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

Abstract

The present invention provides an organic light-emitting diode and an organic light-emitting device comprising: a first electrode; a second electrode facing the first electrode; a first blue light-emitting material layer comprising a first blue light-emitting layer and a second blue light-emitting layer, and a first light-emitting part located between the first electrode and the second electrode, wherein the first blue light-emitting layer comprises a first p-type host and a first n-type host, and the second blue light-emitting layer comprises a second p-type host and a second n-type host, and the first p-type host and the second p-type host have different hole mobilities.

Description

Technology Field

[0001] The present invention relates to an organic light-emitting diode, and more specifically, to an organic light-emitting diode having a low driving voltage and an improved lifespan, and an organic light-emitting device including the same. Background Technology

[0003] With the increasing size of display devices, there is a growing demand for flat display devices that occupy less space. As one of these flat display devices, the technology of organic light emitting display (OLED) devices, which include organic light-emitting diodes and are also called organic electroluminescent devices (OLEDs), is developing rapidly.

[0004] In organic light-emitting diodes, holes injected from the anode and electrons injected from the cathode combine in the light-emitting material layer to form excitons, which become an unstable energy state (excited state) and then return to a stable ground state, emitting light.

[0005] However, conventional organic light-emitting diodes have limitations in luminescence characteristics such as driving voltage and lifespan. In particular, blue organic light-emitting diodes have significant limitations in luminescence characteristics. The problem to be solved

[0007] The present invention aims to solve the problems of high driving voltage and short lifespan of conventional organic light-emitting diodes. means of solving the problem

[0009] To solve the above problem, the present invention comprises: a first electrode; and a second electrode facing the first electrode; The first blue emitting material layer comprising a first blue emitting layer and a second blue emitting layer comprises a first emitting part located between the first electrode and the second electrode, wherein the first blue emitting layer comprises a first p-type host and a first n-type host, and the second blue emitting layer comprises a second p-type host and a second n-type host, and one of the first p-type host and the second p-type host is a first compound represented by Chemical Formula 1a or Chemical Formula 1b, wherein in Chemical Formula 1a, a1 and a4 are each independently integers from 0 to 3, a2, a3, a5 to a8 are each independently integers from 0 to 4, n1 is 0 or 1, and R1 to R8 are each independently deuterium, halogen, cyano group, substituted or unsubstituted C6 to C30 arylsilyl group, substituted or unsubstituted C1 to C20 alkyl group, substituted or unsubstituted C6 Selected from the group consisting of an aryl group of up to C30, a substituted or unsubstituted heteroaryl group of C5 to C60, a substituted or unsubstituted arylamine group of C1 to C30, and a substituted or unsubstituted arylamine group of C6 to C60, wherein in Formula 1b, b1 is an integer from 0 to 3, each of b2 to b4 is independently an integer from 0 to 4, b5 is an integer from 0 to 5, and each of R11 to R15 is independently selected from the group consisting of deuterium, halogen, cyano group, a substituted or unsubstituted arylsilyl group of C6 to C30, a substituted or unsubstituted alkyl group of C1 to C20, a substituted or unsubstituted aryl group of C6 to C30, a substituted or unsubstituted heteroaryl group of C5 to C60, a substituted or unsubstituted arylamine group of C1 to C30, and a substituted or unsubstituted arylamine group of C6 to C60, and the The other of the 1 p-type host and the 2 p-type host is a 2 compound represented by Chemical Formula 3a or Chemical Formula 3b, andIn Formula 3a, d1 and d4 are each independently integers from 0 to 3, d2, d3, d5 to d8 are each independently integers from 0 to 4, n2 and n3 are each independently 0 or 1, and R21 to R28 are each independently selected from the group consisting of deuterium, halogen, cyano group, substituted or unsubstituted C6 to C30 arylsilyl group, substituted or unsubstituted C1 to C20 alkyl group, substituted or unsubstituted C6 to C30 aryl group, substituted or unsubstituted C5 to C60 heteroaryl group, substituted or unsubstituted C1 to C30 arylamine group, and substituted or unsubstituted C6 to C60 arylamine group; in Formula 3b, e1 and e4 are each independently integers from 0 to 3, e2, e3, e5, e6 are each independently integers from 0 to 4, and e7 is The present invention provides an organic light-emitting diode characterized in that R31 to R37 is an integer from 0 to 5, and each of R31 to R37 is independently selected from the group consisting of deuterium, halogen, cyano group, substituted or unsubstituted C6 to C30 arylsilyl group, substituted or unsubstituted C1 to C20 alkyl group, substituted or unsubstituted C6 to C30 aryl group, substituted or unsubstituted C5 to C60 heteroaryl group, substituted or unsubstituted C1 to C30 arylamine group, and substituted or unsubstituted C6 to C60 arylamine group.

[0010] [Chemical Formula 1a]

[0011] [Chemical Formula 1b]

[0012] [Chemical Formula 3a]

[0013] [Chemical Formula 3b]

[0014] In the organic light-emitting diode of the present invention, the first n-type host and the second n-type host are each represented by Chemical Formula 5, wherein in Chemical Formula 5, f1, f5, and f6 are each integers from 0 to 4, f2 to f4 are each independently integers from 0 to 5, X is selected from the group consisting of C, Si, and Ge, and R41 to R47 are each independently selected from the group consisting of deuterium, halogen, cyano group, substituted or unsubstituted C6 to C30 arylsilyl group, substituted or unsubstituted C6 to C30 arylgermanyl group, substituted or unsubstituted C1 to C20 alkyl group, substituted or unsubstituted C6 to C30 aryl group, substituted or unsubstituted C5 to C60 heteroaryl group, substituted or unsubstituted C1 to C30 arylamine group, and substituted or unsubstituted C6 to C60 arylamine group. does.

[0015] [Chemical Formula 5]

[0016] In the organic light-emitting diode of the present invention, the first blue light-emitting layer comprises a first phosphorescent dopant, and the second blue light-emitting layer comprises a second phosphorescent dopant, wherein each of the first phosphorescent dopant and the second phosphorescent dopant is represented by Chemical Formula 7, wherein in Chemical Formula 7, each of R51 to R56 is independently selected from the group consisting of deuterium, halogen, cyano group, substituted or unsubstituted C1 to C20 alkyl group, substituted or unsubstituted C3 to C20 cycloalkyl group, C1 to C20 alkylsilyl group, substituted or unsubstituted C1 to C20 alkylamino group, substituted or unsubstituted C6 to C30 arylamino group, substituted or unsubstituted C6 to C30 arylsilyl group, substituted or unsubstituted C6 to C30 aryl group, substituted or unsubstituted C3 to C30 heteroaryl group, and g1, g2, Each of g3 is independently an integer from 0 to 4, g4 is an integer from 0 to 3, and g5 is an integer from 0 to 2.

[0017] [Chemical Formula 7]

[0018] In the organic light-emitting diode of the present invention, the first p-type host and the first n-type host form a first exciplex in the first blue light-emitting layer, and the difference between the onset wavelength in the absorption spectrum of the first phosphorescent dopant and the onset wavelength in the first exciplex PL spectrum is 10 nm or more, and in the second blue light-emitting layer, the second p-type host and the second n-type host form a second exciplex, and the difference between the onset wavelength in the absorption spectrum of the second phosphorescent dopant and the onset wavelength in the second exciplex PL spectrum is 10 nm or more.

[0019] The organic light-emitting diode of the present invention is characterized in that the difference between the lowest unoccupied molecular orbital (LUMO) energy level of the first phosphorescent dopant and the LUMO energy level of the first n-type host is 0.2 eV or more, and the difference between the LUMO energy level of the second phosphorescent dopant and the LUMO energy level of the second n-type host is 0.2 eV or more.

[0020] In the organic light-emitting diode of the present invention, the first p-type host and the first n-type host form a first exciplex in the first blue light-emitting layer, and the onset wavelength in the PL spectrum of the first phosphorescent dopant is equal to or greater than the onset wavelength in the PL spectrum of the first exciplex, and the second p-type host and the second n-type host form a second exciplex in the second blue light-emitting layer, and the onset wavelength in the PL spectrum of the second phosphorescent dopant is equal to or greater than the onset wavelength in the PL spectrum of the second exciplex.

[0021] The organic light-emitting diode of the present invention is characterized in that the difference between the LUMO energy level of the first p-type host and the LUMO energy level of the first n-type host is 0.2 eV or more, the difference between the energy level of the highest occupied molecular orbital (HOMO) of the first p-type host and the HOMO energy level of the first n-type host is 0.3 eV or more, the difference between the LUMO energy level of the second p-type host and the LUMO energy level of the second n-type host is 0.2 eV or more, and the difference between the energy level of the highest occupied molecular orbital (HOMO) of the second p-type host and the HOMO energy level of the second n-type host is 0.3 eV or more.

[0022] The organic light-emitting diode of the present invention is characterized by including a second blue light-emitting material layer and further including a second light-emitting part located between the first light-emitting part and the first electrode or between the first light-emitting part and the second electrode.

[0023] In the organic light-emitting diode of the present invention, the second blue light-emitting material layer comprises a third blue light-emitting layer and a fourth blue light-emitting layer, the third blue light-emitting layer comprises a third p-type host and a third n-type host, the fourth blue light-emitting layer comprises a fourth p-type host and a fourth n-type host, one of the third p-type host and the fourth p-type host is represented by the chemical formula 1a or the chemical formula 1b, and the other of the third p-type host and the fourth p-type host is represented by the chemical formula 3a or the chemical formula 3b.

[0024] In the organic light-emitting diode of the present invention, the third n-type host and the fourth n-type host are each represented by Chemical Formula 5, wherein in Chemical Formula 5, f1, f5, and f6 are each integers from 0 to 4, f2 to f4 are each independently integers from 0 to 5, X is selected from the group consisting of C, Si, and Ge, and R41 to R47 are each independently selected from the group consisting of deuterium, halogen, cyano group, substituted or unsubstituted C6 to C30 arylsilyl group, substituted or unsubstituted C6 to C30 arylgermanyl group, substituted or unsubstituted C1 to C20 alkyl group, substituted or unsubstituted C6 to C30 aryl group, substituted or unsubstituted C5 to C60 heteroaryl group, substituted or unsubstituted C1 to C30 arylamine group, and substituted or unsubstituted C6 to C60 arylamine group. does.

[0025] [Chemical Formula 5]

[0026] In the organic light-emitting diode of the present invention, the third blue light-emitting layer comprises a third phosphorescent dopant, and the fourth blue light-emitting layer comprises a fourth phosphorescent dopant, wherein each of the third phosphorescent dopant and the fourth phosphorescent dopant is represented by Chemical Formula 7, wherein in Chemical Formula 7, each of R51 to R56 is independently selected from the group consisting of deuterium, halogen, cyano group, substituted or unsubstituted C1 to C20 alkyl group, substituted or unsubstituted C3 to C20 cycloalkyl group, C1 to C20 alkylsilyl group, substituted or unsubstituted C1 to C20 alkylamino group, substituted or unsubstituted C6 to C30 arylamino group, substituted or unsubstituted C6 to C30 arylsilyl group, substituted or unsubstituted C6 to C30 aryl group, substituted or unsubstituted C3 to C30 heteroaryl group, and g1, g2, Each of g3 is independently an integer from 0 to 4, g4 is an integer from 0 to 3, and g5 is an integer from 0 to 2.

[0027] [Chemical Formula 7]

[0028] In the organic light-emitting diode of the present invention, the second blue light-emitting material layer comprises a blue host and a blue dopant, wherein the blue host comprises at least one of the compounds of Chemical Formula 14 below, and the blue dopant is one of the compounds of Chemical Formula 15 below.

[0029] [Chemical Formula 14]

[0030]

[0031] [Chemical Formula 15]

[0032]

[0033] In the organic light-emitting diode of the present invention, the second blue light-emitting material layer further comprises an auxiliary dopant, and the auxiliary dopant is characterized as being one of the compounds of Chemical Formula 16 below.

[0034] [Chemical Formula 16]

[0035]

[0036] The organic light-emitting diode of the present invention is characterized by further including a third light-emitting part located between the first light-emitting part and the second light-emitting part, and including a red light-emitting material layer and a green light-emitting material layer.

[0037] In another aspect, the present invention provides an organic light-emitting device comprising: a substrate; the aforementioned organic light-emitting diode located on the substrate; and an encapsulation layer covering the organic light-emitting diode.

[0038] The organic light-emitting device of the present invention is characterized by further including a color filter layer located between the substrate and the organic light-emitting diode or on the encapsulation layer. Effects of the invention

[0040] The organic light-emitting diode of the present invention comprises adjacent first and second blue light-emitting layers, each of which comprises a p-type host and an n-type host, and the p-type host of the first blue light-emitting layer and the n-type host of the second blue light-emitting layer have different hole mobilities. Accordingly, the organic light-emitting diode of the present invention and the organic light-emitting device including it have the effect of enabling low-power driving by having a low driving voltage and an improved lifespan.

[0041] In other words, the recombination zone of holes and electrons is expanded in the light-emitting material layer by p-type hosts having different hole mobilities, thereby reducing the driving voltage and significantly increasing the lifespan of organic light-emitting diodes and organic light-emitting devices containing them.

[0042] In addition, in each of the first and second blue light-emitting layers, the p-type host and the n-type host form an exciplex, thereby suppressing charge trapping to the phosphorescent dopant in each of the first and second blue light-emitting layers, and accordingly, the driving voltage of the organic light-emitting diode and the organic light-emitting device including it is further reduced and the lifespan is further increased.

[0043] In addition, the organic light-emitting diode of the present invention has a multi-stack structure comprising a first blue light-emitting part including a first blue light-emitting material layer and a second blue light-emitting part including a second blue light-emitting material layer, wherein at least one of the first and second blue light-emitting material layers includes adjacent first and second blue light-emitting layers, and each of the first and second blue light-emitting layers includes a p-type host and an n-type host, and the p-type host of the first blue light-emitting layer and the n-type host of the second blue light-emitting layer have different hole mobilities. Accordingly, the organic light-emitting diode of the present invention and the organic light-emitting device including the same have a low driving voltage and improved lifespan and brightness.

[0044] In addition, the present invention provides a white organic light-emitting diode with a multi-stack structure including a blue light-emitting portion, wherein the light-emitting material layer in the blue light-emitting portion includes adjacent first and second blue light-emitting layers, and each of the first and second blue light-emitting layers includes a p-type host and an n-type host, and the p-type host of the first blue light-emitting layer and the n-type host of the second blue light-emitting layer have different hole mobilities. Accordingly, the organic light-emitting diode of the present invention and the organic light-emitting device including the same have a low driving voltage and improved lifespan and brightness. Brief explanation of the drawing

[0046] FIG. 1 is a schematic circuit diagram of an organic light-emitting display device according to the present invention. FIG. 2 is a schematic cross-sectional view of an organic light-emitting display device according to a first embodiment of the present invention. FIG. 3 is a schematic cross-sectional view of an organic light-emitting diode according to a second embodiment of the present invention. Figures 4a and 4b are graphs showing hole mobility and electron mobility by the host. Figure 5 is a graph showing the photoluminescence (PL) spectrum of the host and the absorption spectrum of the phosphorescent dopant. FIG. 6 is a schematic cross-sectional view of an organic light-emitting diode according to a third embodiment of the present invention. FIG. 7 is a schematic cross-sectional view of an organic light-emitting diode according to a fourth embodiment of the present invention. FIG. 8 is a schematic cross-sectional view of an organic light-emitting diode according to the fifth embodiment of the present invention. FIG. 9 is a schematic cross-sectional view of an organic light-emitting display device according to the 6th embodiment of the present invention. FIG. 10 is a schematic cross-sectional view of an organic light-emitting display device according to the 7th embodiment of the present invention. FIG. 11 is a schematic cross-sectional view of an organic light-emitting diode according to the eighth embodiment of the present invention. FIG. 12 is a schematic cross-sectional view of an organic light-emitting diode according to the ninth embodiment of the present invention. FIG. 13 is a schematic cross-sectional view of an organic light-emitting diode according to the 10th embodiment of the present invention. Specific details for implementing the invention

[0047] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims.

[0048] Shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining embodiments of the present invention are exemplary, and therefore the present invention is not limited to the depicted details. Throughout the specification, the same reference numerals refer to the same components. Furthermore, in describing the present invention, if it is determined that a detailed description of related prior art could unnecessarily obscure the essence of the present invention, such detailed description is omitted. Where terms such as "includes," "has," or "is made up" are used in this specification, other parts may be added unless "only" is used. Where a component is expressed in the singular, it includes cases where it is included in the plural unless specifically stated otherwise.

[0049] In interpreting the components, they are interpreted to include a margin of error even in the absence of a separate explicit statement.

[0050] In the case of describing a positional relationship, for example, when the positional relationship between two parts is described using expressions such as 'on,' 'upper,' 'lower,' or 'next to,' one or more other parts may be located between the two parts unless 'immediately' or 'directly' is used.

[0051] In the case of an explanation of a temporal relationship, for example, when a temporal sequence is explained using 'after', 'following', 'next', 'before', etc., it may include cases where the sequence is not continuous unless 'immediately' or 'directly' is used.

[0052] Although terms such as "first," "second," etc., are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another. Accordingly, the first component mentioned below may be the second component within the technical scope of the present invention.

[0053] The features of each of the various embodiments of the present invention may be combined or combined with one another, either partially or wholly, and may technically enable various interlocking and operation. Each embodiment may be implemented independently of one another or may be implemented together in an associated relationship.

[0054] Hereinafter, preferred embodiments according to the present invention will be described with reference to the drawings.

[0055] The present invention relates to an organic light-emitting diode and an organic light-emitting device comprising an organic light-emitting diode, wherein each adjacent blue light-emitting layer comprises a p-type host and an n-type host, and the p-type host has a different hole mobility. For example, the organic light-emitting device may be an organic light-emitting display device or an organic light-emitting light. As an example, the description will focus on an organic light-emitting display device that is a display device comprising the organic light-emitting diode of the present invention.

[0056] FIG. 1 is a schematic circuit diagram of an organic light-emitting display device according to the present invention.

[0057] As illustrated in FIG. 1, in an organic light-emitting display device, gate wiring (GL), data wiring (DL), and power wiring (PL) are formed intersecting each other to define a pixel area (P). In the pixel area (P), a switching thin-film transistor (Ts), a driving thin-film transistor (Td), a storage capacitor (Cst), and an organic light-emitting diode (D) are formed. The pixel area (P) may include a red pixel area, a green pixel area, and a blue pixel area.

[0058] The switching thin-film transistor (Ts) is connected to the gate wiring (GL) and data wiring (DL), and the driving thin-film transistor (Td) and storage capacitor (Cst) are connected between the switching thin-film transistor (Ts) and the power wiring (PL). The organic light-emitting diode (D) is connected to the driving thin-film transistor (Td).

[0059] In this organic light-emitting display device, when the switching thin-film transistor (Ts) is turned on according to the gate signal applied to the gate wiring (GL), the data signal applied to the data wiring (DL) is applied to the gate electrode of the driving thin-film transistor (Td) and one electrode of the storage capacitor (Cst) through the switching thin-film transistor (Ts).

[0060] The driving thin-film transistor (Td) is turned on according to a data signal applied to the gate electrode, and as a result, a current proportional to the data signal flows from the power wiring (PL) through the driving thin-film transistor (Td) to the organic light-emitting diode (D), and the organic light-emitting diode (D) emits light with a brightness proportional to the current flowing through the driving thin-film transistor (Td).

[0061] At this time, the storage capacitor (Cst) is charged with a voltage proportional to the data signal so that the voltage of the gate electrode of the driving thin-film transistor (Td) is maintained constant during one frame.

[0062] Therefore, the organic light-emitting display device can display a desired image.

[0063] FIG. 2 is a schematic cross-sectional view of an organic light-emitting display device according to a first embodiment of the present invention.

[0064] As illustrated in FIG. 2, the organic light-emitting display device (100) comprises a substrate (110), a thin-film transistor (Tr) located on the substrate (110), a flattening layer (150) covering the thin-film transistor (Tr), and an organic light-emitting diode (D) located on the flattening layer (150) and connected to the thin-film transistor (Tr). A red pixel area, a green pixel area, and a blue pixel area are defined on the substrate (110).

[0065] The substrate (110) may be a glass substrate or a flexible substrate. For example, the flexible substrate may be one of a polyimide (PI) substrate, a polyethersulfone (PES) substrate, a polyethylenenaphthalate (PEN) substrate, a polyethylene terephthalate (PET) substrate, and a polycarbonate (PC) substrate.

[0066] A buffer layer (122) is formed on a substrate (110), and a thin-film transistor (Tr) is formed on the buffer layer (122). The buffer layer (122) may be omitted. The buffer layer (122) may be made of an inorganic insulating material such as silicon oxide or silicon nitride.

[0067] A semiconductor layer (120) is formed on top of a buffer layer (122). For example, the semiconductor layer (120) may be made of an oxide semiconductor material. If the semiconductor layer (120) is made of an oxide semiconductor material, a light-blocking pattern (not shown) may be formed on the bottom of the semiconductor layer (120). The light-blocking pattern prevents light from being incident on the semiconductor layer (120), thereby preventing the semiconductor layer (120) from deteriorating due to light. Alternatively, the semiconductor layer (120) may be made of polycrystalline silicon, in which case impurities may be doped into both edges of the semiconductor layer (120).

[0068] A gate insulating film (124) is formed on the upper surface of the semiconductor layer (120) on the front surface of the substrate (110). The gate insulating film (124) may be made of an inorganic insulating material such as silicon oxide (SiOx) or silicon nitride (SiNx).

[0069] A gate electrode (130) made of a conductive material such as metal is formed on the upper part of the gate insulating film (124) in correspondence with the center of the semiconductor layer (120). In FIG. 2, the gate insulating film (122) is formed on the front surface of the substrate (110), but the gate insulating film (120) may be patterned in the same shape as the gate electrode (130).

[0070] An interlayer insulating film (132) is formed on the front surface of the substrate (110) above the gate electrode (130). The interlayer insulating film (132) may be formed from an inorganic insulating material such as silicon oxide or silicon nitride, or from an organic insulating material such as benzocyclobutene or photoacryl.

[0071] The interlayer insulating film (132) has first and second semiconductor layer contact holes (134, 136) that expose the upper surfaces of both sides of the semiconductor layer (120). The first and second semiconductor layer contact holes (134, 136) are located spaced apart from the gate electrode (130) on both sides of the gate electrode (130). In FIG. 2, the first and second semiconductor layer contact holes (134, 136) are formed in the interlayer insulating film (132) and the gate insulating film (122). Alternatively, if the gate insulating film (122) is patterned in the same shape as the gate electrode (130), the first and second semiconductor layer contact holes (134, 136) may be formed only within the interlayer insulating film (132).

[0072] A source electrode (144) and a drain electrode (146) made of a conductive material such as metal are formed on the upper part of the interlayer insulating film (132). The source electrode (144) and the drain electrode (146) are spaced apart from the gate electrode (130) and contact both sides of the semiconductor layer (120) through the first and second semiconductor layer contact holes (134, 136), respectively.

[0073] The semiconductor layer (120), gate electrode (130), source electrode (144), and drain electrode (146) form a thin-film transistor (Tr), and the thin-film transistor (Tr) functions as a driving element. That is, the thin-film transistor (Tr) is the driving thin-film transistor (Td) of FIG. 1.

[0074] In FIG. 2, the thin-film transistor (Tr) has a coplanar structure in which the gate electrode (130), source electrode (144), and drain electrode (146) are located on top of the semiconductor layer (120). Alternatively, the thin-film transistor (Tr) may have an inverted staggered structure in which the gate electrode is located on the bottom of the semiconductor layer and the source electrode and drain electrode are located on top of the semiconductor layer. In this case, the semiconductor layer may be made of amorphous silicon.

