Light-emitting devices

Abstract

To manufacture light emitting devices that do not cause color mixing.SOLUTION: It has a first light emitting layer formation step to form a first light emitting layer by forming a laminate consisting of a lower reversal resist layer, a light emitting material layer containing the light emitting material of the first light emitting layer, and an upper positive resist layer, stacked in this order from the substrate side (steps S41 to S43), and by patterning the laminate (steps S44 to S45).SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a light-emitting device including a plurality of light-emitting elements, and a method for manufacturing the light-emitting device. [Background technology]

[0002] Patent Document 1 discloses a method of mixing quantum dots into a photoresist and patterning a layer containing quantum dots by photolithography. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US2017 / 0176854A1 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, a layer containing quantum dots of each color is formed over the entire surface, and then patterned by photolithography repeatedly. As a result, quantum dots may remain as residues in the areas where the layer containing quantum dots has been removed, resulting in the problem of color mixing. [Means for solving the problem]

[0005] In order to solve the above-mentioned problems, the manufacturing method of the light-emitting device of the present disclosure is a manufacturing method of a light-emitting device comprising a light-emitting element forming step of forming a first light-emitting element including a first light-emitting layer on a substrate, wherein the light-emitting element forming step comprises a first light-emitting layer forming step of forming the first light-emitting layer by patterning a first laminate obtained by stacking a first reversal resist, a first light-emitting material layer including a light-emitting material of the first light-emitting layer, and a first positive resist in this order from the substrate side.

[0006] In order to solve the above problems, the light-emitting device of the present disclosure includes a first light-emitting element on the substrate, the first light-emitting element including a substrate, a first lower electrode, a first light-emitting layer, and a first upper electrode, stacked in this order from the substrate side; and the first light-emitting element further including a photosensitive resin layer between the first lower electrode and the first light-emitting layer, the photosensitive resin layer including at least one compound selected from the group consisting of compounds represented by the following structural formulas (1) to (3), and at least one compound selected from the group consisting of aromatic hydrocarbons having a hydroxyl group, 1-hydroxyethyl-2-alkylimidazoline, and shellac.

[0007] [ka] Here, R1 and R2 each independently represent a substituted or unsubstituted hydrocarbon group. [Effects of the Invention]

[0008] According to one aspect of the present disclosure, the light-emitting material of the first light-emitting layer is prevented from being mixed as residue into an area where the first light-emitting layer is not formed. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a flowchart illustrating an example of a method for manufacturing a display device according to the present invention. [Figure 2] 1 is a schematic plan view showing an example of the configuration of a display device according to the present invention. [Figure 3] 1 is a schematic cross-sectional view showing an example of the configuration of a display area of a display device according to the present invention. [Figure 4] 1 is a schematic cross-sectional view showing an example of the configuration of a light-emitting element layer in a display device according to one embodiment of the present invention. [Figure 5] FIG. 5 is a schematic flow diagram showing an example of a process for forming the example of the light emitting element layer shown in FIG. 4 on a substrate. [Figure 6] FIG. 6 is a schematic flow diagram showing the steps of performing the process including the formation of a red light-emitting layer and the process including the formation of a green light-emitting layer 35g shown in FIG. 5. [Figure 7] 6 is a schematic flow diagram showing a process performed in the process of performing the process including the formation of the blue light-emitting layer shown in FIG. 5. [Figure 8] 5 is a schematic cross-sectional view showing an example of a process for forming the example of the light emitting element layer shown in FIG. 4 on a substrate. [Figure 9] 5 is a schematic cross-sectional view showing an example of a process for forming the example of the light emitting element layer shown in FIG. 4 on a substrate. [Figure 10] 5 is a schematic cross-sectional view showing an example of a process for forming the example of the light emitting element layer shown in FIG. 4 on a substrate. [Figure 11] 5 is a schematic cross-sectional view showing an example of a process for forming the example of the light emitting element layer shown in FIG. 4 on a substrate. [Figure 12] 5 is a schematic cross-sectional view showing an example of a process for forming the example of the light emitting element layer shown in FIG. 4 on a substrate. [Figure 13] 5 is a schematic cross-sectional view showing an example of a process for forming the example of the light emitting element layer shown in FIG. 4 on a substrate. [Figure 14] 5 is a schematic cross-sectional view showing an example of a process for forming the example of the light emitting element layer shown in FIG. 4 on a substrate. [Figure 15] 5 is a schematic cross-sectional view showing an example of a process for forming the example of the light emitting element layer shown in FIG. 4 on a substrate. [Figure 16] 5 is a schematic cross-sectional view showing an example of a process for forming the example of the light emitting element layer shown in FIG. 4 on a substrate. [Figure 17] 5 is a schematic cross-sectional view showing an example of a process for forming the example of the light emitting element layer shown in FIG. 4 on a substrate. [Figure 18] 5 is a schematic cross-sectional view showing an example of a process for forming the example of the light emitting element layer shown in FIG. 4 on a substrate. [Figure 19] 5 is a schematic cross-sectional view showing an example of a process for forming the example of the light emitting element layer shown in FIG. 4 on a substrate. [Figure 20] FIG. 4 is a schematic cross-sectional view showing another example of the configuration of a light-emitting element layer in a display device according to one embodiment of the present invention. [Figure 21]5 is a schematic cross-sectional view showing another example of the step of forming the example of the light emitting element layer shown in FIG. 4 on a substrate. [Figure 22] 5 is a schematic cross-sectional view showing another example of the step of forming the example of the light emitting element layer shown in FIG. 4 on a substrate. [Figure 23] 5 is a schematic cross-sectional view showing another example of the step of forming the example of the light emitting element layer shown in FIG. 4 on a substrate. [Figure 24] 5 is a schematic cross-sectional view showing another example of the step of forming the example of the light emitting element layer shown in FIG. 4 on a substrate. [Figure 25] 5 is a schematic cross-sectional view showing another example of the step of forming the example of the light emitting element layer shown in FIG. 4 on a substrate. [Figure 26] FIG. 4 is a schematic cross-sectional view showing another example of the configuration of a light-emitting element layer in a display device according to one embodiment of the present invention. [Figure 27] FIG. 27 is a schematic flow diagram showing an example of a process for forming the example of the light emitting element layer shown in FIG. 26 on a substrate. [Figure 28] FIG. 4 is a schematic cross-sectional view showing another example of the configuration of a light-emitting element layer in a display device according to one embodiment of the present invention. [Figure 29] FIG. 5 is a schematic energy level diagram showing an example of the band gaps of the hole transport layer, lower resin layer, light emitting layer, and electron transport layer of the light emitting element layer shown in FIG. [Figure 30] FIG. 21 is a schematic energy level diagram showing an example of the band gaps of the hole transport layer, lower resin layer, light emitting layer, and electron transport layer of the light emitting element layer shown in FIG. [Figure 31] FIG. 21 is a schematic energy level diagram showing an example of the band gaps of the hole transport layer, lower resin layer, light emitting layer, and electron transport layer of the light emitting element layer shown in FIG. [Figure 32] 27 is a schematic energy level diagram showing an example of the band gaps of the hole transport layer, lower resin layer, light emitting layer, and electron transport layer of the light emitting element layer shown in FIG. 26. FIG. [Figure 33] 29 is a schematic energy level diagram showing an example of the band gaps of the hole transport layer, lower resin layer, light emitting layer, and electron transport layer of the light emitting element layer shown in FIG. 28. FIG. [Figure 34] 29 is a schematic energy level diagram showing an example of the band gaps of the hole transport layer, lower resin layer, light emitting layer, and electron transport layer of the light emitting element layer shown in FIG. 28. FIG. [Figure 35] FIG. 10 is a schematic cross-sectional view showing an example of the configuration of a light-emitting element layer in a display device according to another embodiment of the present invention. [Figure 36] 36 is a schematic cross-sectional view showing an example of a process for forming an example of the light emitting element layer shown in FIG. 35 on a substrate. [Figure 37] 36 is a schematic cross-sectional view showing an example of a process for forming an example of the light emitting element layer shown in FIG. 35 on a substrate. [Figure 38] 36 is a schematic cross-sectional view showing an example of a process for forming an example of the light emitting element layer shown in FIG. 35 on a substrate. [Figure 39] 36 is a schematic cross-sectional view showing an example of a process for forming an example of the light emitting element layer shown in FIG. 35 on a substrate. [Figure 40] 36 is a schematic cross-sectional view showing an example of a process for forming an example of the light emitting element layer shown in FIG. 35 on a substrate. [Figure 41] FIG. 10 is a schematic cross-sectional view showing an example of the configuration of a light-emitting element layer in a display device according to yet another embodiment of the present invention. [Figure 42] FIG. 42 is a schematic flow diagram illustrating a process performed to form the light emitting element layer shown in FIG. 41. [Figure 43] 43A to 43C are schematic cross-sectional views illustrating the process shown in FIG. 42. [Figure 44] 43A to 43C are schematic cross-sectional views illustrating the process shown in FIG. 42 and the process shown in FIG. 45 described below. [Figure 45] FIG. 42 is a schematic flow diagram illustrating another process that may be performed to form the light emitting element layer shown in FIG. [Figure 46] 46A to 46C are schematic cross-sectional views illustrating the process shown in FIG. 45. [Figure 47] FIG. 10 is a schematic cross-sectional view showing an example of the configuration of a light-emitting element layer in a display device according to yet another embodiment of the present invention. [Figure 48] 48 is a schematic cross-sectional view showing an example of a process for forming an example of the light emitting element layer shown in FIG. 47 on a substrate. [Figure 49] 48 is a schematic cross-sectional view showing an example of a process for forming an example of the light emitting element layer shown in FIG. 47 on a substrate. [Figure 50] 48 is a schematic cross-sectional view showing an example of a process for forming an example of the light emitting element layer shown in FIG. 47 on a substrate. [Figure 51] 48 is a schematic cross-sectional view showing an example of a process for forming an example of the light emitting element layer shown in FIG. 47 on a substrate. [Figure 52] 48 is a schematic cross-sectional view showing an example of a process for forming an example of the light emitting element layer shown in FIG. 47 on a substrate. [Figure 53] 48 is a schematic cross-sectional view showing an example of a process for forming an example of the light emitting element layer shown in FIG. 47 on a substrate. DETAILED DESCRIPTION OF THE INVENTION

