Display device and method of manufacturing the same

Abstract

A display device and a method for manufacturing the same have improved process stability and reliability by reducing damage to an organic light-emitting display device during a manufacturing process. The organic light-emitting display device includes a substrate, a plurality of pixel electrodes, a pixel defining film, a plurality of hole control layers respectively disposed on the pixel electrodes, a plurality of emission layers respectively disposed on the hole control layers, a plurality of buffer layers respectively disposed on the emission layers, and an opposing electrode provided as a whole above the buffer layers, each of the buffer layers having a highest occupied molecular orbital (HOMO) energy level greater than the HOMO energy level of each of the plurality of emission layers.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2018-0047314 filed on April 24, 2018, in the Korean Intellectual Property Office, the entire contents of which are incorporated by reference. Technical Field

[0003] One or more embodiments of the present disclosure relate to an organic light-emitting display device and a method for manufacturing the organic light-emitting display device, and, for example, to an organic light-emitting display device having improved process stability and reliability by reducing damage to the organic light-emitting device in a manufacturing process, and a method for manufacturing the organic light-emitting display device. Background Art

[0004] An organic light emitting display device is a display device in which pixels include an organic light emitting device. The organic light emitting device may include a pixel electrode, an opposite electrode facing the pixel electrode, and an emission layer provided between the pixel electrode and the opposite electrode.

[0005] For an organic light-emitting display device that realizes full color, each pixel area may emit light having a different color from each other, and a deposition mask may be used to form an emission layer and an opposing electrode of each pixel integrally formed in a plurality of pixels. As the resolution of the organic light-emitting display device gradually increases, the width of the slit of the mask used in the deposition process gradually decreases, and its dispersion is also required to gradually decrease. In addition, in order to manufacture a high-resolution organic light-emitting display device, the shadow effect should be reduced or eliminated. Therefore, a method of performing a deposition process when the substrate and the mask are in close contact with each other can be used.

[0006] However, when a deposition process is performed while the substrate and the mask are in close contact with each other, the mask may damage an upper layer of the pixel electrode. Summary of the invention

[0007] One or more embodiments include an organic light emitting display device having improved process stability and reliability by reducing damage to an organic light emitting device in a manufacturing process and a method of manufacturing the same.

[0008] Additional aspects of the embodiments will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the presented embodiments.

[0009] According to one or more embodiments, a display device includes a substrate; a plurality of pixel electrodes, which are patterned on the substrate to be arranged spaced apart from each other; a pixel defining film, which defines a pixel area by exposing a central portion of each of the plurality of pixel electrodes and covering an edge of each of the plurality of pixel electrodes; a plurality of hole control layers, which are respectively arranged on the plurality of pixel electrodes exposed through the pixel area; a plurality of emission layers, which are respectively arranged on the plurality of hole control layers; a plurality of buffer layers, which are respectively arranged on the plurality of emission layers, each of the plurality of buffer layers having a highest occupied molecular orbital (HOMO) energy level greater than the HOMO energy level of each of the plurality of emission layers; and an opposing electrode provided as a whole above the plurality of buffer layers.

[0010] A lowest unoccupied molecular orbital (LUMO) energy level of each of the plurality of buffer layers may have a value between a work function of the counter electrode and a LUMO energy level of each of the plurality of emission layers.

[0011] Each of the plurality of hole control layers may include at least one selected from a hole injection layer (HIL) and a hole transport layer (HTL).

[0012] The display device may further include an electron control layer integrally provided between the plurality of buffer layers and the counter electrode.

[0013] A lowest unoccupied molecular orbital (LUMO) energy level of each of the plurality of buffer layers may have a value between the LUMO energy level of the electron control layer and the LUMO energy levels of the plurality of emission layers.

[0014] The electron control layer may include at least one selected from an electron injection layer (EIL) and an electron transport layer (EML).

[0015] The plurality of buffer layers may include a low molecular weight organic material.

[0016] The plurality of buffer layers may include an electron transport material.

[0017] The plurality of buffer layers may include a metal oxide material.

[0018] The plurality of buffer layers may be disposed directly on the plurality of emission layers to contact the plurality of emission layers.

[0019] End portions of the plurality of hole control layers, the plurality of emission layers, and the plurality of buffer layers located on any one of the plurality of pixel electrodes may be aligned with each other.

[0020] The plurality of pixel electrodes may include a first pixel electrode for red emission (e.g., configured to emit red light), a second pixel electrode for green emission (e.g., configured to emit green light), and a third pixel electrode for blue emission (e.g., configured to emit blue light), and the plurality of emission layers include a red emission layer provided corresponding to the first pixel electrode (e.g., a layer configured to emit red light), a green emission layer provided corresponding to the second pixel electrode (e.g., a layer configured to emit green light), and a blue emission layer provided corresponding to the third pixel electrode (e.g., a layer configured to emit blue light).

[0021] According to one or more embodiments, a method for manufacturing a display device includes: (a) forming a first pixel electrode for emitting a first color light, a second pixel electrode for emitting a second color light, and a third pixel electrode for emitting a third color light, wherein the first pixel electrode for emitting the first color light, the second pixel electrode for emitting the second color light, and the third pixel electrode for emitting the third color light are patterned on a substrate to be spaced apart from each other; (b) forming a first stripping layer including a fluorine-containing polymer on the first pixel electrode to the third pixel electrode; (c) forming a first photoresist on the first stripping layer; (d) forming a first opening and a second opening in the first photoresist and the first stripping layer in sequence to expose the first pixel electrode, wherein the first photoresist and the first stripping layer are formed at positions corresponding to the first pixel electrode; (e) forming a first hole control layer, a first emission layer, and a first buffer layer in sequence on the first pixel electrode through the first opening and the second opening; (f) removing the first stripping layer and the first photoresist; repeating operations (b) to (f) in sequence for the second pixel electrode; and repeating operations (b) to (f) in sequence for the third pixel electrode.

[0022] Repeating operations (b) to (f) in sequence for the second pixel electrode may include: (b) forming a second stripping layer on the second pixel electrode to the third pixel electrode, the second stripping layer comprising a fluorine-containing polymer; (c) forming a second photoresist on the second stripping layer; (d) forming a third opening and a fourth opening in the second photoresist and the second stripping layer in sequence to expose the second pixel electrode, wherein the second photoresist and the second stripping layer are formed at a position corresponding to the second pixel electrode; (e) forming a second hole control layer, a second emission layer, and a second buffer layer in sequence on the second pixel electrode through the third opening and the fourth opening; and (f) removing the second stripping layer and the second photoresist, wherein the second buffer layer protects the second emission layer when the second stripping layer and the second photoresist are removed.

[0023] Repeating operations (b) to (f) in sequence for the third pixel electrode may include: (b) forming a third stripping layer on the third pixel electrode, the third stripping layer comprising a fluorine-containing polymer; (c) forming a third photoresist on the third stripping layer; (d) forming a fifth opening and a sixth opening in the third photoresist and the third stripping layer in sequence to expose the third pixel electrode, wherein the third photoresist and the third stripping layer are formed at positions corresponding to the third pixel electrode; (e) forming a third hole control layer, a third emission layer and a third buffer layer in sequence on the third pixel electrode through the fifth opening and the sixth opening; and (f) removing the third stripping layer and the third photoresist, wherein the third buffer layer protects the third emission layer when the third stripping layer and the third photoresist are removed.

