile, magnesium sulfate and acidic clay were added and stirred for 30 minutes. After filtering the solution, it was recrystallized from acetonitrile and toluene and washed with toluene. The solid was recrystallized from acetonitrile and tert-butyl methyl ether and purified by sublimation to obtain compound A04 (1.6 g). (Yield 20%, MS [M + H] + = 633)

[0157] 2. Synthesis of Compound A13

[0158] (1) Compound 13-A

[0159] [Reaction formula 2-1]

[0160]

[0161] 2,2'-(4,6-dibromo-1,3-phenylene)diacetonitrile (200g, 637mmol), toluene (6L), copper iodide (CuI, 51mmol), tetrakis(triphenylphosphine)palladium (51mmol), diisopropylamine (3185mmol) and 1-ethynyl-3,5-bis(trifluoromethyl)benzene (637mmol) were mixed and heated to 100°C. After the reaction, the solvent (5L) was distilled off. The mixture was cooled to room temperature and filtered to obtain a solid. After the solid was dissolved in chloroform and extracted with water, magnesium sulfate and acidic clay were added and stirred for 1 hour. The mixture was filtered and the solvent was distilled again. The mixture was recrystallized from ethanol to obtain compound 13-A (105g). (Yield 35%, MS [M+H] + = 471)

[0162] (2) Compound 13-B

[0163] [Reaction formula 2-2]

[0164]

[0165] Compound 13-A (105 g, 223 mmol), toluene (3 L), CuI (18 mmol), tetrakis(triphenylphosphine)palladium (18 mmol), diisopropylamine (1115 mmol) and 4-ethynyl-2-(trifluoromethyl)benzonitrile (223 mmol) were mixed, heated to 100° C., and stirred for 2 hours. After the reaction, the solvent (2 L) was distilled off. The mixture was cooled to room temperature and filtered to obtain a solid. The solid was dissolved in chloroform and extracted with water, and then magnesium sulfate and acidic clay were added and stirred for 1 hour. After filtering the mixture, the solvent was distilled again. The mixture was recrystallized from tetrahydrofuran and ethanol to obtain compound 13-B (32.6 g). (Yield 25%, MS [M+H] + = 586)

[0166] (3) Compound 13-C

[0167] [Reaction formula 2-3]

[0168]

[0169] Compound 13-B (32 g, 55 mmol), 1,4-dioxane (480 mL), diphenyl sulfoxide (330 mmol), CuBr(II) (11 mmol), and palladium acetate (11 mmol) were mixed, heated to 100°C, and stirred for 5 hours. After the reaction, the solvent was distilled off. The mixture was dissolved in chloroform, acidic clay was added, and stirred for 1 hour. After filtering the mixture, the solvent was distilled again. The mixture was reverse precipitated with hexane to obtain a solid. The solid was recrystallized with tetrahydrofuran and hexane, and filtered to obtain compound 13-C (5 g). (Yield 15%, MS [M+H] + = 614)

[0170] (4) Compound A13

[0171] [Reaction formula 2-4]

[0172]

[0173] Compound 13-C (5 g, 8.2 mmol), dichloromethane (150 mL) and malononitrile (49.2 mmol) were added and cooled to 0°C. Titanium (IV) chloride (41 mmol) was slowly added and stirred at 0°C for 1 hour. Pyridine (61.5 mmol) dissolved in dichloromethane (50 mL) was slowly added to the mixture at 0°C and stirred for 1 hour. After the reaction was completed, acetic acid (82 mmol) was added and stirred for another 30 minutes. After the reaction solution was extracted with water, the organic layer was reversely precipitated in hexane to obtain a solid. After the solid was filtered through acetonitrile, magnesium sulfate and acidic clay were added and stirred for 30 minutes. After the solution was filtered, it was recrystallized from acetonitrile and toluene and washed with toluene. The solid was recrystallized from acetonitrile and tert-butyl methyl ether and purified by sublimation to obtain compound A13 (1 g). (Yield 18%, MS [M+H] + = 710)

[0174] 3. Synthesis of Compound A37

[0175] (1) Compound 37-A

[0176] [Reaction formula 3-1]

[0177]

[0178] 2,2'-(4,6-dibromo-2-fluoro-1,3-phenylene)diacetonitrile (300g, 903.7mmol), toluene (9L), CuI (72.3mmol), tetrakis(triphenylphosphine)palladium (72.3mmol), diisopropylamine (4518mmol) and 1-ethynyl-3,5-bis(trifluoromethyl)benzene (903.7mmol) were mixed and heated to 100°C. After the reaction, the solvent (8L) was distilled off. The mixture was cooled to room temperature and filtered to obtain a solid. After the solid was dissolved in chloroform and extracted with water, magnesium sulfate and acidic clay were added and stirred for 1 hour. The mixture was filtered and the solvent was distilled again. The mixture was recrystallized from ethanol to obtain compound 37-A (137g). (Yield 31%, MS [M+H] + = 489)

[0179] (2) Compound 37-B

[0180] [Reaction formula 3-2]

[0181]

[0182] Compound 37-A (137 g, 280 mmol), toluene (4.1 L), CuI (22 mmol), tetrakis(triphenylphosphine)palladium (22 mmol), diisopropylamine (1400 mmol) and 4-ethynyl-2-(trifluoromethyl)benzonitrile (280 mmol) were mixed, heated to 100° C., and stirred for 2 hours. After the reaction, the solvent (3 L) was distilled off. The mixture was cooled to room temperature and filtered to obtain a solid. The solid was dissolved in chloroform and extracted with water, and then magnesium sulfate and acidic clay were added and stirred for 1 hour. After filtering the mixture, the solvent was distilled again. The mixture was recrystallized from tetrahydrofuran and ethanol to obtain compound 37-B (33.8 g). (Yield 20%, MS [M+H] + = 603)

[0183] (3) Compound 37-C

[0184] [Reaction formula 3-3]

[0185]

[0186] Compound 37-B (33 g, 54.7 mmol), 1,4-dioxane (500 mL), diphenyl sulfoxide (328.2 mmol), CuBr(II) (10.9 mmol), and palladium acetate (10.9 mmol) were mixed, heated to 100° C., and stirred for 5 hours. After the reaction, the solvent was distilled off. The mixture was dissolved in chloroform, acidic clay was added, and stirred for 1 hour. After filtering the mixture, the solvent was distilled again. The mixture was reverse precipitated with hexane to obtain a solid. The solid was recrystallized with tetrahydrofuran and hexane, and filtered to obtain compound 37-C (4.8 g). (Yield 14%, MS [M+H] + = 632)

[0187] (4) Compound 37

[0188] [Reaction formula 3-4]

[0189]