[0075] Although not illustrated, gate wiring and data wiring intersect to define a pixel region, and a switching thin-film transistor, which is a switching element connected to the gate wiring and data wiring, is further formed. The switching element is connected to a thin-film transistor (Tr), which is a driving element. Additionally, power wiring is formed spaced apart from the data wiring or parallel to the data wiring, and a storage capacitor may be further configured to maintain the voltage of the gate electrode of the thin-film transistor (Tr) constant during one frame.

[0076] A flattening layer (150) is formed on the front surface of the substrate (110) above the source electrode (144) and the drain electrode (146). The flattening layer (150) has a flat upper surface and has a drain contact hole (152) that exposes the drain electrode (146) of the thin-film transistor (Tr).

[0077] The organic light-emitting diode (D) includes a first electrode (210) located on a planarization layer (150) and connected to the drain electrode (146) of a thin-film transistor (Tr), an organic light-emitting layer (220) and a second electrode (230) sequentially stacked on the first electrode (210). The organic light-emitting diode (D) is located in each of the red pixel region, the green pixel region, and the blue pixel region and can emit red, green, and blue light, respectively.

[0078] The first electrode (210) is formed separately for each pixel area. The first electrode (210) may be an anode and includes a transparent conductive oxide layer made of a conductive material having a relatively large work function value, for example, a transparent conductive oxide (TCO).

[0079] For example, the transparent conductive oxide layer may be composed of any one of indium-tin-oxide (ITO), indium-zinc-oxide (IZO), indium-tin-zinc-oxide (ITZO), tin oxide (SnO), zinc oxide (ZnO), indium-copper-oxide (ICO), and aluminum:zinc oxide (Al:ZnO; AZO).

[0080] The first electrode (210) may have a single-layer structure of a transparent conductive oxide layer. That is, the first electrode (210) may be a transparent electrode.

[0081] In contrast, the first electrode (210) may have a double-layer or triple-layer structure including a reflective layer. That is, the first electrode (210) may be a reflective electrode.

[0082] For example, the reflective layer may be made of silver (Ag) or an alloy of silver with at least one of palladium (Pd), copper (Cu), indium (In), and neodymium (Nd), or an aluminum-palladium-copper (APC) alloy. For example, the first electrode (210) may have a double-layer structure of Ag / ITO or APC / ITO or a triple-layer structure of ITO / Ag / ITO or ITO / APC / ITO.

[0083] Additionally, a bank layer (160) covering the edge of the first electrode (210) is formed on the flattening layer (150). The bank layer (160) exposes the center of the first electrode (210) corresponding to the pixel area.

[0084] An organic light-emitting layer (220) including an emitting material layer (EML) is formed on the first electrode (210). In the organic light-emitting diode (D) of the blue pixel region, the emitting material layer of the organic light-emitting layer (220) includes a first blue light-emitting layer and a second blue light-emitting layer.

[0085] The organic light-emitting layer (220) may have a multilayer structure including at least one of a hole injection layer (HIL), a hole transport layer (HTL), an electron blocking layer (EBL), a hole blocking layer (HBL), an electron transport layer (ETL), and an electron injection layer (EIL).

[0086] In one embodiment, the organic light-emitting layer (220) of the organic light-emitting diode (D) in the blue pixel region has a multi-stack structure including a first blue light-emitting part including a first blue light-emitting material layer and a second blue light-emitting part including a second blue light-emitting material layer, and at least one of the first and second blue light-emitting material layers may include the first blue light-emitting layer and the second blue light-emitting layer. In this case, the organic light-emitting layer (220) may further include a charge generation layer (CGL) located between the first and second blue light-emitting parts.

[0087] As described below, in an organic light-emitting diode (D) of a blue pixel region, the first blue light-emitting layer and the second blue light-emitting layer each include a p-type host and an n-type host, and the p-type host of the first blue light-emitting layer and the p-type host of the second blue light-emitting layer have different hole mobilities. Accordingly, the recombination zone of holes and electrons is expanded in the light-emitting material layer, and thus, the organic light-emitting diode of the present invention and the organic light-emitting display device including it have a low driving voltage and an improved lifespan.

[0088] A second electrode (230) is formed on the substrate (110) on which the organic light-emitting layer (220) is formed. The second electrode (230) is located on the front of the display area and is made of a conductive material with a relatively small work function value and can be used as a cathode. For example, the second electrode (230) may be made of aluminum (Al), magnesium (Mg), calcium (Ca), silver (Ag), or an alloy thereof, for example, a magnesium-silver alloy (MgAg).

[0089] In the case where the organic light-emitting diode (D) is a top-emission type, the first electrode (210) is a reflective electrode and the second electrode (230) has a thin thickness and has light-transmitting (semi-transmitting) characteristics. In contrast, in the case where the organic light-emitting diode (D) is a bottom-emission type, the first electrode (210) is a transmitting electrode and the second electrode (230) is a reflective electrode.

[0090] Although not illustrated, the organic light-emitting diode (D) may further include a capping layer located on the second electrode (230). The light efficiency of the organic light-emitting diode (D) and the organic light-emitting display device (100) can be further improved by the capping layer.

[0091] On the second electrode (230), an encapsulation layer (170, encapsulation film) is formed to prevent external moisture from penetrating into the organic light-emitting diode (D). The encapsulation layer (170) may have a laminated structure of a first inorganic insulating layer (172), an organic insulating layer (174), and a second inorganic insulating layer (176), but is not limited thereto.

[0092] Alternatively, a metal encapsulation plate may be placed on top of the second electrode (230). For example, the encapsulation plate may be attached to the organic light-emitting diode (D) through an adhesive layer.

[0093] Although not illustrated, the organic light-emitting display device (100) may include a color filter layer (not illustrated) corresponding to red, green, and blue pixel regions. For example, the color filter layer may be placed on top of the organic light-emitting diode (D) or between the substrate (110) and the organic light-emitting diode (D). For example, the color filter layer may be formed on an encapsulation layer (170).

[0094] The organic light-emitting display device (100) may further include a polarizing plate (not shown) to reduce the reflection of external light. For example, the polarizing plate (not shown) may be a circular polarizing plate. If the organic light-emitting display device (100) is a bottom-emitting type, the polarizing plate may be located below the substrate (110). Meanwhile, if the organic light-emitting display device (100) of the present invention is a top-emitting type, the polarizing plate may be located above the encapsulation film (170).

[0095] In addition, in the top-emitting type organic light-emitting display device (100), a cover window (not shown) may be attached to an encapsulation film (170) or a polarizing plate. At this time, the substrate (110) and the cover window may have flexible characteristics to form a flexible display device.

[0096] FIG. 3 is a schematic cross-sectional view of an organic light-emitting diode according to a second embodiment of the present invention.

[0097] As illustrated in FIG. 3, the organic light-emitting diode (D1) comprises first and second electrodes (210, 230) facing each other and an organic light-emitting layer (220) located between them, wherein the organic light-emitting layer (220) comprises a blue light-emitting material layer (240). The blue light-emitting material layer (240) comprises a first blue light-emitting layer (250) and a second blue light-emitting layer (260). Additionally, the organic light-emitting diode (D1) may further comprise a capping layer (not shown) formed on the second electrode (230) to enhance light extraction.

[0098] The organic light-emitting display device (100) includes a red pixel area, a green pixel area, and a blue pixel area, and the organic light-emitting diode (D1) is located in the blue pixel area.

[0099] The first electrode (210) may be an anode, and the second electrode (230) may be a cathode. One of the first electrode (210) and the second electrode (230) is a reflective electrode, and the other of the first electrode (210) and the second electrode (230) is a transmissive (semi-transmissive) electrode. For example, the first electrode (210) may have a single-layer structure of ITO, and the second electrode (230) may be made of Al.

[0100] The organic light-emitting layer (220) may further include at least one of a hole transport layer (274) located between the first electrode (210) and the blue light-emitting material layer (240) and an electron transport layer (282) located between the second electrode (230) and the blue light-emitting material layer (240).

[0101] Additionally, the organic light-emitting layer (220) may further include at least one of a hole injection layer (272) located between the first electrode (210) and the hole transport layer (274), and an electron injection layer (284) located between the second electrode (230) and the electron transport layer (282).

[0102] Additionally, the organic light-emitting layer (220) may further include at least one of an electron blocking layer (276) located between the hole transport layer (274) and the blue light-emitting material layer (240), and a hole blocking layer (286) located between the blue light-emitting material layer (240) and the electron transport layer (282).

[0103] In the blue light-emitting material layer (240), the second blue light-emitting layer (260) is in contact with the first blue light-emitting layer (250) and is located on the first blue light-emitting layer (250), so the blue light-emitting material layer (240) has a double-layer structure. Alternatively, the blue light-emitting material layer (240) may have a triple-layer structure by further including a second blue light-emitting layer located below the first blue light-emitting layer (250) and in contact with the first blue light-emitting layer (250), or by further including a first blue light-emitting layer located on the second blue light-emitting layer (250) and in contact with the second blue light-emitting layer (260).

[0104] The first blue light-emitting layer (250) includes a first p-type host (252) and a first n-type host (254), and the second blue light-emitting layer (260) includes a second p-type host (262) and a second n-type host (264). Additionally, the first blue light-emitting layer (250) may further include a first phosphorescent dopant (256), and the second blue light-emitting layer (260) may further include a second phosphorescent dopant (266).

[0105] One of the first p-type host (252) and the second p-type host (262) is a first compound represented by formula 1a or formula 1b.

[0106] [Chemical Formula 1a]

[0107]

[0108] [Chemical Formula 1b]

[0109]

[0110] In Chemical Formula 1a, a1 and a4 are each independently integers from 0 to 3, a2, a3, a5 to a8 are each independently integers from 0 to 4, and n1 is 0 or 1. Each of R1 to R8 is independently selected from the group consisting of deuterium, halogen, cyano group, substituted or unsubstituted C6 to C30 arylsilyl group, substituted or unsubstituted C1 to C20 alkyl group, substituted or unsubstituted C6 to C30 aryl group, substituted or unsubstituted C5 to C60 heteroaryl group, substituted or unsubstituted C1 to C30 arylamine group, and substituted or unsubstituted C6 to C60 arylamine group.

[0111] In Chemical Formula 1b, b1 is an integer from 0 to 3, each of b2 to b4 is independently an integer from 0 to 4, and b5 is an integer from 0 to 5. Each of R11 to R15 is independently selected from the group consisting of deuterium, halogen, cyano group, substituted or unsubstituted C6 to C30 arylsilyl group, substituted or unsubstituted C1 to C20 alkyl group, substituted or unsubstituted C6 to C30 aryl group, substituted or unsubstituted C5 to C60 heteroaryl group, substituted or unsubstituted C1 to C30 arylamine group, and substituted or unsubstituted C6 to C60 arylamine group.

[0112] In the present invention, unless otherwise stated, the substituents of the arylsilyl group, alkyl group, aryl group, heteroaryl group, alkylamine group, and arylamine group may be selected from deuterium, halogen, cyano group, substituted or unsubstituted C6 to C30 arylsilyl group, C6 to C30 arylgermanyl group, C1 to C20 alkyl group, and C6 to C30 aryl group.

[0113] In the present invention, unless otherwise stated, the aryl group of C6 to C30 may be selected from the group consisting of phenyl group, biphenyl group, terphenyl group, naphthyl group, anthracenyl group, pentanerenyl group, indenyl group, indenodenyl group, heptalenyl group, biphenylenyl group, indacenyl group, phenalenyl group, phenanthrenyl group, benzophenanthrenyl group, dibenzophenanthrenyl group, azulenyl group, pyrenyl group, fluoranthenyl group, triphenylenyl group, chrysenyl group, tetraphenyl group, tetracenyl group, plhaedenyl group, pysenyl group, pentaphenyl group, pentacenyl group, fluorenyl group, indenofluorenyl group, and spirofluorenyl group.

[0114] In addition, in the present invention, unless otherwise stated, the heteroaryl group of C3 to C60 is a pyrrolyl group, pyridinyl group, pyrimidinyl group, pyrazinyl group, pyridazinyl group, triazinyl group, tetrazinyl group, imidazoleyl group, pyrazazoleyl group, indoleyl group, isoindoleyl group, indazoleyl group, indolezinyl group, pyrrolizinyl group, carbazoleyl group, benzocarbazoleyl group, dibenzocarbazoleyl group, indolocarbazoleyl group, indenocarbazoleyl group, benzofurocarbazoleyl group, benzothienocarbazoleyl group, quinolinyl group, isoquinolinyl group, phthalazinyl group, quinoxalinyl group, cinolinyl group, quinazolinyl group, quinozolinyl group, quinozolinyl group, purinyl group, phthalazinyl group, Quinoxalinyl group, benzoquinolinyl group, benzisoquinolinyl group, benzoquinazolinyl group, benzoquinoxalinyl group, acrridinyl group, phenanthrolinyl group, perimidinyl group, phenanthridinyl group, pteridinyl group, cinnolinyl group, naphtharidinyl group, furanyl group, pyranyl group, oxazinyl group, oxazolyl group, oxadiazoleyl group, triazoleyl group, deoxynyl group, benzofuranyl group, dibenzofuranyl group, thiopyranyl group, xanthenyl group, cromenyl group, isochromenyl group, thioazinyl group, thiophenyl group, benzothiophenyl group, dibenzothiophenyl group, dipuropyrazinyl group, benzofurodibenzofuranyl group, benzothienobenzothiophenyl group, benzothienodibenzothiophenyl group, It can be selected from the group consisting of benzothienobenzofuranyl groups and benzothienodibenzofuranyl groups.

[0115] For example, in Chemical Formula 1a, n1 can be 1. Also, each of a1 to a8 can be 0. Alternatively, a1 and a4 can each be 3, a2, a3, a5 to a8 can each be 4, and R1 to R8 can each be deuterium.

[0116] For example, in Chemical Formula 1b, each of b1 to b5 may be 0. Alternatively, b1 may be 3, each of b2 to b4 may be 4, b5 may be 5, and each of R11 to R15 may be deuterium.

[0117] In Chemical Formula 1a, the binding site of the carbazole within the bicarbazole moiety can be specified. For example, Chemical Formula 1a can be represented as one of Chemical Formulas 1a-1 to 1a-4.

[0118] [Chemical Formula 1a-1]

[0119]

[0120] [Chemical Formula 1a-2]

[0121]

[0122] [Chemical Formula 1a-3]

[0123]

[0124] [Chemical Formula 1a-4]

[0125]

[0126] In each of Chemical Formulas 1a-1 to 1a-4, a1 to a8, n1, and R1 to R8 are as defined in Chemical Formula 1a.

[0127] In Chemical Formula 1b, the binding site of the carbazole within the bicarbazole moiety can be specified. For example, Chemical Formula 1b can be represented as Chemical Formula 1b-1 or Chemical Formula 1b-2.

[0128] [Chemical Formula 1b-1]

[0129]

[0130] [Chemical Formula 1b-2]

[0131]

[0132] In each of Chemical Formula 1b-1 and Chemical Formula 1b-2, b1 to b5 and R11 to R15 are as defined in Chemical Formula 1b.

[0133] The first compound, which is one of the first p-type host (252) and the second p-type host (262), can be selected from the compounds shown in Formula 2.

[0134] [Chemical Formula 2]

[0135]

[0136] The other of the first p-type host (252) and the second p-type host (262) is a second compound represented by formula 3a or formula 3b.

[0137] [Chemical Formula 3a]

[0138]

[0139] [Chemical Formula 3b]

[0140]

[0141] In Formula 3a, d1 and d4 are each independently integers from 0 to 3, d2, d3, d5 to d8 are each independently integers from 0 to 4, and n2 and n3 are each independently 0 or 1. Each of R21 to R28 is independently selected from the group consisting of deuterium, halogen, cyano group, substituted or unsubstituted C6 to C30 arylsilyl group, substituted or unsubstituted C1 to C20 alkyl group, substituted or unsubstituted C6 to C30 aryl group, substituted or unsubstituted C5 to C60 heteroaryl group, substituted or unsubstituted C1 to C30 arylamine group, and substituted or unsubstituted C6 to C60 arylamine group.

[0142] In Formula 3b, e1 and e4 are each independently integers from 0 to 3, e2, e3, e5, and e6 are each independently integers from 0 to 4, and e7 is an integer from 0 to 5. Each of R31 to R37 is independently selected from the group consisting of deuterium, halogen, cyano group, substituted or unsubstituted C6 to C30 arylsilyl group, substituted or unsubstituted C1 to C20 alkyl group, substituted or unsubstituted C6 to C30 aryl group, substituted or unsubstituted C5 to C60 heteroaryl group, substituted or unsubstituted C1 to C30 arylamine group, and substituted or unsubstituted C6 to C60 arylamine group.

[0143] For example, in Chemical Formula 3a, at least one of n2 and n3 may be 1. Also, one of n2 and n3 may be 0, and the other of n2 and n3 may be 1. Also, each of d1 to d8 may be 0. Alternatively, d1 and d4 may each be 3, a2, a3, d5 to d8 may each be 4, and each of R21 to R28 may be deuterium.

[0144] For example, in Chemical Formula 3b, each of e1 to e7 may be 0. Alternatively, e1 and e4 may each be 3, e2, e3, e5, and e6 may each be 4, e7 may be 5, and each of R31 to R37 may be deuterium.

[0145] In Chemical Formula 3a, the binding site of the carbazole within the bicarbazole moiety can be specified. For example, Chemical Formula 3a can be represented as one of Chemical Formulas 3a-1 to 3a-4.

[0146] [Chemical Formula 3a-1]

[0147]

[0148] [Chemical Formula 3a-2]

[0149]

[0150] [Chemical Formula 3a-3]

[0151]

[0152] [Chemical Formula 3a-4]

[0153]

[0154] In each of Chemical Formulas 3a-1 to 3a-4, d1 to d8, n2, n3, and R21 to R28 are as defined in Chemical Formula 3a.

[0155] In Chemical Formula 3b, the binding site of the carbazole within the bicarbazole moiety can be specified. For example, Chemical Formula 1b can be represented as one of Chemical Formulas 3b-1 to 3b-4.

[0156] [Chemical Formula 3b-1]

[0157]

[0158] [Chemical Formula 3b-2]

[0159]

[0160] [Chemical Formula 3b-3]

[0161]

[0162] [Chemical Formula 3b-4]

[0163]

[0164] In each of Chemical Formulas 3b-1 to 3b-4, e1 to e7 and R31 to R37 are as defined in Chemical Formula 3b.

[0165] The second compound, which is the other of the first p-type host (252) and the second p-type host (262), can be selected from the compounds shown in Formula 4.

[0166] [Chemical Formula 4]

[0167]

[0169] The first n-type host (254) and the second n-type host (264) are each compounds represented by the chemical formula 5.

[0170] [Chemical Formula 5]

[0171]

[0172] In Chemical Formula 5, f1, f5, and f6 are each integers from 0 to 4, and f2 to f4 are each independently integers from 0 to 5. X is selected from the group consisting of C, Si, and Ge, and R41 to R47 are each independently selected from the group consisting of deuterium, halogen, cyano group, substituted or unsubstituted C6 to C30 arylsilyl group, substituted or unsubstituted C6 to C30 arylgermanyl group, substituted or unsubstituted C1 to C20 alkyl group, substituted or unsubstituted C6 to C30 aryl group, substituted or unsubstituted C5 to C60 heteroaryl group, substituted or unsubstituted C1 to C30 arylamine group, and substituted or unsubstituted C6 to C60 arylamine group.

[0173] For example, R47 may be selected from the group consisting of a substituted or unsubstituted C6 to C30 aryl group (e.g., phenyl or triphenylsilylphenyl) and a substituted or unsubstituted C5 to C60 heteroaryl group (e.g., carbazoyl or bicarbazoyl (bicarbazoyl)).

[0174] For example, f2, f3, and f4 are each 5, and R42, R43, and R44 may each be deuterium. f1, f5, and f6 are each 4, and R41, R45, and R46 may each be deuterium. Alternatively, f45 and f46 are each 1, and R45 and R46 may each be a substituted or unsubstituted C5 to C60 heteroaryl group (e.g., carbazoyl).

[0175] The first n-type host (254) and the second n-type host (264) can each be independently selected from the compounds shown in Formula 6. The first n-type host (254) and the second n-type host (264) may be the same or different.

[0176] [Chemical Formula 6]

[0177]

[0178] The first phosphorescent dopant (256) and the second phosphorescent dopant (266) are compounds represented by the chemical formula 7.

[0179] [Chemical Formula 7]

[0180]

[0181] In Formula 7, each of R51 to R56 is independently selected from the group consisting of deuterium, halogen, cyano group, substituted or unsubstituted C1 to C20 alkyl group, substituted or unsubstituted C3 to C20 cycloalkyl group, C1 to C20 alkylsilyl group, substituted or unsubstituted C1 to C20 alkylamino group, substituted or unsubstituted C6 to C30 arylamino group, substituted or unsubstituted C6 to C30 arylsilyl group, substituted or unsubstituted C6 to C30 aryl group, and substituted or unsubstituted C3 to C30 heteroaryl group, and each of g1, g2, and g3 is independently an integer from 0 to 4, g4 is an integer from 0 to 3, and g5 is an integer from 0 to 2.

[0182] For example, each of R51 to R56 may be independently selected from substituted or unsubstituted C1 to C20 alkyl groups (e.g., methyl, tertiary-butyl, adamantanyl) and substituted or unsubstituted C6 to C30 aryl groups (e.g., phenyl). Additionally, at least one of g1 to g5 may be a positive integer.

[0183] The first phosphorescent dopant (256) and the second phosphorescent dopant (266) can each be independently selected from the compounds shown in Formula 8. The first phosphorescent dopant (256) and the second phosphorescent dopant (266) may be the same or different.

[0184] [Chemical Formula 8]

[0185]

[0186] In the first blue light-emitting layer (250), the weight ratio of each of the first p-type host (252) and the first n-type host (254) may be greater than the weight ratio of the first phosphorescent dopant (256), and the weight ratio of the first p-type host (252) and the weight ratio of the first n-type host (254) may be the same or different. For example, in the first blue light-emitting layer (250), the first p-type host (252) and the first n-type host (254) may have the same weight ratio, and with respect to the first phosphorescent dopant (256), each of the first p-type host (252) and the first n-type host (254) may have 200 to 600 parts by weight.

[0187] In the second blue light-emitting layer (260), the weight ratio of each of the second p-type host (262) and the second n-type host (264) may be greater than the weight ratio of the second phosphorescent dopant (266), and the weight ratio of the second p-type host (262) and the weight ratio of the second n-type host (264) may be the same or different. For example, in the second blue light-emitting layer (260), the second p-type host (262) and the second n-type host (264) may have the same weight ratio, and with respect to the second phosphorescent dopant (266), each of the second p-type host (262) and the second n-type host (264) may have 200 to 600 parts by weight.

[0188] The blue light-emitting material layer (240) may have a thickness of 10 to 100 nm, and the first blue light-emitting layer (250) and the second blue light-emitting layer (260) may each have a thickness of 5 to 50 nm. For example, the blue light-emitting material layer (240) may have a thickness of 20 to 40 nm, and the first blue light-emitting layer (250) and the second blue light-emitting layer (260) may each have a thickness of 5 to 30 nm. The thickness of the first blue light-emitting layer (250) and the thickness of the second blue light-emitting layer (260) may be the same or different.