[0024] The method may further include forming a counter electrode integrally provided over the first, second and third buffer layers, wherein a lowest unoccupied molecular orbital (LUMO) energy level of the first buffer layer has a value between a work function of the counter electrode and a LUMO energy level of the first emission layer.

[0025] The method may further include forming an electron control layer provided as a whole above the first buffer layer, the second buffer layer and the third buffer layer; and forming a counter electrode provided as a whole on the electron control layer, wherein the lowest unoccupied molecular orbital (LUMO) energy level of each of the first to third buffer layers has a value between the LUMO energy level of the electron control layer and the LUMO energy level of each of the first to third emission layers.

[0026] A highest occupied molecular orbital (HOMO) energy level of the first buffer layer may be greater than a HOMO energy level of the first emission layer.

[0027] The first buffer layer may include at least one selected from the group consisting of a low molecular weight organic material, an electron transport material, and a metal oxide material.

[0028] End portions of the first hole control layer, the first emission layer, and the first buffer layer located above the first pixel electrode may be aligned with each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] These and / or other aspects of the embodiments will become apparent and more readily understood from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which:

[0030] Figure 1 is a cross-sectional view schematically illustrating a stacked structure of an organic light emitting device according to one embodiment;

[0031] Figure 2 is a cross-sectional view schematically illustrating a stacked structure of a pixel according to one embodiment;

[0032] Figure 3is an energy bandgap diagram of an organic light emitting device according to an embodiment;

[0033] Figure 4 is a cross-sectional view schematically illustrating a stacked structure of an organic light emitting device according to another embodiment;

[0034] Figure 5 is a cross-sectional view schematically illustrating a stacked structure of an organic light emitting device according to another embodiment;

[0035] Figure 6 is a cross-sectional view schematically illustrating a manufacturing process of an organic light emitting display device according to another embodiment;

[0036] Figure 7 is a cross-sectional view schematically illustrating a manufacturing process of an organic light emitting display device according to another embodiment;

[0037] Figures 8A-8H is a cross-sectional view schematically illustrating a manufacturing process of an organic light emitting display device according to another embodiment;

[0038] Figures 9A-9E is a cross-sectional view schematically illustrating a manufacturing process of an organic light emitting display device according to another embodiment;

[0039] Figures 10A-10E is a cross-sectional view schematically illustrating a manufacturing process of an organic light emitting display device according to another embodiment; and

[0040] Fig.11 is a cross-sectional view schematically illustrating a manufacturing process of an organic light emitting display device according to another embodiment. DETAILED DESCRIPTION

[0041] Since the present invention allows for various variations and many embodiments, embodiments of the present invention will be illustrated in the drawings and described in more detail in the written description. However, this is not intended to limit the present invention to a particular mode of practice, and it should be understood that the present invention encompasses all variations, equivalents, and substitutions that do not depart from the spirit and technical scope of the present invention. In this disclosure, when certain detailed explanations of the related art may make the present invention unclear, such detailed explanations will not be provided.

[0042] The subject matter of the present disclosure will now be described in more detail with reference to the accompanying drawings that illustrate embodiments of the present invention. In the entire accompanying drawings, similar reference numerals represent similar elements. In the following description, when the detailed description of known functions or structures makes the present invention unclear, these detailed descriptions will not be provided.

[0043] It should be understood that although the terms "first", "second", etc. may be used herein to describe various components, these components are not limited by these terms. These components are only used to distinguish one component from another component. As used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0044] It should be further understood that the terms "comprises" and / or "comprising" used herein indicate the presence of the recited features or components, but do not exclude the presence or addition of one or more other features or components. In addition, it should be understood that when a layer, region or component is referred to as being "formed on" another layer, region or component, it can be directly or indirectly formed on the other layer, region or component. For example, there may be intervening layers, regions or components.

[0045] For the convenience of explanation, the sizes of components in the drawings may be exaggerated. In other words, since the sizes and thicknesses of components in the drawings may be arbitrarily shown for the convenience of explanation, the following embodiments are not limited thereto.

[0046] In the following embodiments, the x-axis, y-axis, and z-axis are not limited to the three axes of the rectangular coordinate system, but can be interpreted in a broader sense. For example, the x-axis, y-axis, and z-axis may be perpendicular to each other (e.g., substantially perpendicular), or may represent different directions that are not perpendicular to each other.

[0047] When a certain embodiment can be implemented differently, a specific process order can be performed in a different order than described. For example, two processes described in succession can be performed simultaneously (eg, substantially simultaneously) or in a reverse order to the described order.

[0048] Figure 1 is a cross-sectional view schematically illustrating a stacked structure of an organic light emitting device 1 according to one embodiment.

[0049] refer to Figure 1 According to one embodiment, an organic light-emitting display device may include an organic light-emitting device 1. The organic light-emitting device 1 may include a pixel electrode 10, an opposing electrode 30 above the pixel electrode 10, and an intermediate layer 20 between the pixel electrode 10 and the opposing electrode 30. The intermediate layer 20 may include a hole control layer 20H, an emission layer 23 on the hole control layer 20H, a buffer layer 24 on the emission layer 23, and an electron control layer 20E on the buffer layer 24. In this case, the hole control layer 20H may optionally include a hole injection layer 21 (see Figure 4 ) and the hole transport layer 22 (see Figure 4 ), and the electron control layer 20E may optionally include an electron injection layer 26 (see Figure 4 ) and electron transport layer 25 (see Figure 4 )。

[0050] In the present embodiment, the buffer layer 24 may be on the emission layer 23. Optionally, an electron control layer 20E including an electron injection layer 26 and an electron transport layer 25 may be on the buffer layer 24, or the counter electrode 30 may be directly on the buffer layer 24 without the electron control layer 20E therebetween.

[0051] The buffer layer 24 may include an organic material and / or a metal oxide material. When the buffer layer 24 includes an organic material, the buffer layer 24 may include, for example, a low molecular weight organic material, the low molecular weight organic material including at least one selected from BAlq (bis(2-methyl-8-hydroxyquinoline)-4-(phenylphenol)aluminum), BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), DTBT (dithienylbenzothiadiazole), TPBi (1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene), PBD (2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole), TAZ (3-(4-biphenylyl)4-phenyl-5-tert-butylphenyl-1,2,4-triazole), C60F42, Liq (lithium 8-hydroxyquinoline), and spiro-PBD, and / or at least one selected from oligomers, polymers, and copolymer derivatives based on the low molecular weight organic material.

[0052] In addition, when the buffer layer 24 includes an organic material, the buffer layer 24 may include, for example, BND, OXD-7, OXD-star, Alq 3 (aluminum tris(8-hydroxyquinoline)), Bphen, NTAZ, Bphen (4,7-diphenyl-1,10-phenanthroline), NTAZ (4-(naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4-triazole), t-Bu-PBD (2-(4-biphenylyl)-5-(4-tert-butyl-phenyl)-1,3,4-oxadiazole), t-Bu-PND, Bebq 2 (beryllium bis(10-hydroxybenzo[h]quinoline)), ADN (9,10-bis(2-naphthyl)anthracene), or a mixture thereof.

[0053] In addition, when the buffer layer 24 includes a metal oxide material, the buffer layer 24 may include, for example, CuO x (0 < x ≤ 3), MoO x (0 < x ≤ 3), WO x (0 < x ≤ 3), ZnO, or a mixture thereof. In this case, a doping material may be added to the buffer layer 24 to improve the electrical properties of the buffer layer 24 and ensure process stability.