[0190] Compound 37-C (4.8 g, 7.6 mmol), dichloromethane (145 mL) and malononitrile (45.6 mmol) were added and cooled to 0°C. Titanium (IV) chloride (38 mmol) was slowly added and stirred at 0°C for 1 hour. Pyridine (57 mmol) dissolved in dichloromethane (48 mL) was slowly added to the mixture at 0°C and stirred for 1 hour. After the reaction was completed, acetic acid (76 mmol) was added and stirred for another 30 minutes. After the reaction solution was extracted with water, the organic layer was reversely precipitated in hexane to obtain a solid. After the solid was filtered through acetonitrile, magnesium sulfate and acidic clay were added and stirred for 30 minutes. After the solution was filtered, it was recrystallized from acetonitrile and toluene, and then washed with toluene. The solid was recrystallized from acetonitrile and tert-butyl methyl ether and purified by sublimation to obtain compound A37 (1.1 g). (Yield 20%, MS [M+H] + = 728)

[0191] The weight percentage of the p-type dopant 212 in the first p-type doping layer 210 may be less than the weight percentage of each of the p-type dopant 222 in the m-th p-type doping layer 220 and the p-type dopant 232 in the n-th p-type doping layer 230. In addition, when the p-type dopant 222 in the m-th p-type doping layer 220 and the p-type dopant 232 in the n-th p-type doping layer 230 may both be symmetric indacene derivatives (e.g., compounds S01 to S49 in Formula 3) or asymmetric indacene derivatives (e.g., compounds A01 to A96), the weight percentage of the p-type dopant 222 in the m-th p-type doping layer 220 may be greater than the weight percentage of the p-type dopant 232 in the n-th p-type doping layer 230.

[0192] The p-type dopant 212 in the first p-type doping layer 210 may have a weight of 1-20%, the p-type dopant 222 in the m-th p-type doping layer 220 may have a weight of 10-50%, and the p-type dopant 232 in the n-th p-type doping layer 230 may have a weight of 5-25%. For example, the p-type dopant 212 in the first p-type doping layer 210 may have a weight of 5-15%, the p-type dopant 222 in the m-th p-type doping layer 220 may have a weight of 10-30%, and the p-type dopant 232 in the n-th p-type doping layer 230 may have a weight of 10-20%.

[0193] The p-type dopants 212, 222, and 232 of the first p-type doping layer 210, the m-th p-type doping layer 220, and the n-th p-type doping layer 230 may be the same or different. For example, when the p-type dopants 212, 222, and 232 of the first p-type doping layer 210, the m-th p-type doping layer 220, and the n-th p-type doping layer 230 are asymmetric compounds of Formula 1-4, the lifetime of the OLED D is further increased.

[0194] The bodies 214, 224, and 234 of the first p-type doping layer 210, the m-th p-type doping layer 220, and the n-th p-type doping layer 230 may be the same or different. For example, the bodies 214 and 234 of the first p-type doping layer 210 and the n-th p-type doping layer 230 may be the second organic compound in Formula 2-3, and the body 224 of the m-th p-type doping layer 220 may be the second organic compound in Formula 2-2.

[0195] As described above, the OLED D includes the first p-type doping layer 210 closer to the first electrode 160 serving as the anode, the nth p-type doping layer 230 closer to the second electrode 164 serving as the cathode, and the mth p-type doping layer 220 located between the first p-type doping layer 210 and the nth p-type doping layer 230. Furthermore, the conductivity of the nth p-type doping layer 230 is greater than that of the first p-type doping layer 210 and is equal to or less than that of the mth p-type doping layer 220. Therefore, the OLED D has advantages in terms of driving voltage, emission efficiency, and lifespan.

[0196] Furthermore, when the conductivity of the mth p-type doping layer 220 is greater than the conductivity of the nth p-type doping layer 230 , the driving voltage of the OLED D is further reduced, and the emission efficiency and lifespan of the OLED D are further increased.

[0197] In addition, when each of the first p-type doping layer 210, the m-th p-type doping layer 220, and the n-th p-type doping layer 230 includes the first organic compound of Formula 1-1 as the p-type dopant 212, 222, and 232 and the second organic compound of Formula 2-1 as the host 214, 224, and 234, the driving voltage of the OLED D is significantly reduced, and the emission efficiency and lifespan of the OLED D are significantly increased.

[0198] Figure 4 is a schematic cross-sectional view of an organic light-emitting device according to a third embodiment of the present disclosure, and Figure 5 is a schematic cross-sectional view of an OLED according to a fourth embodiment of the present disclosure.

[0199] like Figure 4 As shown, the organic light-emitting display device 300 includes: a first substrate 310 in which red pixels BP, green pixels GP and blue pixels BP are defined; a second substrate 370 facing the first substrate 310; an OLED D located between the first substrate 310 and the second substrate 370 and providing white light emission, and a color filter layer 380 located between the OLED D and the second substrate 370.

[0200] Each of the first substrate 310 and the second substrate 370 may be a glass substrate or a flexible substrate. For example, each of the first substrate 310 and the second substrate 370 may be a polyimide (PI) substrate, a polyethersulfone (PES) substrate, a polyethylene naphthalate (PEN) substrate, a polyethylene terephthalate (PET) substrate, or a polycarbonate (PC) substrate.

[0201] A buffer layer 320 is formed on the substrate, and a TFT Tr corresponding to each of the red, green, and blue pixels RP, GP, and BP is formed on the buffer layer 320. The buffer layer 320 may be omitted.

[0202] A semiconductor layer 322 is formed on the buffer layer 320. The semiconductor layer 322 may include an oxide semiconductor material or polysilicon.

[0203] A gate insulating layer 324 is formed on the semiconductor layer 322. The gate insulating layer 324 may be formed of an inorganic insulating material such as silicon oxide or silicon nitride.

[0204] A gate electrode 330 formed of a conductive material (eg, metal) is formed on the gate insulating layer 324 to correspond to the center of the semiconductor layer 322 .

[0205] An interlayer insulating layer 332 formed of an insulating material is formed on the gate electrode 330. The interlayer insulating layer 332 may be formed of an inorganic insulating material such as silicon oxide or silicon nitride or an organic insulating material such as benzocyclobutene or photopropylene.

[0206] The interlayer insulating layer 332 includes a first contact hole 334 and a second contact hole 336 exposing both sides of the semiconductor layer 322. The first contact hole 334 and the second contact hole 336 are located on both sides of the gate electrode 330 to be spaced apart from the gate electrode 330.

[0207] A source electrode 340 and a drain electrode 342 formed of a conductive material (eg, metal) are formed on the interlayer insulating layer 332 .

[0208] The source electrode 340 and the drain electrode 342 are spaced apart from each other with respect to the gate electrode 330 , and contact both sides of the semiconductor layer 322 through the first contact hole 334 and the second contact hole 336 , respectively.

[0209] The semiconductor layer 322, the gate electrode 330, the source electrode 340, and the drain electrode 342 constitute a TFT Tr. The TFT Tr serves as a driving element. That is, the TFT Tr may correspond to the driving TFT Td ( Figure 1 ).

[0210] Although not shown, gate lines and data lines cross each other to define pixels, and a switching TFT is formed to be connected to the gate lines and the data lines. The switching TFT is connected to a TFT Tr as a driving element.