[0189] The hole injection layer 272 is 4,4',4"-tris(3-methylphenylamino)triphenylamine (MTDATA), 4,4',4"-tris(N,N-diphenyl-amino)triphenylamine (NATA), 4,4',4"-tris(N-(naphthalene-1-yl)-N-phenyl-amino)triphenylamine(1T-NATA), 4,4',4"-tris(N-(naphthalene-2-yl)-N-phenyl-amino)triphenylamine(2T-NATA), copper phthalocyanine(CuPc), tris(4-carbazoyl-9-yl-phenyl)amine (TCTA), N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4"-diamine (NPB; NPD), It may include a hole injection material selected from 1,4,5,8,9,11-hexaazariphenylenehexacarbonitrile (dipyrazino[2,3-f:2'3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile; HAT-CN), 1,3,5-tris[4-(diphenylamino)phenyl]benzene (TDAPB), poly(3,4-ethylenedioxythiphene)polystyrene sulfonate (PEDOT / PSS), and N-(biphenyl-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine. Alternatively, the hole injection material of the hole injection layer (272) may include the compound of Formula 9 below (host) and the compound of Formula 10 below (dopant). In this case, In the hole injection layer (272), the compound of Formula 10 may have a weight ratio of 1 to 10 wt%. The hole injection layer (272) may have a thickness of 1 to 30 nm.

[0190] The hole transport layer (274) is N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine; TPD), NPB (NPD), 4,4'-bis(N-carbazolyl)-1,1'-biphenyl(CBP), poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)-benzidine](Poly-TPD), (poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))] (TFB), di-[4-(N,N-di-p-tolyl-amino)-phenyl]cyclohexane(TAPC), 3,5-di(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, It may include a hole transport material selected from N-(biphenyl-4-yl)-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)biphenyl-4-amine. Alternatively, the hole transport material of the hole transport layer (274) may be a compound of the following chemical formula 9. The hole transport layer (274) may have a thickness of 10 to 100 nm.

[0191] The electron transport layer 282 is tris-(8-hydroxyquinoline aluminum (Alq3), 2-biphenyl-4-yl-5-(4-t-butylphenyl)-1,3,4-oxadiazole (PBD), spiro-PBD, lithium quinolate (Liq), 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene(TPBi), bis(2-methyl-8-quinolinolato-N1,O8)-(1,1'-biphenyl-4-olato)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-(naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4-triazole(NTAZ), 1,3,5-tri(p-pyrid-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), diphenyl-4-triphenylsilyl-phenylphosphine oxide (TSPO1) It may include an electron transport material. Alternatively, the electron transport material of the electron transport layer (282) may be a compound of the following chemical formula 11. The electron transport layer (274) may have a thickness of 10 to 100 nm.

[0192] The electron injection layer (284) may include an electron injection material selected from alkali metals such as Li, alkali halide materials such as LiF, CsF, NaF, BaF2, and / or organometallic materials such as LiQ, lithium benzoate, sodium stearate. The electron injection layer (284) may have a thickness of 0.1 to 10 nm.

[0193] The electron blocking layer 276 is 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, MTDATA, 1,3-bis(carbazol-9-yl)benzene(mCP), 3,3'-bis(N-carbazolyl)-1,1'-biphenyl(mCBP), CuPc, Electron blocking material selected from N,N'-bis[4-[bis(3-methylphenyl)amino]phenyl]-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine(DNTPD), TDAPB, DCDPA, 2,8-bis(9-phenyl-9H-carbazol-3-yl)dibenzo[b,d]thiophene) to include Alternatively, the electron blocking material of the electron blocking layer (276) may be the same material as the first p-type host (252) of the first blue light-emitting layer (250) or the second p-type host (262) of the second blue light-emitting layer (260). The electron blocking layer (286) may have a thickness of 5 to 40 nm.

[0194] The hole blocking layer (286) may include a hole blocking material selected from BCP, BAlq, Alq3, PBD, spiro-PBD, Liq, bis[2-(diphenylphosphino)phenyl]ether oxide (DPEPO), 9-(6-9H-carbazol-9-yl)pyridine-3-yl)-9H-3,9'-bicarbazole, and TSPO1. Alternatively, the hole blocking material of the hole blocking layer (286) may be the same material as the first n-type host (254) of the first blue light-emitting layer (250) or the second n-type host (264) of the second blue light-emitting layer (260). The hole blocking layer (286) may have a thickness of 1 to 20 nm.

[0195] The first p-type host (252) and the second p-type host (262) have different hole mobilities. For example, the hole mobility of the first compound shown in Formula 1a or Formula 1b is greater than the hole mobility of the second compound shown in Formula 3a or Formula 3b. Accordingly, the recombination zone of holes and electrons is expanded in the light-emitting material layer (240), thereby reducing the driving voltage and greatly increasing the lifespan of the organic light-emitting diode (D1) and the organic light-emitting display device (100) containing it.

[0196] [Hole Only Device (HOD)]

[0197] A positive electrode (ITO, 50 nm), a hole injection layer (compound of formula 9 + compound of formula 10 (5 wt% doping), 10 nm), a hole transport layer (compound of formula 9, 40 nm), a first electron blocking layer (15 nm), a light-emitting material layer (30 nm), a second electron blocking layer (15 nm), a hole transport layer (compound of formula 9, 40 nm), and a negative electrode (Al, 100 nm) were sequentially stacked.

[0198] (1) HOD1

[0199] A luminescent material layer was formed using compound 1-1 of chemical formula 2 (PH-A-1, 44 wt%), compound 3-1 of chemical formula 6 (NH-A, 44 wt%), and compound 4-1 of chemical formula 8 (PD, 12 wt%), and a first and second electron blocking layer was formed using compound 1-1 of chemical formula 2.

[0200] (2) HOD2

[0201] A luminescent material layer was formed using compound 2-5 of chemical formula 4 (PH-B-1, 44 wt%), compound 3-1 of chemical formula 6 (NH-A, 44 wt%), and compound 4-1 of chemical formula 8 (PD, 12 wt%), and a first and second electron blocking layer was formed using compound 2-5 of chemical formula 4.

[0202] [Chemical Formula 9]

[0203]

[0204] [Chemical Formula 10]

[0205]

[0206] The charge densities measured at HOD1 and HOD2 are shown in Fig. 4a. As shown in Fig. 4a, hole movement depends on the p-type host, and the first compound represented by Formula 1a or Formula 1b has a faster hole mobility than the second compound represented by Formula 3a or Formula 3b.

[0207] [Electron Only Device (EOD)]

[0208] A positive electrode (ITO, 50 nm), an electron transport layer (compound of chemical formula 11, 30 nm), a first hole blocking layer (5 nm), a light-emitting material layer (30 nm), a second hole blocking layer (5 nm), an electron transport layer (compound of chemical formula 11, 30 nm), an electron injection layer (LiF, 1 nm), and a negative electrode (Al, 100 nm) were sequentially stacked.

[0209] (1) EOD1

[0210] A luminescent material layer was formed using compound 1-1 of chemical formula 2 (PH-A-1, 44 wt%), compound 3-1 of chemical formula 6 (NH-A, 44 wt%), and compound 4-1 of chemical formula 8 (PD, 12 wt%), and first and second hole blocking layers were formed using compound 3-1 of chemical formula 6.

[0211] (2) EOD2

[0212] A luminescent material layer was formed using compound 2-5 of chemical formula 4 (PH-B-1, 44 wt%), compound 3-1 of chemical formula 6 (NH-A, 44 wt%), and compound 4-1 of chemical formula 8 (PD, 12 wt%), and first and second hole blocking layers were formed using compound 3-1 of chemical formula 6.

[0213] [Chemical Formula 11]

[0214]

[0215] The charge densities measured at EOD1 and EOD2 are shown in Fig. 4b. As shown in Fig. 4b, electron movement does not depend on the p-type host.

[0216] In each of the first blue light-emitting layer (250) and the second blue light-emitting layer (260), the maximum light-emitting wavelength (λmax) of the mixture of p-type host and n-type host (PH:NH) ) is 480 nm or less, and the maximum emission wavelength (λmax) of the n-type host NH It is greater than ). (480 nm ≥ λmax (PH:NH) > λmax NH )

[0217] In addition, in each of the first blue light-emitting layer (250) and the second blue light-emitting layer (260), the lowest unoccupied molecular orbital (LUMO) energy level of the p-type host (LUMO PH ) and LUMO energy levels of an n-type host (LUMO NHThe difference is greater than 0.2 eV, and the energy level of the highest occupied molecular orbital (HOMO) of the p-type host (HOMO PH ) and HOMO energy levels of an n-type host (HOMO NH The difference of ) is greater than 0.3 eV. (LUMO PH - LUMO NH ≥0.2 eV, HOMO PH - HOMO NH ≥0.3 eV)

[0218] The first compound represented by Chemical Formula 1a or Chemical Formula 1b and the second compound represented by Chemical Formula 3a or Chemical Formula 3b comprise a bicarbazole (biscarbazole) structure in which a carbazole is bound to the 3rd or 4th position of the carbazole, and each of the first and second compounds satisfies the above conditions with an n-type host represented by Chemical Formula 5.

[0219] Accordingly, the first p-type host (252) and the first n-type host (254) form an exciplex in the first blue light-emitting layer (250), and the second p-type host (262) and the second n-type host (264) form an exciplex in the second blue light-emitting layer (260). Accordingly, the driving voltage of the organic light-emitting diode (D1) and the organic light-emitting display device (100) including it is reduced and the lifespan is increased.

[0220] In each of the first blue light-emitting layer (250) and the second blue light-emitting layer (260), the onset wavelength (λonset) in the absorption spectrum of the phosphorescent dopant Abs (PD)) and onset wavelength (λonset) in the exciplex PL spectrum PL The difference in (Exciplex) is more than 10nm. (λonset Abs (PD) - λonset PL (Exciplex) ≥ 10 nm) Accordingly, the energy transfer efficiency to the phosphorescent dopant is improved.

[0221] Here, the onset wavelength is the wavelength value at the point where the X-axis (wavelength) intersects the extrapolation line in the linear region of the short wavelength region in the absorption spectrum and the PL spectrum, respectively. More specifically, the onset wavelength can be defined as the wavelength corresponding to the short wavelength among the two wavelengths in the absorption spectrum and the PL spectrum where the intensity of the spectrum is 1 / 10 of the maximum value.

[0222] In each of the first blue light-emitting layer (250) and the second blue light-emitting layer (260), the LUMO energy level (LUMO) of the phosphorescent dopant PD ) and LUMO energy levels of an n-type host (LUMO NH The difference of ) is greater than 0.2 eV. (LUMO PD - LUMO NH ≥ 0.2 eV) Accordingly, charge trapping to phosphorescent dopants in each of the first and second blue light-emitting layers is suppressed, and the driving voltage of the organic light-emitting diode (D1) and the organic light-emitting display device (100) including it is further reduced and the lifespan is further increased.

[0223] In each of the first blue light-emitting layer (250) and the second blue light-emitting layer (260), the onset wavelength (λonset) in the PL spectrum of the phosphorescent dopant PL (PD)) is the onset wavelength (λonset) in the PL spectrum of the exciplex. PL Equal to or greater than ) (λonset PL (PD) ≥ λonset PL (PH : NH)) For example, in each of the first blue emitting layer (250) and the second blue emitting layer (260), the onset wavelength (λonset) in the PL spectrum of the phosphorescent dopant PL (PD)) is the onset wavelength (λonset) in the PL spectrum of the exciplex. PL It can be greater than ). Therefore, non-emission quenching of triplet excitons is suppressed.

[0224] The PL spectrum of a mixture of compound 1-1 (PH-A-1) of formula 2 and compound 3-1 (NH-A) of formula 6, the PL spectrum of a mixture of compound 1-10 (PH-A-2) of formula 2 and compound 3-1 (NH-A) of formula 6, the PL spectrum of a mixture of compound 2-5 (PH-B-1) of formula 4 and compound 3-1 (NH-A) of formula 6, the PL spectrum of a mixture of compound 2-2 (PH-B-2) of formula 4 and compound 3-1 (NH-A) of formula 6, the PL spectrum of compound 3-1 (NH-A) of formula 6, and the PL spectrum and absorption spectrum of compound 4-1 (PD) of formula 8 were measured and are shown in Fig. 5, and the measurement results are listed in Table 1. In addition, the HOMO energy levels and LUMO energy levels of each of the compounds of Formula 2, 1-1 (PH-A-1), 1-10 (PH-A-2), 4-5 (PH-B-1), 4-2 (PH-B-2), 6-1 (NH-A), and 8-4 (PD) are listed in Table 2.

[0225] PL spectra can be measured at room temperature (i.e., 25°C) in organic solvents such as toluene. For example, about 1 x 10⁻⁶ -5 A 30 nm thin film can be formed using a compound solution dissolved in an organic solvent (e.g., toluene) having a concentration of M, and can be measured using a fluorescence spectrometer such as the FS-5 fluorescence spectrometer (Edinburgh Instruments) with PL detection (with photoluminescence detection).

[0226] In addition, HOMO energy levels can be determined (measured) by various known methods. For example, HOMO energy levels can be determined using conventional surface analyzers, such as the AC3 surface analyzer manufactured by RKI Instruments. Surface analyzers can be used to measure a single film (pure film) of a compound with a thickness of 50 nm. LUMO energy levels can be calculated as follows.

[0227] LUMO = HOMO - band gap

[0228] The bandgap can be calculated using any conventional method known to those skilled in the art, such as UV-vis measurements of a single film having a thickness of 50 nm. For example, the bandgap can be measured using a SCINCO S-3100 spectrophotometer. The HOMO and LUMO values ​​of the compounds disclosed in the present invention can be determined in this manner. That is, the HOMO and LUMO values ​​may be experimentally or empirically determined values ​​of a thin film, such as a 50 nm film.

[0229] PD NH-A-1 PH-A-1: NH-A PH-A-2:NH-A PH-B-1:NH-A PH-B-2:NH-A λmax (nm) 434 465 469 463 465 λonset PL (nm) 442 375 410 410 400 404 λonset ABS (nm) 430

[0230] PD PH-A-1 PH-A-2 PH-B-1 PH-B-2 NH-A LUMO (eV) -2.6 -2.6 -2.7 -2.7 -2.8 -3.0 HOMO (eV) -5.5 -6.0 -6.1 -6.1 -6.1 -6.5

[0231] As described above, in the organic light-emitting diode (D1) of the blue pixel region, the blue light-emitting material layer (240) of the organic light-emitting layer (220) comprises a first blue light-emitting layer (250) comprising a first p-type host (252) and a first n-type host (254), and a second blue light-emitting layer (260) comprising a second p-type host (262) and a second n-type host (264). One of the first p-type host (252) and the second p-type host (262) is a first compound represented by Chemical Formula 1, and the other of the first p-type host (252) and the second p-type host (262) is a second compound represented by Chemical Formula 3. That is, the first p-type host (252) and the second p-type host (262) have different hole mobilities. Accordingly, the recombination region of holes and electrons is expanded in the blue light-emitting material layer (240), thereby reducing the driving voltage and greatly increasing the lifespan of the organic light-emitting diode (D1) and the organic light-emitting display device (100) including it.

[0232] In addition, in each of the first and second blue light-emitting layers (250, 260), the p-type host (252, 262) and the n-type host (254, 264) form an exciplex, thereby suppressing charge trapping to the phosphorescent dopant (PD) in each of the first and second blue light-emitting layers (250, 260), and accordingly, the driving voltage of the organic light-emitting diode (D1) and the organic light-emitting display device (100) including it is further reduced and the lifespan is further increased.

[0233] [Organic Light Emitting Diode]

[0234] A blue organic light-emitting diode was formed by sequentially stacking a positive electrode (ITO, 50 nm), a hole injection layer (compound of formula 9 + compound of formula 10 (5 wt% doping), 10 nm), a hole transport layer (compound of formula 9, 40 nm), an electron blocking layer (15 nm), a light-emitting material layer (30 nm), a hole blocking layer (5 nm), an electron transport layer (compound of formula 11, 30 nm), an electron injection layer (LiF, 1 nm), and a negative electrode (Al, 100 nm).

[0235] 1. Comparative Example

[0236] (1) Comparative Example 1 (Ref1)

[0237] A blue emitting material layer was formed using Compound 1-1 of Formula 2 (44 wt%), Compound 3-1 of Formula 6 (44 wt%), and Compound 4-1 of Formula 8 (12 wt%). Additionally, an electron blocking layer was formed using Compound 1-1 of Formula 2, and a hole blocking layer was formed using Compound 3-1 of Formula 6.

[0238] (2) Comparative Example 2 (Ref2)

[0239] A blue emitting material layer was formed using Compound 2-5 (44 wt%) of Chemical Formula 4, Compound 3-1 (44 wt%) of Chemical Formula 6, and Compound 4-1 (12 wt%) of Chemical Formula 8. Additionally, an electron blocking layer was formed using Compound 1-1 of Chemical Formula 2, and a hole blocking layer was formed using Compound 3-1 of Chemical Formula 6.

[0240] (3) Comparative Example 3 (Ref3)

[0241] A blue emitting material layer was formed using the compound of Chemical Formula 12 (44 wt%), the compound 3-1 of Chemical Formula 6 (44 wt%), and the compound 4-1 of Chemical Formula 8 (12 wt%). Additionally, an electron blocking layer was formed using the compound 1-1 of Chemical Formula 2, and a hole blocking layer was formed using the compound 3-1 of Chemical Formula 6.

[0242] (4) Comparative Example 4 (Ref4)

[0243] A blue emitting material layer was formed using Compound 1-1 of Formula 2 (44 wt%), Compound 13 (44 wt%), and Compound 4-1 of Formula 8 (12 wt%). Additionally, an electron blocking layer was formed using Compound 1-1 of Formula 2, and a hole blocking layer was formed using Compound 3-1 of Formula 6.

[0244] (5) Comparative Example 5 (Ref5)

[0245] A blue emitting material layer was formed using Compound 2-5 of Chemical Formula 4 (44 wt%), Compound of Chemical Formula 13 (44 wt%), and Compound 4-1 of Chemical Formula 8 (12 wt%). Additionally, an electron blocking layer was formed using Compound 1-1 of Chemical Formula 2, and a hole blocking layer was formed using Compound 3-1 of Chemical Formula 6.

[0246] [Chemical Formula 12]

[0247]

[0248] [Chemical Formula 13]

[0249]

[0250] 2. Experimental Example

[0251] (1) Experimental Example 1 (Ex1)

[0252] A first blue light-emitting layer (5 nm) was formed using compound 1-1 of formula 2 (44 wt%), compound 3-1 of formula 6 (44 wt%), and compound 4-1 of formula 8 (12 wt%), and a second blue light-emitting layer (25 nm) was formed using compound 2-5 of formula 4 (44 wt%), compound 3-1 of formula 6 (44 wt%), and compound 4-1 of formula 8 (12 wt%). Additionally, an electron blocking layer was formed using compound 1-1 of formula 2, and a hole blocking layer was formed using compound 3-1 of formula 6.

[0253] (2) Experimental Example 2 (Ex2)

[0254] A first blue light-emitting layer (10 nm) was formed using compound 1-1 of formula 2 (44 wt%), compound 3-1 of formula 6 (44 wt%), and compound 4-1 of formula 8 (12 wt%), and a second blue light-emitting layer (20 nm) was formed using compound 2-5 of formula 4 (44 wt%), compound 3-1 of formula 6 (44 wt%), and compound 4-1 of formula 8 (12 wt%). Additionally, an electron blocking layer was formed using compound 1-1 of formula 2, and a hole blocking layer was formed using compound 3-1 of formula 6.

[0255] (3) Experimental Example 3 (Ex3)

[0256] A first blue light-emitting layer (15 nm) was formed using compound 1-1 of formula 2 (44 wt%), compound 3-1 of formula 6 (44 wt%), and compound 4-1 of formula 8 (12 wt%), and a second blue light-emitting layer (15 nm) was formed using compound 2-5 of formula 4 (44 wt%), compound 3-1 of formula 6 (44 wt%), and compound 4-1 of formula 8 (12 wt%). Additionally, an electron blocking layer was formed using compound 1-1 of formula 2, and a hole blocking layer was formed using compound 3-1 of formula 6.

[0257] (4) Experimental Example 4 (Ex4)

[0258] A first blue light-emitting layer (20 nm) was formed using compound 1-1 of formula 2 (44 wt%), compound 3-1 of formula 6 (44 wt%), and compound 4-1 of formula 8 (12 wt%), and a second blue light-emitting layer (10 nm) was formed using compound 2-5 of formula 4 (44 wt%), compound 3-1 of formula 6 (44 wt%), and compound 4-1 of formula 8 (12 wt%). Additionally, an electron blocking layer was formed using compound 1-1 of formula 2, and a hole blocking layer was formed using compound 3-1 of formula 6.

[0259] (5) Experimental Example 5 (Ex5)

[0260] A first blue light-emitting layer (25 nm) was formed using compound 1-1 of formula 2 (44 wt%), compound 3-1 of formula 6 (44 wt%), and compound 4-1 of formula 8 (12 wt%), and a second blue light-emitting layer (5 nm) was formed using compound 2-5 of formula 4 (44 wt%), compound 3-1 of formula 6 (44 wt%), and compound 4-1 of formula 8 (12 wt%). Additionally, an electron blocking layer was formed using compound 1-1 of formula 2, and a hole blocking layer was formed using compound 3-1 of formula 6.

[0261] (6) Experimental Example 6 (Ex6)

[0262] A first blue light-emitting layer (5 nm) was formed using compound 2-5 (44 wt%) of chemical formula 4, compound 3-1 (44 wt%) of chemical formula 6, and compound 4-1 (12 wt%) of chemical formula 8, and a second blue light-emitting layer (25 nm) was formed using compound 1-1 (44 wt%) of chemical formula 2, compound 3-1 (44 wt%) of chemical formula 6, and compound 4-1 (12 wt%) of chemical formula 8. Additionally, an electron blocking layer was formed using compound 1-1 of chemical formula 2, and a hole blocking layer was formed using compound 3-1 of chemical formula 6.

[0263] (7) Experimental Example 7 (Ex7)

[0264] A first blue light-emitting layer (10 nm) was formed using compound 2-5 (44 wt%) of chemical formula 4, compound 3-1 (44 wt%) of chemical formula 6, and compound 4-1 (12 wt%) of chemical formula 8, and a second blue light-emitting layer (20 nm) was formed using compound 1-1 (44 wt%) of chemical formula 2, compound 3-1 (44 wt%) of chemical formula 6, and compound 4-1 (12 wt%) of chemical formula 8. Additionally, an electron blocking layer was formed using compound 1-1 of chemical formula 2, and a hole blocking layer was formed using compound 3-1 of chemical formula 6.

[0265] (8) Experimental Example 8 (Ex8)

[0266] A first blue light-emitting layer (15 nm) was formed using compound 2-5 (44 wt%) of chemical formula 4, compound 3-1 (44 wt%) of chemical formula 6, and compound 4-1 (12 wt%) of chemical formula 8, and a second blue light-emitting layer (15 nm) was formed using compound 1-1 (44 wt%) of chemical formula 2, compound 3-1 (44 wt%) of chemical formula 6, and compound 4-1 (12 wt%) of chemical formula 8. Additionally, an electron blocking layer was formed using compound 1-1 of chemical formula 2, and a hole blocking layer was formed using compound 3-1 of chemical formula 6.

[0267] (9) Experimental Example 9 (Ex9)

[0268] A first blue light-emitting layer (20 nm) was formed using compound 2-5 (44 wt%) of chemical formula 4, compound 3-1 (44 wt%) of chemical formula 6, and compound 4-1 (12 wt%) of chemical formula 8, and a second blue light-emitting layer (10 nm) was formed using compound 1-1 (44 wt%) of chemical formula 2, compound 3-1 (44 wt%) of chemical formula 6, and compound 4-1 (12 wt%) of chemical formula 8. Additionally, an electron blocking layer was formed using compound 1-1 of chemical formula 2, and a hole blocking layer was formed using compound 3-1 of chemical formula 6.