[0054] In addition, when the buffer layer 24 includes an organic material, the organic material may have a structure in which, for example, at least some of the molecules are cross-linked with each other by chemical bonds (such as CO bonds, CC bonds, CN bonds, CS bonds, C=C bonds and / or C=O bonds) to have a bonding energy of 60 kcal / mol or higher.

[0055] In this embodiment, the buffer layer 24 directly on the emission layer 23 can protect the emission layer 23 from being damaged and oxidized in subsequent processes. Figure 6 This is described in more detail in the illustrated method of manufacture description and in the subsequent description and drawings.

[0056] Figure 2 is a cross-sectional view schematically illustrating a stacked structure of pixels R, G, and B according to one embodiment.

[0057] refer to Figure 2 , an organic light emitting display device according to one embodiment may include a plurality of pixel electrodes 10R, 10G, and 10B. Although for ease of explanation, Figure 2 The pixel electrodes 10R, 10G, and 10B are shown to be in contact with each other, but the pixel electrodes 10R, 10G, and 10B may be patterned to be spaced apart from each other.

[0058] The pixel electrodes 10R, 10G, and 10B may include a first pixel electrode 10R for red (R) emission (e.g., the first pixel electrode 10R emits light having a red color), a second pixel electrode 10G for green (G) emission (e.g., the second pixel electrode 10G emits light having a green color), and a third pixel electrode 10B for blue (B) emission (e.g., the first pixel electrode 10B emits light having a blue color). The first, second, and third hole injection layers 21R, 21G, and 21B and the first, second, and third hole transport layers 22R, 22G, and 22B may be on and above the first, second, and third pixel electrodes 10R, 10G, and 10B, respectively. The first, second, and third hole injection layers 21R, 21G, and 21B and the first, second, and third hole transport layers 22R, 22G, and 22B may correspond to Figure 1In the present embodiment, although the hole control layer 20H includes all of the first, second and third hole injection layers 21R, 21G and 21B and the first, second and third hole transport layers 22R, 22G and 22B, the hole control layer 20H may optionally and selectively include the first, second and third hole injection layers 21R, 21G and 21B and the first, second and third hole transport layers 22R, 22G and 22B as desired or required. For example, the hole control layer 20H may include only the first, second and third hole injection layers 21R, 21G and 21B, or the hole control layer 20H may include only the first, second and third hole transport layers 22R, 22G and 22B. In some embodiments, the hole control layer 20H may include only one of the first, second, and third hole injection layers 21R, 21G, and 21B, or the hole control layer 20H may include only one of the first, second, and third hole transport layers 22R, 22G, and 22B.

[0059] The first, second and third hole injection layers 21R, 21G and 21B may include, for example, phthalocyanine compounds such as copper phthalocyanine; DNTPD (N,N'-diphenyl-N,N'-bis-[4-(phenyl-m-tolyl-amino)-phenyl]-biphenyl-4,4'-diamine), m-MTDATA (4,4',4"-tris(3-methylphenylphenylamino)triphenylamine), TDATA (4,4',4"-tris(N,N-diphenylamino)triphenylamine), 2T NATA (4,4',4"-tri{N-(2-naphthyl)-N-phenylamino}-triphenylamine), PEDOT / PSS (poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate)), PANI / DBSA (polyaniline / dodecylbenzenesulfonic acid), PANI / CSA (polyaniline / camphorsulfonic acid) and / or PANI / PSS ((polyaniline) / poly(4-styrenesulfonate)), but the material included in the hole injection layer is not limited to the above compounds.

[0060] The first, second and third hole transport layers 22R, 22G and 22B may include, for example, N-phenylcarbazole, carbazole-based derivatives (such as polyvinylcarbazole), fluorine-based derivatives, TPD (N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine), triphenylamine-based derivatives (such as TCTA (4,4',4"-tri(N-carbazolyl)triphenylamine)), NPB (N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine) and / or TAPC (4,4'-cyclohexylenebis[N,N-bis(4-methylphenyl)aniline]), but the present invention is not limited thereto.

[0061] The first, second and third emission layers 23R, 23G and 23B may be on the first, second and third hole transport layers 22R, 22G and 22B, respectively. In other words, the red (R) emission layer 23R may be on the first pixel electrode 10R, the green (G) emission layer 23G may be on the second pixel electrode 10G, and the blue (B) emission layer 23B may be on the third pixel electrode 10B.

[0062] As an optional embodiment, a first auxiliary layer SL_R corresponding to the resonance control layer may be between the first hole transport layer 22R and the first emission layer 23R. In addition, a second auxiliary layer SL_G corresponding to the resonance control layer may be between the second hole transport layer 22G and the second emission layer 23G. An auxiliary layer may be provided between the third hole transport layer 22B and the third emission layer 23B as needed or desired.

[0063] The first, second and third buffer layers 24R, 24G and 24B are on the first, second and third emission layers 23R, 23G and 23B, respectively. In other words, the first buffer layer 24R may be on the red (R) emission layer 23R, the second buffer layer 24G may be on the green (G) emission layer 23G, and the third buffer layer 24B may be on the blue (B) emission layer 23B. The first, second and third buffer layers 24R, 24G and 24B may correspond to Figure 1 The buffer layer 24 described in .

[0064] The electron transport layer 25 may be on the first, second and third buffer layers 24R, 24G and 24B. The electron transport layer 25 is a common layer, which may be integrally provided on the first, second and third buffer layers 24R, 24G and 24B. The electron transport layer 25 may include, for example, Alq 3 (tris(8-hydroxyquinoline)aluminum), TPBi(1,3,5-tris(1-phenyl-1H-benzo[d]imidazol-2-yl)phenyl), BCP(2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), Bphen(4,7-diphenyl-1,10-phenanthroline), TAZ(3-(4-biphenyl-4-phenyl-4-phenyl-5-tert-butylphenyl-1,2,4-triazole), NTAZ(4-(naphthalene-1-yl)-3,5-diphenyl-4H-1,2,4-triazole), tBu-PBD(2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole), BAlq(bis(2-methyl-8-hydroxyquinoline)-4-(phenylphenol)aluminum), Bebq 2 (bis(10-hydroxybenzo[h]quinolinolato)beryllium), AND (9,10-di(naphthalene-2-yl)anthracene) or a mixture thereof, but the present invention is not limited thereto.

[0065] In some embodiments, the electron injection layer 26 may be further disposed between the counter electrode 30 and the electron transport layer 25. Figure 4 The electron injection layer 26 may include, for example, a lanthanide metal (or a compound including a lanthanide metal), such as LiF, Liq (8-hydroxyquinoline lithium), Li 2 O, BaO, NaCl, CsF or Yb; or a metal halide such as RbCl or RbI, but the present invention is not limited thereto.

[0066] Back to reference Figure 2 The counter electrode 30 may be above the first, second, and third buffer layers 24R, 24G, and 24B. The counter electrode 30 is a common layer, which may be integrally provided on the electron transport layer 25.

[0067] Optionally, a cover layer 40 and an encapsulation layer 50 may be further disposed on the counter electrode 30 .