[0211] In addition, a power supply line parallel to and spaced apart from one of the gate line and the data line, and a storage capacitor for maintaining a voltage of the gate electrode of the TFT Tr in one frame may be further formed.

[0212] The planarization layer 350 is formed to cover the TFT Tr, and includes a drain contact hole 352 exposing the drain electrode 342 of the TFT Tr.

[0213] A first electrode 360 ​​connected to the drain electrode 342 of the TFT Tr through the drain contact hole 352 is formed in each pixel and on the planarization layer 350. The first electrode 360 ​​may be an anode and may be formed of a conductive material having a relatively high work function, such as a transparent conductive oxide (TCO). The first electrode 360 ​​may further include a reflective electrode or a reflective layer. For example, the reflective electrode or the reflective layer may be formed of silver (Ag) or an aluminum-palladium-copper (APC) alloy. In the top-emission organic light-emitting display device 300, the first electrode 360 ​​may have a three-layer structure of ITO / Ag / ITO or ITO / APC / ITO.

[0214] A bank layer 366 is formed on the planarization layer 350 to cover the edges of the first electrode 360. That is, the bank layer 366 is located at the boundary of the pixel and exposes the center of the first electrode 360 ​​in the pixel. Since the OLED D emits white light in the red, green, and blue pixels RP, GP, and BP, the organic emission layer 162 can be formed as a common layer in the red, green, and blue pixels RP, GP, and BP without being separated. The bank layer 366 can be formed to prevent current leakage at the edge of the first electrode 360, and the bank layer 366 can be omitted.

[0215] An organic emission layer 362 is formed on the first electrode 360 ​​.

[0216] refer to Figure 5 The organic emission layer 362 includes a first emission portion 440, a second emission portion 450, a third emission portion 460, a first p-type doping layer 410 located between the first emission portion 440 and the first electrode 360, a second p-type doping layer 420 located between the first emission portion 440 and the second emission portion 450, and a third p-type doping layer 430 located between the second emission portion 450 and the third emission portion 460.

[0217] That is, the OLED D of the present disclosure includes three emission parts 440 , 450 , and 460 and three p-type doping layers 410 , 420 , and 430 .

[0218] The first transmitting portion 440 includes a first EML 442 .

[0219] In addition, the first emission portion 440 may further include at least one of a first hole-assisting layer 444 located below the first EML 442 and a first electron-assisting layer 446 located on (or above) the first EML 442. That is, the first hole-assisting layer 444 is disposed between the first p-type doped layer 410 and the first EML 442, and the first electron-assisting layer 446 is disposed between the first EML 442 and the second p-type doped layer 420. For example, the first hole-assisting layer 444 may be a hole transport layer (HTL), and the first electron-assisting layer 446 may be an electron transport layer (ETL).

[0220] Although not shown, the first emission portion 440 may further include at least one of an electron blocking layer (EBL) between the first hole assisting layer 444 and the first EML 442 and a hole blocking layer (HBL) between the first EML 442 and the first electron assisting layer 446 .

[0221] The second transmitting portion 450 includes a second EML 452 .

[0222] In addition, the second emission portion 450 may further include at least one of a second hole assisting layer 454 below the second EML 452 and a second electron assisting layer 456 on (or above) the second EML 452. That is, the second hole assisting layer 454 is disposed between the second p-type doping layer 420 and the second EML 452, and the second electron assisting layer 456 is disposed between the second EML 452 and the third p-type doping layer 430. For example, the second hole assisting layer 454 may be an HTL, and the second electron assisting layer 456 may be an ETL.

[0223] The third transmitting portion 460 includes a third EML 462 .

[0224] In addition, the third emission portion 460 may further include at least one of a third hole assisting layer 464 below the third EML 462 and a third electron assisting layer 466 on (or over) the third EML 462. That is, the third hole assisting layer 464 is disposed between the third p-type doping layer 430 and the third EML 462, and the third electron assisting layer 466 is disposed between the third EML 462 and the second electrode 364. For example, the third hole assisting layer 464 may be an HTL, and the third electron assisting layer 466 may include at least one of an ETL and an electron injection layer (EIL).

[0225] Although not shown, the third emission portion 460 may further include at least one of an electron blocking layer (EBL) between the third hole assisting layer 464 and the third EML 462 and a hole blocking layer (HBL) between the third EML 462 and the third electron assisting layer 466 .

[0226] The first HTL included in the first hole assisting layer 444, the second HTL included in the second hole assisting layer 454, and the third HTL included in the third hole assisting layer 464 may include the same material, for example, NPD. The thickness of the third HTL included in the third hole assisting layer 464 may be less than the thickness of the first HTL included in the first hole assisting layer 444, and may be greater than the thickness of the second HTL included in the second hole assisting layer 454.

[0227] The first ETL included in the first electron assisting layer 446 and the third ETL included in the third electron assisting layer 466 may include an azine-based compound, for example, TmPyPB, and the second ETL included in the second electron assisting layer 456 may include an imidazole-based compound, for example, TPBi. The first ETL included in the first electron assisting layer 446 and the second ETL included in the second electron assisting layer 456 may have the same thickness, and the thickness of the third ETL included in the third electron assisting layer 466 may be greater than the thickness of each of the first ETL included in the first electron assisting layer 446 and the second ETL included in the second electron assisting layer 456.

[0228] The EIL included in the third electron assist layer 466 may include at least one of an alkali metal (e.g., Li), an alkali halide material (e.g., LiF, CsF, NaF, or BaF2), and an organometallic material (e.g., Liq, lithium benzoate, or sodium stearate), but is not limited thereto. For example, the EIL may have a thickness of 1-10 nm, preferably 1-5 nm.

[0229] Each of the first and third EMLs 442 and 462 provides light having a wavelength range of approximately 440-480 nm, and the second EML 452 provides light having a wavelength range of approximately 500-550 nm. The thickness of each of the first and third EMLs 442 and 462 may be equal to or less than that of the second EML 452.

[0230] exist Figure 5, the second EML 452 has a single-layer structure. Alternatively, the second EML 452 may have a double-layer structure having a first layer including a host and a red dopant and emitting red light, and a second layer including a host and a green dopant and emitting green light, or may have a triple-layer structure having a first layer including a host and a red dopant and emitting red light, a second layer including a host and a yellow-green dopant and emitting yellow-green light, and a third layer including a host and a green dopant and emitting green light.

[0231] In each of the first EML 442 and the third EML 462 having a wavelength range of 440 to 480 nm, the host may be an anthracene derivative, and the dopant may be a pyrene derivative. For example, in each of the first EML 442 and the third EML 462, the host may be 9,10-di(naphthalene-2-yl)anthracene, and the dopant may be 1,6-bis(diphenylamino)pyrene.