[0010] [Embodiment 1] (Display device manufacturing method and configuration) In the following, "same layer" means that it is formed in the same process (film formation process), "lower layer" means that it is formed in an earlier process than the layer being compared, and "upper layer" means that it is formed in a later process than the layer being compared.

[0011] Fig. 1 is a flowchart showing an example of a method for manufacturing a display device. Fig. 2 is a plan view showing an example of the configuration of a display device 2 (light-emitting device). Fig. 3 is a schematic cross-sectional view showing an example of the configuration of a display area DA of the display device 2 shown in Fig. 2.

[0012] When manufacturing a flexible display device 2, as shown in FIGS. 1 to 3, first, a resin layer 12 is formed on a light-transmitting support substrate (e.g., mother glass) (step S1). Next, a barrier layer 3 is formed (step S2). Next, a thin-film transistor layer 4 (TFT layer) is formed (step S3). Next, a top-emission light-emitting element layer 5 is formed (step S4). Next, a sealing layer 6 is formed (step S5). Next, an upper film 9 is attached onto the sealing layer 6 via an adhesive layer 8 (step S6).

[0013] Next, the support substrate is peeled off from the resin layer 12 by irradiation with laser light or the like (step S7). Next, a lower surface film 10 is attached to the lower surface of the resin layer 12 (step S8). Next, the laminate including the lower surface film 10, resin layer 12, barrier layer 3, thin-film transistor layer 4, light-emitting element layer 5, and encapsulating layer 6 is cut into a plurality of individual pieces (step S9). Next, a functional film 39 is attached to the obtained individual pieces via an adhesive layer 38 (step S10). Next, an electronic circuit board (e.g., an IC chip and FPC) is mounted on a part (terminal portion) of the frame area NA (non-display area) surrounding the display area DA in which a plurality of sub-pixels are formed (step S11). Note that steps S1 to S11 are performed by a display device manufacturing apparatus (including a film-forming apparatus that performs each of steps S1 to S5).

[0014] The light-emitting element layer 5 includes an anode 22 (positive electrode, so-called pixel electrode) above the planarization film 21, an insulating edge cover 23 covering the edge of the anode 22, an active layer 24 which is an EL (electroluminescence) layer above the edge cover 23, and a cathode 25 (negative electrode, so-called common electrode) above the active layer 24.

[0015] For each subpixel, a light-emitting element ES (electroluminescent element) which is a QLED and includes an island-shaped anode 22, an active layer 24, and a cathode 25 is formed in the light-emitting element layer 5, and a sub-pixel circuit which controls the light-emitting element ES is formed in the thin-film transistor layer 4.

[0016] The sealing layer 6 is light-transmitting and includes an inorganic sealing film 26 that covers the cathode 25, an organic buffer film 27 that is located above the inorganic sealing film 26, and an inorganic sealing film 28 that is located above the organic buffer film 27. The sealing layer 6 that covers the light-emitting element layer 5 prevents foreign substances such as water and oxygen from penetrating into the light-emitting element layer 5.

[0017] Although flexible display devices have been described above, when manufacturing a non-flexible display device, forming a resin layer, replacing a substrate, etc. is generally not required, so for example, lamination processes of steps S2 to S5 are performed on a glass substrate, and then the process proceeds to step S9. Furthermore, when manufacturing a non-flexible display device, instead of or in addition to forming the sealing layer 6, a light-transmitting sealing member may be bonded under a nitrogen atmosphere using a sealing adhesive. The light-transmitting sealing member can be formed from glass, plastic, or the like, and is preferably concave.

[0018] The present embodiment 1 particularly relates to the step (step S4) of forming the light emitting element layer 5 in the above-described method of manufacturing the display device. The present embodiment 1 particularly relates to the active layer 24 in the configuration of the above-described display device.

[0019] (Configuration of light-emitting element layer) FIG. 4 is a schematic cross-sectional view showing an example of the configuration of the light emitting element layer 5 in the display device 2 according to the first embodiment.

[0020] 4, a red subpixel Pr (first light-emitting element, red light-emitting element), a green subpixel Pg (second light-emitting element, green light-emitting element), and a blue subpixel Pb (third light-emitting element, blue light-emitting element) are formed on a substrate (i.e., the lower film 10 or a mother glass 70 described below). Hereinafter, the red subpixel Pr, the green subpixel Pg, and the blue subpixel Pb will be collectively referred to as "subpixels P."

[0021] An example of the light-emitting element layer 5 shown in Figure 4 includes, in order from the substrate side (the lower side of Figure 4), an anode 22 (lower electrode, first lower electrode), a hole injection layer 31, a hole transport layer 33 (carrier transport layer), a red lower resin layer 34r (photosensitive resin layer), a red light-emitting layer 35r (first light-emitting layer), an electron transport layer 37, and a cathode 25 (upper electrode, first upper electrode) in the region of the red sub-pixel Pr.

[0022] Similarly, an example of the light-emitting element layer 5 includes, in order from the substrate side, an anode 22 (second lower electrode), a hole injection layer 31, a hole transport layer 33, a green lower resin layer 34g (photosensitive resin layer), a green light-emitting layer 35g (second light-emitting layer), an electron transport layer 37, and a cathode 25 (second upper electrode) in the region of the green sub-pixel Pg.

[0023] Similarly, an example of the light emitting element layer 5 includes, in order from the substrate side, an anode 22 (third lower electrode), a hole injection layer 31, a hole transport layer 33, and a blue light emitting layer 35b (third lower electrode) in the region of the blue subpixel Pb. 3 light-emitting layer), an electron transport layer 37, and a cathode 25 (third upper electrode).

[0024] Hereinafter, the red lower resin layer 34r and the green lower resin layer 34g will be collectively referred to as the "lower resin layer 34." The red light-emitting layer 35r, the green light-emitting layer 35g, and the blue light-emitting layer 35b will be collectively referred to as the "light-emitting layer 35."

[0025] The hole injection layer 31 may be omitted.

[0026] The hole transport layer 33 includes a hole transporting material. Examples of the hole transporting material include inorganic materials such as NiO, CuI, Cu2O, CoO, Cr2O3, and CuAlS. Examples of the hole transporting material include PEDOT:PSS, poly((9,9-dioctylfluorenyl-2,7-diyl)-co(4,4'-(N-(4-sec-butylphenyl)diphenylamine))) (TFB), poly(N,N'-diphenyl-N,N'-di(m-tolyl)benzidine) (poly-TPD), (1,1-bis(4-(N,N-di(p-tolyl)amino)phenyl)cyclohexane) (TAPC), organic polysilane compounds, and N4,N4'-bis(4-(6-((3-ethyloxetan-3-yl)methoxy)hexyl)phenyl-N4,N4'- Photocurable organic materials such as N,N'-(4,4'-(cyclohexane-1,1-diyl)bis(4,4-phenylene))bis(N-(4-(6-(2-ethyloxetane-2-yloxy)hexyl)phenyl)-3,4,5-trifluoroaniline) (X-F6-TAPC) are also used.