[0269] (10) Experimental Example 10 (Ex10)

[0270] A first blue light-emitting layer (25 nm) was formed using compound 2-5 (44 wt%) of chemical formula 4, compound 3-1 (44 wt%) of chemical formula 6, and compound 4-1 (12 wt%) of chemical formula 8, and a second blue light-emitting layer (5 nm) was formed using compound 1-1 (44 wt%) of chemical formula 2, compound 3-1 (44 wt%) of chemical formula 6, and compound 4-1 (12 wt%) of chemical formula 8. Additionally, an electron blocking layer was formed using compound 1-1 of chemical formula 2, and a hole blocking layer was formed using compound 3-1 of chemical formula 6.

[0271] The characteristics (driving voltage (V), external quantum efficiency (EQE), color coordinates (CIEx, CIEy), lifetime (LT95)) of the organic light-emitting diodes fabricated in Comparative Examples 1 to 5 and Experimental Examples 1 to 10 were measured and listed in Table 3.

[0272] V (%) EQE (%) CIEx CIEy LT95 (%) Ref1 100 20 0.135 0.140 100 Ref2 109 19 0.136 0.142 145 Ref3 101 17 0.135 0.140 77 Ref4 91 21 0.135 0.140 31 Ref5 94 21 0.137 0.141 38 Ex1 108 19 0.136 0.142 172 Ex2 107 20 0.135 0.141 180 Ex3 104 20 0.135 0.141 186 Ex4 103 20 0.135 0.141 176 Ex5 101 20 0.136 0.140 152 Ex6 103 20 0.136 0.141 147 Ex7 105 20 0.135 0.141 157 Ex8 107 20 0.135 0.142 172 Ex9 109 19 0.135 0.142 153 Ex10 109 19 0.135 0.142 151

[0273] As shown in Table 3, compared to the organic light-emitting diodes of Comparative Examples 1 to 5, the lifetime of the organic light-emitting diodes of Experimental Examples 1 to 10 is significantly increased in that the blue light-emitting material layer comprises an adjacent first blue light-emitting layer and a second blue light-emitting layer, the first blue light-emitting layer comprises a p-type host that is one of the first compound (Chemical Formula 1a or Chemical Formula 1b) and the second compound (Chemical Formula 3a or Chemical Formula 3b), an n-type host indicated by Chemical Formula 5, and a phosphorescent dopant indicated by Chemical Formula 7, and the second blue light-emitting layer comprises a p-type host that is the other of the first compound (Chemical Formula 1a or Chemical Formula 1b) and the second compound (Chemical Formula 3a or Chemical Formula 3b), an n-type host indicated by Chemical Formula 5, and a phosphorescent dopant indicated by Chemical Formula 7.

[0274] In particular, in the organic light-emitting diodes of Comparative Examples 3 to 5 using the compound of Chemical Formula 12 and the compound of Chemical Formula 13, the lifespan of the organic light-emitting diode is significantly reduced because an exciplex is not formed between the p-type host and the n-type host.

[0275] 3. Comparative Example

[0276] (1) Comparative Example 6 (Ref6)

[0277] In Comparative Example 1, Compound 1-10 of Formula 2 was used instead of Compound 1-1 of Formula 2.

[0278] (2) Comparative Example 7 (Ref7)

[0279] In Comparative Example 2, compound 2-2 of chemical formula 4 was used instead of compound 2-5 of chemical formula 4.

[0280] 4. Experimental Example

[0281] (1) Experimental Example 11 (Ex11)

[0282] Instead of Compound 1-1 of Formula 2 and Compound 2-5 of Formula 4 from Experimental Example 1, Compound 1-10 of Formula 2 and Compound 2-2 of Formula 4 were used, respectively.

[0283] (2) Experimental Example 12 (Ex12)

[0284] Instead of Compound 1-1 of Formula 2 and Compound 2-5 of Formula 4 in Experimental Example 2, Compound 1-10 of Formula 2 and Compound 2-2 of Formula 4 were used, respectively.

[0285] (3) Experimental Example 13 (Ex13)

[0286] Instead of Compound 1-1 of Formula 2 and Compound 2-5 of Formula 4 in Experimental Example 3, Compound 1-10 of Formula 2 and Compound 2-2 of Formula 4 were used, respectively.

[0287] (4) Experimental Example 14 (Ex14)

[0288] Instead of Compound 1-1 of Formula 2 and Compound 2-5 of Formula 4 in Experimental Example 4, Compound 1-10 of Formula 2 and Compound 2-2 of Formula 4 were used, respectively.

[0289] (5) Experimental Example 15 (Ex15)

[0290] Instead of Compound 1-1 of Formula 2 and Compound 2-5 of Formula 4 in Experimental Example 5, Compound 1-10 of Formula 2 and Compound 2-2 of Formula 4 were used, respectively.

[0291] (6) Experimental Example 16 (Ex16)

[0292] Instead of Compound 1-1 of Formula 2 and Compound 2-5 of Formula 4 in Experimental Example 6, Compound 1-10 of Formula 2 and Compound 2-2 of Formula 4 were used, respectively.

[0293] (7) Experimental Example 17 (Ex17)

[0294] Instead of Compound 1-1 of Formula 2 and Compound 2-5 of Formula 4 in Experimental Example 7, Compound 1-10 of Formula 2 and Compound 2-2 of Formula 4 were used, respectively.

[0295] (8) Experimental Example 18 (Ex18)

[0296] Instead of Compound 1-1 of Formula 2 and Compound 2-5 of Formula 4 in Experimental Example 8, Compound 1-10 of Formula 2 and Compound 2-2 of Formula 4 were used, respectively.

[0297] (9) Experimental Example 19 (Ex19)

[0298] Instead of Compound 1-1 of Formula 2 and Compound 2-5 of Formula 4 in Experimental Example 9, Compound 1-10 of Formula 2 and Compound 2-2 of Formula 4 were used, respectively.

[0299] (10) Experimental Example 20 (Ex20)

[0300] Instead of Compound 1-1 of Formula 2 and Compound 2-5 of Formula 4 in Experimental Example 10, Compound 1-10 of Formula 2 and Compound 2-2 of Formula 4 were used, respectively.

[0301] The characteristics (driving voltage (V), external quantum efficiency (EQE), color coordinates (CIEx, CIEy), lifetime (LT95)) of the organic light-emitting diodes fabricated in Comparative Example 6, Comparative Example 7, and Experimental Examples 11 to 20 were measured and listed in Table 4.

[0302] V (%) EQE (%) CIEx CIEy LT95 (%) Ref6 100 21 0.135 0.139 100 Ref7 113 21 0.136 0.142 131 Ex11 110 21 0.136 0.142 145 Ex12 108 21 0.135 0.141 157 Ex13 105 21 0.135 0.141 163 Ex14 103 20 0.135 0.141 151 Ex15 102 20 0.136 0.140 140 Ex16 103 20 0.136 0.141 138 Ex17 107 21 0.135 0.141 152 Ex18 109 21 0.135 0.142 160 Ex19 110 21 0.135 0.142 155 Ex20 111 21 0.135 0.142 142

[0303] As shown in Table 4, compared to the organic light-emitting diodes of Comparative Example 6 and Comparative Example 7, the lifetime of the organic light-emitting diodes of Experimental Examples 11 to 20 is significantly increased in that the blue light-emitting material layer comprises an adjacent first blue light-emitting layer and a second blue light-emitting layer, the first blue light-emitting layer comprises a p-type host that is one of the first compound (Chemical Formula 1a or Chemical Formula 1b) and the second compound (Chemical Formula 3a or Chemical Formula 3b), an n-type host indicated by Chemical Formula 5, and a phosphorescent dopant indicated by Chemical Formula 7, and the second blue light-emitting layer comprises a p-type host that is the other of the first compound (Chemical Formula 1a or Chemical Formula 1b) and the second compound (Chemical Formula 3a or Chemical Formula 3b), an n-type host indicated by Chemical Formula 5, and a phosphorescent dopant indicated by Chemical Formula 7.

[0304] FIG. 6 is a schematic cross-sectional view of an organic light-emitting diode according to a third embodiment of the present invention.

[0305] As illustrated in FIG. 6, the organic light-emitting diode (D2) comprises first and second electrodes (210, 230) facing each other and an organic light-emitting layer (220) located between them, wherein the organic light-emitting layer (220) comprises a first light-emitting part (ST1) comprising a first blue light-emitting material layer (310) and a second light-emitting part (ST2) comprising a second blue light-emitting material layer (350). Additionally, the organic light-emitting layer (220) may further comprise a charge-generating layer (390) located between the first and second light-emitting parts (ST1, ST2). Furthermore, the organic light-emitting diode (D2) may further comprise a capping layer (not shown) formed on the second electrode (230) to enhance light extraction.

[0306] The organic light-emitting display device (100) includes a red pixel area, a green pixel area, and a blue pixel area, and the organic light-emitting diode (D2) is located in the blue pixel area.

[0307] The first electrode (210) may be an anode, and the second electrode (230) may be a cathode. One of the first electrode (210) and the second electrode (230) is a reflective electrode, and the other of the first electrode (210) and the second electrode (230) is a transmissive (semi-transmissive) electrode. For example, the first electrode (210) may have a single-layer structure of ITO, and the second electrode (230) may be made of Al.

[0308] The first light-emitting part (ST1) may further include at least one of a first hole transport layer (344) located below the first blue light-emitting material layer (310) and a first electron transport layer (346) located above the first blue light-emitting material layer (310).

[0309] Additionally, the first light-emitting part (ST1) may further include a hole injection layer (342) located between the first electrode (210) and the first hole transport layer (344).

[0310] Additionally, the first light-emitting part (ST1) may further include at least one of an electron blocking layer (not shown) located between the first hole transport layer (344) and the first blue light-emitting material layer (310), and a hole blocking layer (not shown) located between the first blue light-emitting material layer (310) and the first electron transport layer (346).

[0311] The second light-emitting part (ST2) may further include at least one of a second hole transport layer (382) located below the second blue light-emitting material layer (350) and a second electron transport layer (384) located above the second blue light-emitting material layer (350).

[0312] Additionally, the second light-emitting part (ST2) may further include an electron injection layer (386) located between the second electrode (230) and the second electron transport layer (384).

[0313] Additionally, the second light-emitting part (ST2) may further include at least one of an electron blocking layer (not shown) located between the second hole transport layer (382) and the second blue light-emitting material layer (350), and a hole blocking layer (not shown) located between the second blue light-emitting material layer (350) and the second electron transport layer (384).

[0314] For example, the hole injection layer (342) may include the hole injection material described above. The hole injection layer (342) may have a thickness of 1 to 30 nm.

[0315] Each of the first hole transport layer (344) and the second hole transport layer (382) may include the aforementioned hole transport material. Each of the first hole transport layer (344) and the second hole transport layer (382) may have a thickness of 10 to 100 nm.

[0316] Each of the first electron transport layer (346) and the second electron transport layer (384) may include the aforementioned electron transport material. Each of the first electron transport layer (346) and the second electron transport layer (384) may have a thickness of 10 to 100 nm.

[0317] The electron injection layer (386) may include the aforementioned electron injection material. The electron injection layer (386) may have a thickness of 0.1 to 10 nm.

[0318] Each of the first electron blocking layer and the second electron blocking layer may include the aforementioned electron blocking material. Each of the first electron blocking layer and the second electron blocking layer may have a thickness of 5 to 40 nm.

[0319] Each of the first hole blocking layer and the second hole blocking layer may include the aforementioned hole blocking material. Each of the first hole blocking layer and the second hole blocking layer may have a thickness of 1 to 20 nm.

[0320] The charge generation layer (390) is located between the first light-emitting part (ST1) and the second light-emitting part (ST2). That is, the first light-emitting part (ST1) and the second light-emitting part (ST2) are connected by the charge generation layer (390). The charge generation layer (390) may be a PN junction charge generation layer in which an N-type charge generation layer (392) and a P-type charge generation layer (394) are joined.

[0321] The N-type charge generation layer (392) is located between the first electron transport layer (346) and the second hole transport layer (382), and the P-type charge generation layer (394) is located between the N-type charge generation layer (392) and the second hole transport layer (382).

[0322] The N-type charge generating layer (392) transfers electrons to the first blue light-emitting material layer (310) of the first light-emitting part (ST1), and the P-type charge generating layer (394) transfers holes to the second blue light-emitting material layer (350) of the second light-emitting part (ST2).

[0323] The N-type charge generating layer (392) may be an organic layer doped with an alkali metal such as Li, Na, K, Cs and / or an alkaline earth metal such as Mg, Sr, Ba, Ra. For example, the N-type charge generating layer (392) comprises a host, which is an organic material such as 4,7-diphenyl-1,10-phenanthroline (4,7-dipheny-1,10-phenanthroline; Bphen) and MTDATA, and a dopant, which is an alkali metal or an alkaline earth metal, wherein the dopant may be doped in an amount of 0.01 to 30 weight%.

[0324] The P-type charge generating layer (394) may be composed of an inorganic material selected from the group consisting of tungsten oxide (WOx), molybdenum oxide (MoOx), beryllium oxide (Be2O3), vanadium oxide (V2O5) and combinations thereof, and an organic material selected from the group consisting of NPD, HAT-CN, F4TCNQ, TPD, TNB, TCTA, N,N'-dioctyl-3,4,9,10-perylenedicarboximide (PTCDI-C8) and combinations thereof.

[0325] The first blue light-emitting material layer (310) includes an adjacent first blue light-emitting layer (320) and a second blue light-emitting layer (330). For example, the first blue light-emitting layer (320) is located between the first electrode (210) and the second blue light-emitting layer (330).

[0326] In the first blue light-emitting material layer (310), the second blue light-emitting layer (330) is in contact with the first blue light-emitting layer (320) and is positioned on the first blue light-emitting layer (320), so that the first blue light-emitting material layer (310) has a double-layer structure.

[0327] The first blue light-emitting layer (320) includes a first p-type host (322) and a first n-type host (324), and the second blue light-emitting layer (330) includes a second p-type host (332) and a second n-type host (334). Additionally, the first blue light-emitting layer (320) may further include a first phosphorescent dopant (326), and the second blue light-emitting layer (330) may further include a second phosphorescent dopant (336).

[0328] One of the first p-type host (322) and the second p-type host (332) is a first compound represented by Chemical Formula 1a or Chemical Formula 1b, and the other of the first p-type host (322) and the second p-type host (332) is a second compound represented by Chemical Formula 3a or Chemical Formula 3b. For example, one of the first p-type host (322) and the second p-type host (332) may be selected from the compound of Chemical Formula 2, and the other of the first p-type host (322) and the second p-type host (332) may be selected from the compound of Chemical Formula 4.

[0329] The first n-type host (324) and the second n-type host (334) are each compounds represented by Chemical Formula 5. For example, the first n-type host (324) and the second n-type host (334) may each be independently selected from the compounds of Chemical Formula 6. The first n-type host (324) and the second n-type host (334) may be the same or different.

[0330] The first phosphorescent dopant (326) and the second phosphorescent dopant (336) are each compounds represented by Chemical Formula 7. For example, the first phosphorescent dopant (326) and the second phosphorescent dopant (336) may each be independently selected from the compounds of Chemical Formula 8. The first phosphorescent dopant (326) and the second phosphorescent dopant (336) may be the same or different.

[0331] In the first blue light-emitting layer (320), the weight ratio of each of the first p-type host (322) and the first n-type host (324) may be greater than the weight ratio of the first phosphorescent dopant (326), and the weight ratio of the first p-type host (322) and the weight ratio of the first n-type host (324) may be the same or different. For example, in the first blue light-emitting layer (320), the first p-type host (322) and the first n-type host (324) may have the same weight ratio, and with respect to the first phosphorescent dopant (326), each of the first p-type host (322) and the first n-type host (324) may have 200 to 600 parts by weight.

[0332] In the second blue light-emitting layer (330), the weight ratio of the second p-type host (332) and the second n-type host (334) may be greater than the weight ratio of the second phosphorescent dopant (336), and the weight ratio of the second p-type host (332) and the weight ratio of the second n-type host (334) may be the same or different. For example, in the second blue light-emitting layer (330), the second p-type host (332) and the second n-type host (334) may have the same weight ratio, and with respect to the second phosphorescent dopant (336), the second p-type host (332) and the second n-type host (334) may each have 200 to 600 parts by weight.

[0333] The first blue light-emitting material layer (310) may have a thickness of 10 to 100 nm, and the first blue light-emitting layer (320) and the second blue light-emitting layer (330) may each have a thickness of 5 to 50 nm. For example, the first blue light-emitting material layer (310) may have a thickness of 20 to 40 nm, and the first blue light-emitting layer (320) and the second blue light-emitting layer (330) may each have a thickness of 5 to 30 nm. The thickness of the first blue light-emitting layer (320) and the thickness of the second blue light-emitting layer (330) may be the same or different.

[0334] The second blue light-emitting material layer (350) has a single-layer structure. The second blue light-emitting material layer (350) may have a thickness of 10 to 100 nm.

[0335] The second blue light-emitting material layer (350) may include a blue host (352) and a blue dopant (354, a light-emitting body). Additionally, the second blue light-emitting material layer (350) may further include an auxiliary dopant (auxiliary host). In the second blue light-emitting material layer (350), the weight ratio of the blue dopant (354) may be smaller than the weight ratio of the blue host (352) and the auxiliary dopant, respectively.

[0336] For example, the blue host 352 is mCP, 9-(3-(9H-carbazol-9-yl)phenyl)-9H-carbazole-3-carbonitrile (mCP-CN), mCBP, CBP-CN, 9-(3-(9H-Carbazol-9-yl)phenyl)-3-(diphenylphosphoryl)-9H-carbazole (mCPPO1) 3,5-Di(9H-carbazol-9-yl)biphenyl (Ph-mCP), TSPO1, 9-(3′carbazol-9-yl)-[1,1′-biphenyl]-3-yl)-9H-pyrido[2,3-b]indole (CzBPCb), bis(2-methylphenyl)diphenylsilane (UGH-1), 1,4-bis(triphenylsilyl)benzene (UGH-2), 1,3-bis(triphenylsilyl)benzene It may be one of (UGH-3), 9,9-spiorobifluoren-2-yl-diphenyl-phosphine oxide (SPPO1), or 9,9'-(5-(triphenylsilyl)-1,3-phenylene)bis(9H-carbazole) (SimCP).

[0337] For example, the blue dopant 354 is perylene, 4,4'-bis[4-(di-p-tolylamino)styryl]biphenyl (DPAVBi), 4-(di-p-tolylamino)-4-4'-[(di-p-tolylamino)styryl]stilbene (DPAVB), 4,4'-bis[4-(diphenylamino)styryl]biphenyl (BDAVBi), 2,7-bis(4-diphenylamino)styryl)-9,9-spirofluorene (spiro-DPVBi), [1,4-bis[2-[4-[N,N-di(p-tolyl)amino]phenyl]vinyl] benzene (DSB), 1-4-di-[4-(N,N-diphenyl)amino]styryl-benzene (DSA), It may be one of 2,5,8,11-tetra-tetr-butylperylene (TBPe), bis(2-hydroxylphenyl)-pyridine)beryllium (Bepp2), or 9-(9-Phenylcarbazole-3-yl)-10-(naphthalene-1-yl)anthracene (PCAN).

[0338] In one embodiment, the blue host (352) may include at least one of the compounds of Formula 14.

[0339] [Chemical Formula 14]

[0340]

[0341] The blue dopant (354) may be a fluorescent compound. In one embodiment, the blue dopant (354) may be selected from the compounds of Formula 15.

[0342] [Chemical Formula 15]

[0343]

[0344] The auxiliary dopant may be a phosphorescent compound or a delayed-fluorescence compound. In one embodiment, the auxiliary dopant may be selected from the compounds of Formula 16.

[0345] [Chemical Formula 16]

[0346]

[0347] For example, the second blue light-emitting material layer (350) may be a fluorescent light-emitting layer comprising compound H-1 of formula 14 and compound FD-1 of formula 15.

[0348] The second blue light-emitting material layer (350) may be a phosphor-sensitized fluorescence (PSF) light-emitting layer comprising compound H-2 of formula 14, compound H-3 of formula 14, compound FD-2 of formula 15, compound A-1 or compound A-2 of formula 16.

[0349] The second blue light-emitting material layer (350) may be a hyperfluorescence light-emitting layer comprising compound H-2 of formula 14, compound H-3 of formula 14, compound FD-2 of formula 15, and compound A-3 of formula 16.

[0350] In the blue pixel region, the organic light-emitting layer (220) of the organic light-emitting diode (D2) has a tandem structure including a first blue light-emitting material layer (310) and a second blue light-emitting material layer (350).

[0351] The first blue light-emitting material layer (310) comprises a first blue light-emitting layer (320) comprising a first p-type host (322), a first n-type host (324), and a first phosphorescent dopant (326), and a second blue light-emitting layer (330) comprising a second p-type host (332), a second n-type host (334), and a second phosphorescent dopant (336). One of the first p-type host (322) and the second p-type host (332) is a first compound represented by Chemical Formula 1a or Chemical Formula 1b, and the other of the first p-type host (322) and the second p-type host (332) is a second compound represented by Chemical Formula 3a or Chemical Formula 3b. Additionally, the first n-type host (324) and the second n-type host (334) are each a compound represented by Chemical Formula 5, and the first phosphorescent dopant (326) and the second phosphorescent dopant (336) are each a compound represented by Chemical Formula 7.

[0352] Accordingly, the organic light-emitting diode (D2) of the present invention and the organic light-emitting display device (100) including it have advantages in driving voltage and lifespan.

[0353] FIG. 7 is a schematic cross-sectional view of an organic light-emitting diode according to a fourth embodiment of the present invention.

[0354] As illustrated in FIG. 7, the organic light-emitting diode (D3) comprises first and second electrodes (210, 230) facing each other and an organic light-emitting layer (220) located between them, wherein the organic light-emitting layer (220) comprises a first light-emitting part (ST1) comprising a first blue light-emitting material layer (410) and a second light-emitting part (ST2) comprising a second blue light-emitting material layer (450). Additionally, the organic light-emitting layer (220) may further comprise a charge-generating layer (490) located between the first and second light-emitting parts (ST1, ST2). Furthermore, the organic light-emitting diode (D2) may further comprise a capping layer (not shown) formed on the second electrode (230) to enhance light extraction.

[0355] The organic light-emitting display device (100) includes a red pixel area, a green pixel area, and a blue pixel area, and the organic light-emitting diode (D3) is located in the blue pixel area.

[0356] The first electrode (210) may be an anode, and the second electrode (230) may be a cathode. One of the first electrode (210) and the second electrode (230) is a reflective electrode, and the other of the first electrode (210) and the second electrode (230) is a transmissive (semi-transmissive) electrode. For example, the first electrode (210) may have a single-layer structure of ITO, and the second electrode (230) may be made of Al.

[0357] The first light-emitting part (ST1) may further include at least one of a first hole transport layer (444) located below the first blue light-emitting material layer (410) and a first electron transport layer (446) located above the first blue light-emitting material layer (410).

[0358] Additionally, the first light-emitting part (ST1) may further include a hole injection layer (442) located between the first electrode (210) and the first hole transport layer (444).

[0359] Additionally, the first light-emitting part (ST1) may further include at least one of an electron blocking layer (not shown) located between the first hole transport layer (444) and the first blue light-emitting material layer (410), and a hole blocking layer (not shown) located between the first blue light-emitting material layer (410) and the first electron transport layer (446).

[0360] The second light-emitting part (ST2) may further include at least one of a second hole transport layer (482) located below the second blue light-emitting material layer (450) and a second electron transport layer (484) located above the second blue light-emitting material layer (450).

[0361] Additionally, the second light-emitting part (ST2) may further include an electron injection layer (486) located between the second electrode (230) and the second electron transport layer (484).