[0232] In the second EML 452 having a wavelength range of 500 to 550 nm, the host may be a carbazole derivative, and the dopant may be an iridium derivative (complex). For example, in the second EML 452, the host may be 4,4'-bis(N-carbazolyl)-1,1'-biphenyl (CBP), and the dopant may be tris(2-phenylpyridine)iridium(III) (Ir(ppy)3).

[0233] The first p-type doped layer 410 provides holes into the first emission portion 440 , the second p-type doped layer 420 provides holes into the second emission portion 450 , and the third p-type doped layer 430 provides holes into the third emission portion 460 .

[0234] For example, holes are provided from the first p-type doping layer 410 to the first EML 442 through the first hole assisting layer 444, and holes are provided from the second p-type doping layer 420 to the second EML 452 through the second hole assisting layer 454. In addition, holes are provided from the third p-type doping layer 430 to the third EML 462 through the third hole assisting layer 464.

[0235] The first p-type doped layer 410 may contact the first electrode 360 ​​and may be a hole injection layer. An n-type CGL 226 is disposed below the second p-type doped layer 420, and the second p-type doped layer 420 may be a p-type CGL. In this case, the second p-type doped layer 420 and the n-type CGL 426 below the second p-type doped layer 420 form a first CGL 428. An n-type CGL 436 is disposed below the third p-type doped layer 430, and the third p-type doped layer 430 may be a p-type CGL. In this case, the third p-type doped layer 430 and the n-type CGL 436 below the third p-type doped layer 430 form a second CGL 438.

[0236] That is, the second p-type doped layer 420 may be included in the first CGL 428 disposed between the first emission portion 440 and the second emission portion 450 , and the third p-type doped layer 430 may be included in the second CGL 438 disposed between the second emission portion 450 and the third emission portion 460 .

[0237] The n-type CGLs 426 and 436 provide electrons to the electron assisting layers 446 and 456, respectively, and the electrons are provided to the first emission portion 440 and the second emission portion 450 through the electron assisting layers 446 and 456. Therefore, the driving voltage of the OLED D having the multiple series structure is reduced, and the emission efficiency of the OLED D is improved.

[0238] For example, each of n-type CGLs 426 and 436 may include an n-type charge generation material, such as Bphen, and may have a thickness of 10-20 nm. In addition, each of n-type CGLs 426 and 436 may further include an auxiliary n-type charge generation material, such as Li.

[0239] The first p-type doped layer 410, serving as the HIL, has a first conductivity, the second p-type doped layer 420, serving as the p-type CGL of the first CGL 428, has a second conductivity, and the third p-type doped layer 430, serving as the p-type CGL of the second CGL 438, has a third conductivity. Each of the second and third conductivity is greater than the first conductivity, and the second conductivity is equal to or greater than the third conductivity. Preferably, the second conductivity may be greater than the third conductivity.

[0240] That is, the electrical conductivity of the first p-type doping layer 410, which is closer to the first electrode 360 ​​serving as the anode, is smaller than the electrical conductivity of each of the second p-type doping layer 420 and the third p-type doping layer 430, which are farther from the first electrode 360. In addition, the electrical conductivity of the third p-type doping layer 430, which is closer to the second electrode 364 serving as the cathode, is equal to or smaller than the electrical conductivity of the second p-type doping layer 420 located between the first p-type doping layer 410 and the third p-type doping layer 430.

[0241] In other words, the third p-type doping layer 430 has a conductivity greater than that of the first p-type doping layer 410 and equal to or less than that of the second p-type doping layer 420 .

[0242] For example, the conductivity of the first p-type doped layer 410 may be 1*10 -5 -1*10 -4 The conductivity of the second p-type doped layer 420 can be within the range of 1*10 -4 -1*10 -3S / cm, and the conductivity of the third p-type doped layer 430 can be within the range of 3*10 -5 -6*10 -4 Within the range of S / ㎝.

[0243] Each of the first p-type doping layer 410, the second p-type doping layer 420, and the third p-type doping layer 430 includes a p-type dopant 412, 422, and 432 and a bulk 414, 424, and 434. In each of the first p-type doping layer 410, the second p-type doping layer 420, and the third p-type doping layer 430, the weight percentage of the p-type dopant 412, 422, and 432 is less than the weight percentage of the bulk 414, 424, and 434.

[0244] The p-type dopants 412, 422 and 432 of the first p-type doping layer 410, the second p-type doping layer 420 and the third p-type doping layer 430 can be the first organic compound in Formula 1-1, and the bodies 414, 424 and 434 of the first p-type doping layer 410, the second p-type doping layer 420 and the third p-type doping layer 430 can be the second organic compound in Formula 2-1.

[0245] The weight percentage of the p-type dopant 412 in the first p-type doping layer 410 may be less than the weight percentage of each of the p-type dopant 422 in the second p-type doping layer 420 and the p-type dopant 432 in the third p-type doping layer 430. In addition, the weight percentage of the p-type dopant 422 in the second p-type doping layer 420 may be greater than the weight percentage of the p-type dopant 432 in the third p-type doping layer 430.

[0246] The p-type dopant 412 in the first p-type doping layer 410 may have a weight percentage of 1-20%, the p-type dopant 422 in the second p-type doping layer 420 may have a weight percentage of 10-50%, and the p-type dopant 432 in the third p-type doping layer 430 may have a weight percentage of 5-25%. For example, the p-type dopant 412 in the first p-type doping layer 410 may have a weight percentage of 5-15%, the p-type dopant 422 in the second p-type doping layer 420 may have a weight percentage of 10-30%, and the p-type dopant 432 in the third p-type doping layer 430 may have a weight percentage of 10-20%.

[0247] The p-type dopants 412, 422, and 432 of the first p-type doping layer 410, the second p-type doping layer 420, and the third p-type doping layer 430 may be the same or different. For example, when the p-type dopants 412, 422, and 432 of the first p-type doping layer 410, the second p-type doping layer 420, and the third p-type doping layer 430 are asymmetric compounds of Formula 1-4, the lifetime of the OLED D is further increased.

[0248] The bodies 414, 424, and 434 of the first p-type doping layer 410, the second p-type doping layer 420, and the third p-type doping layer 430 may be the same or different. For example, the bodies 414 and 434 of the first p-type doping layer 410 and the third p-type doping layer 430 may be the second organic compound of Formula 2-3, and the body 424 of the second p-type doping layer 420 may be the second organic compound of Formula 2-2.

[0249] The OLED including the first emission portion 440, the third emission portion 460, and the second emission portion 450 provides white light emission. Since the first CGL 428 and the second CGL 438 including the first organic compound of Formula 1-1 and the second organic compound of Formula 2-1 are respectively disposed between the first emission portion 440 and the second emission portion 450 and between the second emission portion 450 and the third emission portion 460, the OLED D has advantages in terms of driving voltage, emission efficiency, and lifespan.