[0027] The lower resin layer 34 is a resin layer formed from a reversal resist material. In this specification, the term "reversal resist material" refers to a material including a reversal photoresist. In contrast, the term "positive resist material" refers to a material including a positive photoresist.

[0028] A positive resist contains, for example, an uncured resin and a sensitizer. The resin is soluble in a developer, such as an acrylic resin, a novolac resin, a rubber resin, a styrene resin, or an epoxy resin. The sensitizer is, for example, an NQD (Naphtoquinone Diazide) compound. The NQD compound is insoluble in the developer. The NQD compound is converted into an indene carboxylic acid compound by exposure to light, as shown in the following reaction formula (1). The indene carboxylic acid is soluble in the developer. The NQD compound is also called a DNQ (DiazoNaphtoQuinone) compound.

[0029] [ka] Here, R1 is the portion of the NQD compound other than the NQD group, and represents a substituted or unsubstituted hydrocarbon group.

[0030] The developer is an alkaline aqueous solution or an organic solvent. Examples of alkaline aqueous solutions include aqueous solutions of inorganic materials such as KOH and NaOH, and aqueous solutions of organic materials such as tetramethylammonium chloride (TMAH). Examples of organic solvents include propylene glycol monomethyl ether acetate (PGMEA), acetone, N-methyl-2-pyrrolidone (NMP), dimethyl sulfoxide (DMSO), and isopropanol (IPA).

[0031] Therefore, the positive resist is insoluble in the developer in the initial state before exposure, and becomes soluble in the developer upon exposure to light.

[0032] Reversal resists are, for example, positive resists to which negative-working agents have been added. Examples of negative-working agents include amines, aromatic hydrocarbons with hydroxyl groups, 1-hydroxyethyl-2-alkylimidazolines, and shellacs. During reversal baking, the negative-working agent acts as a catalyst on the indene carboxylic acid compound, promoting decarboxylation. Therefore, as shown in the following reaction formulas (2) to (4), the indene carboxylic acid compound is converted into a compound insoluble in the developer by heating. In particular, reversal resists harden when the crosslinking reaction shown in reaction formula (2) is dominant. [ka] [ka]

[0033] [ka] Here, R2 is a resin contained in the reversal resist or a portion of an indene carboxylic acid compound other than the indene carboxyl group, and represents a substituted or unsubstituted hydrocarbon group.

[0034] For this reason, reversal resist, like positive resist, is insoluble in a developer in its initial state before exposure to light, and becomes soluble in the developer upon exposure to light. Furthermore, after being solubilized by exposure to light, reversal resist is again made insoluble in the developer by further heating or laser irradiation. In this specification, "re-insolubilization" means that the reversal resist becomes insoluble again after it has become soluble in the developer. Re-insolubilized reversal resist does not become soluble even when exposed to light again.

[0035] The lower resin layer 34 is formed by re-insolubilizing the reversal resist as described above, or by re-insolubilizing and then baking the reversal resist. Therefore, the lower resin layer 34 contains at least one compound selected from the group consisting of compounds represented by the following structural formulas (1) to (3), and at least one compound selected from the group consisting of aromatic hydrocarbons having a hydroxyl group, 1-hydroxyethyl-2-alkylimidazoline, and shellac.

[0036] [ka] Here, R1 and R2 each independently represent a substituted or unsubstituted hydrocarbon group.

[0037] The thickness of the lower resin layer 34 is preferably 50 nm or less, and more preferably 40 nm or less. Resins are generally dielectrics with high electrical resistivity, so the thickness of the lower resin layer 34 significantly affects the electrical resistance of the entire light-emitting device. Therefore, in order to reduce the electrical resistance of the entire light-emitting device in the direction perpendicular to the substrate of the light-emitting layer 35, it is preferable that the lower resin layer 34 be thin.

[0038] The red lower resin layer 34r and the green lower resin layer 34g may be integral with each other or may be separate.

[0039] The light-emitting material contained in each of the light-emitting layers 35 may be an organic light-emitting material or an inorganic light-emitting material such as quantum dots. The quantum dots may be core-shell quantum dots or core-multishell quantum dots. Examples of core / shell material combinations for core-shell quantum dots include CdSe / CdS, CdSe / ZnS, CdTe / CdS, INP / ZNS, GaP / ZNS, Si / ZNS, INN / GaN, INP / CdSSe, INP / ZNSeTe, GaINP / ZNSe, GaINP / ZNS, Si / AlP, INP / ZNSTe, GaINP / ZNSTe, and GaINP / ZNSSe. In this specification, the light-emitting material contained in the red light-emitting layer 35r is referred to as the red light-emitting material. The red light-emitting material emits red light. The light-emitting material contained in the green light-emitting layer 35g is referred to as the green light-emitting material. The green light-emitting material, which is different from the red light-emitting material, emits green light. The light-emitting material contained in the blue light-emitting layer 34b is referred to as a blue light-emitting material. The blue light-emitting material emits blue light and is different from both the red light-emitting material and the green light-emitting material.

[0040] The light-emitting material contained in each of the light-emitting layers 35 is preferably quantum dots for the development step described below, because quantum dots allow the developer to penetrate the light-emitting material layer and develop the layers below the light-emitting material layer from above.

[0041] The electron transport layer 37 includes an electron transporting material, such as a metal oxide such as ZnO, ZrO, MgZnO, AlZnO, or TiO2, or a metal sulfide such as ZnS.

[0042] (Manufacturing method) Hereinafter, an example of the step of forming an example of the light emitting element layer 5 shown in FIG. 4 on a substrate (step S4, light emitting element forming step) will be described in detail with reference to FIGS.

[0043] Fig. 5 is a schematic flow diagram showing an example of the step (step S4) of forming an example of the light-emitting element layer 5 shown in Fig. 4 on a substrate. Fig. 6 is a schematic flow diagram showing a process (process P1) performed in the step (step S25) of performing a process including forming the red light-emitting layer 35r and the step (step S26) of performing a process including forming the green light-emitting layer 35g shown in Fig. 5. Fig. 7 is a schematic flow diagram showing a process (process P2) performed in the step (step S27) of performing a process including forming the blue light-emitting layer 35b shown in Fig. 5.

[0044] 8 to 19 are each a schematic cross-sectional view showing an example of the step (step S4) of forming an example of the light-emitting element layer 5 shown in FIG. 4 on a substrate.

[0045] First, the above-mentioned steps S1 to S3 (see FIG. 1) are carried out to prepare a substrate in which the resin layer 12, the barrier layer 3, and the thin film transistor layer 4 are formed in this order on the mother glass 70 (substrate).

[0046] 5 and 8, the anode 22 is formed in an island shape in each sub-pixel P region (step S21), an edge cover 23 is formed to cover the edge of the anode 22 (step S22), a hole injection layer 31 is formed over the entire surface (step S23), and a hole transport layer 33 is formed over the entire surface (step S24). In this specification, "over the entire surface" means that a target layer is formed in common across multiple sub-pixels P without patterning.

[0047] <Processing including formation of red light-emitting layer> 6 and 8 to 11, a process including the formation of the red light-emitting layer 35r is performed (step S25). In this process, the red lower resin layer 34r before main baking is also formed. In step S25, the process P1 shown in FIG. 6 is executed.

[0048] 6 and 8, a reversal resist material is first applied to the entire surface of the hole transport layer 33 to form (i.e., form) a red lower reversal resist layer 41 (first reversal resist) (step S41, part of the laminate formation process of the first light-emitting layer formation process). Subsequently, a red light-emitting material layer 44 (first light-emitting material layer) is formed on the entire surface of the red lower reversal resist layer 41 by vapor-depositing a material containing a red light-emitting material (a light-emitting material of the first light-emitting image) or by applying a solution containing a red light-emitting material and volatilizing the solvent from the solution (step S42, part of the laminate formation process of the first light-emitting layer formation process). Subsequently, a positive resist material is applied to the entire surface of the red light-emitting material layer 44 to form a red upper positive resist layer 45 (first positive resist) to a sufficient thickness (described later) (step S43, part of the laminate formation process of the first light-emitting layer formation process).