[0362] Additionally, the second light-emitting part (ST2) may further include at least one of an electron blocking layer (not shown) located between the second hole transport layer (482) and the second blue light-emitting material layer (450), and a hole blocking layer (not shown) located between the second blue light-emitting material layer (450) and the second electron transport layer (484).

[0364] For example, the hole injection layer (442) may include the hole injection material described above. The hole injection layer (442) may have a thickness of 1 to 30 nm.

[0365] Each of the first hole transport layer (444) and the second hole transport layer (482) may include the aforementioned hole transport material. Each of the first hole transport layer (444) and the second hole transport layer (482) may have a thickness of 10 to 100 nm.

[0366] Each of the first electron transport layer (446) and the second electron transport layer (484) may include the aforementioned electron transport material. Each of the first electron transport layer (446) and the second electron transport layer (484) may have a thickness of 10 to 100 nm.

[0367] The electron injection layer (486) may include the aforementioned electron injection material. The electron injection layer (486) may have a thickness of 0.1 to 10 nm.

[0368] Each of the first electron blocking layer and the second electron blocking layer may include the aforementioned electron blocking material. Each of the first electron blocking layer and the second electron blocking layer may have a thickness of 5 to 40 nm.

[0369] Each of the first hole blocking layer and the second hole blocking layer may include the aforementioned hole blocking material. Each of the first hole blocking layer and the second hole blocking layer may have a thickness of 1 to 20 nm.

[0370] The charge generation layer (490) is located between the first light-emitting part (ST1) and the second light-emitting part (ST2). That is, the first light-emitting part (ST1) and the second light-emitting part (ST2) are connected by the charge generation layer (490). The charge generation layer (490) may be a PN junction charge generation layer in which an N-type charge generation layer (492) and a P-type charge generation layer (494) are joined.

[0371] The N-type charge generation layer (492) is located between the first electron transport layer (446) and the second hole transport layer (482), and the P-type charge generation layer (494) is located between the N-type charge generation layer (492) and the second hole transport layer (482).

[0372] The N-type charge generating layer (492) transfers electrons to the first blue light-emitting material layer (410) of the first light-emitting part (ST1), and the P-type charge generating layer (494) transfers holes to the second blue light-emitting material layer (450) of the second light-emitting part (ST2).

[0373] The N-type charge generating layer (492) may be an organic layer doped with an alkali metal such as Li, Na, K, Cs and / or an alkaline earth metal such as Mg, Sr, Ba, Ra. For example, the N-type charge generating layer (492) comprises a host, which is an organic material such as 4,7-diphenyl-1,10-phenanthroline (4,7-dipheny-1,10-phenanthroline; Bphen) and MTDATA, and a dopant, which is an alkali metal or an alkaline earth metal, wherein the dopant may be doped in an amount of 0.01 to 30 weight%.

[0374] The P-type charge generating layer (494) may be composed of an inorganic material selected from the group consisting of tungsten oxide (WOx), molybdenum oxide (MoOx), beryllium oxide (Be2O3), vanadium oxide (V2O5) and combinations thereof, and an organic material selected from the group consisting of NPD, HAT-CN, F4TCNQ, TPD, TNB, TCTA, N,N'-dioctyl-3,4,9,10-perylenedicarboximide (PTCDI-C8) and combinations thereof.

[0375] The first blue light-emitting material layer (410) has a single-layer structure. The first blue light-emitting material layer (410) may have a thickness of 10 to 100 nm.

[0376] The first blue light-emitting material layer (410) may include a host (412) and a dopant (414, a light-emitting body). Additionally, the first blue light-emitting material layer (410) may further include an auxiliary dopant (auxiliary host). In the first blue light-emitting material layer (410), the weight ratio of the blue dopant (414) may be smaller than the weight ratio of the blue host (412) and the auxiliary dopant, respectively.

[0377] For example, the blue host (412) may be at least one of the compounds of Formula 14, the blue dopant (414) may be selected from the compounds of Formula 15, and the auxiliary dopant may be selected from the compounds of Formula 16.

[0378] The first blue light-emitting material layer (410) may be one of a fluorescent light-emitting layer, a phosphorescent-sensitive fluorescent light-emitting layer, or a superfluorescent light-emitting layer.

[0379] The second blue light-emitting material layer (450) includes an adjacent first blue light-emitting layer (460) and a second blue light-emitting layer (470). For example, the second blue light-emitting layer (470) is located between the second electrode (230) and the first blue light-emitting layer (460).

[0380] In the second blue light-emitting material layer (450), the second blue light-emitting layer (470) is in contact with the first blue light-emitting layer (460) and is positioned on the first blue light-emitting layer (460), so that the second blue light-emitting material layer (450) has a double-layer structure.

[0381] The first blue light-emitting layer (460) includes a first p-type host (462) and a first n-type host (464), and the second blue light-emitting layer (470) includes a second p-type host (472) and a second n-type host (474). Additionally, the first blue light-emitting layer (460) may further include a first phosphorescent dopant (466), and the second blue light-emitting layer (470) may further include a second phosphorescent dopant (476).

[0382] One of the first p-type host (462) and the second p-type host (472) is a first compound represented by Chemical Formula 1a or Chemical Formula 1b, and the other of the first p-type host (462) and the second p-type host (472) is a second compound represented by Chemical Formula 3a or Chemical Formula 3b. For example, one of the first p-type host (462) and the second p-type host (472) may be selected from the compound of Chemical Formula 2, and the other of the first p-type host (462) and the second p-type host (472) may be selected from the compound of Chemical Formula 4.

[0383] The first n-type host (464) and the second n-type host (474) are each compounds represented by Chemical Formula 5. For example, the first n-type host (464) and the second n-type host (474) may each be independently selected from compounds of Chemical Formula 6. The first n-type host (464) and the second n-type host (474) may be the same or different.

[0384] The first phosphorescent dopant (466) and the second phosphorescent dopant (476) are each compounds represented by Chemical Formula 7. For example, the first phosphorescent dopant (466) and the second phosphorescent dopant (476) may each be independently selected from the compounds of Chemical Formula 8. The first phosphorescent dopant (466) and the second phosphorescent dopant (476) may be the same or different.

[0385] In the first blue light-emitting layer (460), the weight ratio of each of the first p-type host (462) and the first n-type host (464) may be greater than the weight ratio of the first phosphorescent dopant (466), and the weight ratio of the first p-type host (462) and the weight ratio of the first n-type host (464) may be the same or different. For example, in the first blue light-emitting layer (460), the first p-type host (462) and the first n-type host (464) may have the same weight ratio, and with respect to the first phosphorescent dopant (466), each of the first p-type host (462) and the first n-type host (464) may have 200 to 600 parts by weight.

[0386] In the second blue light-emitting layer (470), the weight ratio of each of the second p-type host (472) and the second n-type host (474) may be greater than the weight ratio of the second phosphorescent dopant (476), and the weight ratio of the second p-type host (472) and the weight ratio of the second n-type host (474) may be the same or different. For example, in the second blue light-emitting layer (470), the second p-type host (472) and the second n-type host (474) may have the same weight ratio, and with respect to the second phosphorescent dopant (476), each of the second p-type host (472) and the second n-type host (474) may have 200 to 600 parts by weight.

[0387] The second blue light-emitting material layer (450) may have a thickness of 10 to 100 nm, and the first blue light-emitting layer (460) and the second blue light-emitting layer (470) may each have a thickness of 5 to 50 nm. For example, the second blue light-emitting material layer (450) may have a thickness of 20 to 40 nm, and the first blue light-emitting layer (460) and the second blue light-emitting layer (470) may each have a thickness of 5 to 30 nm. The thickness of the first blue light-emitting layer (460) and the thickness of the second blue light-emitting layer (470) may be the same or different.

[0388] In the blue pixel region, the organic light-emitting layer (220) of the organic light-emitting diode (D3) has a tandem structure including a first blue light-emitting material layer (410) and a second blue light-emitting material layer (450).

[0389] The second blue light-emitting material layer (450) comprises a first blue light-emitting layer (460) comprising a first p-type host (462), a first n-type host (464), and a first phosphorescent dopant (466), and a second blue light-emitting layer (470) comprising a second p-type host (472), a second n-type host (474), and a second phosphorescent dopant (476). One of the first p-type host (462) and the second p-type host (472) is a first compound represented by Chemical Formula 1a or Chemical Formula 1b, and the other of the first p-type host (462) and the second p-type host (472) is a second compound represented by Chemical Formula 3a or Chemical Formula 3b. Additionally, the first n-type host (464) and the second n-type host (474) are each compounds represented by Chemical Formula 5, and the first phosphorescent dopant (466) and the second phosphorescent dopant (476) are each compounds represented by Chemical Formula 7.

[0390] Accordingly, the organic light-emitting diode (D3) of the present invention and the organic light-emitting display device (100) including it have advantages in driving voltage and lifespan.

[0391] FIG. 8 is a schematic cross-sectional view of an organic light-emitting diode according to the fifth embodiment of the present invention.

[0392] As illustrated in FIG. 8, the organic light-emitting diode (D4) comprises first and second electrodes (210, 230) facing each other and an organic light-emitting layer (220) located between them, wherein the organic light-emitting layer (220) comprises a first light-emitting part (ST1) comprising a first blue light-emitting material layer (510) and a second light-emitting part (ST2) comprising a second blue light-emitting material layer (550). Additionally, the organic light-emitting layer (220) may further comprise a charge-generating layer (590) located between the first and second light-emitting parts (ST1, ST2). Furthermore, the organic light-emitting diode (D2) may further comprise a capping layer (not shown) formed on the second electrode (230) to enhance light extraction.

[0393] The organic light-emitting display device (100) includes a red pixel area, a green pixel area, and a blue pixel area, and the organic light-emitting diode (D2) is located in the blue pixel area.

[0394] The first electrode (210) may be an anode, and the second electrode (230) may be a cathode. One of the first electrode (210) and the second electrode (230) is a reflective electrode, and the other of the first electrode (210) and the second electrode (230) is a transmissive (semi-transmissive) electrode. For example, the first electrode (210) may have a single-layer structure of ITO, and the second electrode (230) may be made of Al.

[0395] The first light-emitting part (ST1) may further include at least one of a first hole transport layer (544) located below the first blue light-emitting material layer (510) and a first electron transport layer (546) located above the first blue light-emitting material layer (510).

[0396] Additionally, the first light-emitting part (ST1) may further include a hole injection layer (542) located between the first electrode (210) and the first hole transport layer (544).

[0397] Additionally, the first light-emitting part (ST1) may further include at least one of an electron blocking layer (not shown) located between the first hole transport layer (544) and the first blue light-emitting material layer (510), and a hole blocking layer (not shown) located between the first blue light-emitting material layer (510) and the first electron transport layer (546).

[0398] The second light-emitting part (ST2) may further include at least one of a second hole transport layer (582) located below the second blue light-emitting material layer (550) and a second electron transport layer (584) located above the second blue light-emitting material layer (550).

[0399] Additionally, the second light-emitting part (ST2) may further include an electron injection layer (586) located between the second electrode (230) and the second electron transport layer (584).

[0400] Additionally, the second light-emitting part (ST2) may further include at least one of an electron blocking layer (not shown) located between the second hole transport layer (582) and the second blue light-emitting material layer (550), and a hole blocking layer (not shown) located between the second blue light-emitting material layer (550) and the second electron transport layer (584).

[0401] For example, the hole injection layer (542) may include the hole injection material described above. The hole injection layer (542) may have a thickness of 1 to 30 nm.

[0402] Each of the first hole transport layer (544) and the second hole transport layer (582) may include the aforementioned hole transport material. Each of the first hole transport layer (544) and the second hole transport layer (582) may have a thickness of 10 to 100 nm.

[0403] Each of the first electron transport layer (546) and the second electron transport layer (584) may include the aforementioned electron transport material. Each of the first electron transport layer (546) and the second electron transport layer (584) may have a thickness of 10 to 100 nm.

[0404] The electron injection layer (586) may include the aforementioned electron injection material. The electron injection layer (586) may have a thickness of 0.1 to 10 nm.

[0405] Each of the first electron blocking layer and the second electron blocking layer may include the aforementioned electron blocking material. Each of the first electron blocking layer and the second electron blocking layer may have a thickness of 5 to 40 nm.

[0406] Each of the first hole blocking layer and the second hole blocking layer may include the aforementioned hole blocking material. Each of the first hole blocking layer and the second hole blocking layer may have a thickness of 1 to 20 nm.

[0407] The charge generation layer (590) is located between the first light-emitting part (ST1) and the second light-emitting part (ST2). That is, the first light-emitting part (ST1) and the second light-emitting part (ST2) are connected by the charge generation layer (590). The charge generation layer (590) may be a PN junction charge generation layer in which an N-type charge generation layer (592) and a P-type charge generation layer (594) are joined.

[0408] The N-type charge generation layer (592) is located between the first electron transport layer (546) and the second hole transport layer (582), and the P-type charge generation layer (594) is located between the N-type charge generation layer (592) and the second hole transport layer (582).

[0409] The N-type charge generating layer (592) transfers electrons to the first blue light-emitting material layer (510) of the first light-emitting part (ST1), and the P-type charge generating layer (594) transfers holes to the second blue light-emitting material layer (550) of the second light-emitting part (ST2).

[0410] The N-type charge generating layer (592) may be an organic layer doped with an alkali metal such as Li, Na, K, Cs and / or an alkaline earth metal such as Mg, Sr, Ba, Ra. For example, the N-type charge generating layer (592) comprises a host, which is an organic material such as 4,7-diphenyl-1,10-phenanthroline (4,7-dipheny-1,10-phenanthroline; Bphen) and MTDATA, and a dopant, which is an alkali metal or an alkaline earth metal, wherein the dopant may be doped in an amount of 0.01 to 30 weight%.

[0411] The P-type charge generating layer (594) may be composed of an inorganic material selected from the group consisting of tungsten oxide (WOx), molybdenum oxide (MoOx), beryllium oxide (Be2O3), vanadium oxide (V2O5) and combinations thereof, and an organic material selected from the group consisting of NPD, HAT-CN, F4TCNQ, TPD, TNB, TCTA, N,N'-dioctyl-3,4,9,10-perylenedicarboximide (PTCDI-C8) and combinations thereof.

[0412] The first blue light-emitting material layer (510) includes an adjacent first blue light-emitting layer (520) and a second blue light-emitting layer (530). For example, the first blue light-emitting layer (520) is located between the first electrode (210) and the second blue light-emitting layer (530).

[0413] In the first blue light-emitting material layer (510), the second blue light-emitting layer (530) is in contact with the first blue light-emitting layer (520) and is positioned on the first blue light-emitting layer (520), so that the first blue light-emitting material layer (510) has a double-layer structure.

[0414] The first blue light-emitting layer (520) includes a first p-type host (522) and a first n-type host (524), and the second blue light-emitting layer (530) includes a second p-type host (532) and a second n-type host (534). Additionally, the first blue light-emitting layer (520) may further include a first phosphorescent dopant (526), ​​and the second blue light-emitting layer (530) may further include a second phosphorescent dopant (536).

[0415] One of the first p-type host (522) and the second p-type host (532) is a first compound represented by Chemical Formula 1a or Chemical Formula 1b, and the other of the first p-type host (522) and the second p-type host (532) is a second compound represented by Chemical Formula 3a or Chemical Formula 3b. For example, one of the first p-type host (522) and the second p-type host (532) may be selected from the compound of Chemical Formula 2, and the other of the first p-type host (522) and the second p-type host (532) may be selected from the compound of Chemical Formula 4.

[0416] The first n-type host (524) and the second n-type host (534) are each compounds represented by Chemical Formula 5. For example, the first n-type host (524) and the second n-type host (534) may each be independently selected from compounds of Chemical Formula 6. The first n-type host (524) and the second n-type host (534) may be the same or different.

[0417] The first phosphorescent dopant (526) and the second phosphorescent dopant (536) are each compounds represented by Chemical Formula 7. For example, the first phosphorescent dopant (526) and the second phosphorescent dopant (536) may each be independently selected from the compounds of Chemical Formula 8. The first phosphorescent dopant (526) and the second phosphorescent dopant (536) may be the same or different.

[0418] In the first blue light-emitting layer (520), the weight ratio of each of the first p-type host (522) and the first n-type host (524) may be greater than the weight ratio of the first phosphorescent dopant (526), ​​and the weight ratio of the first p-type host (522) and the weight ratio of the first n-type host (524) may be the same or different. For example, in the first blue light-emitting layer (520), the first p-type host (522) and the first n-type host (524) may have the same weight ratio, and with respect to the first phosphorescent dopant (526), ​​each of the first p-type host (522) and the first n-type host (524) may have 200 to 600 parts by weight.

[0419] In the second blue light-emitting layer (530), the weight ratio of each of the second p-type host (532) and the second n-type host (534) may be greater than the weight ratio of the second phosphorescent dopant (536), and the weight ratio of the second p-type host (532) and the weight ratio of the second n-type host (534) may be the same or different. For example, in the second blue light-emitting layer (530), the second p-type host (532) and the second n-type host (534) may have the same weight ratio, and with respect to the second phosphorescent dopant (536), each of the second p-type host (532) and the second n-type host (534) may have 200 to 600 parts by weight.

[0420] The first blue light-emitting material layer (510) may have a thickness of 10 to 100 nm, and the first blue light-emitting layer (520) and the second blue light-emitting layer (530) may each have a thickness of 5 to 50 nm. For example, the first blue light-emitting material layer (510) may have a thickness of 20 to 40 nm, and the first blue light-emitting layer (520) and the second blue light-emitting layer (530) may each have a thickness of 5 to 30 nm. The thickness of the first blue light-emitting layer (520) and the thickness of the second blue light-emitting layer (530) may be the same or different.

[0421] The second blue light-emitting material layer (550) includes an adjacent third blue light-emitting layer (560) and a fourth blue light-emitting layer (570). For example, the fourth blue light-emitting layer (570) is located between the second electrode (230) and the third blue light-emitting layer (560).

[0422] In the second blue light-emitting material layer (550), the fourth blue light-emitting layer (570) is in contact with the third blue light-emitting layer (560) and is positioned on the third blue light-emitting layer (560), so that the second blue light-emitting material layer (550) has a double-layer structure.

[0423] The third blue light-emitting layer (560) includes a third p-type host (562) and a third n-type host (564), and the fourth blue light-emitting layer (570) includes a fourth p-type host (572) and a fourth n-type host (574). Additionally, the third blue light-emitting layer (560) may further include a third phosphorescent dopant (566), and the fourth blue light-emitting layer (570) may further include a fourth phosphorescent dopant (576).

[0424] One of the third p-type host (562) and the fourth p-type host (572) is a first compound represented by Chemical Formula 1a or Chemical Formula 1b, and the other of the third p-type host (562) and the fourth p-type host (572) is a second compound represented by Chemical Formula 3a or Chemical Formula 3b. For example, one of the third p-type host (562) and the fourth p-type host (572) may be selected from the compound of Chemical Formula 2, and the other of the third p-type host (562) and the fourth p-type host (572) may be selected from the compound of Chemical Formula 4.

[0425] The third n-type host (564) and the fourth n-type host (574) are each compounds represented by Chemical Formula 5. For example, the third n-type host (564) and the fourth n-type host (574) may each be independently selected from the compounds of Chemical Formula 6. The third n-type host (564) and the fourth n-type host (574) may be the same or different.

[0426] The third phosphorescent dopant (566) and the fourth phosphorescent dopant (576) are each compounds represented by Chemical Formula 7. For example, the third phosphorescent dopant (566) and the fourth phosphorescent dopant (576) may each be independently selected from the compounds of Chemical Formula 8. The third phosphorescent dopant (566) and the fourth phosphorescent dopant (576) may be the same or different.

[0427] In the third blue light-emitting layer (560), the weight ratio of the third p-type host (562) and the third n-type host (564) may be greater than the weight ratio of the third phosphorescent dopant (566), and the weight ratio of the third p-type host (562) and the weight ratio of the third n-type host (564) may be the same or different. For example, in the third blue light-emitting layer (560), the third p-type host (562) and the third n-type host (564) may have the same weight ratio, and with respect to the third phosphorescent dopant (566), the third p-type host (562) and the third n-type host (564) may each have 200 to 600 parts by weight.

[0428] In the fourth blue light-emitting layer (570), the weight ratio of each of the fourth p-type host (572) and the fourth n-type host (574) may be greater than the weight ratio of the fourth phosphorescent dopant (576), and the weight ratio of the fourth p-type host (572) and the weight ratio of the fourth n-type host (574) may be the same or different. For example, in the fourth blue light-emitting layer (570), the fourth p-type host (572) and the fourth n-type host (574) may have the same weight ratio, and with respect to the fourth phosphorescent dopant (576), each of the fourth p-type host (572) and the fourth n-type host (574) may have 200 to 600 parts by weight.

[0429] The second blue light-emitting material layer (550) may have a thickness of 10 to 100 nm, and the third blue light-emitting layer (560) and the fourth blue light-emitting layer (570) may each have a thickness of 5 to 50 nm. For example, the second blue light-emitting material layer (550) may have a thickness of 20 to 40 nm, and the third blue light-emitting layer (560) and the fourth blue light-emitting layer (570) may each have a thickness of 5 to 30 nm. The thickness of the third blue light-emitting layer (560) and the thickness of the fourth blue light-emitting layer (570) may be the same or different.

[0430] In the blue pixel region, the organic light-emitting layer (220) of the organic light-emitting diode (D4) has a tandem structure including a first blue light-emitting material layer (510) and a second blue light-emitting material layer (550).

[0431] The first blue light-emitting material layer (510) comprises a first blue light-emitting layer (520) comprising a first p-type host (522), a first n-type host (524), and a first phosphorescent dopant (526), ​​and a second blue light-emitting layer (530) comprising a second p-type host (532), a second n-type host (534), and a second phosphorescent dopant (536). One of the first p-type host (522) and the second p-type host (532) is a first compound represented by Chemical Formula 1a or Chemical Formula 1b, and the other of the first p-type host (522) and the second p-type host (532) is a second compound represented by Chemical Formula 3a or Chemical Formula 3b. Additionally, the first n-type host (524) and the second n-type host (534) are each compounds represented by Chemical Formula 5, and the first phosphorescent dopant (526) and the second phosphorescent dopant (536) are each compounds represented by Chemical Formula 7.

[0432] Additionally, the second blue light-emitting material layer (550) comprises a third blue light-emitting layer (560) comprising a third p-type host (562), a third n-type host (564), and a third phosphorescent dopant (566), and a second blue light-emitting layer (570) comprising a fourth p-type host (572), a fourth n-type host (574), and a fourth phosphorescent dopant (576). One of the third p-type host (562) and the fourth p-type host (572) is a first compound represented by Chemical Formula 1a or Chemical Formula 1b, and the other of the third p-type host (562) and the fourth p-type host (572) is a second compound represented by Chemical Formula 3a or Chemical Formula 3b. Additionally, the third n-type host (564) and the fourth n-type host (574) are each compounds represented by Chemical Formula 5, and the third phosphorescent dopant (566) and the fourth phosphorescent dopant (576) are each compounds represented by Chemical Formula 7.

[0433] Accordingly, the organic light-emitting diode (D4) of the present invention and the organic light-emitting display device (100) including it have advantages in driving voltage and lifespan.

[0434] FIG. 9 is a schematic cross-sectional view of an organic light-emitting display device according to the 6th embodiment of the present invention.

[0435] As illustrated in FIG. 9, the organic light-emitting display device (600) includes a first substrate (610) in which a red pixel (RP), a green pixel (GP), and a blue pixel (BP) are defined, a second substrate (670) facing the first substrate (610), an organic light-emitting diode (D) located between the first substrate (610) and the second substrate (670) and emitting blue light, and a color conversion layer (680) located between the organic light-emitting diode (D) and the second substrate (670).