[0250] In addition, OLED D includes a first p-type doping layer 410 closer to the first electrode 360 ​​serving as an anode, a third p-type doping layer 430 closer to the second electrode 364 serving as a cathode, and a second p-type doping layer 420 located between the first p-type doping layer 410 and the third p-type doping layer 430. Furthermore, the conductivity of the third p-type doping layer 430 is greater than that of the first p-type doping layer 410 and is equal to or less than that of the second p-type doping layer 420. Therefore, OLED D has advantages in terms of driving voltage, emission efficiency, and lifespan.

[0251] Furthermore, when the conductivity of the second p-type doping layer 420 is greater than the conductivity of the third p-type doping layer 430 , the driving voltage of the OLED D is further reduced, and the emission efficiency and lifespan of the OLED D are further increased.

[0252] In addition, when each of the first p-type doping layer 410, the second p-type doping layer 420 and the third p-type doping layer 430 includes the first organic compound in Formula 1-1 as the p-type dopant 412, 422 and 432 and the second organic compound in Formula 2-1 as the host 414, 424 and 434, the driving voltage of the OLED D is significantly reduced, and the emission efficiency and lifespan of the OLED D are significantly increased.

[0253] The second electrode 364 is formed on the first substrate 310 in which the organic emission layer 362 is formed.

[0254] In the organic light emitting display device 300 , since light emitted from the organic emission layer 362 is incident on the color filter layer 380 through the second electrode 364 , the second electrode 364 has a thin profile for transmitting the light.

[0255] The first electrode 360 ​​, the organic light emitting layer 362 , and the second electrode 364 constitute an OLED D.

[0256] The color filter layer 380 is positioned over the OLED D and includes a red filter 382, ​​a green filter 384, and a blue filter 386 corresponding to the red, green, and blue pixels RP, GP, and BP, respectively. The red filter 382 may include at least one of a red dye and a red pigment, the green filter 384 may include at least one of a green dye and a green pigment, and the blue filter 386 may include at least one of a blue dye and a blue pigment.

[0257] Although not shown, the color filter layer 380 may be attached to the OLED D by using an adhesive layer. Alternatively, the color filter layer 380 may be formed directly on the OLED D.

[0258] An encapsulation film (not shown) may be formed to prevent moisture from penetrating into the OLED D. For example, the encapsulation film may include a first inorganic insulating layer, an organic insulating layer, and a second inorganic insulating layer stacked in sequence, but is not limited thereto. The encapsulation film may be omitted.

[0259] A polarizing plate (not shown) for reducing ambient light reflection may be disposed on the top-emission type OLED D. For example, the polarizing plate may be a circular polarizing plate.

[0260] exist Figure 4 In the OLED D, the first electrode 360 ​​and the second electrode 364 are a reflective electrode and a transparent (or semi-transparent) electrode, respectively, and the color filter layer 380 is provided on the OLED D. Alternatively, when the first electrode 360 ​​and the second electrode 364 are a transparent (or semi-transparent) electrode and a reflective electrode, respectively, the color filter layer 380 may be provided between the OLED D and the first substrate 310.

[0261] A color conversion layer (not shown) may be formed between the OLED D and the color filter layer 380. The color conversion layer may include a red conversion layer, a green conversion layer, and a blue conversion layer corresponding to the red, green, and blue pixels RP, GP, and BP, respectively. The red, green, and blue conversion layers convert white light from the OLED D into red, green, and blue light, respectively. For example, the color conversion layer may include quantum dots. Thus, the color purity of the organic light-emitting display device 300 can be further improved.

[0262] A color conversion layer may be included instead of the color filter layer 380 .

[0263] As described above, in the organic light emitting display device 300, the OLEDs D in the red, green, and blue pixels RP, GP, and BP emit white light, and the white light from the organic light emitting diodes D passes through the red color filter 382, ​​the green color filter 384, and the blue color filter 386. Therefore, red light, green light, and blue light are provided from the red pixel RP, the green pixel GP, and the blue pixel BP, respectively.

[0264] exist Figure 4 In the present invention, an OLED D emitting white light is used in a display device. Alternatively, the OLED D can be formed on the entire surface of a substrate, without requiring at least one of a driving element and a color filter layer for an illumination device. Display devices and illumination devices each including an OLED D of the present disclosure can be referred to as organic light-emitting devices.

[0265] In the OLED D and the organic light-emitting display device 300, each of the first p-type doping layer 410 serving as the HIL, the second p-type doping layer 420 serving as the p-type CGL, and the third p-type doping layer 430 serving as the p-type CGL includes the first organic compound (e.g., a p-type dopant) of Formula 1-1 and the second organic compound (e.g., a host) of Formula 2-1, and the first p-type doping layer 410, which is closer to the first electrode 360 ​​serving as the anode, has a lower electrical conductivity than each of the second p-type doping layer 420 and the third p-type doping layer 430. Therefore, the driving voltage of the OLED D and the organic light-emitting display device 300 is reduced, and the emission efficiency and lifetime of the OLED D and the organic light-emitting display device 300 are increased.

[0266] In addition, the conductivity of the third p-type doping layer 430, which is closer to the second electrode 364 serving as the cathode, is lower than the conductivity of the second p-type doping layer 420. Therefore, the driving voltage of the OLED D and the organic light-emitting display device 300 is further reduced, and the emission efficiency and lifespan of the OLED D and the organic light-emitting display device 300 are further increased.

[0267] [OLED1]

[0268] On the anode (ITO), the HIL (10 nm), the first HTL (HTL1, 100 nm, NPD), the first EML (EML1, 20 nm, host (9,10-di(naphthalene-2-yl)anthracene) and dopant (1,6-bis(diphenylamino)pyrene, 3 wt %)), the first ETL (EYL1, 20 nm, 1,3,5-tris(m-pyridin-3-ylphenyl)benzene (TmPyPB)), the first n-type CGL (N-CGL1, 15 nm, Bphen+Li (2 wt %)), the first p-type CGL (P-CGL1, 10 nm), the second HTL (HTL2, 15 nm, NPD), the second EML (EML2, host (CBP) and dopant (Ir(ppy))) were deposited in sequence. , 8wt%)), a second ETL (ETL2, 20nm, 2,2',2"-(1,3,5-benzenetrimethyl)-tris(1-phenyl-1-Hbenzimidazole) (TPBi)), a second n-type CGL (N-CGL2, 15nm, Bphen+Li(2wt%)), a second p-type CGL (P-CGL2, 10nm), a third HTL (HTL2, 80nm, NPD), a third EML (EML3, 20nm, host (9,10-di(naphthalene-2-yl)anthracene) and dopant (1,6-bis(diphenylamino)pyrene, 3wt%), a third ETL (ETL3, 25nm, TmPyPB), an EIL (LiF, 1nm) and a cathode (Al, 150nm) to form an OLED.

[0269] 1. Comparative Example

[0270] (1) Comparative Example 1 (Ref 1)

[0271] A HIL is formed using compound S7 (10 wt %) in Formula 3 and compound C12 (90 wt %) in Formula 4, a first p-type CGL is formed using compound S7 (10 wt %) in Formula 3 and compound C12 (90 wt %) in Formula 4, and a second p-type CGL is formed using compound S7 (20 wt %) in Formula 3 and compound C12 (80 wt %) in Formula 4.