[0049] In this specification, unless otherwise specified, the method for applying the material of each member may be any method such as an inkjet method, a spin coating method, or a bar coating method.

[0050] The resin material and sensitizer contained in the positive resist material in step S43 are preferably the same as the resin material and sensitizer contained in the reversal resist material in step S41, because this allows the red lower reversal resist layer 41 and the red upper positive resist layer 45 to be patterned using photolithography techniques under the same conditions, including the exposure wavelength and developer.

[0051] In this way, a laminate (first laminate) is formed that includes, in this order from the substrate side, the red lower reversal resist layer 41, the red light emitting material layer 44, and the red upper positive resist layer 45. At this time, each of the red lower reversal resist layer 41 and the red upper positive resist layer 45 is insoluble in a developer.

[0052] Next, the laminate is subjected to a first exposure to ultraviolet light using a red first mask 47 (step S44, laminate exposure step of the first light-emitting layer formation step). By using the red first mask 47, part of the laminate is exposed to light and the other part is not exposed to light. The red first mask 47 has an optical opening 47A formed therein so that the part corresponding to the formation region of the red light-emitting layer 35r is light-blocking and the other part is light-transmitting.

[0053] At this time, in the red lower reversal resist layer 41 and the red upper positive resist layer 45, a photochemical reaction caused by ultraviolet irradiation converts the NQD compound, which is insoluble in the developer, into an indene carboxylic acid compound, which is soluble in the developer, as shown in reaction formula (1) above.

[0054] As a result, the portions of the red lower reversal resist layer 41 and the red upper positive resist layer 45 that do not correspond to the optical opening 47A (i.e., the portions that overlap the red light-emitting layer 35r) do not undergo a photochemical reaction and remain as insoluble portions 41A and 45A that are insoluble in the developer. On the other hand, the other portions that correspond to the optical opening 47A undergo a photochemical reaction to become soluble portions 41B and 45B that are soluble in the developer.

[0055] Next, as shown in Figures 6 and 9, development is performed using a strong developer (step S45, the development step of the first light-emitting layer formation step). In this specification, a "strong developer" refers to the developer described above that (i) can dissolve the soluble portions of the resist layer above the light-emitting material layer (or light-emitting layer) from the top and sides, thereby dissolving the entire soluble portions, and (ii) can dissolve the soluble portions of the resist layer below the light-emitting material layer from the sides, thereby (iii) liberating the soluble portions of the lower resist layer of the light-emitting material layer. Furthermore, as described above, when the light-emitting material is quantum dots, the developer can penetrate the light-emitting material layer and dissolve the soluble portions of the resist layer below the light-emitting material layer from the top and sides.

[0056] A strong developer is, for example, a concentrated alkaline aqueous solution or an alkaline solution to which a surfactant is added at a high concentration. A concentrated alkaline aqueous solution has, for example, a pH of 12 or higher. The surfactant is, for example, a nonionic surfactant such as a fatty acid ester, polyoxyethylene alkyl ether, fatty acid polyethylene glycol, or fatty acid alkanolamide, and a high concentration is, for example, 1% by weight or higher. Nonionic surfactants are less susceptible to the effects of acids and alkalis. The surfactant promotes penetration into the light-emitting material layer. In this specification, development using a strong developer is referred to as "strong development" or "strong development."

[0057] As a result, the soluble portion 41B (exposed first reversal resist) of the red lower reversal resist layer 41 is removed, and the exposed portion of the laminate, including the red light-emitting material layer 44, is removed. Meanwhile, the insoluble portion 41A of the red lower reversal resist layer 41 remains, so the unexposed portion of the laminate remains. Therefore, the soluble portions 41B, 45B of the red lower reversal resist layer 41 and the red upper positive resist layer 45, and the portion of the red light-emitting material layer 44 therebetween are removed. Meanwhile, the insoluble portions 41A, 45A of the red lower reversal resist layer 41 and the red upper positive resist layer 45, and the portion of the red light-emitting material layer 44 therebetween remain. This remaining portion of the red light-emitting material layer 44 becomes the red light-emitting layer 35r.

[0058] In this way, the above-described laminate is patterned using photolithography and re-insolubilization of the reversal resist, resulting in the formation of the red light-emitting layer 35r. At the same time, the insoluble portions 41A and 45A of the red lower reversal resist layer 41 and the red upper positive resist layer 45 are formed so as to overlap the red light-emitting layer 35r in a plan view perpendicular to the substrate.

[0059] 6 and 10, the patterned laminate is subjected to a second exposure to ultraviolet light using a red second mask 48 (step S46, a reversal resist exposure step in the first re-insolubilization step). The red second mask 48 has an optical opening 48A formed therein so that a portion corresponding to the formation region of the red light-emitting layer 35r is light-transmitting and the other portion is light-blocking.

[0060] As a result, the insoluble portion 41A of the red lower reversal resist layer 41 (the first reversal resist overlapping the first light-emitting layer) and the insoluble portion 45A of the red upper positive resist layer 45 undergo a photochemical reaction to become soluble portions 41C (the exposed first reversal resist) that are soluble in a developer and soluble portions 45C. Note that the second exposure may be performed without using a mask, but it is preferable to use a red second mask 48 from the viewpoint of reducing photodegradation.

[0061] Next, as shown in FIGS. 6 and 11, the patterned laminate is subjected to reversal baking (step S47, a heating step in the first reinsolubilization step). Reversal baking involves heating or laser irradiation so that the red upper positive resist layer 45 does not harden, while the red lower reversal resist layer 41 is reinsolubilized. Reversal baking by heating is preferred for its simplicity. Reversal baking by heating is preferably performed at a temperature lower than the temperature at which the positive resist constituting the red upper positive resist layer 45 hardens, and for a time shorter than the hardening time. For example, if the red upper positive resist layer 45 hardens at 120° C. or higher for 10 minutes or longer, reversal baking is preferably performed at a temperature lower than 120° C. and for less than 10 minutes.

[0062] At this time, in the red lower reversal resist layer 41, the developer-soluble indene carboxylic acid compound is converted into a developer-insoluble compound by decarboxylation as shown in the above reaction formulas (2) to (4). On the other hand, in the red upper positive resist layer 45, the developer-soluble indene carboxylic acid compound remains as an indene carboxylic acid compound.

[0063] As a result, the soluble portions 41C of the red lower reversal resist layer 41 are decarboxylated to become reinsoluble portions 41D that are insoluble in the developer. The reinsoluble portions 41D of the red lower reversal resist layer 41 become the red lower resin layer 34r as they are, or after undergoing the main baking (step S29) described below. On the other hand, the soluble portions 45C of the red upper positive resist layer 45 remain as soluble portions 45C.

[0064] As described above, in step S25, the red light-emitting layer 35r is formed in a state where it is sandwiched between the insoluble portion 41D of the lower red reversal resist layer 41 and the soluble portion 45C of the upper red positive resist layer 45 and protected.

[0065] <Processing including formation of green light-emitting layer> 5 and 12 to 15, a process including the formation of a green light-emitting layer 35g is performed (step S26). In this process, a green lower resin layer 34g before main baking is also formed. In step S26, process P1 shown in FIG. 6 is also performed.

[0066] 6 and 12, a reversal resist material is first applied to the entire surface of the hole transport layer 33 and the soluble portion 45C of the red upper positive resist layer 45 to form a green lower reversal resist layer 51 (second reversal resist) (step S41, part of the second light-emitting layer forming process). Subsequently, a green light-emitting material layer 54 (second light-emitting material layer) is formed by entirely depositing a material containing a green light-emitting material (light-emitting material of the second light-emitting layer) on the green lower reversal resist layer 51, or by entirely applying a solution containing a green light-emitting material and volatilizing the solvent from the solution (step S42, part of the second light-emitting layer forming process). Subsequently, a positive resist material is applied to the entire surface of the green light-emitting material layer 54 to form a green upper positive resist layer 55 (second positive resist) to a sufficient thickness (described later) (step S43, part of the second light-emitting layer forming process).

[0067] The reversal resist material used in process P1 in step S26 preferably has the same composition as the reversal resist material used in process P1 in step S25 described above. This is because the green lower reversal resist layer 51 can be patterned and re-insolubilized under the same conditions as the red lower reversal resist layer 41. The positive resist material used in process P1 in step S26 preferably has the same composition as the positive resist material used in process P1 in step S25 described above. This is because the green upper positive resist layer 55 can be patterned under the same conditions as the red upper positive resist layer 45.

[0068] In this way, a laminate (second laminate) is formed which includes the green lower reversal resist layer 51, the green light emitting material layer 54, and the green upper positive resist layer 55 in this order from the substrate side.