[0436] Although not shown, a color filter may be formed between each of the second substrate (670) and the color conversion layer (680).

[0437] Each of the first substrate (610) and the second substrate (670) may be a glass substrate or a flexible substrate. For example, the flexible substrate may be any one of a polyimide (PI) substrate, a polyethersulfone (PES) substrate, a polyethylenenaphthalate (PEN) substrate, a polyethylene terephthalate (PET) substrate, and a polycarbonate (PC) substrate.

[0438] On the first substrate (610), a thin film transistor (Tr) is provided corresponding to each of the red pixel (RP), green pixel (GP), and blue pixel (BP), and a protective layer (650) is formed covering the thin film transistor (Tr) and having a drain contact hole (652) that exposes one electrode of the thin film transistor (Tr), for example, the drain electrode.

[0439] The organic light-emitting diode (D) formed on the protective layer (650) includes a first electrode (210), an organic light-emitting layer (220), and a second electrode (230). At this time, the first electrode (210) can be connected to the drain electrode of a thin-film transistor (Tr) through a drain contact hole (652).

[0440] The first electrode (210) may be an anode, and the second electrode (230) may be a cathode. One of the first electrode (210) and the second electrode (230) is a reflective electrode, and the other of the first electrode (210) and the second electrode (230) is a transmissive (semi-transmissive) electrode. For example, the first electrode (210) may have a single-layer structure of ITO, and the second electrode (230) may be made of Al.

[0441] Additionally, a bank layer (666) covering the edge of the first electrode (660) is formed at the boundary of each of the red pixel (RP), green pixel (GP), and blue pixel (BP). Since the organic light-emitting diode (D) emits blue light from the red pixel (RP), green pixel (GP), and blue pixel (BP), the light-emitting layer (662) can be formed as a common layer without needing to be separated from the red pixel (RP), green pixel (GP), and blue pixel (BP). The bank layer (666) is formed to prevent current leakage at the edge of the first electrode (660), and the bank layer (666) may be omitted.

[0442] At this time, the organic light-emitting diode (D) can emit blue light having the structure of FIG. 3, FIG. 6, FIG. 7, or FIG. 8. That is, the organic light-emitting diode (D) is provided in each of the red pixel (RP), green pixel (GP), and blue pixel (BP) to provide blue light.

[0443] For example, as illustrated in FIG. 3, the organic light-emitting layer (220) of the organic light-emitting diode (D) comprises a blue light-emitting material layer (240), and the blue light-emitting material layer (240) comprises a first blue light-emitting layer (250) comprising a first p-type host (252), a first n-type host (254), and a first phosphorescent dopant (256), and a second blue light-emitting layer (260) comprising a second p-type host (262), a second n-type host (264), and a second phosphorescent dopant (266).

[0444] One of the first p-type host (252) and the second p-type host (262) is a first compound represented by Chemical Formula 1a or Chemical Formula 1b, and the other of the first p-type host (252) and the second p-type host (262) is a second compound represented by Chemical Formula 3a or Chemical Formula 3b. Additionally, the first n-type host (254) and the second n-type host (264) are each compounds represented by Chemical Formula 5, and the first phosphorescent dopant (256) and the second phosphorescent dopant (266) are each compounds represented by Chemical Formula 7.

[0445] Since the organic light-emitting diode (D) emits blue light from the red pixel (RP), green pixel (GP), and blue pixel (BP), the organic light-emitting layer (220) can be formed as a common layer without needing to be separated from the red pixel (RP), green pixel (GP), and blue pixel (BP). The bank layer (666) is formed to prevent current leakage at the edge of the first electrode (210), and the bank layer (666) can be omitted.

[0446] The color conversion layer (680) includes a first color conversion layer (682) corresponding to a red pixel (RP) and a second color conversion layer (684) corresponding to a green pixel (BP). For example, the color conversion layer (680) may be made of an inorganic light-emitting material such as a quantum dot. A color conversion layer is not formed on the blue pixel (BP), and the organic light-emitting diode (D) of the blue pixel (BP) may face directly with the second substrate (670).

[0447] Blue light from the organic light-emitting diode (D) in the red pixel (RP) is converted into red light by the first color conversion layer (682), and blue light from the organic light-emitting diode (D) in the green pixel (GP) is converted into green light by the second color conversion layer (684).

[0448] Therefore, the organic light-emitting display device (600) can display a color image.

[0449] Meanwhile, when light from the organic light-emitting diode (D) passes through the first substrate (610) and is displayed, the color conversion layer (680) may be provided between the organic light-emitting diode (D) and the first substrate (610).

[0450] FIG. 10 is a schematic cross-sectional view of an organic light-emitting display device according to the 7th embodiment of the present invention.

[0451] As illustrated in FIG. 10, the organic light-emitting display device (700) includes a first substrate (710) in which a red pixel (RP), a green pixel (GP), and a blue pixel (BP) are defined, a second substrate (770) facing the first substrate (710), an organic light-emitting diode (D) located between the first substrate (710) and the second substrate (770) and emitting white light, and a color filter layer (780) located between the organic light-emitting diode (D) and the second substrate (770).

[0452] Each of the first substrate (710) and the second substrate (770) may be a glass substrate or a flexible substrate. For example, the flexible substrate may be any one of a polyimide (PI) substrate, a polyethersulfone (PES) substrate, a polyethylenenaphthalate (PEN) substrate, a polyethylene terephthalate (PET) substrate, and a polycarbonate (PC) substrate.

[0453] A buffer layer (720) is formed on the first substrate (710), and a thin-film transistor (Tr) is formed on the buffer layer (720) corresponding to each of the red pixel (RP), green pixel (GP), and blue pixel (BP). The buffer layer (720) may be omitted.

[0454] A semiconductor layer (722) is formed on the buffer layer (720). The semiconductor layer (722) may be made of an oxide semiconductor material or polycrystalline silicon.

[0455] A gate insulating film (724) made of an insulating material is formed on the upper surface of the semiconductor layer (722). The gate insulating film (724) may be made of an inorganic insulating material such as silicon oxide or silicon nitride.

[0456] A gate electrode (730) made of a conductive material such as metal is formed on the upper part of the gate insulating film (724) in correspondence with the center of the semiconductor layer (722).

[0457] An interlayer insulating film (732) made of an insulating material is formed on the upper part of the gate electrode (730). The interlayer insulating film (732) may be formed of an inorganic insulating material such as silicon oxide or silicon nitride, or may be formed of an organic insulating material such as benzocyclobutene or photoacryl.

[0458] The interlayer insulating film (732) has first and second contact holes (734, 736) that expose both sides of the semiconductor layer (722). The first and second contact holes (734, 736) are located on both sides of the gate electrode (730) and spaced apart from the gate electrode (730).

[0459] On the interlayer insulating film (732), a source electrode (740) and a drain electrode (742) made of a conductive material such as metal are formed.

[0460] The source electrode (740) and the drain electrode (742) are spaced apart from the gate electrode (730) and contact both sides of the semiconductor layer (722) through the first and second contact holes (734, 736), respectively.

[0461] The semiconductor layer (722), the gate electrode (730), the source electrode (740), and the drain electrode (742) form the thin-film transistor (Tr), and the thin-film transistor (Tr) functions as a driving element.

[0462] Although not illustrated, gate wiring and data wiring intersect to define a pixel, and switching elements connected to the gate wiring and data wiring are further formed. The switching elements are connected to thin-film transistors (Tr), which are driving elements.

[0463] In addition, power wiring is formed spaced apart from data wiring or parallel to data wiring, and a storage capacitor may be further configured to maintain a constant voltage of the gate electrode of a thin-film transistor (Tr), which is a driving element, during one frame.

[0464] A protective layer (750) having a drain contact hole (752) that exposes the drain electrode (742) of the thin-film transistor (Tr) is formed to cover the thin-film transistor (Tr).

[0465] On the protective layer (750), a first electrode (810) connected to the drain electrode (742) of the thin-film transistor (Tr) through a drain contact hole (752) is formed separately for each pixel area. The first electrode (810) may be an anode and includes a transparent conductive oxide layer made of a conductive material having a relatively large work function value, for example, a transparent conductive oxide (TCO).

[0466] For example, the transparent conductive oxide layer may be composed of any one of indium-tin-oxide (ITO), indium-zinc-oxide (IZO), indium-tin-zinc-oxide (ITZO), tin oxide (SnO), zinc oxide (ZnO), indium-copper-oxide (ICO), and aluminum:zinc oxide (Al:ZnO; AZO).

[0467] Additionally, the first electrode (810) may have a double-layer or triple-layer structure by further including a reflective layer. That is, the first electrode (810) may be a reflective electrode.

[0468] For example, the reflective layer may be made of silver (Ag) or an alloy of silver with at least one of palladium (Pd), copper (Cu), indium (In), and neodymium (Nd), or an aluminum-palladium-copper (APC) alloy. For example, the first electrode (810) may have a double-layer structure of Ag / ITO or APC / ITO or a triple-layer structure of ITO / Ag / ITO or ITO / APC / ITO.

[0469] A bank layer (766) covering the edge of the first electrode (810) is formed on the protective layer (750). The bank layer (766) exposes the center of the first electrode (810) corresponding to the red, green, and blue pixels (Rp, GP, BP). Since the organic light-emitting diode (D) emits white light from the red, green, and blue pixels (Rp, GP, BP), the organic light-emitting layer (820) can be formed as a common layer without needing to be separated from the red, green, and blue pixels (Rp, GP, BP). The bank layer (766) is formed to prevent current leakage at the edge of the first electrode (810), and the bank layer (766) may be omitted.

[0470] An organic light-emitting layer (820) is formed on the first electrode (810).

[0471] A second electrode (830) is formed on the upper part of the first substrate (710) on which the organic light-emitting layer (820) is formed.

[0472] In the organic light-emitting display device (700) of the present invention, light emitted from the organic light-emitting layer (820) is incident on the color filter layer (780) through the second electrode (830), so the second electrode (830) has a thin thickness so that light can be transmitted.

[0473] The first electrode (810), the organic light-emitting layer (820), and the second electrode (830) form an organic light-emitting diode (D).

[0474] The color filter layer (780) is located on top of the organic light-emitting diode (D) and includes a red color filter (782), a green color filter (784), and a blue color filter (786) corresponding to each of the red pixel (RP), the green pixel (GP), and the blue pixel (BP). The red color filter (782) may include at least one of a red dye and a red pigment, the green color filter (784) may include at least one of a green dye and a green pigment, and the blue color filter (786) may include at least one of a blue dye and a blue pigment.

[0475] Although not illustrated, the color filter layer (780) may be attached to the organic light-emitting diode (D) by an adhesive layer. Alternatively, the color filter layer (780) may be formed directly on the organic light-emitting diode (D). Additionally, if an encapsulation layer (encapsulation film) covering the organic light-emitting diode (D) is formed, the color filter layer (780) may be formed on the encapsulation layer.

[0476] Although not shown, an encapsulation film may be formed to prevent external moisture from penetrating into the organic light-emitting diode (D). For example, the encapsulation film may have a laminated structure of a first inorganic insulating layer, an organic insulating layer, and a second inorganic insulating layer, but is not limited thereto.

[0477] In contrast, in a bottom-emitting type organic light-emitting display device (700), a metal encapsulation plate may be placed above the second electrode (830). For example, the encapsulation plate may be attached to an organic light-emitting diode (D) through an adhesive layer.

[0478] Additionally, a polarizing plate may be attached to the outer surface of the second substrate (770) to reduce external light reflection. For example, the polarizing plate may be a circular polarizing plate.

[0479] In the organic light-emitting diode (D) of FIG. 10, the first electrode (810) is a reflective electrode and the second electrode (830) is a transmissive (semi-transmissive) electrode, and a color filter layer (780) is placed on the upper part of the organic light-emitting diode (D).

[0480] Alternatively, the first electrode (810) may be a transmissive (semi-transmissive) electrode and the second electrode (7830) may be a reflective electrode, in which case the color filter layer (780) may be placed between the organic light-emitting diode (D) and the first substrate (710). In this case, the first electrode (810) may have a single-layer structure of a transparent conductive oxide layer.

[0481] Additionally, a color conversion layer (not shown) may be provided between the organic light-emitting diode (D) and the color filter layer (780). The color conversion layer includes a red color conversion layer, a green color conversion layer, and a blue color conversion layer corresponding to each pixel, and can convert white light from the organic light-emitting diode (D) into red, green, and blue, respectively. For example, the color conversion layer may include quantum dots. Thus, the color purity of the organic light-emitting display device (700) can be further improved.

[0482] In addition, a color conversion layer may be included instead of the color filter layer (780).

[0483] As described above, in the organic light-emitting display device (700), the organic light-emitting diodes (D) of the red pixel (RP), green pixel (GP), and blue pixel (BP) emit white light, and the light from the organic light-emitting diodes (D) passes through the red color filter (782), green color filter (784), and blue color filter (786), thereby displaying green, red, and blue colors in the red pixel (RP), green pixel (GP), and blue pixel (BP), respectively.

[0484] Meanwhile, in FIG. 10, an organic light-emitting diode (D) that emits white light is used in a display device. Alternatively, the organic light-emitting diode (D) may be formed on the front surface of a substrate without a driving element such as a thin-film transistor (Tr) and a color filter layer (780) and used in a lighting device. In the present invention, the organic light-emitting device includes a display device and a lighting device.

[0485] FIG. 11 is a schematic cross-sectional view of an organic light-emitting diode according to the eighth embodiment of the present invention.

[0486] As illustrated in FIG. 11, the organic light-emitting diode (D5) includes a first electrode (810) and a second electrode (830) facing each other, and an organic light-emitting layer (820) located between the first and second electrodes (810, 830). The organic light-emitting layer (820) includes a first light-emitting part (ST1) including a first blue light-emitting material layer (910), a second light-emitting part (ST2) including a second blue light-emitting material layer (940), and a third light-emitting part (ST3) including a third light-emitting material layer (970) that emits red and green light. The organic light-emitting layer (820) may further include a first charge-generating layer (980) located between the first light-emitting part (ST1) and the third light-emitting part (ST3), and a second charge-generating layer (990) located between the second light-emitting part (ST2) and the third light-emitting part (ST3). Additionally, the organic light-emitting diode (D5) may further include a capping layer (not shown) formed on the second electrode (830) to improve light extraction.

[0487] The organic light-emitting display device (700) includes a red pixel area (RP), a green pixel area (GP), and a blue pixel area (BP), and the organic light-emitting diode (D5) emits white light in the red pixel area (RP), the green pixel area (GP), and the blue pixel area (BP).

[0488] The first electrode (810) may be an anode, and the second electrode (830) may be a cathode. One of the first electrode (810) and the second electrode (830) is a reflective electrode, and the other of the first electrode (810) and the second electrode (830) is a transmissive (semi-transmissive) electrode. For example, the first electrode (810) may have a single-layer structure of ITO, and the second electrode (830) may be made of Al.

[0489] The first light-emitting part (ST1) may further include at least one of a first hole transport layer (914) located below the first blue light-emitting material layer (910) and a first electron transport layer (916) located above the first blue light-emitting material layer (910).

[0490] Additionally, the first light-emitting part (ST1) may further include a hole injection layer (912) located below the first hole transport layer (914).

[0491] Although not illustrated, the first light-emitting part (ST1) may further include at least one of a first electron blocking layer located between the first blue light-emitting material layer (910) and the first hole transport layer (914), and a first hole blocking layer located between the first blue light-emitting material layer (910) and the first electron transport layer (916).

[0492] The second light-emitting part (ST2) may further include at least one of a second hole transport layer (942) located below the second blue light-emitting material layer (940) and a second electron transport layer (944) located above the second blue light-emitting material layer (940).

[0493] Additionally, the second light-emitting part (ST2) may further include an electron injection layer (946) located above the second electron transport layer (944).

[0494] Although not illustrated, the second light-emitting part (ST2) may further include at least one of a second electron blocking layer located between the second blue light-emitting material layer (940) and the second hole transport layer (942), and a second hole blocking layer located between the second blue light-emitting material layer (940) and the second electron transport layer (944).

[0495] In the third light-emitting part (ST3), the third light-emitting material layer (970) may include a red light-emitting material layer (970a), a yellow-green light-emitting material layer (970c), and a green light-emitting material layer (970b). In this case, the yellow-green light-emitting material layer (970c) is located between the red light-emitting material layer (970a) and the green light-emitting material layer (970b). Alternatively, the yellow-green light-emitting material layer (970c) may be omitted, and the third light-emitting material layer (970) may have a double-layer structure of the red light-emitting material layer (970a) and the green light-emitting material layer (970b).

[0496] The red emitting material layer (970a) comprises a red host and a red dopant, the green emitting material layer (970b) comprises a green host and a green dopant, and the yellow-green emitting material layer (970c) comprises a yellow-green host and a yellow-green dopant. Each of the red dopant, green dopant, and yellow-green dopant may be one of a fluorescent compound, a phosphorescent compound, or a delayed fluorescent compound.

[0497] The third light-emitting part (ST3) may further include a third hole transport layer (972) located below the third light-emitting material layer (970) and a third electron transport layer (974) located above the third light-emitting material layer (970).

[0498] Although not illustrated, the third light-emitting part (ST3) may further include at least one of a third electron blocking layer located between the third light-emitting material layer (970) and the third hole transport layer (972), and a third hole blocking layer located between the third light-emitting material layer (970) and the third electron transport layer (974).

[0499] For example, the hole injection layer (912) may include the hole injection material described above. The hole injection layer (912) may have a thickness of 1 to 30 nm.

[0500] Each of the first hole transport layer (914), the second hole transport layer (942), and the third hole transport layer (972) may include the aforementioned hole transport material. Each of the first hole transport layer (914), the second hole transport layer (942), and the third hole transport layer (972) may have a thickness of 10 to 100 nm.

[0501] Each of the first electron transport layer (916), the second electron transport layer (944), and the third electron transport layer (974) may include the aforementioned electron transport material. Each of the first electron transport layer (916), the second electron transport layer (944), and the third electron transport layer (974) may have a thickness of 10 to 100 nm.

[0502] The electron injection layer (946) may include the aforementioned electron injection material. The electron injection layer (946) may have a thickness of 0.1 to 10 nm.

[0503] Each of the first electron blocking layer, the second electron blocking layer, and the third electron blocking layer may include the aforementioned electron blocking material. Each of the first electron blocking layer, the second electron blocking layer, and the third electron blocking layer may have a thickness of 5 to 40 nm.

[0504] Each of the first hole blocking layer, the second hole blocking layer, and the third hole blocking layer may include the aforementioned hole blocking material. Each of the first hole blocking layer, the second hole blocking layer, and the third hole blocking layer may have a thickness of 1 to 20 nm.

[0505] The first charge generating layer (980) is located between the first light-emitting part (ST1) and the third light-emitting part (ST3), and the second charge generating layer (990) is located between the second light-emitting part (ST2) and the third light-emitting part (ST3). That is, the first light-emitting part (ST1), the first charge generating layer (980), the third light-emitting part (ST3), the second charge generating layer (990), and the second light-emitting part (ST2) are sequentially stacked on the first electrode (810). In other words, the first light-emitting part (ST1) is located between the first electrode (810) and the first charge generating layer (980), the third light-emitting part (ST3) is located between the first and second charge generating layers (980, 990), and the second light-emitting part (ST2) is located between the second charge generating layer (990) and the second electrode (830).

[0506] The first charge generating layer (980) may be a PN junction charge generating layer in which an N-type charge generating layer (982) and a P-type charge generating layer (984) are joined, and the second charge generating layer (990) may be a PN junction charge generating layer in which an N-type charge generating layer (992) and a P-type charge generating layer (994) are joined.

[0507] In the first charge generation layer (980), the N-type charge generation layer (982) is located between the first electron transport layer (916) and the third hole transport layer (972), and the P-type charge generation layer (984) is located between the N-type charge generation layer (982) and the third hole transport layer (972).

[0508] In the second charge generation layer (990), the N-type charge generation layer (992) is located between the third electron transport layer (974) and the second hole transport layer (942), and the P-type charge generation layer (994) is located between the N-type charge generation layer (992) and the second hole transport layer (942).

[0509] Each of the first N-type charge generating layer (982) and the second N-type charge generating layer (992) may be an organic layer doped with an alkali metal such as Li, Na, K, Cs and / or an alkaline earth metal such as Mg, Sr, Ba, Ra. For example, each of the first N-type charge generating layer (982) and the second N-type charge generating layer (992) comprises a host which is an organic material such as 4,7-diphenyl-1,10-phenanthroline (4,7-dipheny-1,10-phenanthroline; Bphen) and MTDATA, and a dopant which is an alkali metal or an alkaline earth metal, and the dopant may be doped in an amount of 0.01 to 30 weight%.

[0510] Each of the first P-type charge generating layer (984) and the second P-type charge generating layer (994) may be composed of an inorganic material selected from the group consisting of tungsten oxide (WOx), molybdenum oxide (MoOx), beryllium oxide (Be2O3), vanadium oxide (V2O5) and combinations thereof, and an organic material selected from the group consisting of NPD, HAT-CN, F4TCNQ, TPD, TNB, TCTA, N,N'-dioctyl-3,4,9,10-perylenedicarboximide (PTCDI-C8) and combinations thereof.

[0511] The first blue light-emitting material layer (910) includes an adjacent first blue light-emitting layer (920) and a second blue light-emitting layer (930). For example, the first blue light-emitting layer (920) is located between the first electrode (810) and the second blue light-emitting layer (930).

[0512] In the first blue light-emitting material layer (910), the second blue light-emitting layer (930) is in contact with the first blue light-emitting layer (920) and is positioned on the first blue light-emitting layer (920), so that the first blue light-emitting material layer (910) has a double-layer structure.

[0513] The first blue light-emitting layer (920) includes a first p-type host (922) and a first n-type host (924), and the second blue light-emitting layer (930) includes a second p-type host (932) and a second n-type host (934). Additionally, the first blue light-emitting layer (920) may further include a first phosphorescent dopant (926), and the second blue light-emitting layer (930) may further include a second phosphorescent dopant (936).

[0514] One of the first p-type host (922) and the second p-type host (932) is a first compound represented by Chemical Formula 1a or Chemical Formula 1b, and the other of the first p-type host (922) and the second p-type host (932) is a second compound represented by Chemical Formula 3a or Chemical Formula 3b. For example, one of the first p-type host (922) and the second p-type host (932) may be selected from the compound of Chemical Formula 2, and the other of the first p-type host (922) and the second p-type host (932) may be selected from the compound of Chemical Formula 4.

[0515] The first n-type host (924) and the second n-type host (934) are each compounds represented by Formula 5. For example, the first n-type host (924) and the second n-type host (934) may each be independently selected from the compounds of Formula 6. The first n-type host (924) and the second n-type host (934) may be the same or different.

[0516] The first phosphorescent dopant (926) and the second phosphorescent dopant (936) are each compounds represented by Chemical Formula 7. For example, the first phosphorescent dopant (926) and the second phosphorescent dopant (936) may each be independently selected from the compounds of Chemical Formula 8. The first phosphorescent dopant (926) and the second phosphorescent dopant (936) may be the same or different.

[0517] In the first blue light-emitting layer (920), the weight ratio of each of the first p-type host (922) and the first n-type host (924) may be greater than the weight ratio of the first phosphorescent dopant (926), and the weight ratio of the first p-type host (922) and the weight ratio of the first n-type host (924) may be the same or different. For example, in the first blue light-emitting layer (920), the first p-type host (922) and the first n-type host (924) may have the same weight ratio, and with respect to the first phosphorescent dopant (926), each of the first p-type host (922) and the first n-type host (924) may have 200 to 600 parts by weight.