[0068] like Figure 2 As shown, the electron transport layer 25, the counter electrode 30, the capping layer 40 and the encapsulation layer 50 on the first, second and third buffer layers 24R, 24G and 24B may be provided as a common layer. In contrast, the layer below the first, second and third buffer layers 24R, 24G and 24B may be provided by patterning each pixel. In other words, the first, second and third pixel electrodes 10R, 10G and 10B may be patterned for each pixel to provide a pixel defining film to cover the edges of the first, second and third pixel electrodes 10R, 10G and 10B, the first, second and third hole injection layers 21R, 21G and 21B, the first, second and third hole transport layers 22R, 22G and 22B, the first, second and third emission layers 23R, 23G and 23B and the first, second and third buffer layers 24R, 24G and 24B may be patterned and provided on the first, second and third pixel electrodes 10R, 10G and 10B exposed by the opening of the pixel defining film. Below is Figure 6 This is described in more detail in the description of the manufacturing method shown in and in the subsequent description and drawings.

[0069] Figure 3 is a diagram of an energy band gap of an organic light emitting device according to one embodiment.

[0070] exist Figure 3 , an organic light emitting device including a hole injection layer 21 , a hole transport layer 22 , an emission layer 23 , a buffer layer 24 and an electron transport layer 25 between a pixel electrode 10 and an opposing electrode 30 is shown.

[0071] refer to Figure 3According to one embodiment, the highest occupied molecular orbital (HOMO) energy level 24_H of the buffer layer 24 may be generally greater than the HOMO energy level 23_H of the emissive layer 23. In embodiments where the electron transport layer 25 is on the buffer layer 24, the lowest unoccupied molecular orbital (LUMO) energy level 24_L of the buffer layer 24 may have a value between the LUMO energy level 25_L of the electron transport layer 25 and the LUMO energy level 23_L of the emissive layer 23.

[0072] In another embodiment, the organic light emitting display device according to the embodiment may include an organic light emitting device including a hole injection layer 21 , a hole transport layer 22 , an emission layer 23 , and a buffer layer 24 between a pixel electrode 10 and an opposing electrode 30 .

[0073] In this case, HOMO level 24_H of buffer layer 24 may be generally greater than HOMO level 23_H of emission layer 23. In addition, LUMO level 24_L of buffer layer 24 may have a value between the work function of counter electrode 30 and LUMO level 23_L of emission layer 23.

[0074] The buffer layer 24 according to one embodiment is directly on the emission layer 23 to protect the emission layer 23 from being damaged and oxidized in subsequent processes. However, due to the buffer layer 24 provided in the intermediate layer 20, there is a problem of reduced efficiency of the organic light-emitting device, which needs to be solved. Therefore, the buffer layer 24 is characterized in preventing the holes injected into the emission layer 23 from the pixel electrode 10 from being transferred to the electron transport layer 25 or the opposite electrode 30 (or reducing the transfer of holes to the electron transport layer 25 or the opposite electrode 30), and thus the buffer layer 24 can prevent or reduce the degradation of the characteristics of the organic light-emitting device.

[0075] Figure 4 is a cross-sectional view schematically illustrating a stacked structure of an organic light emitting device 2 according to another embodiment. Figure 5 is a cross-sectional view schematically illustrating a stacked structure of an organic light emitting device 3 according to another embodiment.

[0076] refer to Figure 4 , an organic light emitting display apparatus according to another embodiment may include an organic light emitting device 2 . Figure 4 The organic light emitting device 2 and Figure 1 The organic light emitting device 1 is substantially the same except that the hole control layer 20H includes a hole injection layer 21 and a hole transport layer 22 , and the electron control layer 20E includes an electron injection layer 26 and an electron transport layer 25 .

[0077] The organic light-emitting device 2 may include a pixel electrode 10, an opposing electrode 30 above the pixel electrode 10, and an intermediate layer 20 between the pixel electrode 10 and the opposing electrode 30. The intermediate layer 20 may include a hole injection layer 21, a hole transport layer 22 on the hole injection layer 21, an emission layer 23 on the hole transport layer 22, a buffer layer 24 on the emission layer 23, an electron transport layer 25 on the buffer layer 24, and an electron injection layer 26 on the electron transport layer 25.

[0078] refer to Figure 5 According to another embodiment, an organic light emitting display device may include an organic light emitting device 3 . Figure 5 The organic light emitting device 3 shown is Figure 1 The embodiment is substantially the same except that the hole control layer 20H includes a hole injection layer 21 and a hole transport layer 22, the electron control layer 20E includes an electron injection layer 26, and the organic light emitting device 3 includes a first buffer layer 24a and a second buffer layer 24b.

[0079] The organic light emitting device 3 may include a pixel electrode 10, an opposing electrode 30 above the pixel electrode 10, and an intermediate layer 20 between the pixel electrode 10 and the opposing electrode 30. The intermediate layer 20 may include a hole injection layer 21, a hole transport layer 22 on the hole injection layer 21, an emission layer 23 on the hole transport layer 22, a first buffer layer 24a on the emission layer 23, a second buffer layer 24b on the first buffer layer 24a, and an electron injection layer 26 on the second buffer layer 24b.

[0080] Above Figure 4-5 The embodiments are exemplary embodiments, and the present disclosure is not limited to the thickness of the layers shown in the drawings. The thickness and number of the buffer layer 24 may vary depending on the configuration of the intermediate layer 20.

[0081] Although the organic light emitting display device is mainly described in the above description, the present disclosure is not limited thereto. For example, a method for manufacturing the above organic light emitting display device is also within the scope of the present disclosure.

[0082] Figure 6-10E is a cross-sectional view schematically illustrating a manufacturing process of an organic light emitting display device according to one embodiment.

[0083] First, refer to Figure 6, a first pixel electrode 101 for first color emission (e.g., a first pixel electrode configured to emit first color light), a second pixel electrode 102 for second color emission (e.g., a second pixel electrode configured to emit second color light), and a third pixel electrode 103 for third color emission (e.g., a third pixel electrode configured to emit third color light) may be formed on a substrate 100. The first pixel electrode 101, the second pixel electrode 102, and the third pixel electrode 103 may be patterned to be arranged spaced apart from each other.

[0084] The arrangement of the first, second and third pixel electrodes 101, 102 and 103 on the substrate 100 may include not only the case where the first, second and third pixel electrodes 101, 102 and 103 are directly arranged on the substrate 100, but also the case where various suitable layers are formed on the substrate 100 and the first, second and third pixel electrodes 101, 102 and 103 are arranged on the various suitable layers. For example, a thin film transistor may be on the substrate 100, a planarization film may cover the thin film transistor, and the first, second and third pixel electrodes 101, 102 and 103 may be on the planarization film. Although the drawings show that the first, second and third pixel electrodes 101, 102 and 103 are directly on the substrate 100 for the sake of convenience of explanation, the above description also applies to the following description for the sake of convenience of explanation.

[0085] The substrate 100 may be formed of various suitable materials. For example, the substrate 100 may be formed of glass and / or plastic. The substrate 100 may be formed of a material having excellent heat resistance and durability, such as polyimide, polyethylene naphthalate, polyethylene terephthalate, polyarylate, polycarbonate, polyetherimide and / or polyethersulfone.