[0272] (2) Comparative Example 2 (Ref2)

[0273] A HIL is formed using compound S7 (10 wt %) in Formula 3 and compound C12 (90 wt %) in Formula 4, a first p-type CGL is formed using compound S7 (20 wt %) in Formula 3 and compound C12 (80 wt %) in Formula 4, and a second p-type CGL is formed using compound S7 (30 wt %) in Formula 3 and compound C12 (70 wt %) in Formula 4.

[0274] (3) Comparative Example 3 (Ref3)

[0275] A HIL is formed using compound S7 (10 wt %) in Formula 3 and compound C12 (90 wt %) in Formula 4, a first p-type CGL is formed using compound S7 (20 wt %) in Formula 3 and compound D8 (80 wt %) in Formula 4, and a second p-type CGL is formed using compound S7 (20 wt %) in Formula 3 and compound C12 (80 wt %) in Formula 4.

[0276] 2. Examples

[0277] (1) Example 1 (Ex1)

[0278] A HIL is formed using compound S7 (10 wt %) in Formula 3 and compound C12 (90 wt %) in Formula 4, a first p-type CGL is formed using compound S7 (20 wt %) in Formula 3 and compound C12 (80 wt %) in Formula 4, and a second p-type CGL is formed using compound S7 (20 wt %) in Formula 3 and compound C12 (80 wt %) in Formula 4.

[0279] (2) Example 2 (Ex2)

[0280] A HIL is formed using compound S7 (5wt%) in Formula 3 and compound C12 (95wt%) in Formula 4, a first p-type CGL is formed using compound S7 (20wt%) in Formula 3 and compound C12 (80wt%) in Formula 4, and a second p-type CGL is formed using compound S7 (20wt%) in Formula 3 and compound C12 (80wt%) in Formula 4.

[0281] (3) Example 3 (Ex3)

[0282] A HIL is formed using compound S7 (15 wt %) in Formula 3 and compound C12 (85 wt %) in Formula 4, a first p-type CGL is formed using compound S7 (20 wt %) in Formula 3 and compound C12 (80 wt %) in Formula 4, and a second p-type CGL is formed using compound S7 (20 wt %) in Formula 3 and compound C12 (80 wt %) in Formula 4.

[0283] (4) Example 4 (Ex4)

[0284] A HIL is formed using compound S7 (10 wt %) in Formula 3 and compound C12 (90 wt %) in Formula 4, a first p-type CGL is formed using compound S7 (30 wt %) in Formula 3 and compound C12 (70 wt %) in Formula 4, and a second p-type CGL is formed using compound S7 (20 wt %) in Formula 3 and compound C12 (80 wt %) in Formula 4.

[0285] (5) Example 5 (Ex5)

[0286] A HIL is formed using compound S7 (10 wt %) in Formula 3 and compound C12 (90 wt %) in Formula 4, a first p-type CGL is formed using compound S7 (20 wt %) in Formula 3 and compound C12 (80 wt %) in Formula 4, and a second p-type CGL is formed using compound S7 (10 wt %) in Formula 3 and compound C12 (90 wt %) in Formula 4.

[0287] (6) Example 6 (Ex6)

[0288] A HIL is formed using compound S7 (10 wt %) in Formula 3 and compound D8 (90 wt %) in Formula 4, a first p-type CGL is formed using compound S7 (20 wt %) in Formula 3 and compound C12 (80 wt %) in Formula 4, and a second p-type CGL is formed using compound S7 (20 wt %) in Formula 3 and compound C12 (80 wt %) in Formula 4.

[0289] (7) Example 7 (Ex7)

[0290] A HIL is formed using compound S7 (10 wt %) in Formula 3 and compound C12 (90 wt %) in Formula 4, a first p-type CGL is formed using compound S7 (20 wt %) in Formula 3 and compound C12 (80 wt %) in Formula 4, and a second p-type CGL is formed using compound S7 (20 wt %) in Formula 3 and compound D8 (80 wt %) in Formula 4.

[0291] (8) Example 8 (Ex8)

[0292] A HIL is formed using compound S7 (5wt%) in Formula 3 and compound C12 (95wt%) in Formula 4, a first p-type CGL is formed using compound S7 (30wt%) in Formula 3 and compound C12 (70wt%) in Formula 4, and a second p-type CGL is formed using compound S7 (10wt%) in Formula 3 and compound C12 (90wt%) in Formula 4.

[0293] (9) Example 9 (Ex9)

[0294] A HIL is formed using compound S7 (5wt%) in Formula 3 and compound C12 (95wt%) in Formula 4, a first p-type CGL is formed using compound S7 (30wt%) in Formula 3 and compound C12 (70wt%) in Formula 4, and a second p-type CGL is formed using compound S7 (20wt%) in Formula 3 and compound D8 (80wt%) in Formula 4.

[0295] (10) Example 10 (Ex10)

[0296] A HIL is formed using compound S7 (10 wt %) in Formula 3 and compound D8 (90 wt %) in Formula 4, a first p-type CGL is formed using compound S7 (30 wt %) in Formula 3 and compound C12 (70 wt %) in Formula 4, and a second p-type CGL is formed using compound S7 (20 wt %) in Formula 3 and compound D8 (80 wt %) in Formula 4.

[0297] (11) Example 11 (Ex11)

[0298] A HIL is formed using compound S20 (10 wt %) in Formula 3 and compound C12 (90 wt %) in Formula 4, a first p-type CGL is formed using compound S20 (30 wt %) in Formula 3 and compound C12 (70 wt %) in Formula 4, and a second p-type CGL is formed using compound S20 (20 wt %) in Formula 3 and compound D8 (80 wt %) in Formula 4.

[0299] (12) Example 12 (Ex12)

[0300] A HIL is formed using compound S20 (10 wt %) in Formula 3 and compound D8 (90 wt %) in Formula 4, a first p-type CGL is formed using compound S20 (30 wt %) in Formula 3 and compound D8 (70 wt %) in Formula 4, and a second p-type CGL is formed using compound S20 (20 wt %) in Formula 3 and compound D8 (80 wt %) in Formula 4.

[0301] (13) Example 13 (Ex13)

[0302] A HIL is formed using compound S20 (10 wt %) in Formula 3 and compound D8 (90 wt %) in Formula 4, a first p-type CGL is formed using compound S20 (30 wt %) in Formula 3 and compound C12 (70 wt %) in Formula 4, and a second p-type CGL is formed using compound S20 (20 wt %) in Formula 3 and compound C12 (80 wt %) in Formula 4.

[0303] (14) Example 14 (Ex14)

[0304] A HIL is formed using compound S20 (10 wt %) in Formula 3 and compound D8 (90 wt %) in Formula 4, a first p-type CGL is formed using compound S20 (30 wt %) in Formula 3 and compound C12 (70 wt %) in Formula 4, and a second p-type CGL is formed using compound S20 (10 wt %) in Formula 3 and compound C12 (90 wt %) in Formula 4.