[0069] Next, the laminate is subjected to a first exposure to ultraviolet light using a green first mask 57 (step S44, part of the second light-emitting layer forming step). Because the green first mask 57 is used, part of the laminate is exposed to light and the other parts are not exposed. The green first mask 57 has an optical opening 57A formed therein so that the part corresponding to the formation region of the green light-emitting layer 35g is light-blocking and the other parts are light-transmitting.

[0070] As a result, no photochemical reaction occurs in the portions of green lower reversal resist layer 51 and green upper positive resist layer 55 that do not correspond to optical opening 57A (i.e., the portions that overlap green light-emitting layer 35g), and these portions remain as insoluble portions 51A and 55A that are insoluble in the developer. On the other hand, the remaining portions that correspond to optical opening 47A undergo a photochemical reaction to become soluble portions 51B and 55B that are soluble in the developer.

[0071] Next, as shown in FIGS. 6 and 13, strong development is carried out (step S45, part of the second light-emitting layer forming step).

[0072] As a result, the soluble portion 51B of the green lower reversal resist layer 51 is removed, and the exposed portion of the laminate, including the green light-emitting material layer 54, is removed. Meanwhile, the insoluble portion 51A of the green lower reversal resist layer 51 remains, so the unexposed portion of the laminate remains. Therefore, the soluble portions 51B, 55B of the green lower reversal resist layer 51 and the green upper positive resist layer 55, and the portion of the green light-emitting material layer 54 therebetween, are removed. Meanwhile, the insoluble portions 51A, 55A of the green lower reversal resist layer 51 and the green upper positive resist layer 55, and the portion of the green light-emitting material layer 54 therebetween, remain. This remaining portion of the green light-emitting material layer 54 becomes the green light-emitting layer 35g.

[0073] At this time, it should be noted that after the soluble portions 55B of the green upper positive resist layer 55 are removed, the upper surface of the soluble portions 45C of the red upper positive resist layer 45 is exposed to a strong developer. Therefore, the soluble portions 45C of the red upper positive resist layer 45 are formed in the above-mentioned step S25 to a thickness sufficient to maintain protection of the red light-emitting layer 35r by the soluble portions 45C of the red upper positive resist layer 45 in this step S26 (and in step S27, which will be described later). Furthermore, the re-insoluble portions 41D of the red lower reversal resist layer 41 are insoluble even in a strong developer. For these reasons, the red light-emitting layer 35r is not removed and remains protected as described above.

[0074] In this way, the above-described laminate is patterned using photolithography and re-insolubilization of the reversal resist, resulting in the formation of green light-emitting layer 35g. At the same time, insoluble portions 51A and 55A of green lower reversal resist layer 51 and green upper positive resist layer 55 are formed so as to overlap green light-emitting layer 35g in a plan view perpendicular to the substrate.

[0075] 6 and 14, the patterned laminate is subjected to a second exposure to ultraviolet light using a second green mask 58 (step S46, part of the second re-insolubilization step). The second green mask 58 has an optical opening 58A formed therein so that a portion corresponding to the formation region of the green light-emitting layer 35g is light-transmitting and the other portion is light-blocking.

[0076] As a result, insoluble portions 51A, 55A of green lower reversal resist layer 51 and green upper positive resist layer 55 are converted by a photochemical reaction into soluble portions 51C, 55C that are soluble in a developer. Note that, although the second exposure may be performed without using a mask, it is preferable to use green second mask 58 from the viewpoint of reducing photodegradation.

[0077] 6 and 15, the patterned laminate is subjected to reversal baking (step S47, part of the second reinsolubilization step). The reversal baking is heating or laser irradiation performed so that the red upper positive resist layer 45 and the green upper positive resist layer 55 do not harden, while the green lower reversal resist layer 51 is reinsolubilized.

[0078] As a result, the soluble portions 51C of the green lower reversal resist layer 51 are decarboxylated to become insoluble portions 51D that are insoluble in the developer, while the soluble portions 55C of the green upper positive resist layer 55 remain as soluble portions 55C.

[0079] As described above, in step S26, the green light-emitting layer 35g is formed in a state where it is sandwiched between the insoluble portion 51D of the green lower reversal resist layer 51 and the soluble portion 55C of the green upper positive resist layer 55 and protected.

[0080] <Processing including formation of blue light-emitting layer> 5 and 16 to 18, a process including the formation of the blue light-emitting layer 35b is performed (step S27). In step S27, a process P2 shown in FIG.

[0081] 7 and 16, a blue light-emitting material layer 64 (third light-emitting material layer) is formed on the entire surface by depositing a material containing a blue light-emitting material (light-emitting material of the third light-emitting layer) on the hole transport layer 33 and the soluble portions 45C, 55C of the red upper positive resist layer 45 and the green upper positive resist layer 55, or by applying a solution containing a blue light-emitting material and volatilizing the solvent from the solution (step S42, part of the third light-emitting layer forming step). Subsequently, a positive resist material is applied on the entire surface of the blue light-emitting material layer 64 to form a blue upper positive resist layer 65 (third positive resist) (step S43, part of the third light-emitting layer forming step).

[0082] The positive resist material used in the process P1 in step S27 preferably has the same composition as the positive resist material used in the process P1 in steps S25 and S26 described above, because the blue upper positive resist layer 65 can be patterned under the same conditions as the red upper positive resist layer 45 and the green upper positive resist layer 55.

[0083] In this way, a laminate (third laminate) including the blue light emitting material layer 64 and the blue upper positive resist layer 65 in this order from the substrate side is formed.

[0084] Next, the laminate is subjected to a first exposure to ultraviolet light using a blue first mask 67 (step S44, part of the third light-emitting layer forming step). By using the blue first mask 67, part of the laminate is exposed to light and the other parts are not exposed. The blue first mask 67 has an optical opening 67A formed therein so that the part corresponding to the formation region of the blue light-emitting layer 35b is light-blocking and the other parts are light-transmitting.

[0085] As a result, the portions of the blue lower reversal resist layer 61 and the blue upper positive resist layer 65 that do not correspond to the optical opening 67A (i.e., the portions that overlap the blue light-emitting layer 35b) do not undergo a photochemical reaction and remain as insoluble portions 61A and 65A that are insoluble in the developer. On the other hand, the remaining portions that correspond to the optical opening 47A undergo a photochemical reaction to become soluble portions 61B and 65B that are soluble in the developer.

[0086] Next, as shown in FIGS. 7 and 17, strong development is carried out (step S45, part of the third light-emitting layer forming step).

[0087] As a result, the soluble portion 65B of the blue upper positive resist layer 65 is removed, and the soluble portions 45C and 55C of the red upper positive resist layer 45 and the green upper positive resist layer 55 are partially removed. As a result, the exposed portion of the laminate, including the blue light-emitting material layer 64, is removed. Since the insoluble portion 65A of the blue upper positive resist layer 65 remains, the unexposed portion of the laminate remains. Therefore, the soluble portion 65B of the blue upper positive resist layer 65 and the underlying portion of the blue light-emitting material layer 64 are removed. Meanwhile, the insoluble portion 65A of the blue upper positive resist layer 65 and the underlying portion of the blue light-emitting material layer 64 remain. This remaining portion of the blue light-emitting material layer 64 becomes the blue light-emitting layer 35b.

[0088] As a result, the soluble portion 51B of the green lower reversal resist layer 51 is removed, and the exposed portion of the laminate is removed, including the green light-emitting material layer 54. On the other hand, the insoluble portion 51A of the green lower reversal resist layer 51 remains, so that the unexposed portion of the laminate remains.

[0089] Note that after the soluble portion 65B of the blue upper positive resist layer 65 is removed, the upper surfaces of the soluble portions 45C, 55C of the red upper positive resist layer 45 and the green upper positive resist layer 55 are exposed to a strong developer. Therefore, the soluble portion 45C of the red upper positive resist layer 45 is formed in step S25 to a thickness sufficient to maintain protection of the red light-emitting layer 35r by the soluble portion 45C of the red upper positive resist layer 45 in step S27. The red light-emitting layer 35r remains protected by being sandwiched between the insoluble portion 41D of the red lower reversal resist layer 41 and the soluble portion 45C of the red upper positive resist layer 45. Similarly, the soluble portion 55C of the green upper positive resist layer 55 is formed in step S26 to a thickness sufficient to maintain protection of the green light-emitting layer 35g by the soluble portion 55C of the green upper positive resist layer 55 in step S27. Furthermore, the insoluble portions 41D and 51D of the red lower reversal resist layer 41 and the green lower reversal resist layer 51 are insoluble even in a strong developer, so the red light-emitting layer 35r and the green light-emitting layer 35g are not removed and remain protected as described above.