[0086] The first, second and third pixel electrodes 101, 102 and 103 formed on the substrate 100 may be formed as (semi) transparent electrodes or reflective electrodes. When the first, second and third pixel electrodes 101, 102 and 103 are formed as (semi) transparent electrodes, the first, second and third pixel electrodes 101, 102 and 103 may be made of, for example, ITO, IZO, ZnO, In 2 O 3 , IGO and / or AZO. When the first, second and third pixel electrodes 101, 102 and 103 are formed as reflective electrodes, each of the first, second and third pixel electrodes 101, 102 and 103 may have a reflective film formed of Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr and / or a compound thereof and a reflective film formed of ITO, IZO, ZnO, In 2 O 3, IGO and / or AZO. The present disclosure is not limited thereto, and various appropriate modifications may be made. For example, the first, second and third pixel electrodes 101, 102 and 103 may be formed of various suitable materials in a single layer or multiple layers.

[0087] Next, if Figure 7 As shown, a pixel defining film 110 may be formed that exposes a central portion of each of the first pixel electrode 101, the second pixel electrode 102, and the third pixel electrode 103 and covers an edge portion thereof. The pixel defining film 110 defines a pixel region and prevents or reduces arcing due to electric field concentration at end portions of the first, second, and third pixel electrodes 101, 102, and 103 during driving.

[0088] The pixel defining film 110 may be provided as, for example, an organic insulating film. The organic insulating film may include an acrylic-based polymer such as polymethyl methacrylate (PMMA), polystyrene (PS), a polymer derivative having a phenol group, an imide-based polymer, an aryl ether-based polymer, an amide-based polymer, a fluorine-based polymer, a p-xylene-based polymer, a vinyl alcohol-based polymer, or a mixture thereof.

[0089] Next, if Figures 8A-8H As shown, an intermediate layer 101A may be formed on the first pixel electrode 101 (see Figure 8H ). The intermediate layer 101A may refer to a first hole injection layer 141, a first hole transport layer 151, a first emission layer 161, and a first buffer layer 171. An electron control layer, such as an electron transport layer, may be further formed in a subsequent process.

[0090] Figures 8A-8H The process of can be regarded as a first unit process corresponding to the first pixel electrode 101. Then, a second unit process corresponding to the second pixel electrode 102 can be Figures 9A-9E The third unit process corresponding to the third pixel electrode 103 can be performed by Figures 10A-10E In this case, the first unit process, the second unit process, and the third unit process may be the same process that is repeatedly performed.

[0091] First, refer to Fig. 8A, a first peeling layer 121 including a fluorine-containing polymer may be formed on the first pixel electrode 101, the second pixel electrode 102, and the third pixel electrode 103. The fluorine-containing polymer included in the first peeling layer 121 may be formed as a polymer having a fluorine content of 20 wt% to 60 wt%. For example, the fluorine-containing polymer may include at least one copolymer selected from the following: a copolymer of polytetrafluoroethylene, polychlorotrifluoroethylene, polydichlorodifluoroethylene, chlorotrifluoroethylene, and dichlorodifluoroethylene; a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether; a copolymer of chlorotrifluoroethylene and perfluoroalkyl vinyl ether; a copolymer of tetrafluoroethylene; and a copolymer of chlorotrifluoroethylene and perfluoroalkyl vinyl ether.

[0092] The first peeling layer 121 may be formed on the substrate 100 by a method such as coating, printing or deposition. When the first peeling layer 121 is formed by coating and printing, a process of forming a photoresist may be performed after curing and polymerization as necessary.

[0093] The thickness of the first peeling layer 121 may be between 0.2 μm and 5.0 μm. When the thickness of the first peeling layer 121 is too large, the time to melt the first peeling layer 121 for patterning may increase, and thus the manufacturing process time may be extended. When the thickness of the first peeling layer 121 is too small, it is difficult to perform peeling.

[0094] The first peeling layer 121 may further include a moisture absorbent. The moisture absorbent may include various suitable materials. The desiccant may be a compound in which a metal (such as calcium (e.g., calcium oxide), barium (e.g., barium oxide), aluminum (e.g., aluminum oxide) and / or magnesium (e.g., magnesium oxide) is coupled (or connected) by oxygen, and may include a material that forms a metal hydroxide when reacting with water. In addition, the desiccant may include any one selected from the group consisting of metal halides, metal inorganic salts, organic acid salts, porous inorganic compounds and combinations thereof. The desiccant may include an acrylic-based, methacrylic-based, polyisoprene-based, ethylene-based, epoxy-based, urethane-based and / or cellulose-based organic material. The desiccant may include a titanium dioxide-based, silicon oxide-based, zirconium oxide-based and / or aluminum oxide-based inorganic material. The desiccant may include a sealant made of epoxy silane, vinyl silane, amine silane and / or methacrylate silane. The desiccant may capture moisture generated during the first unit process and thereby prevent or reduce degradation of the first emission layer 161 formed during the first unit process.

[0095] The first photoresist 131 may be formed on the first peeling layer 121. The first photoresist 131 may be exposed or developed by using a first photomask. The first photoresist 131 may be a positive type (or kind) or a negative type (or kind). In this embodiment, an example of a positive type (or kind) is described below.

[0096] refer to Figure 8B , the first photoresist 131 is patterned. The exposed and developed first photoresist 131 is removed from the first portion 131-1 (i.e., the position corresponding to the first pixel electrode 101), and the first photoresist 131 in the second portion 131-2 (i.e., the area other than the first portion 131-1) remains. The first opening OP1 may be formed in the first photoresist 131 corresponding to the first portion 131-1.

[0097] refer to Figure 8C , by using Figure 8B The first peeling layer 121 is etched using the pattern of the first photoresist 131 as an etching mask.

[0098] Since the first peeling layer 121 includes a fluoropolymer, a solvent capable of etching the fluoropolymer may be used as an etchant. A first solvent including fluorine may be used as an etchant. The first solvent may include a hydrofluoroether. Hydrofluoroether is an electrochemically stable material due to its low interaction reactivity with other materials, and is an environmentally stable material due to its low global warming potential and low toxicity.

[0099] In the etching process, the first peeling layer 121 formed at a position corresponding to the first portion 131-1 (i.e., on the upper side of the first pixel electrode 101) is etched. The first peeling layer 121 is etched so as to be spaced apart from the side surface of the first pixel electrode 101 by a set or specific distance by forming a first undercut profile UC1 under the boundary surface of the first portion 131-1 of the first photoresist 131. Therefore, the second opening OP2 may be formed in the first peeling layer 121 corresponding to the first portion 131-1. The first pixel electrode 101 may be exposed through the second opening OP2.

[0100] refer to Fig.8D , an intermediate layer may be formed on the first photoresist 131. The intermediate layer may include a first emission layer 161. In addition, the intermediate layer may further include at least one selected from an organic functional layer such as a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer.

[0101] In this embodiment, a case where the intermediate layer includes the hole injection layer, the hole transport layer, and the electron transport layer is described as an example, but the present invention is not limited thereto.

[0102] In this embodiment, the intermediate layer can be formed by vacuum deposition. In the deposition process, the first peeling layer 121 and the first photoresist 131 function as a deposition mask. A portion of the intermediate layer can cover the upper surface of the first pixel electrode 101. Another portion of the intermediate layer is formed on the second portion 131-2 of the first photoresist 131.

[0103] refer to Fig.8D ,exist Figure 8C The first hole injection layer 141 is formed on the structure of the first photoresist 131. A portion of the first hole injection layer 141 may be formed on the first pixel electrode 101 through the first opening OP1 and the second opening OP2 formed in the first photoresist 131 and the first peeling layer 121 as a mask. The other portion of the first hole injection layer 141 may be formed on the second portion 131-2 of the first photoresist 131.