[0518] In the second blue light-emitting layer (930), the weight ratio of the second p-type host (932) and the second n-type host (934) may be greater than the weight ratio of the second phosphorescent dopant (936), and the weight ratio of the second p-type host (932) and the weight ratio of the second n-type host (934) may be the same or different. For example, in the second blue light-emitting layer (930), the second p-type host (932) and the second n-type host (934) may have the same weight ratio, and with respect to the second phosphorescent dopant (936), the second p-type host (932) and the second n-type host (934) may each have 200 to 600 parts by weight.

[0519] The first blue light-emitting material layer (910) may have a thickness of 10 to 100 nm, and the first blue light-emitting layer (920) and the second blue light-emitting layer (930) may each have a thickness of 5 to 50 nm. For example, the first blue light-emitting material layer (910) may have a thickness of 20 to 40 nm, and the first blue light-emitting layer (920) and the second blue light-emitting layer (930) may each have a thickness of 5 to 30 nm. The thickness of the first blue light-emitting layer (920) and the thickness of the second blue light-emitting layer (930) may be the same or different.

[0520] The second blue light-emitting material layer (940) has a single-layer structure. The second blue light-emitting material layer (940) may have a thickness of 10 to 100 nm.

[0521] The second blue light-emitting material layer (940) may include a blue host (940a) and a blue dopant (940b, a light source). Additionally, the second blue light-emitting material layer (940) may further include an auxiliary dopant (auxiliary host). In the second blue light-emitting material layer (940), the weight ratio of the blue dopant (940b) may be smaller than the weight ratio of the blue host (940a) and the auxiliary dopant, respectively.

[0522] For example, the blue host (940a) may be at least one of the compounds of Formula 14, the blue dopant (940b) may be selected from the compounds of Formula 15, and the auxiliary dopant may be selected from the compounds of Formula 16.

[0523] The second blue light-emitting material layer (940) may be one of a fluorescent light-emitting layer, a phosphorescent-sensitive fluorescent light-emitting layer, or a superfluorescent light-emitting layer.

[0524] The organic light-emitting layer (820) of the organic light-emitting diode (D5) has a tandem structure comprising a first light-emitting part (ST1) including a first blue light-emitting material layer (910), a second light-emitting part (ST2) including a second blue light-emitting material layer (940), and a third light-emitting part (ST3) including red, yellow-green, and green light-emitting material layers (970a, 970c, 970b).

[0525] At this time, the first blue light-emitting material layer (910) includes a first blue light-emitting layer (920) comprising a first p-type host (922), a first n-type host (924), and a first phosphorescent dopant (926), and a second blue light-emitting layer (930) comprising a second p-type host (932), a second n-type host (934), and a second phosphorescent dopant (936). One of the first p-type host (922) and the second p-type host (932) is a first compound represented by Chemical Formula 1a or Chemical Formula 1b, and the other of the first p-type host (922) and the second p-type host (932) is a second compound represented by Chemical Formula 3a or Chemical Formula 3b. Additionally, the first n-type host (924) and the second n-type host (934) are each a compound represented by Chemical Formula 5, and the first phosphorescent dopant (926) and the second phosphorescent dopant (936) are each a compound represented by Chemical Formula 7.

[0526] Accordingly, in the organic light-emitting diode (D5) and the organic light-emitting device (700) including it, the driving voltage is reduced and the luminous efficiency, color purity, and lifespan are improved.

[0527] FIG. 12 is a schematic cross-sectional view of an organic light-emitting diode according to the ninth embodiment of the present invention.

[0528] As illustrated in FIG. 12, the organic light-emitting diode (D6) includes a first electrode (810) and a second electrode (830) facing each other, and an organic light-emitting layer (820) located between the first and second electrodes (810, 830). The organic light-emitting layer (820) includes a first light-emitting part (ST1) including a first blue light-emitting material layer (1010), a second light-emitting part (ST2) including a second blue light-emitting material layer (1040), and a third light-emitting part (ST3) including a third light-emitting material layer (1070) that emits red and green light. The organic light-emitting layer (820) may further include a first charge generating layer (1080) located between the first light-emitting part (ST1) and the third light-emitting part (ST3), and a second charge generating layer (1090) located between the second light-emitting part (ST2) and the third light-emitting part (ST3). Additionally, the organic light-emitting diode (D6) may further include a capping layer (not shown) formed on the second electrode (830) to improve light extraction.

[0529] The organic light-emitting display device (700) includes a red pixel area (RP), a green pixel area (GP), and a blue pixel area (BP), and the organic light-emitting diode (D6) emits white light in the red pixel area (RP), the green pixel area (GP), and the blue pixel area (BP).

[0530] The first electrode (810) may be an anode, and the second electrode (830) may be a cathode. One of the first electrode (810) and the second electrode (830) is a reflective electrode, and the other of the first electrode (810) and the second electrode (830) is a transmissive (semi-transmissive) electrode. For example, the first electrode (810) may have a single-layer structure of ITO, and the second electrode (830) may be made of Al.

[0531] The first light-emitting part (ST1) may further include at least one of a first hole transport layer (1014) located below the first blue light-emitting material layer (1010) and a first electron transport layer (1016) located above the first blue light-emitting material layer (1010).

[0532] Additionally, the first light-emitting part (ST1) may further include a hole injection layer (1012) located below the first hole transport layer (1014).

[0533] Although not illustrated, the first light-emitting part (ST1) may further include at least one of a first electron blocking layer located between the first blue light-emitting material layer (1010) and the first hole transport layer (1014), and a first hole blocking layer located between the first blue light-emitting material layer (1010) and the first electron transport layer (1016).

[0534] The second light-emitting part (ST2) may further include at least one of a second hole transport layer (1042) located below the second blue light-emitting material layer (1040) and a second electron transport layer (1044) located above the second blue light-emitting material layer (1040).

[0535] Additionally, the second light-emitting part (ST2) may further include an electron injection layer (1046) located above the second electron transport layer (1044).

[0536] Although not illustrated, the second light-emitting part (ST2) may further include at least one of a second electron blocking layer located between the second blue light-emitting material layer (1040) and the second hole transport layer (1042), and a second hole blocking layer located between the second blue light-emitting material layer (1040) and the second electron transport layer (1044).

[0537] In the third light-emitting part (ST3), the third light-emitting material layer (1070) may include a red light-emitting material layer (1070a), a yellow-green light-emitting material layer (1070c), and a green light-emitting material layer (1070b). In this case, the yellow-green light-emitting material layer (1070c) is located between the red light-emitting material layer (1070a) and the green light-emitting material layer (1070b). Alternatively, the yellow-green light-emitting material layer (1070c) may be omitted, and the third light-emitting material layer (1070) may have a double-layer structure of the red light-emitting material layer (1070a) and the green light-emitting material layer (1070b).

[0538] The red emitting material layer (1070a) comprises a red host and a red dopant, the green emitting material layer (1070b) comprises a green host and a green dopant, and the yellow-green emitting material layer (1070c) comprises a yellow-green host and a yellow-green dopant. Each of the red dopant, green dopant, and yellow-green dopant may be one of a fluorescent compound, a phosphorescent compound, or a delayed fluorescent compound.

[0539] The third light-emitting part (ST3) may further include a third hole transport layer (1072) located below the third light-emitting material layer (1070) and a third electron transport layer (1074) located above the third light-emitting material layer (1070).

[0540] Although not illustrated, the third light-emitting part (ST3) may further include at least one of a third electron blocking layer located between the third light-emitting material layer (1070) and the third hole transport layer (1072), and a third hole blocking layer located between the third light-emitting material layer (1070) and the third electron transport layer (1074).

[0541] For example, the hole injection layer (1012) may include the hole injection material described above. The hole injection layer (1012) may have a thickness of 1 to 30 nm.

[0542] Each of the first hole transport layer (1014), the second hole transport layer (1042), and the third hole transport layer (1072) may include the aforementioned hole transport material. Each of the first hole transport layer (1014), the second hole transport layer (1042), and the third hole transport layer (1072) may have a thickness of 10 to 100 nm.

[0543] Each of the first electron transport layer (1016), the second electron transport layer (1044), and the third electron transport layer (1074) may include the aforementioned electron transport material. Each of the first electron transport layer (1016), the second electron transport layer (1044), and the third electron transport layer (1074) may have a thickness of 10 to 100 nm.

[0544] The electron injection layer (1046) may include the aforementioned electron injection material. The electron injection layer (1046) may have a thickness of 0.1 to 10 nm.

[0545] Each of the first electron blocking layer, the second electron blocking layer, and the third electron blocking layer may include the aforementioned electron blocking material. Each of the first electron blocking layer, the second electron blocking layer, and the third electron blocking layer may have a thickness of 5 to 40 nm.

[0546] Each of the first hole blocking layer, the second hole blocking layer, and the third hole blocking layer may include the aforementioned hole blocking material. Each of the first hole blocking layer, the second hole blocking layer, and the third hole blocking layer may have a thickness of 1 to 20 nm.

[0547] The first charge generating layer (1080) is located between the first light-emitting part (ST1) and the third light-emitting part (ST3), and the second charge generating layer (1090) is located between the second light-emitting part (ST2) and the third light-emitting part (ST3). That is, the first light-emitting part (ST1), the first charge generating layer (1080), the third light-emitting part (ST3), the second charge generating layer (1090), and the second light-emitting part (ST2) are sequentially stacked on the first electrode (810). In other words, the first light-emitting part (ST1) is located between the first electrode (810) and the first charge generating layer (1080), the third light-emitting part (ST3) is located between the first and second charge generating layers (1080, 1090), and the second light-emitting part (ST2) is located between the second charge generating layer (1090) and the second electrode (830).

[0548] The first charge generating layer (1080) may be a PN junction charge generating layer in which an N-type charge generating layer (1082) and a P-type charge generating layer (1084) are joined, and the second charge generating layer (1090) may be a PN junction charge generating layer in which an N-type charge generating layer (1092) and a P-type charge generating layer (1094) are joined.

[0549] In the first charge generation layer (1080), the N-type charge generation layer (1082) is located between the first electron transport layer (1016) and the third hole transport layer (1072), and the P-type charge generation layer (1084) is located between the N-type charge generation layer (1082) and the third hole transport layer (1072).

[0550] In the second charge generation layer (1090), the N-type charge generation layer (1092) is located between the third electron transport layer (1074) and the second hole transport layer (1042), and the P-type charge generation layer (1094) is located between the N-type charge generation layer (1092) and the second hole transport layer (1042).

[0551] Each of the first N-type charge generating layer (1082) and the second N-type charge generating layer (1092) may be an organic layer doped with an alkali metal such as Li, Na, K, Cs and / or an alkaline earth metal such as Mg, Sr, Ba, Ra. For example, each of the first N-type charge generating layer (1082) and the second N-type charge generating layer (1092) comprises a host which is an organic material such as 4,7-diphenyl-1,10-phenanthroline (4,7-dipheny-1,10-phenanthroline; Bphen) and MTDATA, and a dopant which is an alkali metal or an alkaline earth metal, and the dopant may be doped in an amount of 0.01 to 30 weight%.

[0552] Each of the first P-type charge generating layer (1084) and the second P-type charge generating layer (1094) may be composed of an inorganic material selected from the group consisting of tungsten oxide (WOx), molybdenum oxide (MoOx), beryllium oxide (Be2O3), vanadium oxide (V2O5) and combinations thereof, and an organic material selected from the group consisting of NPD, HAT-CN, F4TCNQ, TPD, TNB, TCTA, N,N'-dioctyl-3,4,9,10-perylenedicarboximide (PTCDI-C8) and combinations thereof.

[0553] The first blue light-emitting material layer (1010) has a single-layer structure. The first blue light-emitting material layer (1010) may have a thickness of 10 to 100 nm.

[0554] The first blue light-emitting material layer (1010) may include a host (1010a) and a dopant (1010b, a light-emitting body). Additionally, the first blue light-emitting material layer (1010) may further include an auxiliary dopant (auxiliary host). In the first blue light-emitting material layer (1010), the weight ratio of the blue dopant (1010b) may be smaller than the weight ratio of the blue host (1010a) and the auxiliary dopant, respectively.

[0555] For example, the blue host (1010a) may be at least one of the compounds of Formula 14, the blue dopant (1010b) may be selected from the compounds of Formula 15, and the auxiliary dopant may be selected from the compounds of Formula 16.

[0556] The first blue light-emitting material layer (1010) may be one of a fluorescent light-emitting layer, a phosphorescent-sensitive fluorescent light-emitting layer, or a superfluorescent light-emitting layer.

[0557] The second blue light-emitting material layer (1040) includes an adjacent first blue light-emitting layer (1050) and a second blue light-emitting layer (1060). For example, the second blue light-emitting layer (1060) is located between the second electrode (230) and the first blue light-emitting layer (1050).

[0558] In the second blue light-emitting material layer (1040), the second blue light-emitting layer (1060) is in contact with the first blue light-emitting layer (1050) and is positioned on the first blue light-emitting layer (1050), so that the second blue light-emitting material layer (1040) has a double-layer structure.

[0559] The first blue light-emitting layer (1050) includes a first p-type host (1052) and a first n-type host (1054), and the second blue light-emitting layer (1060) includes a second p-type host (1062) and a second n-type host (1064). Additionally, the first blue light-emitting layer (1050) may further include a first phosphorescent dopant (1056), and the second blue light-emitting layer (1060) may further include a second phosphorescent dopant (1066).

[0560] One of the first p-type host (1052) and the second p-type host (1062) is a first compound represented by Chemical Formula 1a or Chemical Formula 1b, and the other of the first p-type host (1052) and the second p-type host (1062) is a second compound represented by Chemical Formula 3a or Chemical Formula 3b. For example, one of the first p-type host (1052) and the second p-type host (1062) may be selected from the compound of Chemical Formula 2, and the other of the first p-type host (1052) and the second p-type host (1062) may be selected from the compound of Chemical Formula 4.

[0561] The first n-type host (1054) and the second n-type host (1064) are each compounds represented by Chemical Formula 5. For example, the first n-type host (1054) and the second n-type host (1064) may each be independently selected from the compounds of Chemical Formula 6. The first n-type host (1054) and the second n-type host (1064) may be the same or different.

[0562] The first phosphorescent dopant (1056) and the second phosphorescent dopant (1066) are each compounds represented by Chemical Formula 7. For example, the first phosphorescent dopant (1056) and the second phosphorescent dopant (1066) may each be independently selected from the compounds of Chemical Formula 8. The first phosphorescent dopant (1056) and the second phosphorescent dopant (1066) may be the same or different.

[0563] In the first blue light-emitting layer (1050), the weight ratio of each of the first p-type host (1052) and the first n-type host (1054) may be greater than the weight ratio of the first phosphorescent dopant (1056), and the weight ratio of the first p-type host (1052) and the weight ratio of the first n-type host (1054) may be the same or different. For example, in the first blue light-emitting layer (1050), the first p-type host (1052) and the first n-type host (1054) may have the same weight ratio, and with respect to the first phosphorescent dopant (1056), each of the first p-type host (1052) and the first n-type host (1054) may have 200 to 600 parts by weight.

[0564] In the second blue light-emitting layer (1060), the weight ratio of the second p-type host (1062) and the second n-type host (1064) may be greater than the weight ratio of the second phosphorescent dopant (1066), and the weight ratio of the second p-type host (1062) and the weight ratio of the second n-type host (1064) may be the same or different. For example, in the second blue light-emitting layer (1060), the second p-type host (1062) and the second n-type host (1064) may have the same weight ratio, and with respect to the second phosphorescent dopant (1066), the second p-type host (1062) and the second n-type host (1064) may each have 200 to 600 parts by weight.

[0565] The second blue light-emitting material layer (1040) may have a thickness of 10 to 100 nm, and the first blue light-emitting layer (1050) and the second blue light-emitting layer (1060) may each have a thickness of 5 to 50 nm. For example, the second blue light-emitting material layer (1040) may have a thickness of 20 to 40 nm, and the first blue light-emitting layer (1050) and the second blue light-emitting layer (1060) may each have a thickness of 5 to 30 nm. The thickness of the first blue light-emitting layer (1050) and the thickness of the second blue light-emitting layer (1060) may be the same or different.

[0566] The organic light-emitting layer (820) of the organic light-emitting diode (D6) has a tandem structure comprising a first light-emitting part (ST1) comprising a first blue light-emitting material layer (1010), a second light-emitting part (ST2) comprising a second blue light-emitting material layer (1040), and a third light-emitting part (ST3) comprising red, yellow-green, and green light-emitting material layers (1070a, 1070c, 1070b).

[0567] The second blue light-emitting material layer (1040) comprises a first blue light-emitting layer (1050) comprising a first p-type host (1052), a first n-type host (1054), and a first phosphorescent dopant (1056), and a second blue light-emitting layer (1060) comprising a second p-type host (1062), a second n-type host (1064), and a second phosphorescent dopant (1066). One of the first p-type host (1052) and the second p-type host (1062) is a first compound represented by Chemical Formula 1a or Chemical Formula 1b, and the other of the first p-type host (1052) and the second p-type host (1062) is a second compound represented by Chemical Formula 3a or Chemical Formula 3b. Additionally, the first n-type host (1054) and the second n-type host (1064) are each a compound represented by Chemical Formula 5, and the first phosphorescent dopant (1056) and the second phosphorescent dopant (1066) are each a compound represented by Chemical Formula 7.

[0568] Accordingly, in the organic light-emitting diode (D6) and the organic light-emitting device (700) including it, the driving voltage is reduced and the luminous efficiency, color purity, and lifespan are improved.

[0569] As illustrated in FIG. 13, the organic light-emitting diode (D7) includes a first electrode (810) and a second electrode (830) facing each other, and an organic light-emitting layer (820) located between the first and second electrodes (810, 830). The organic light-emitting layer (820) includes a first light-emitting part (ST1) including a first blue light-emitting material layer (1110), a second light-emitting part (ST2) including a second blue light-emitting material layer (1140), and a third light-emitting part (ST3) including a third light-emitting material layer (1170) that emits red and green light. The organic light-emitting layer (820) may further include a first charge generating layer (1180) located between the first light-emitting part (ST1) and the third light-emitting part (ST3), and a second charge generating layer (1190) located between the second light-emitting part (ST2) and the third light-emitting part (ST3). Additionally, the organic light-emitting diode (D7) may further include a capping layer (not shown) formed on the second electrode (830) to improve light extraction.

[0570] The organic light-emitting display device (700) includes a red pixel area (RP), a green pixel area (GP), and a blue pixel area (BP), and the organic light-emitting diode (D7) emits white light in the red pixel area (RP), the green pixel area (GP), and the blue pixel area (BP).

[0571] The first electrode (810) may be an anode, and the second electrode (830) may be a cathode. One of the first electrode (810) and the second electrode (830) is a reflective electrode, and the other of the first electrode (810) and the second electrode (830) is a transmissive (semi-transmissive) electrode. For example, the first electrode (810) may have a single-layer structure of ITO, and the second electrode (830) may be made of Al.

[0572] The first light-emitting part (ST1) may further include at least one of a first hole transport layer (1114) located below the first blue light-emitting material layer (1110) and a first electron transport layer (1116) located above the first blue light-emitting material layer (1110).

[0573] Additionally, the first light-emitting part (ST1) may further include a hole injection layer (1112) located below the first hole transport layer (1114).

[0574] Although not illustrated, the first light-emitting part (ST1) may further include at least one of a first electron blocking layer located between the first blue light-emitting material layer (1110) and the first hole transport layer (1114), and a first hole blocking layer located between the first blue light-emitting material layer (1110) and the first electron transport layer (1116).

[0575] The second light-emitting part (ST2) may further include at least one of a second hole transport layer (1142) located below the second blue light-emitting material layer (1140) and a second electron transport layer (1144) located above the second blue light-emitting material layer (1140).

[0576] Additionally, the second light-emitting part (ST2) may further include an electron injection layer (1146) located above the second electron transport layer (1144).

[0577] Although not illustrated, the second light-emitting part (ST2) may further include at least one of a second electron blocking layer located between the second blue light-emitting material layer (1140) and the second hole transport layer (1142), and a second hole blocking layer located between the second blue light-emitting material layer (1140) and the second electron transport layer (1144).

[0578] In the third light-emitting part (ST3), the third light-emitting material layer (1170) may include a red light-emitting material layer (1170a), a yellow-green light-emitting material layer (1170c), and a green light-emitting material layer (1170b). In this case, the yellow-green light-emitting material layer (1170c) is located between the red light-emitting material layer (1170a) and the green light-emitting material layer (1170b). Alternatively, the yellow-green light-emitting material layer (1170c) may be omitted, and the third light-emitting material layer (1170) may have a double-layer structure of the red light-emitting material layer (1170a) and the green light-emitting material layer (1170b).

[0579] The red emitting material layer (1170a) comprises a red host and a red dopant, the green emitting material layer (1170b) comprises a green host and a green dopant, and the yellow-green emitting material layer (1170c) comprises a yellow-green host and a yellow-green dopant. Each of the red dopant, green dopant, and yellow-green dopant may be one of a fluorescent compound, a phosphorescent compound, or a delayed fluorescent compound.

[0580] The third light-emitting part (ST3) may further include a third hole transport layer (1172) located below the third light-emitting material layer (1170) and a third electron transport layer (1174) located above the third light-emitting material layer (1170).

[0581] Although not illustrated, the third light-emitting part (ST3) may further include at least one of a third electron blocking layer located between the third light-emitting material layer (1170) and the third hole transport layer (1172), and a third hole blocking layer located between the third light-emitting material layer (1170) and the third electron transport layer (1174).

[0582] For example, the hole injection layer (1112) may include the hole injection material described above. The hole injection layer (1112) may have a thickness of 1 to 30 nm.

[0583] Each of the first hole transport layer (1114), the second hole transport layer (1142), and the third hole transport layer (1172) may include the aforementioned hole transport material. Each of the first hole transport layer (1114), the second hole transport layer (1142), and the third hole transport layer (1172) may have a thickness of 10 to 100 nm.

[0584] Each of the first electron transport layer (1116), the second electron transport layer (1144), and the third electron transport layer (1174) may include the aforementioned electron transport material. Each of the first electron transport layer (1116), the second electron transport layer (1144), and the third electron transport layer (1174) may have a thickness of 10 to 100 nm.

[0585] The electron injection layer (1146) may include the aforementioned electron injection material. The electron injection layer (1146) may have a thickness of 0.1 to 10 nm.

[0586] Each of the first electron blocking layer, the second electron blocking layer, and the third electron blocking layer may include the aforementioned electron blocking material. Each of the first electron blocking layer, the second electron blocking layer, and the third electron blocking layer may have a thickness of 5 to 40 nm.

[0587] Each of the first hole blocking layer, the second hole blocking layer, and the third hole blocking layer may include the aforementioned hole blocking material. Each of the first hole blocking layer, the second hole blocking layer, and the third hole blocking layer may have a thickness of 1 to 20 nm.

[0588] The first charge generating layer (1180) is located between the first light-emitting part (ST1) and the third light-emitting part (ST3), and the second charge generating layer (1190) is located between the second light-emitting part (ST2) and the third light-emitting part (ST3). That is, the first light-emitting part (ST1), the first charge generating layer (1180), the third light-emitting part (ST3), the second charge generating layer (1190), and the second light-emitting part (ST2) are sequentially stacked on the first electrode (810). In other words, the first light-emitting part (ST1) is located between the first electrode (810) and the first charge generating layer (1180), the third light-emitting part (ST3) is located between the first and second charge generating layers (1180, 1190), and the second light-emitting part (ST2) is located between the second charge generating layer (1190) and the second electrode (830).

[0589] The first charge generating layer (1180) may be a PN junction charge generating layer in which an N-type charge generating layer (1182) and a P-type charge generating layer (1184) are joined, and the second charge generating layer (1190) may be a PN junction charge generating layer in which an N-type charge generating layer (1192) and a P-type charge generating layer (1194) are joined.