[0090] In this way, the above-described laminate is patterned using photolithography and re-insolubilization of the reversal resist, resulting in the formation of the blue light-emitting layer 35b. At the same time, the insoluble portion 65A of the blue upper positive resist layer 65 is formed so as to overlap the blue light-emitting layer 35b in a plan view seen from a direction perpendicular to the substrate.

[0091] 7 and 18, the patterned laminate is subjected to a second exposure to ultraviolet light using a blue second mask 68 (step S46). The blue second mask 68 has an optical opening 68A formed therein so that a portion corresponding to the blue light-emitting layer 35b is light-transmitting and the other portion is light-blocking.

[0092] As a result, the insoluble portions 65A of the blue upper positive resist layer 65 become soluble portions 55C that are soluble in the developer through a photochemical reaction. Although the second exposure may be performed without using a mask, it is preferable to use a blue second mask 68 from the viewpoint of reducing photodegradation.

[0093] As described above, in step S27, the blue light-emitting layer 35b is formed in a state where it is covered and protected under the soluble portion 65C of the blue upper positive resist layer 65.

[0094] Next, as shown in Figures 5 and 19, development is performed using a weak developer (step S28, positive resist removal process). In this specification, a "weak developer" refers to the developer described above that (i) can dissolve the soluble portions of the resist layer above the light-emitting material layer (or light-emitting layer) from the top and sides, thereby dissolving the entire soluble portions, but (ii) cannot dissolve the soluble portions of the resist layer below the light-emitting material layer from the sides, thereby resulting in (ii) being unable to liberate the light-emitting material layer. Examples of weak developers include a dilute alkaline aqueous solution to which no surfactant is added, or an organic solvent to which no surfactant is added. A dilute alkaline aqueous solution has a pH of, for example, 7 or higher but lower than 11.

[0095] As a result, the soluble portions 45C, 55C, and 65C of the red upper positive resist layer 45, the green upper positive resist layer 55, and the blue upper positive resist layer 65 are removed from the upper layers of the light-emitting layers 35. Meanwhile, the light-emitting layers 35 remain. Also, the insoluble portions 41D and 51D of the red lower reversal resist layer 41 and the green lower reversal resist layer 51 remain.

[0096] Next, main baking is performed (step S29), as a result of which the insoluble portions 41D, 51D of the red lower reversal resist layer 41 and the green lower reversal resist layer 51 are hardened to become the red lower resin layer 34r and the green lower resin layer 34g.

[0097] 5, the electron transport layer 37 is formed over the entire surface of the light-emitting layer 35 (step S30), and the cathode 25 is formed over the entire surface of the electron transport layer 37 (step S31). In this way, the light-emitting element layer 5 shown in FIG.

[0098] (Variation 1) In the method according to the first embodiment, step S29 (see FIG. 5) does not have to be performed. If step S29 is not performed, the insoluble portions 41D and 51D remain uncured and become the red lower resin layer 34r and the green lower resin layer 34g.

[0099] (Variation 2) FIG. 20 is a schematic cross-sectional view showing another example of the configuration of the light-emitting element layer 5 in the display device 2 (light-emitting device) according to the first embodiment.

[0100] In the method according to the first embodiment, the order of steps S25 to S27 (see FIG. 5) can be interchanged. When the order is interchanged, the process P2 shown in FIG. 7 is executed in the last step of steps S25 to S27, and the process P1 shown in FIG. 6 is executed in the steps other than the last. As a result, the lower resin layer 34 is not formed below the light-emitting layer of the color that is formed last among the light-emitting layers 35, and the lower resin layers 34 are formed below the light-emitting layers of the other colors.

[0101] For example, among steps S25 to S27, step S25 may be performed last. In this case, as shown in Fig. 20, the red lower resin layer is not formed below the red light-emitting layer 35r, and instead, the blue lower resin layer 34b is formed below the blue light-emitting layer 35b. In this case, the green lower resin layer 34g and the blue lower resin layer 34b are collectively referred to as the "lower resin layer 34."

[0102] (Variation 3) 21 to 25 are each a schematic cross-sectional view showing another example of the step (step S4) of forming an example of the light-emitting element layer 5 shown in FIG. 4 on a substrate.

[0103] In the method according to the first embodiment, the final step among the multiple steps of performing process P1 can use a third mask different from the first and second masks for the first exposure (step S44) in process P1 shown in Fig. 6. At least the portions of the third mask that correspond to the formation regions of the light-emitting layer formed in the final step are light-blocking. Optionally, the third mask may additionally have light-blocking properties in some of the portions that correspond to the formation regions of the light-emitting layer that has already been formed, and may have light-blocking properties in some of the portions that correspond to the gap regions between the formation regions of the light-emitting layer.

[0104] For example, the case where step S25 performs process P1, step S26 performs process P1, and then step S27 performs process P2 is shown below. In this example, step S26 performs process P1 as shown in Figures 21 to 24 instead of Figures 12 to 15.

[0105] First, as shown in FIGS. 6 and 21, a laminate including a green lower reversal resist layer 51, a green light-emitting material layer 54, and a green upper positive resist layer 55, in this order from the substrate side, is formed (steps S41 to S43). Next, a first exposure of the laminate to ultraviolet light is performed using a green third mask 59 (step S44). The green third mask 59 is light-blocking in a portion corresponding to the formation region of the green light-emitting layer 35g. In addition, the green third mask 59 is light-blocking in a portion corresponding to the formation region of the red light-emitting layer 35r and in a portion corresponding to the gap region between the formation regions of the red light-emitting layer 35r and the green light-emitting layer 35g. An optical opening 59A is formed in the green third mask 59 so that the remaining portion is light-transmitting.

[0106] As a result, no photochemical reaction occurs in the portions of green lower reversal resist layer 51 and green upper positive resist layer 55 that overlap green light-emitting layer 35g, as well as in the portions that overlap red light-emitting layer 35r and the portions corresponding to the gaps between red light-emitting layer 35r and green light-emitting layer 35g, and these remain as insoluble portions 51A and 55A that are insoluble in the developer.On the other hand, the other portions become soluble portions 51B and 55B that are soluble in the developer through the photochemical reaction.

[0107] 6 and 22, development is performed using a strong developer (step S45). As a result, insoluble portions 51A and 55A of green lower reversal resist layer 51 and green upper positive resist layer 55, and the portion of green light-emitting material layer 54 therebetween, remain. In this modification, of the remaining portion of green light-emitting material layer 54, the portion corresponding to the formation region of green light-emitting layer 35g becomes green light-emitting layer 35g, while the uncorresponding excess portion 54A is ultimately removed.

[0108] Next, as shown in FIGS. 6 and 23, the patterned laminate is subjected to a second exposure to ultraviolet light using a green second mask 58 (step S46).

[0109] As a result, the exposed portions of insoluble portions 51A, 55A of green lower reversal resist layer 51 and green upper positive resist layer 55 become soluble portions 51C, 55C that are soluble in a developer through a photochemical reaction. The unexposed portions of insoluble portions 51A, 55A do not undergo a photochemical reaction and remain insoluble in a developer. Here, the unexposed portions of insoluble portions 51A, 55A are referred to as insoluble portions 51E, 55E.

[0110] It should be noted that, unlike the case where the green first mask 57 was used in the first exposure, in the second exposure (step S46), it is necessary to use a mask having openings formed therein so that the portion corresponding to the excess portion 54A of the green light-emitting material layer 54 is light-blocking and the portion corresponding to the green light-emitting layer 35g is light-transmitting.

[0111] Next, as shown in FIGS. 6 and 24, the patterned laminate is subjected to reversal baking (step S47).

[0112] As a result, soluble portions 51C of green lower reversal resist layer 51 are decarboxylated to become re-insoluble portions 51D that are insoluble in the developer. Meanwhile, soluble portions 55C of green upper positive resist layer 55 remain as soluble portions 55C. Similarly, insoluble portions 51E, 55E of green lower reversal resist layer 51 and green upper positive resist layer 55 remain as insoluble portions 51E, 55E.

[0113] Next, proceeding to the step of forming the blue light-emitting layer 35b (Step S27 in FIG. 5), a laminate including a blue light-emitting material layer 64 and a blue upper positive resist layer 65, in this order from the substrate side, is formed (Steps S42 to S43), as shown in FIGS. 6, 7, and 25. Next, the laminate is subjected to a first exposure to ultraviolet light using a first blue mask 67 (Step S44).