[0104] Next, refer to Fig. 8E ,exist Fig.8D The first hole transport layer 151 is formed on the structure of FIG. A portion of the first hole transport layer 151 may be formed on the first hole injection layer 141 corresponding to the first pixel electrode 101 through the first opening OP1 and the second opening OP2. The other portion of the first hole transport layer 151 may be formed on the second portion 131-2 on which the first hole injection layer 141 is formed.

[0105] Next, refer to Figure 8F ,exist Fig. 8E The first emission layer 161 is formed on the structure of FIG. A portion of the first emission layer 161 may be formed on the first hole transport layer 151 corresponding to the first pixel electrode 101 through the first opening OP1 and the second opening OP2. The other portion of the first emission layer 161 may be formed on the second portion 131-2 on which the first hole transport layer 151 is formed. In the present embodiment, the first emission layer 161 may be a red emission layer (e.g., a layer configured to emit red light), but the present invention is not limited thereto.

[0106] Next, refer to Figure 8G ,exist Figure 8F A first buffer layer 171 may be formed on the structure of FIG. A portion of the first buffer layer 171 may be formed on the first emission layer 161 corresponding to the first pixel electrode 101 through the first opening OP1 and the second opening OP2. Another portion of the first buffer layer 171 may be formed on the second portion 131-2 on which the first emission layer 161 is formed.

[0107] Since the first buffer layer 171 is directly formed on the first emission layer 161, the first buffer layer 171 can play a barrier function to protect the first emission layer 161 from the influence of solvents used in subsequent processes after the first emission layer 161 is formed. Figure 1-3 The buffer layer 24 described in the embodiment of the present invention is made of the same material (e.g., substantially the same material) and has the same Figure 1-3 The buffer layer 24 has the same (eg, substantially the same) characteristics as described above, and therefore, a redundant description thereof will not be repeated here.

[0108] Next, refer to Figure 8H ,exist Figure 8G The peeling process is performed on the structure.

[0109] By stripping off the first stripping layer 121 formed under the second portion 131-2 of the first photoresist 131, the first hole injection layer 141, the first hole transport layer 151, the first emission layer 161 and the first buffer layer 171 formed on the second portion 131-2 of the first photoresist 131 are removed, so that the first hole injection layer 141, the first hole transport layer 151, the first emission layer 161 and the first buffer layer 171 formed on the first pixel electrode 101 are retained as a pattern.

[0110] Since the first peeling layer 121 includes a fluorine-containing polymer, a fluorine-containing second solvent is used in the peeling process. In addition, since the peeling process is performed after forming the first emission layer 161, a material having low reactivity with the first emission layer 161 can be used as the second solvent. For example, the second solvent may include hydrofluoroether like the first solvent.

[0111] However, although a material having low reactivity with the first emission layer 161 is used as the second solvent, there is a problem that the first emission layer 161 may be damaged during the lift-off process by decomposing (or dissolving) components of the organic material.

[0112] In the deposition process for forming an organic light-emitting device, a low molecular weight organic material (e.g., small molecule) having advantages in synthetic reproducibility, characteristics, and processability is used as an organic material. However, in the thin film structure formed by the low molecular weight organic material, each molecule interacts through a van der Waals bond (e.g., van der Waals force), a hydrogen bond, and / or a π-π stacking bond, which provides a low non-covalent interaction energy of about 30 kcal / mol. Therefore, the low molecular weight organic material can be easily decomposed (or dissolved) in a solution method (such as, for example, an orthogonal solvent method). The organic material decomposed (or dissolved) as described above may damage the emission layer 23, thereby reducing the quality of the pixel.

[0113] Therefore, according to one embodiment, since the first buffer layer 171 is directly formed on the first emission layer 161 so that the first buffer layer 171 covers the first emission layer 161 , damage to the first emission layer 161 by a solvent in a subsequent stripping process can be reduced.

[0114] Available in Figures 9A-9E The second unit process and Figures 10A-10E Repeat in the third unit process Figures 8A-8H The first unit process is described in more detail below.

[0115] References below Figures 9A-9EA second unit process corresponding to the second pixel electrode 102 is described.

[0116] refer to Fig.9A , which can be formed Figure 8H A second release layer 122 including a fluorine-containing polymer and a second photoresist 132 are sequentially formed on the substrate 100 having the structure.

[0117] The second peeling layer 122 may be formed by a method such as a coating method, a printing method, or a deposition method. The second peeling layer 122 may be formed of the same material (eg, substantially the same material) as the first peeling layer 121 described above.

[0118] The second photoresist 132 may be exposed and developed using a second photomask. The second photoresist 132 may be a positive type (or kind) or a negative type (or kind). In the present embodiment, an example of a positive type (or kind) is described below.

[0119] Next, refer to Fig. 9B , patterning the second photoresist 132. The exposed and developed second photoresist 132 is removed from the first portion 132-1 (ie, the position corresponding to the second pixel electrode 102), and the second photoresist 132 in the second portion 132-2 (ie, the area other than the first portion 132-1) is retained.

[0120] Next, refer to Fig. 9C , by using Fig. 9B The second peeling layer 122 is etched using the pattern of the second photoresist 132 as an etching mask. Since the second peeling layer 122 includes a fluorine-containing polymer, a solvent capable of etching the fluorine-containing polymer is used as an etchant. A first solvent including fluorine may be used as an etchant. The first solvent may include a hydrofluoroether as in the first unit process described above. The first solvent may include a material different from the material used in the first unit process.

[0121] The second peeling layer 122 formed at a position corresponding to the first portion 132-1 (for example, on the second pixel electrode 102) is etched by an etching process. The second peeling layer 122 is etched so as to be spaced apart from the side surface of the second pixel electrode 102 by forming a second undercut profile UC2 under the boundary surface of the first portion 132-1 of the second photoresist 132 to be spaced apart by a set or specific distance.

[0122] Next, refer to Fig.9D ,like Figure 8D-8G, the second hole injection layer 142, the second hole transport layer 152, the second emission layer 162 and the second buffer layer 172 may be sequentially deposited on the second pixel electrode 102. In this embodiment, the second emission layer 162 may be a green emission layer (eg, a layer configured to emit green light), but the present invention is not limited thereto.

[0123] Next, refer to Fig.9E ,exist Fig.9D The peeling process is performed on the structure.

[0124] By stripping off the second stripping layer 122 formed under the second portion 132-2 of the second photoresist 132, the second hole injection layer 142, the second hole transport layer 152, the second emission layer 162 and the second buffer layer 172 formed on the second portion 132-2 of the second photoresist 132 are removed, and the second hole injection layer 142, the second hole transport layer 152, the second emission layer 162 and the second buffer layer 172 formed on the second pixel electrode 102 are retained as a pattern.

[0125] Since the second peeling layer 122 includes a fluorine-containing polymer, a fluorine-containing second solvent is used in the peeling process. In addition, since the peeling process is performed after forming the second emission layer 162, a material having low reactivity with the second emission layer 162 can be used as the second solvent. For example, the second solvent may include a hydrofluoroether like the first solvent.

[0126] However, although a material having low reactivity with the second emission layer 162 is used as the second solvent, there is a problem that the second emission layer 162 may be damaged during the lift-off process by decomposing (or dissolving) components of the organic material.