[0305] (15) Example 15 (Ex15)

[0306] A HIL is formed using compound S20 (10 wt %) in Formula 3 and compound D8 (90 wt %) in Formula 4, a first p-type CGL is formed using compound S20 (10 wt %) in Formula 3 and compound C12 (90 wt %) in Formula 4, and a second p-type CGL is formed using compound S20 (20 wt %) in Formula 3 and compound D8 (80 wt %) in Formula 4.

[0307] (16) Example 16 (Ex16)

[0308] A HIL is formed using compound S20 (10 wt %) in Formula 3 and compound D8 (90 wt %) in Formula 4, a first p-type CGL is formed using compound S20 (30 wt %) in Formula 3 and compound C12 (70 wt %) in Formula 4, and a second p-type CGL is formed using compound S20 (20 wt %) in Formula 3 and compound D8 (80 wt %) in Formula 4.

[0309] (17) Example 17 (Ex17)

[0310] A HIL is formed using compound A13 (10 wt %) in Formula 3 and compound C12 (90 wt %) in Formula 4, a first p-type CGL is formed using compound A13 (30 wt %) in Formula 3 and compound C12 (70 wt %) in Formula 4, and a second p-type CGL is formed using compound A13 (20 wt %) in Formula 3 and compound D8 (80 wt %) in Formula 4.

[0311] (18) Example 18 (Ex18)

[0312] A HIL is formed using compound A13 (10 wt %) in Formula 3 and compound D8 (90 wt %) in Formula 4, a first p-type CGL is formed using compound A13 (30 wt %) in Formula 3 and compound D8 (70 wt %) in Formula 4, and a second p-type CGL is formed using compound A13 (20 wt %) in Formula 3 and compound D8 (80 wt %) in Formula 4.

[0313] (19) Example 19 (Ex19)

[0314] A HIL is formed using compound A13 (10 wt %) in Formula 3 and compound D8 (90 wt %) in Formula 4, a first p-type CGL is formed using compound A13 (30 wt %) in Formula 3 and compound C12 (70 wt %) in Formula 4, and a second p-type CGL is formed using compound A13 (20 wt %) in Formula 3 and compound C12 (80 wt %) in Formula 4.

[0315] (20) Example 20 (Ex20)

[0316] A HIL is formed using compound A13 (10 wt %) in Formula 3 and compound D8 (90 wt %) in Formula 4, a first p-type CGL is formed using compound A13 (30 wt %) in Formula 3 and compound C12 (70 wt %) in Formula 4, and a second p-type CGL is formed using compound A13 (10 wt %) in Formula 3 and compound C12 (90 wt %) in Formula 4.

[0317] (21) Example 21 (Ex21)

[0318] A HIL is formed using compound A13 (10 wt %) in Formula 3 and compound D8 (90 wt %) in Formula 4, a first p-type CGL is formed using compound A13 (10 wt %) in Formula 3 and compound C12 (90 wt %) in Formula 4, and a second p-type CGL is formed using compound A13 (20 wt %) in Formula 3 and compound D8 (80 wt %) in Formula 4.

[0319] (22) Example 22 (Ex22)

[0320] A HIL is formed using compound A13 (10 wt %) in Formula 3 and compound D8 (90 wt %) in Formula 4, a first p-type CGL is formed using compound A13 (30 wt %) in Formula 3 and compound C12 (70 wt %) in Formula 4, and a second p-type CGL is formed using compound A13 (20 wt %) in Formula 3 and compound D8 (80 wt %) in Formula 4.

[0321] In the OLEDs of Comparative Examples 1 to 3 (Ref1 to Ref3) and Examples 1 to 22 (Ex1 to Ex22), the conductivity (S) and performance, i.e., driving voltage (V), efficiency (Cd / A), and lifetime (hr), of each of the HIL, the first p-type CGL (P-CGL1), and the second p-type CGL (P-CGL2) were measured and listed in Tables 1 and 2.

[0322] Table 1

[0323]

[0324] Table 2

[0325]

[0326] As shown in Tables 1 and 2, compared to the OLEDs of Ref1 to Ref3 in which the conductivity of the first p-type CGL (e.g., the second p-type doping layer) is not greater than the conductivity of the HIL (e.g., the first p-type doping layer) and / or less than the conductivity of the second p-type CGL (e.g., the third p-type doping layer), in the OLEDs of Ex1 to Ex22, in which the conductivity of the second p-type CGL (e.g., the third p-type doping layer) is greater than the conductivity of the HIL (e.g., the first p-type doping layer) and equal to or less than the conductivity of the first p-type CGL (e.g., the second p-type doping layer), the driving voltage is reduced and the emission efficiency is improved. In particular, the lifetime of the OLEDs of Ex1 to Ex22 is significantly improved.

[0327] Furthermore, the lifespan of the OLEDs of Ex17 to Ex22 using the indacene derivatives having an asymmetric structure as the p-type dopant is further increased compared to the OLEDs of Ex1 to Ex16 using the indacene derivatives having a symmetric structure as the p-type dopant.

[0328] In addition, in the OLEDs of Ex10, Ex15, Ex16, Ex21 and Ex22, in which the first organic compound in Formula 2-3 is included in the HIL (e.g., the first p-type doping layer) and the second p-type CGL (e.g., the third p-type doping layer), and the first organic compound in Formula 2-2 is included in the first p-type CGL (e.g., the second p-type doping layer), the lifespan is significantly increased.

[0329] It will be apparent to those skilled in the art that various modifications and variations may be made to the embodiments of the present disclosure without departing from the spirit or scope of the present disclosure. Therefore, as long as these modifications and variations fall within the scope of the appended claims and their equivalents, these modifications and variations are included in the present disclosure.

Claims

1. An organic light emitting diode, comprising: a first electrode; a second electrode facing the first electrode; a first p-type doped layer, located between the first electrode and the second electrode; a second p-type doped layer, located between the first p-type doped layer and the second electrode; a third p-type doped layer, located between the second p-type doped layer and the second electrode; a first emission material layer, located between the first p-type doped layer and the second p-type doped layer; a second emission material layer, located between the second p-type doped layer and the third p-type doped layer; and a third emission material layer located between the third p-type doped layer and the second electrode, The electrical conductivity of the third p-type doping layer is greater than the electrical conductivity of the first p-type doping layer and is equal to or less than the electrical conductivity of the second p-type doping layer.

2. The organic light emitting diode according to claim 1, wherein: The electrical conductivity of the third p-type doping layer is less than the electrical conductivity of the second p-type doping layer.

3. The organic light emitting diode according to claim 1, wherein: The conductivity of the first p-type doped layer is 1*10 -5 -1*10 -4 S / ㎝, the conductivity of the second p-type doped layer is within the range of 1×10 -4 -1*10 -3 S / cm, and the conductivity of the third p-type doped layer is within 3*10 -5 -6*10 -4 Within the range of S / ㎝.