[0114] As a result, the portions of the blue lower reversal resist layer 61 and the blue upper positive resist layer 65 that do not overlap with the blue light-emitting layer 35b become soluble portions 61B and 65B that are soluble in a developer through a photochemical reaction. At the same time, the insoluble portions 51E and 55E of the green lower reversal resist layer 51 and the green upper positive resist layer 55 become soluble portions 51F and 55F that are soluble in a developer through a photochemical reaction.

[0115] Next, strong development is carried out (step S45).

[0116] As a result, the soluble portions 61B and 65B of the blue lower reversal resist layer 61 and the blue upper positive resist layer 65, and the portion of the blue light-emitting material layer 64 therebetween, are removed. At the same time, the soluble portions 51F and 55F of the green lower reversal resist layer 51 and the green upper positive resist layer 55, and the portion of the green light-emitting material layer 54 therebetween are removed.

[0117] Therefore, by the above-described process, a stacked body having a structure similar to that of the stacked body in each sub-pixel shown in FIG. 17 can be obtained.

[0118] (Variation 4) 26 and 28 are each a schematic cross-sectional view showing yet another example of the configuration of the light-emitting element layer 5 in the display device 2 (light-emitting device) according to the first embodiment.

[0119] FIG. 27 is a schematic flow diagram showing an example of a step (step S4) of forming an example of the light emitting element layer 5 shown in FIG. 26 on a substrate.

[0120] The light-emitting element layer 5 may include, in order from the substrate side, a cathode 25 (first lower electrode), an electron transport layer 37, a lower resin layer 34 (photosensitive resin), a light-emitting layer 35, a hole transport layer 33, a hole injection layer 31, and an anode 22 (first upper electrode), as shown in FIG.

[0121] In this case, as shown in FIG. 27, the process of forming the light-emitting element layer 5 (Step S4) includes forming the cathode 25 in an island shape for each sub-pixel P region (Step S31), forming the edge cover 23 so as to cover the edge of the cathode 25 (Step S22), forming the electron transport layer 37 over the entire surface (Step S30), performing a process including forming the red light-emitting layer 35r (Step S25), performing a process including forming the green light-emitting layer 35g (Step S26), performing a process including forming the blue light-emitting layer 35b (Step S27), performing weak development (Step S28), performing main baking (Step S29), forming the hole transport layer 33 over the entire surface (Step S24), forming the hole injection layer 31 over the entire surface (Step S23), and forming the anode 22 over the entire surface (Step S21).

[0122] In this case, the order of steps S25 to S27 can be reversed. The last step among steps S25 to S27 is process P2 shown in FIG. 7, and the remaining steps are process P1 shown in FIG. 6. For example, step S25 may be performed last. In this case, as shown in FIG. 28, the red lower resin layer is not formed below the red light-emitting layer 35r, and instead, the blue lower resin layer 34b is formed below the blue light-emitting layer 35b.

[0123] (Variation 5) In step S42, which is performed by step S25, the red light-emitting material layer 44 may be formed by applying a solution containing a light-emitting material and a positive resist to the entire surface and then volatilizing the solvent from the solution. In this case, in step S44, the positive resist contained in the portion of the red light-emitting material layer 44 other than the region where the red light-emitting layer 35r is to be formed becomes soluble in the developer. Therefore, in the subsequent step S45, the portion of the red light-emitting material layer 44 other than the region where the red light-emitting layer 35r is to be formed is more easily removed than when the red light-emitting material layer 44 is formed from a solution that does not contain the positive resist.

[0124] As a result, development can be performed using a slightly stronger developer in step S45. In this specification, a "slightly stronger developer" refers to the developer described above that (i) can dissolve the soluble portions of the resist layer above the light-emitting material layer (or light-emitting layer) from the top and sides, thereby dissolving the entire soluble portions, and (ii) can dissolve or penetrate the light-emitting material layer formed from a solution containing a positive resist, and as a result, (iii) can dissolve the soluble portions of the resist layer below the light-emitting material layer from the top and sides, thereby dissolving the entire soluble portions. Examples of slightly stronger developers include a slightly concentrated alkaline aqueous solution, a weak alkaline solution to which a surfactant is added at a low concentration, or an organic solvent to which a surfactant is added at a low concentration. A slightly concentrated alkaline aqueous solution has a pH of 11 or more but less than 12. A low concentration is, for example, less than 0.5 wt %.

[0125] By using a slightly stronger developer, damage to each layer or member can be reduced compared to when a stronger developer is used.

[0126] In addition, in the display device 2, the red light-emitting layer 35r contains a positive photosensitive resin derived from a positive resist.

[0127] Similarly, in each of step S42 performed by step S26 and step S27, the green light-emitting material layer 54 and the blue light-emitting material layer 64 may be formed by applying a solution containing a light-emitting material and a positive resist to the entire surface and volatilizing the solvent from the solution.

[0128] (Variation 6) In the above description, an example has been described in which two of the three subpixels, the red subpixel Pr, the green subpixel Pg, and the blue subpixel Pb, have a lower resin layer, but the scope of this embodiment is not limited to this, and examples ranging from examples in which only one of N light-emitting elements has a lower resin layer to examples in which only (N-1) of N light-emitting elements have lower resin layers are included in this embodiment 1, where N is an integer of 2 or greater.

[0129] The above-described Modifications 1 to 6 can be combined with each other in any combination. Furthermore, the above-described Modifications 1 to 5 and any combination thereof can be applied to the below-described Embodiment 2. Furthermore, the above-described Modifications 2 to 6 and any combination thereof can be applied to the below-described Embodiment 3. Furthermore, the above-described Modifications 1 to 6 and any combination thereof can be applied to the below-described Embodiment 4.

[0130] (Energy levels of light-emitting element layer) The band gap of the lower resin layer 34 according to this embodiment will be described in detail below with reference to FIGS.

[0131] FIG. 29 is a schematic energy level diagram showing an example of the band gaps of the hole transport layer 33, the lower resin layer 34, the light emitting layer 35, and the electron transport layer 37 of the light emitting element layer 5 shown in FIG.

[0132] 30 and 31 are schematic energy level diagrams showing examples of band gaps of the hole transport layer 33, the lower resin layer 34, the light emitting layer 35, and the electron transport layer 37 of the light emitting element layer 5 shown in FIG.

[0133] FIG. 32 is a schematic energy level diagram showing the band gaps of the hole transport layer 33, the lower resin layer 34, the light emitting layer 35, and the electron transport layer 37 of the light emitting element layer 5 shown in FIG.

[0134] 33 and 34 are schematic energy level diagrams showing the band gaps of the hole transport layer 33, the lower resin layer 34, the light emitting layer 35, and the electron transport layer 37 of the light emitting element layer 5 shown in FIG. 28, respectively.

[0135] 29 to 34 show the conduction band on the upper side and the valence band on the lower side. Hereinafter, the term "shallow" refers to the lowest unoccupied molecular orbital (LUMO) or the bottom of the conduction band, or the highest occupied molecular orbital (HOMO) or the top of the valence band being close to the vacuum energy level (i.e., located in the upper side of FIGS. 29 to 34, and the electron affinity or ionization energy is small). The term "deep" refers to the energy level being far from the vacuum energy level (i.e., located in the lower side of FIGS. 29 to 34, and the electron affinity or ionization energy is large).

[0136] 4 and 20, in a configuration in which the lower resin layer 34 is located between the hole transport layer 33 and the light-emitting layer 35, the HOMO of the lower resin layer 34 needs to be deeper than the HOMO of the hole transport layer 33, as shown in Figures 29 to 31. This is because if the HOMO of the lower resin layer 34 is equal to or shallower than the HOMO of the hole transport layer 33, holes moving from the hole transport layer 33 toward the light-emitting layer 35 will be trapped in the lower resin layer 34.

[0137] In the configurations shown in FIGS. 4 and 20 , if the HOMO of the red lower resin layer 34r is deeper than the HOMO of the hole-transport layer 33 and deeper than the upper end of the valence band of the red-light-emitting layer 35r, the red lower resin layer 34r can function as a layer that inhibits hole injection from the hole-transport layer 33 to the red-light-emitting layer 35r. As a result, excessive hole injection can be reduced. On the other hand, if the HOMO of the red lower resin layer 34r is deeper than the HOMO of the hole-transport layer 33 and shallower than the upper end of the valence band of the red-light-emitting layer 35r, the red lower resin layer 34r can function as a layer that assists hole injection from the hole-transport layer 33 to the red-light-emitting layer 35r. The same applies to the green lower resin layer 34g and the blue lower resin layer 34b.