[0590] In the first charge generation layer (1180), the N-type charge generation layer (1182) is located between the first electron transport layer (1116) and the third hole transport layer (1172), and the P-type charge generation layer (1184) is located between the N-type charge generation layer (1182) and the third hole transport layer (1172).

[0591] In the second charge generation layer (1190), the N-type charge generation layer (1192) is located between the third electron transport layer (1174) and the second hole transport layer (1142), and the P-type charge generation layer (1194) is located between the N-type charge generation layer (1192) and the second hole transport layer (1142).

[0592] Each of the first N-type charge generating layer (1182) and the second N-type charge generating layer (1192) may be an organic layer doped with an alkali metal such as Li, Na, K, Cs and / or an alkaline earth metal such as Mg, Sr, Ba, Ra. For example, each of the first N-type charge generating layer (1182) and the second N-type charge generating layer (1192) comprises a host which is an organic material such as 4,7-diphenyl-1,10-phenanthroline (4,7-dipheny-1,10-phenanthroline; Bphen) and MTDATA, and a dopant which is an alkali metal or an alkaline earth metal, and the dopant may be doped in an amount of 0.01 to 30 weight%.

[0593] Each of the first P-type charge generating layer (1184) and the second P-type charge generating layer (1194) may be composed of an inorganic material selected from the group consisting of tungsten oxide (WOx), molybdenum oxide (MoOx), beryllium oxide (Be2O3), vanadium oxide (V2O5) and combinations thereof, and an organic material selected from the group consisting of NPD, HAT-CN, F4TCNQ, TPD, TNB, TCTA, N,N'-dioctyl-3,4,9,10-perylenedicarboximide (PTCDI-C8) and combinations thereof.

[0594] The first blue light-emitting material layer (1110) includes an adjacent first blue light-emitting layer (1120) and a second blue light-emitting layer (1130). For example, the first blue light-emitting layer (1120) is located between the first electrode (810) and the second blue light-emitting layer (1130).

[0595] In the first blue light-emitting material layer (1110), the second blue light-emitting layer (1130) is in contact with the first blue light-emitting layer (1120) and is positioned on the first blue light-emitting layer (1120), so that the first blue light-emitting material layer (1110) has a double-layer structure.

[0596] The first blue light-emitting layer (1120) includes a first p-type host (1122) and a first n-type host (1124), and the second blue light-emitting layer (1130) includes a second p-type host (1132) and a second n-type host (1134). Additionally, the first blue light-emitting layer (1120) may further include a first phosphorescent dopant (1126), and the second blue light-emitting layer (1130) may further include a second phosphorescent dopant (1136).

[0597] One of the first p-type host (1122) and the second p-type host (1132) is a first compound represented by Chemical Formula 1a or Chemical Formula 1b, and the other of the first p-type host (1122) and the second p-type host (1132) is a second compound represented by Chemical Formula 3a or Chemical Formula 3b. For example, one of the first p-type host (1122) and the second p-type host (1132) may be selected from the compound of Chemical Formula 2, and the other of the first p-type host (1122) and the second p-type host (1132) may be selected from the compound of Chemical Formula 4.

[0598] The first n-type host (1124) and the second n-type host (1134) are each compounds represented by Chemical Formula 5. For example, the first n-type host (1124) and the second n-type host (1134) may each be independently selected from the compounds of Chemical Formula 6. The first n-type host (1124) and the second n-type host (1134) may be the same or different.

[0599] The first phosphorescent dopant (1126) and the second phosphorescent dopant (1136) are each compounds represented by Chemical Formula 7. For example, the first phosphorescent dopant (1126) and the second phosphorescent dopant (1136) may each be independently selected from the compounds of Chemical Formula 8. The first phosphorescent dopant (1126) and the second phosphorescent dopant (1136) may be the same or different.

[0600] In the first blue light-emitting layer (1120), the weight ratio of each of the first p-type host (1122) and the first n-type host (1124) may be greater than the weight ratio of the first phosphorescent dopant (1126), and the weight ratio of the first p-type host (1122) and the weight ratio of the first n-type host (1124) may be the same or different. For example, in the first blue light-emitting layer (1120), the first p-type host (1122) and the first n-type host (1124) may have the same weight ratio, and with respect to the first phosphorescent dopant (1126), each of the first p-type host (1122) and the first n-type host (1124) may have 200 to 600 parts by weight.

[0601] In the second blue light-emitting layer (1130), the weight ratio of the second p-type host (1132) and the second n-type host (1134) may be greater than the weight ratio of the second phosphorescent dopant (1136), and the weight ratio of the second p-type host (1132) and the weight ratio of the second n-type host (1134) may be the same or different. For example, in the second blue light-emitting layer (1130), the second p-type host (1132) and the second n-type host (1134) may have the same weight ratio, and with respect to the second phosphorescent dopant (1136), the second p-type host (1132) and the second n-type host (1134) may each have 200 to 600 parts by weight.

[0602] The first blue light-emitting material layer (1110) may have a thickness of 10 to 100 nm, and the first blue light-emitting layer (1120) and the second blue light-emitting layer (1130) may each have a thickness of 5 to 50 nm. For example, the first blue light-emitting material layer (1110) may have a thickness of 20 to 40 nm, and the first blue light-emitting layer (1120) and the second blue light-emitting layer (1130) may each have a thickness of 5 to 30 nm. The thickness of the first blue light-emitting layer (1120) and the thickness of the second blue light-emitting layer (1130) may be the same or different.

[0603] The second blue light-emitting material layer (1140) includes an adjacent third blue light-emitting layer (1150) and a fourth blue light-emitting layer (1160). For example, the fourth blue light-emitting layer (1160) is located between the second electrode (230) and the third blue light-emitting layer (1150).

[0604] In the second blue light-emitting material layer (1140), the fourth blue light-emitting layer (1160) is in contact with the third blue light-emitting layer (1150) and is positioned on the third blue light-emitting layer (1150), so that the second blue light-emitting material layer (1140) has a double-layer structure.

[0605] The third blue light-emitting layer (1150) includes a third p-type host (1152) and a third n-type host (1154), and the fourth blue light-emitting layer (1160) includes a fourth p-type host (1162) and a fourth n-type host (1164). Additionally, the third blue light-emitting layer (1150) may further include a third phosphorescent dopant (1156), and the fourth blue light-emitting layer (1160) may further include a fourth phosphorescent dopant (1166).

[0606] One of the third p-type host (1152) and the fourth p-type host (1162) is a first compound represented by Formula 1a or Formula 1b, and the other of the third p-type host (1152) and the fourth p-type host (1162) is a second compound represented by Formula 3a or Formula 3b. For example, one of the third p-type host (1152) and the fourth p-type host (1162) may be selected from the compound of Formula 2, and the other of the third p-type host (1152) and the fourth p-type host (1162) may be selected from the compound of Formula 4.

[0607] The third n-type host (1154) and the fourth n-type host (1164) are each compounds represented by Chemical Formula 5. For example, the third n-type host (1154) and the fourth n-type host (1164) may each be independently selected from the compounds of Chemical Formula 6. The third n-type host (1154) and the fourth n-type host (1164) may be the same or different.

[0608] The third phosphorescent dopant (1156) and the fourth phosphorescent dopant (1166) are each compounds represented by Chemical Formula 7. For example, the third phosphorescent dopant (1156) and the fourth phosphorescent dopant (1166) may each be independently selected from the compounds of Chemical Formula 8. The third phosphorescent dopant (1156) and the fourth phosphorescent dopant (1166) may be the same or different.

[0609] In the third blue light-emitting layer (1150), the weight ratio of the third p-type host (1152) and the third n-type host (1154) may be greater than the weight ratio of the third phosphorescent dopant (1156), and the weight ratio of the third p-type host (1152) and the weight ratio of the third n-type host (1154) may be the same or different. For example, in the third blue light-emitting layer (1150), the third p-type host (1152) and the third n-type host (1154) may have the same weight ratio, and with respect to the third phosphorescent dopant (1156), the third p-type host (1152) and the third n-type host (1154) may each have 200 to 600 parts by weight.

[0610] In the fourth blue light-emitting layer (1160), the weight ratio of the fourth p-type host (1162) and the fourth n-type host (1164) may be greater than the weight ratio of the fourth phosphorescent dopant (1166), and the weight ratio of the fourth p-type host (1162) and the weight ratio of the fourth n-type host (1164) may be the same or different. For example, in the fourth blue light-emitting layer (1160), the fourth p-type host (1162) and the fourth n-type host (1164) may have the same weight ratio, and with respect to the fourth phosphorescent dopant (1166), the fourth p-type host (1162) and the fourth n-type host (1164) may each have 200 to 600 parts by weight.

[0611] The second blue light-emitting material layer (1140) may have a thickness of 10 to 100 nm, and the third blue light-emitting layer (1150) and the fourth blue light-emitting layer (1160) may each have a thickness of 5 to 50 nm. For example, the second blue light-emitting material layer (1140) may have a thickness of 20 to 40 nm, and the third blue light-emitting layer (1150) and the fourth blue light-emitting layer (1160) may each have a thickness of 5 to 30 nm. The thickness of the third blue light-emitting layer (1150) and the thickness of the fourth blue light-emitting layer (1160) may be the same or different.

[0612] The organic light-emitting layer (820) of the organic light-emitting diode (D6) has a tandem structure comprising a first light-emitting part (ST1) comprising a first blue light-emitting material layer (1110), a second light-emitting part (ST2) comprising a second blue light-emitting material layer (1140), and a third light-emitting part (ST3) comprising red, yellow-green, and green light-emitting material layers (1170a, 1170c, 1170b).

[0613] The first blue light-emitting material layer (1110) comprises a first blue light-emitting layer (1120) comprising a first p-type host (1122), a first n-type host (1124), and a first phosphorescent dopant (1126), and a second blue light-emitting layer (1130) comprising a second p-type host (1132), a second n-type host (1134), and a second phosphorescent dopant (1136). One of the first p-type host (1122) and the second p-type host (1132) is a first compound represented by Chemical Formula 1a or Chemical Formula 1b, and the other of the first p-type host (1122) and the second p-type host (1132) is a second compound represented by Chemical Formula 3a or Chemical Formula 3b. Additionally, the first n-type host (1124) and the second n-type host (1134) are each a compound represented by Chemical Formula 5, and the first phosphorescent dopant (1126) and the second phosphorescent dopant (1136) are each a compound represented by Chemical Formula 7.

[0614] The second blue light-emitting material layer (1140) comprises a third blue light-emitting layer (1150) comprising a third p-type host (1152), a third n-type host (1154), and a third phosphorescent dopant (1156), and a fourth blue light-emitting layer (1160) comprising a fourth p-type host (1162), a fourth n-type host (1164), and a fourth phosphorescent dopant (1166). One of the third p-type host (1152) and the fourth p-type host (1162) is a first compound represented by Chemical Formula 1a or Chemical Formula 1b, and the other of the third p-type host (1152) and the fourth p-type host (1162) is a second compound represented by Chemical Formula 3a or Chemical Formula 3b. Additionally, the third n-type host (1154) and the fourth n-type host (1164) are each compounds represented by Chemical Formula 5, and the third phosphorescent dopant (1156) and the fourth phosphorescent dopant (1166) are each compounds represented by Chemical Formula 7.

[0615] Accordingly, in the organic light-emitting diode (D6) and the organic light-emitting device (700) including it, the driving voltage is reduced and the luminous efficiency, color purity, and lifespan are improved.

[0617] Although the present invention has been described above based on exemplary embodiments and examples, the present invention is not limited to the technical concept described in the embodiments and examples. Rather, those skilled in the art to which the present invention pertains can easily devise various modifications and changes based on the aforementioned embodiments and examples. However, it is evident from the appended claims that all such modifications and changes fall within the scope of the present invention. Explanation of the symbols

[0619] 100, 600, 700: Organic light-emitting display device 210, 610, 810: First electrode 220, 620, 820: Organic light-emitting layer 230, 630, 830: Second electrode 240, 310, 350, 410, 450, 510, 550, 910, 940, 1010, 1040, 1110, 1140: Blue luminescent material layer 250, 260, 320, 330, 460, 470, 520, 530, 560, 570, 920, 930, 1050, 1060, 1120, 1130, 1150, 1160: Blue light-emitting layer 252, 262, 322, 332, 462, 472, 522, 532, 562, 572, 922, 932, 1052, 1062, 1122, 1132, 1152, 1162: p-type host 254, 264, 324, 334, 464, 474, 524, 534, 564, 574, 924, 934, 1054, 1064, 1124, 1134, 1154, 1164: n-type host 256, 266, 326, 336, 466, 476, 526, 536, 566, 576, 926, 936, 1056, 1066, 1126, 1136, 1156, 1166: Phosphorescent dopant D1, D2, D3, D5, D6, D7: Organic light-emitting diodes

Claims

Claim 1 A first electrode; a second electrode facing the first electrode; a first blue emitting material layer comprising a first blue emitting layer and a second blue emitting layer, and a first emitting part located between the first electrode and the second electrode, wherein the first blue emitting layer comprises a first p-type host and a first n-type host, and the second blue emitting layer comprises a second p-type host and a second n-type host, and one of the first p-type host and the second p-type host is a first compound represented by Chemical Formula 1a or Chemical Formula 1b, [Chemical Formula 1a] [Chemical Formula 1b] In Formula 1a, a1 and a4 are each independently integers from 0 to 3, a2, a3, a5 to a8 are each independently integers from 0 to 4, n1 is 0 or 1, and R1 to R8 are each independently selected from the group consisting of deuterium, halogen, cyano group, substituted or unsubstituted C6 to C30 arylsilyl group, substituted or unsubstituted C1 to C20 alkyl group, substituted or unsubstituted C6 to C30 aryl group, substituted or unsubstituted C5 to C60 heteroaryl group, substituted or unsubstituted C1 to C30 arylamine group, and substituted or unsubstituted C6 to C60 arylamine group; and in Formula 1b, b1 is an integer from 0 to 3, b2 to b4 are each independently integers from 0 to 4, b5 is an integer from 0 to 5, and R11 to R15 are each independently deuterium, Selected from the group consisting of a halogen, a cyano group, a substituted or unsubstituted C6 to C30 arylsilyl group, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C5 to C60 heteroaryl group, a substituted or unsubstituted C1 to C30 arylamine group, and a substituted or unsubstituted C6 to C60 arylamine group, wherein the other of the first p-type host and the second p-type host is a second compound represented by Formula 3a or Formula 3b, [Formula 3a] [Chemical Formula 3b] In Formula 3a, d1 and d4 are each independently integers from 0 to 3, d2, d3, d5 to d8 are each independently integers from 0 to 4, n2 and n3 are each independently 0 or 1, and R21 to R28 are each independently selected from the group consisting of deuterium, halogen, cyano group, substituted or unsubstituted C6 to C30 arylsilyl group, substituted or unsubstituted C1 to C20 alkyl group, substituted or unsubstituted C6 to C30 aryl group, substituted or unsubstituted C5 to C60 heteroaryl group, substituted or unsubstituted C1 to C30 arylamine group, and substituted or unsubstituted C6 to C60 arylamine group; in Formula 3b, e1 and e4 are each independently integers from 0 to 3, e2, e3, e5, e6 are each independently integers from 0 to 4, and e7 is An organic light-emitting diode characterized by being an integer from 0 to 5, wherein each of R31 to R37 is independently selected from the group consisting of deuterium, halogen, cyano group, substituted or unsubstituted C6 to C30 arylsilyl group, substituted or unsubstituted C1 to C20 alkyl group, substituted or unsubstituted C6 to C30 aryl group, substituted or unsubstituted C5 to C60 heteroaryl group, substituted or unsubstituted C1 to C30 arylamine group, and substituted or unsubstituted C6 to C60 arylamine group. Claim 2 An organic light-emitting diode according to claim 1, wherein the first compound is one of the compounds of Chemical Formula 2.[Chemical Formula 2] Claim 3 An organic light-emitting diode according to claim 1, wherein the second compound is one of the compounds of Chemical Formula 4.[Chemical Formula 4] Claim 4 In claim 1, each of the first n-type host and the second n-type host is represented by Chemical Formula 5, [Chemical Formula 5] An organic light-emitting diode characterized in that, in Chemical Formula 5, f1, f5, and f6 are each integers from 0 to 4, f2 to f4 are each independently integers from 0 to 5, X is selected from the group consisting of C, Si, and Ge, and R41 to R47 are each independently selected from the group consisting of deuterium, halogen, cyano group, substituted or unsubstituted C6 to C30 arylsilyl group, substituted or unsubstituted C6 to C30 arylgermanyl group, substituted or unsubstituted C1 to C20 alkyl group, substituted or unsubstituted C6 to C30 aryl group, substituted or unsubstituted C5 to C60 heteroaryl group, substituted or unsubstituted C1 to C30 arylamine group, and substituted or unsubstituted C6 to C60 arylamine group. Claim 5 An organic light-emitting diode according to claim 4, wherein each of the first n-type host and the second n-type host is independently selected from the compounds of Formula 6.[Formula 6] Claim 6 In claim 1, the first blue emitting layer comprises a first phosphorescent dopant, and the second blue emitting layer comprises a second phosphorescent dopant, wherein each of the first phosphorescent dopant and the second phosphorescent dopant is represented by Chemical Formula 7, [Chemical Formula 7] An organic light-emitting diode characterized in that, in Formula 7, each of R51 to R56 is independently selected from the group consisting of deuterium, halogen, cyano group, substituted or unsubstituted C1 to C20 alkyl group, substituted or unsubstituted C3 to C20 cycloalkyl group, C1 to C20 alkylsilyl group, substituted or unsubstituted C1 to C20 alkylamino group, substituted or unsubstituted C6 to C30 arylamino group, substituted or unsubstituted C6 to C30 aryl group, substituted or unsubstituted C6 to C30 heteroaryl group, and each of g1, g2, and g3 is independently an integer from 0 to 4, g4 is an integer from 0 to 3, and g5 is an integer from 0 to 2. Claim 7 An organic light-emitting diode according to claim 6, wherein the first phosphorescent dopant and the second phosphorescent dopant are each independently selected from the compounds of Formula 8.[Formula 8] Claim 8 An organic light-emitting diode according to claim 6, wherein in the first blue light-emitting layer, the first p-type host and the first n-type host form a first exciplex, and the difference between the onset wavelength in the absorption spectrum of the first phosphorescent dopant and the onset wavelength in the first exciplex PL spectrum is 10 nm or more, and in the second blue light-emitting layer, the second p-type host and the second n-type host form a second exciplex, and the difference between the onset wavelength in the absorption spectrum of the second phosphorescent dopant and the onset wavelength in the second exciplex PL spectrum is 10 nm or more. Claim 9 An organic light-emitting diode according to claim 8, characterized in that the difference between the lowest unoccupied molecular orbital (LUMO) energy level of the first phosphorescent dopant and the LUMO energy level of the first n-type host is 0.2 eV or more, and the difference between the LUMO energy level of the second phosphorescent dopant and the LUMO energy level of the second n-type host is 0.2 eV or more. Claim 10 An organic light-emitting diode according to claim 9, wherein in the first blue light-emitting layer, the first p-type host and the first n-type host form a first exciplex, and the onset wavelength in the PL spectrum of the first phosphorescent dopant is equal to or greater than the onset wavelength in the PL spectrum of the first exciplex, and in the second blue light-emitting layer, the second p-type host and the second n-type host form a second exciplex, and the onset wavelength in the PL spectrum of the second phosphorescent dopant is equal to or greater than the onset wavelength in the PL spectrum of the second exciplex. Claim 11 An organic light-emitting diode according to claim 1, characterized in that the difference between the LUMO energy level of the first p-type host and the LUMO energy level of the first n-type host is 0.2 eV or more, the difference between the energy level of the highest occupied molecular orbital (HOMO) of the first p-type host and the HOMO energy level of the first n-type host is 0.3 eV or more, the difference between the LUMO energy level of the second p-type host and the LUMO energy level of the second n-type host is 0.2 eV or more, and the difference between the energy level of the highest occupied molecular orbital (HOMO) of the second p-type host and the HOMO energy level of the second n-type host is 0.3 eV or more. Claim 12 An organic light-emitting diode according to claim 1, further comprising a second blue light-emitting material layer and a second light-emitting part located between the first light-emitting part and the first electrode or between the first light-emitting part and the second electrode. Claim 13 An organic light-emitting diode according to claim 12, wherein the second blue light-emitting material layer comprises a third blue light-emitting layer and a fourth blue light-emitting layer, the third blue light-emitting layer comprises a third p-type host and a third n-type host, the fourth blue light-emitting layer comprises a fourth p-type host and a fourth n-type host, one of the third p-type host and the fourth p-type host is represented by the chemical formula 1a or the chemical formula 1b, and the other of the third p-type host and the fourth p-type host is represented by the chemical formula 3a or the chemical formula 3b. Claim 14 In claim 13, each of the third n-type host and the fourth n-type host is represented by Chemical Formula 5, [Chemical Formula 5] An organic light-emitting diode characterized in that, in Chemical Formula 5, f1, f5, and f6 are each integers from 0 to 4, f2 to f4 are each independently integers from 0 to 5, X is selected from the group consisting of C, Si, and Ge, and R41 to R47 are each independently selected from the group consisting of deuterium, halogen, cyano group, substituted or unsubstituted C6 to C30 arylsilyl group, substituted or unsubstituted C6 to C30 arylgermanyl group, substituted or unsubstituted C1 to C20 alkyl group, substituted or unsubstituted C6 to C30 aryl group, substituted or unsubstituted C5 to C60 heteroaryl group, substituted or unsubstituted C1 to C30 arylamine group, and substituted or unsubstituted C6 to C60 arylamine group. Claim 15 In claim 13, the third blue emitting layer comprises a third phosphorescent dopant, and the fourth blue emitting layer comprises a fourth phosphorescent dopant, wherein each of the third phosphorescent dopant and the fourth phosphorescent dopant is represented by Chemical Formula 7, [Chemical Formula 7] An organic light-emitting diode characterized in that, in Formula 7, each of R51 to R56 is independently selected from the group consisting of deuterium, halogen, cyano group, substituted or unsubstituted C1 to C20 alkyl group, substituted or unsubstituted C3 to C20 cycloalkyl group, C1 to C20 alkylsilyl group, substituted or unsubstituted C1 to C20 alkylamino group, substituted or unsubstituted C6 to C30 arylamino group, substituted or unsubstituted C6 to C30 aryl group, substituted or unsubstituted C6 to C30 heteroaryl group, and each of g1, g2, and g3 is independently an integer from 0 to 4, g4 is an integer from 0 to 3, and g5 is an integer from 0 to 2. Claim 16 An organic light-emitting diode according to claim 12, wherein the second blue light-emitting material layer comprises a blue host and a blue dopant, the blue host comprises at least one of the compounds of Chemical Formula 14 below, and the blue dopant is one of the compounds of Chemical Formula 15 below. [Chemical Formula 14] [Chemical Formula 15] Claim 17 An organic light-emitting diode according to claim 16, wherein the second blue light-emitting material layer further comprises an auxiliary dopant, and the auxiliary dopant is one of the compounds of Chemical Formula 16 below. [Chemical Formula 16] Claim 18 An organic light-emitting diode according to claim 12, further comprising a red light-emitting material layer and a green light-emitting material layer, and a third light-emitting part located between the first light-emitting part and the second light-emitting part. Claim 19 An organic light-emitting device comprising: a substrate; an organic light-emitting diode described in one of claims 1 to 18 located on the substrate; and an encapsulation layer covering the organic light-emitting diode. Claim 20 An organic light-emitting device according to claim 19, further comprising a color filter layer located between the substrate and the organic light-emitting diode or on the encapsulation layer.

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