[0127] At the same time, there is a problem that damage to the first emission layer 161 may accumulate because the first emission layer 161 first formed in the manufacture of the previous structure is exposed to the second solvent of the stripping process included in the second unit process, and since each unit process is repeated for each pixel, it will be exposed to the stripping process several times.

[0128] Therefore, in an organic light-emitting display device and a manufacturing method thereof according to one embodiment, since the first buffer layer 171 is formed on the first emission layer 161 and the second buffer layer 172 is formed on the second emission layer 162, and the first buffer layer 171 and the second buffer layer 172 act as barriers, damage to the first emission layer 161 and the second emission layer 162 during the stripping process can be reduced.

[0129] refer to Figures 10A-10E A third unit process corresponding to the third pixel electrode 103 is described.

[0130] refer to Fig. 10A, which can be formed Fig.9E A third peeling layer 123 including a fluorine-containing polymer and a third photoresist 133 are sequentially formed on the substrate 100 having the structure.

[0131] The third peeling layer 123 may be formed by a method such as a coating method, a printing method, or a deposition method. The third peeling layer 123 may be formed of the same material (eg, substantially the same material) as the first and second peeling layers 121 and 122.

[0132] The third photoresist 133 may be exposed and developed by using a third photomask. The third photoresist 133 may be a positive type (or kind) or a negative type (or kind). In this embodiment, an example of a positive type (or kind) is described below.

[0133] Next, refer to Fig. 10B , patterning the third photoresist 133. The exposed and developed third photoresist 133 is removed from the first portion 133-1 (ie, the position corresponding to the third pixel electrode 103), and the third photoresist 133 in the second portion 133-2 (ie, the area except the first portion 133-1) is retained.

[0134] Next, refer to Fig. 10C , by using Fig. 10B The third peeling layer 123 is etched using the pattern of the third photoresist 133 as an etching mask. Since the third peeling layer 123 includes a fluorine-containing polymer, a solvent capable of etching the fluorine-containing polymer may be used as an etchant. A first solvent including fluorine may be used as an etchant. The first solvent may include a hydrofluoroether as in the first unit process described above. The first solvent may include a material different from the material used in the first unit process.

[0135] The third peeling layer 123 formed at a position corresponding to the first portion 133-1 (e.g., on the third pixel electrode 103) is etched by an etching process. The third peeling layer 123 is etched so as to be spaced apart from the side surface of the third pixel electrode 103 by forming a third undercut profile UC3 under the boundary surface of the first portion 133-1 of the third photoresist 133 so as to be spaced apart by a set or specific distance.

[0136] Next, refer to Fig. 10D ,like Figure 8D-8G , a third hole injection layer 143, a third hole transport layer 153, a third emission layer 163 and a third buffer layer 173 may be sequentially deposited on the third pixel electrode 103. In this embodiment, the third emission layer 163 may be a blue emission layer (eg, a layer configured to emit blue light), but the present invention is not limited thereto.

[0137] Next, refer to Fig. 10E ,exist Fig. 10D The peeling process is performed on the structure.

[0138] By stripping off the third stripping layer 123 formed under the second portion 133-2 of the third photoresist 133, the third hole injection layer 143, the third hole transport layer 153, the third emission layer 163 and the third buffer layer 173 formed on the second portion 133-2 of the third photoresist 133 are removed, and the third hole injection layer 143, the third hole transport layer 153, the third emission layer 163 and the third buffer layer 173 formed on the third pixel electrode 103 are retained as a pattern.

[0139] Since the third peeling layer 123 includes a fluorine-containing polymer, a fluorine-containing third solvent is used in the peeling process. In addition, since the peeling process is performed after forming the third emission layer 163, a material having low reactivity with the third emission layer 163 can be used as the third solvent. In addition, the third solvent may include hydrofluoroether like the first solvent.

[0140] However, although a material having low reactivity with the third emission layer 163 is used as the third solvent, there is a problem that the third emission layer 163 may be damaged during the lift-off process by decomposing (or dissolving) components of the organic material.

[0141] At the same time, there is a problem that damage to the first emission layer 161 and the second emission layer 162 may accumulate because the first emission layer 161 first formed in the manufacture of the previous structure is exposed to the third solvent of the stripping process included in the third unit process, and since each unit process is repeated for each pixel, it will be exposed to the stripping process several times.

[0142] Therefore, in an organic light-emitting display device and a manufacturing method thereof according to one embodiment, since the first buffer layer 171 is formed on the first emission layer 161, the second buffer layer 172 is formed on the second emission layer 162, and the third buffer layer 173 is formed on the third emission layer 163, the first buffer layer 171, the second buffer layer 172 and the third buffer layer 173 act as barriers, thereby reducing damage to each emission layer during the stripping process.

[0143] refer to Fig. 10E , the end portions of the first hole injection layer 141, the first hole transport layer 151, the first emission layer 161, and the first buffer layer 171 on the first pixel electrode 101 may be aligned with each other. The end portions aligned with each other may be understood as a result of the above-mentioned manufacturing method. Figure 8D-8GIn the embodiment, the first hole injection layer 141, the first hole transport layer 151, the first emission layer 161 and the first buffer layer 171 are all patterned through the same opening of the first opening OP1 and the second opening OP2, using the first peeling layer 121 and the first photoresist 131 as a mask. Therefore, all of the first hole injection layer 141, the first hole transport layer 151, the first emission layer 161 and the first buffer layer 171 can have the same shape (e.g., substantially the same shape). The same applies to the second hole injection layer 142, the second hole transport layer 152, the second emission layer 162 and the second buffer layer 172 corresponding to the second pixel electrode 102, and the third hole injection layer 143, the third hole transport layer 153, the third emission layer 163 and the third buffer layer 173 corresponding to the third pixel electrode 103.

[0144] refer to Fig.11 The electronic control layer 180, the counter electrode 190, the cover layer 200 and the encapsulation layer 210 can be deposited sequentially as common layers. Fig. 10E in terms of structure.

[0145] As described above, according to the above embodiments, since damage to the organic light emitting device in the manufacturing process is reduced, an organic light emitting display device having improved process stability and reliability and a method for manufacturing the same can be realized. The scope of the present invention is not limited by the above effects.

[0146] For ease of explanation, spatially relative terms such as "below," "below," "bottom," "under," "above," "above," etc. may be used herein to describe the relationship of one element or feature shown in the figures to another element or feature. It should be understood that in addition to the orientation shown in the figures, spatially relative terms are intended to cover different orientations of the device in use or operation. For example, if the device in the figure is turned over, the elements described as "below" or "below" or "below" other elements or features will be oriented as "above" the other elements or features. Therefore, the exemplary terms "below" and "below" may include two orientations of "above" and "below." The device can be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and the spatially relative descriptors used herein should be interpreted accordingly.

[0147] As used herein, the terms "substantially", "about" and similar terms are used as approximate terms, rather than as terms of degree, and are intended to take into account the inherent deviations of measurements or calculations that one of ordinary skill in the art would recognize. In addition, when describing embodiments of the present disclosure, the use of "may" refers to "one or more embodiments of the present disclosure." As used herein, the terms "use," "using," and "used" may be considered synonyms of the terms "utilize," "utilizing," and "utilized," respectively. In addition, the term "exemplary" is intended to refer to an example or illustration.