4. The organic light emitting diode according to claim 1, wherein: Each of the first p-type doping layer, the second p-type doping layer, and the third p-type doping layer includes a p-type dopant and a host, The p-type dopant is a first organic compound of formula 1-1: [Formula 1-1] wherein R1 and R2 are each independently selected from hydrogen (H), deuterium (D), halogen and cyano, wherein each of R3 to R6 is independently selected from halogen, cyano, malononitrile, C1-C10 haloalkyl and C1-C10 haloalkoxy, and at least one of R3 and R4 and at least one of R5 and R6 is malononitrile, wherein X and Y are each independently a phenyl group substituted with at least one of a C1-C10 alkyl group, a halogen group, a cyano group, a malononitrile group, a C1-C10 haloalkyl group, and a C1-C10 haloalkoxy group, The host is the second organic compound of formula 2-1: [Formula 2-1] wherein X and Y are each independently selected from C6-C30 aryl and C5-C30 heteroaryl, and L is selected from C6-C30 arylene and C5-C30 heteroarylene, where a is 0 or 1, and wherein each of R1 to R14 is independently selected from H, D, a C1-C10 alkyl group, a C6-C30 aryl group, and a C5-C30 heteroaryl group, or adjacent two of R1 to R14 are connected to each other to form a condensed ring.

5. The organic light emitting diode according to claim 4, wherein the first organic compound is represented by one of Formulas 1-2 to 1-4: [Formula 1-2] [Formula 1-3] and [Formula 1-4] Wherein in Formula 1-4, each of X1 to X3 and each of Y1 to Y3 are independently selected from H, C1-C10 alkyl, halogen, cyano, malononitrile, C1-C10 haloalkyl and C1-C10 haloalkoxy, and satisfy at least one of the following conditions: i) X1 and Y1 are different, and ii) X2 is different from Y2 and Y3, or X3 is different from Y2 and Y3.

6. The organic light emitting diode according to claim 4, wherein the second organic compound is represented by Formula 2-2 or 2-3: [Formula 2-2] and [Formula 2-3] 7 . The organic light emitting diode according to claim 6 , wherein the host in each of the first p-type doping layer and the third p-type doping layer is represented by Formula 2-3, and the host in the second p-type doping layer is represented by Formula 2-2.

8. The organic light emitting diode according to claim 4, wherein the first organic compound is one of the compounds of Formula 3: [Formula 3] 9. The organic light emitting diode according to claim 4, wherein the second organic compound is one of the compounds of Formula 4: [Formula 4] 10. The organic light emitting diode according to claim 1, wherein: The p-type doped layer is a hole injection layer in contact with the first electrode.

11. The organic light emitting diode according to claim 1, wherein: Each of the second p-type doping layer and the third p-type doping layer is a p-type charge generation layer.

12. The organic light emitting diode according to claim 1, wherein: Each of the first emitting material layer and the third emitting material layer has an emission wavelength range of 440 to 480 nm, and the second emitting material layer has an emission wavelength range of 500 to 550 nm.

13. An organic light-emitting device, comprising: substrate; An organic light-emitting diode, the organic light-emitting diode being located on the substrate and comprising: a first electrode; a second electrode facing the first electrode; a first p-type doped layer located between the first electrode and the second electrode; a second p-type doped layer located between the first p-type doped layer and the second electrode; a third p-type doped layer located between the second p-type doped layer and the second electrode; a first emission material layer located between the first p-type doped layer and the second p-type doped layer; a second emission material layer located between the second p-type doped layer and the third p-type doped layer; and a third emission material layer located between the third p-type doped layer and the second electrode; and an encapsulation film covering the organic light emitting diode, The electrical conductivity of the third p-type doping layer is greater than the electrical conductivity of the first p-type doping layer and is equal to or less than the electrical conductivity of the second p-type doping layer.

14. The organic light-emitting device according to claim 13, wherein: A red pixel, a green pixel, and a blue pixel are defined on the substrate, and the organic light emitting diode corresponds to each of the red pixel, the green pixel, and the blue pixel, and The organic light-emitting device further comprises: A color filter layer is provided between the substrate and the organic light emitting diode or on the organic light emitting diode, and corresponds to a red pixel, a green pixel, and a blue pixel.

15. The organic light-emitting device according to claim 13, wherein: The conductivity of the first p-type doped layer is 1*10 -5 -1*10 -4 S / ㎝, the conductivity of the second p-type doped layer is within the range of 1×10 -4 -1*10 -3 S / cm, and the conductivity of the third p-type doped layer is within 3*10 -5 -6*10 -4 Within the range of S / ㎝.

16. The organic light-emitting device according to claim 13, wherein: Each of the first p-type doping layer, the second p-type doping layer, and the third p-type doping layer includes a p-type dopant and a host, The p-type dopant is a first organic compound of formula 1-1: [Formula 1-1] wherein R1 and R2 are each independently selected from hydrogen (H), deuterium (D), halogen and cyano, wherein each of R3 to R6 is independently selected from halogen, cyano, malononitrile, C1-C10 haloalkyl and C1-C10 haloalkoxy, and at least one of R3 and R4 and at least one of R5 and R6 is malononitrile, wherein X and Y are each independently a phenyl group substituted with at least one of a C1-C10 alkyl group, a halogen group, a cyano group, a malononitrile group, a C1-C10 haloalkyl group, and a C1-C10 haloalkoxy group, The host is the second organic compound of formula 2-1: [Formula 2-1] wherein X and Y are each independently selected from C6-C30 aryl and C5-C30 heteroaryl, and L is selected from C6-C30 arylene and C5-C30 heteroarylene, where a is 0 or 1, and wherein each of R1 to R14 is independently selected from H, D, a C1-C10 alkyl group, a C6-C30 aryl group, and a C5-C30 heteroaryl group, or adjacent two of R1 to R14 are connected to each other to form a condensed ring.

17. The organic light-emitting device according to claim 16, wherein the first organic compound is represented by one of Formulas 1-2 to 1-4: [Formula 1-2] [Formula 1-3] and [Formula 1-4] Wherein in Formula 1-4, each of X1 to X3 and each of Y1 to Y3 are independently selected from H, C1-C10 alkyl, halogen, cyano, malononitrile, C1-C10 haloalkyl and C1-C10 haloalkoxy, and satisfy at least one of the following conditions: i) X1 and Y1 are different, and ii) X2 is different from Y2 and Y3, or X3 is different from Y2 and Y3.

18. The organic light-emitting device according to claim 16, wherein the second organic compound is represented by Formula 2-2 or 2-3: [Formula 2-2] and [Formula 2-3] 19. The organic light-emitting device according to claim 16, wherein the first organic compound is one of the compounds of Formula 3: [Formula 3] 20. The organic light-emitting device according to claim 16, wherein the second organic compound is one of the compounds of Formula 4: [Formula 4]

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