[0148] In addition, any numerical range described herein is expected to include all sub-ranges of the same numerical precision falling within the range. For example, it is expected that the range of "1.0 to 10.0" includes all sub-ranges (including both endpoints) between the described minimum value 1.0 and the described maximum value 10.0, i.e., a sub-range with a minimum value greater than or equal to 1.0 and a maximum value less than or equal to 10.0, such as, for example, 2.4 to 7.6. It is expected that any maximum numerical limit described herein includes all smaller numerical limits falling therein, and it is expected that any minimum numerical limit described in this specification includes all larger numerical limits falling therein. Therefore, the applicant reserves the right to modify this specification (including claims) to explicitly describe any sub-range falling within the range explicitly described in this specification.

[0149] It should be understood that the embodiments described herein should be considered only as descriptive and not for purposes of limitation. Descriptions of features or aspects in each embodiment should generally be considered as available for other similar features or aspects in other embodiments.

[0150] While one or more embodiments have been described with reference to the drawings, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the following claims and their equivalents.

Claims

1. A display device, include: substrate; a plurality of pixel electrodes patterned on the substrate and spaced apart from each other; a pixel defining film that defines a pixel area by exposing a central portion of each of the plurality of pixel electrodes and covering an edge of each of the plurality of pixel electrodes; a plurality of hole control layers, the plurality of hole control layers being respectively disposed on the plurality of pixel electrodes exposed through the pixel area; A plurality of emission layers, wherein the plurality of emission layers are respectively arranged on the plurality of hole control layers; A plurality of buffer layers, the plurality of buffer layers being respectively disposed on the plurality of emission layers, each of the plurality of buffer layers having a highest occupied molecular orbital energy level greater than a highest occupied molecular orbital energy level of each of the plurality of emission layers; an opposing electrode, the opposing electrode being entirely provided above the plurality of buffer layers; and an electron control layer being entirely provided between the plurality of buffer layers and the opposing electrode, wherein the lowest unoccupied molecular orbital energy level of each of the plurality of buffer layers has a value between the lowest unoccupied molecular orbital energy level of the electron control layer and the lowest unoccupied molecular orbital energy level of each of the plurality of emission layers, and The highest occupied molecular orbital energy level of each of the plurality of buffer layers is greater than the highest occupied molecular orbital energy level of the electron control layer. 2 . The display device according to claim 1 , wherein the lowest unoccupied molecular orbital energy level of each of the plurality of buffer layers has a value between a work function of the counter electrode and the lowest unoccupied molecular orbital energy level of each of the plurality of emission layers. 3 . The display device according to claim 1 , wherein each of the plurality of hole control layers comprises at least one selected from a hole injection layer and a hole transport layer. The display device according to claim 1 , wherein the electron control layer comprises at least one selected from an electron injection layer and an electron transport layer. The display device according to claim 1 , wherein the plurality of buffer layers include a low molecular weight organic material. The display device according to claim 1 , wherein the plurality of buffer layers include an electron transport material. The display device according to claim 1 , wherein the plurality of buffer layers comprise a metal oxide material. 8 . The display device of claim 1 , wherein the plurality of buffer layers are disposed directly on the plurality of emission layers to contact the plurality of emission layers. 9 . The display device according to claim 1 , wherein end portions of the plurality of hole control layers, the plurality of emission layers, and the plurality of buffer layers on any one of the plurality of pixel electrodes are aligned with each other.

10. The display device according to claim 1, wherein the plurality of pixel electrodes include a first pixel electrode configured to emit red light, a second pixel electrode configured to emit green light, and a third pixel electrode configured to emit blue light, and The plurality of emission layers include a red emission layer provided corresponding to the first pixel electrode, a green emission layer provided corresponding to the second pixel electrode, and a blue emission layer provided corresponding to the third pixel electrode.

11. A method for manufacturing a display device, the method include: (a) forming a first pixel electrode configured to emit a first color light, a second pixel electrode configured to emit a second color light, and a third pixel electrode configured to emit a third color light, wherein the first pixel electrode, the second pixel electrode, and the third pixel electrode are patterned on a substrate and spaced apart from each other; (b) forming a first release layer including a fluorine-containing polymer on the first pixel electrode to the third pixel electrode; (c) forming a first photoresist on the first release layer; (d) sequentially forming a first opening and a second opening in the first photoresist and the first lift-off layer to expose the first pixel electrode, wherein the first photoresist and the first lift-off layer are formed at positions corresponding to the first pixel electrode; (e) sequentially forming a first hole control layer, a first emission layer and a first buffer layer on the first pixel electrode through the first opening and the second opening; (f) removing the first release layer and the first photoresist; Repeating operations (b) to (f) sequentially for the second pixel electrode; and Repeating operations (b) to (f) for the third pixel electrode in sequence, wherein the repeating operations (b) to (f) for the second pixel electrode in sequence includes: (b) forming a second peeling layer on the second pixel electrode, wherein the second peeling layer comprises a fluorine-containing polymer; (c) forming a second photoresist on the second release layer; (d) sequentially forming a third opening and a fourth opening in the second photoresist and the second lift-off layer to expose the second pixel electrode, wherein the second photoresist and the second lift-off layer are formed at positions corresponding to the second pixel electrode; (e) sequentially forming a second hole control layer, a second emission layer, and a second buffer layer on the second pixel electrode through the third opening and the fourth opening; and (f) removing the second release layer and the second photoresist, The step of sequentially repeating operations (b) to (f) for the third pixel electrode comprises: (b) forming a third peeling layer on the third pixel electrode, wherein the third peeling layer comprises a fluorine-containing polymer; (c) forming a third photoresist on the third release layer; (d) sequentially forming a fifth opening and a sixth opening in the third photoresist and the third lift-off layer to expose the third pixel electrode, wherein the third photoresist and the third lift-off layer are formed at positions corresponding to the third pixel electrode; (e) sequentially forming a third hole control layer, a third emission layer and a third buffer layer on the third pixel electrode through the fifth opening and the sixth opening; and (f) removing the third lift-off layer and the third photoresist, Wherein the method further comprises: forming an electron control layer integrally provided over the first buffer layer, the second buffer layer, and the third buffer layer; and forming a counter electrode integrally provided on the electron control layer, wherein each of the first to third buffer layers has a highest occupied molecular orbital energy level greater than the highest occupied molecular orbital energy level of each of the first to third emission layers, wherein the lowest unoccupied molecular orbital energy level of each of the first to third buffer layers has a value between the lowest unoccupied molecular orbital energy level of the electron control layer and the lowest unoccupied molecular orbital energy level of each of the first to third emission layers, and The highest occupied molecular orbital energy level of each of the first to third buffer layers is greater than the highest occupied molecular orbital energy level of the electron control layer. 12 . The method of claim 11 , wherein the second buffer layer protects the second emission layer when the second lift-off layer and the second photoresist are removed. 13 . The method of claim 12 , wherein the third buffer layer protects the third emission layer when the third lift-off layer and the third photoresist are removed. 14 . The method of claim 13 , wherein the lowest unoccupied molecular orbital energy level of the first buffer layer has a value between a work function of the counter electrode and the lowest unoccupied molecular orbital energy level of the first emission layer. 15 . The method according to claim 11 , wherein the first buffer layer comprises at least one selected from the group consisting of a low molecular weight organic material, an electron transport material, and a metal oxide material. 16 . The method of claim 11 , wherein end portions of the first hole control layer, the first emission layer, and the first buffer layer over the first pixel electrode are aligned with each other.

Images