[0138] 4, the HOMO of the lower resin layer 34 is preferably deeper than the upper end of the valence band of the blue light-emitting layer 35b, as shown in FIG. 29. This inhibits the movement of holes from the hole-transport layer 33 to the red light-emitting layer 35r and the green light-emitting layer 35g. In other words, in a configuration in which a lower resin layer is not formed between the light-emitting layer having the deepest upper end of the valence band and the hole-transport layer among the plurality of different light-emitting layers, but a lower resin layer is formed between the other light-emitting layers and the hole-transport layer, it is preferable that the HOMO of the lower resin layer is deeper than the upper end of the valence band of the light-emitting layer having the deepest upper end of the valence band among the plurality of different light-emitting layers.

[0139] In the configuration shown in Fig. 20, the HOMO of the lower resin layer 34 is preferably shallower than the upper end of the valence band of the blue light-emitting layer 35b, as shown in Figs. 30 and 31. This allows the HOMO of the hole-transport layer 33, the HOMO of the blue lower resin layer 34b, and the upper end of the valence band of the blue light-emitting layer 35b to be arranged in this order in a stepped manner. As a result, hole movement from the hole-transport layer 33 to the blue light-emitting layer 35b is promoted. In other words, in a configuration in which a lower resin layer is not formed between a light-emitting layer having the shallowest upper end of the valence band and a hole-transport layer among a plurality of different light-emitting layers, but a lower resin layer is formed between the other light-emitting layers and a hole-transport layer, it is preferable that the HOMO of the lower resin layer be shallower than the upper end of the valence band of the light-emitting layer having the deepest upper end of the valence band among a plurality of different light-emitting layers.

[0140] 26 and 28, in a configuration in which the lower resin layer 34 is located between the electron transport layer 37 and the light-emitting layer 35, the LUMO of the lower resin layer 34 needs to be shallower than the LUMO of the electron transport layer 37, as shown in Figures 32 to 34. This is because, if the LUMO of the lower resin layer 34 is equal to or deeper than the LUMO of the electron transport layer 37, electrons moving from the electron transport layer 37 toward the light-emitting layer 35 will be trapped in the lower resin layer 34.

[0141] In the configurations shown in FIGS. 26 and 28 , if the LUMO of the red lower resin layer 34r is shallower than the LUMO of the electron transport layer 37 and shallower than the lower end of the conduction band of the red light-emitting layer 35r, the red lower resin layer 34r can function as a layer that inhibits electron injection from the electron transport layer 37 to the red light-emitting layer 35r. As a result, excessive electron injection can be reduced. On the other hand, if the LUMO of the red lower resin layer 34r is shallower than the LUMO of the electron transport layer 37 and deeper than the lower end of the conduction band of the red light-emitting layer 35r, the red lower resin layer 34r can function as a layer that assists electron injection from the electron transport layer 37 to the red light-emitting layer 35r. The same applies to the green lower resin layer 34g and the blue lower resin layer 34b.

[0142] 26, it is preferable that the LUMO of the lower resin layer 34 is shallower than the lower end of the conduction band of the blue light-emitting layer 35b, as shown in FIG. 32. This inhibits electron movement from the electron transport layer 37 to the red light-emitting layer 35r and the green light-emitting layer 35g. In other words, in a configuration in which a lower resin layer is not formed between the light-emitting layer with the shallowest lower end of the conduction band among a plurality of different light-emitting layers and the electron transport layer, and a lower resin layer is formed between the other light-emitting layers and the electron transport layer, it is preferable that the LUMO of the lower resin layer is shallower than the lower end of the conduction band of the light-emitting layer with the shallowest lower end of the conduction band among a plurality of different light-emitting layers.

[0143] In the configuration shown in FIG. 28, the LUMO of the lower resin layer 34 is preferably deeper than the lower end of the conduction band of the blue light-emitting layer 35b, as shown in FIGS. 33 and 34. This allows the LUMO of the electron transport layer 37, the LUMO of the blue lower resin layer 34b, and the lower end of the conduction band of the blue light-emitting layer 35b to be arranged in this order in a stepped manner. As a result, electron transfer from the electron transport layer 37 to the blue light-emitting layer 35b is promoted. In other words, in a configuration in which a lower resin layer is not formed between the light-emitting layer with the deepest conduction band lower end among multiple different light-emitting layers and the electron transport layer, but is formed between the other light-emitting layers and the hole transport layer, it is preferable that the LUMO of the lower resin layer is deeper than the lower end of the conduction band of the light-emitting layer with the shallowest conduction band lower end among multiple different light-emitting layers.

[0144] (Action and effect) According to the method of the first embodiment, the layer containing quantum dots and the layer containing photoresist are separate, so that the layer containing quantum dots contains sufficient quantum dots and can be patterned.

[0145] According to the method of the first embodiment, the red light-emitting material layer 44 is formed on the red lower reversal resist layer 41 as shown in FIG. 8, and the unnecessary portions of the red light-emitting material layer 44 (i.e., the portions that do not become the red light-emitting layer 35r) are removed together with the soluble portions 41B of the red lower reversal resist layer 41 as shown in FIG. 9. This reduces the possibility of the light-emitting material of the red light-emitting layer 35r being mixed as residue into areas other than the area where the red light-emitting layer 35r is formed. Similarly, it reduces the possibility of the light-emitting material of the green light-emitting layer 35g being mixed as residue into areas other than the area where the green light-emitting layer 35g is formed. This reduction in mixing reduces color mixing between sub-pixels (light-emitting elements).

[0146] According to the method of the first embodiment, a red light-emitting material layer 44 is formed over the entire surface between the lower red reversal resist layer 41 and the upper red positive resist layer 45. The red light-emitting layer 35r is then formed by patterning the red light-emitting material 44 using photoresist technology. Therefore, even when the red light-emitting material layer 44 is formed by applying a solution containing the red light-emitting material over the entire surface and volatilizing the solvent from the solution, the red light-emitting layer 35r does not suffer from unevenness due to the coffee ring effect or surface tension. As a result, the red light-emitting layer 35r can be formed flat and uniformly. The same applies to the green light-emitting layer 35g and the blue light-emitting layer 35b.

[0147] According to the method of the first embodiment, the blue light-emitting material layer 64 is formed on the soluble portions 45C, 55C of the red upper positive resist layer 45 and the green upper positive resist layer 55, as shown in Fig. 16. After unnecessary portions of the blue light-emitting material layer 64 (i.e., portions that will not become the blue light-emitting layer 35b) are removed as shown in Fig. 17, the soluble portions 45C, 55C of the red upper positive resist layer 45 and the green upper positive resist layer 55 are removed as shown in Fig. 19. This makes it possible to reduce the amount of the light-emitting material of the blue light-emitting layer 35b that gets mixed as residue into the regions of the red sub-pixel Pr and the green sub-pixel Pg.

[0148] According to the method of the first embodiment, following the formation of the red light-emitting layer 35r, the insoluble portions 41A of the red lower reversal resist layer 41 are converted into developer-insoluble portions 41D by exposure and reversal baking. The developer-insoluble portions 41D remain insoluble in the developer even after further exposure or baking. This reduces the likelihood of the red light-emitting layer 35r being removed by the developer in subsequent steps. Similarly, this reduces the likelihood of the green light-emitting layer 35g being removed by the developer. This makes it easier to control the thicknesses of the red light-emitting layer 35r, green light-emitting layer 35g, and blue light-emitting layer 35b.

[0149] According to the method of the first embodiment, the soluble portion 45C of the red upper positive resist layer 45 is removed as shown in FIG. 19 . Therefore, in the display device 2, the red upper positive resist layer 45 or a resin layer derived from the red upper positive resist layer 45 is not present on the red light-emitting layer 35r. This improves the luminous efficiency of the red sub-pixel Pr. Similarly, the luminous efficiency of the green sub-pixel Pg and the blue sub-pixel Pb can be improved.

[0150] Furthermore, because the red upper positive resist layer 45 is removed, increasing the thickness of the red upper positive resist layer 45 does not affect the luminous efficiency of the red sub-pixel Pr. Therefore, the red upper positive resist layer 45 can be made sufficiently thick so that the red light-emitting layer 35r is not damaged or thinned during the period from when the red upper positive resist layer 45 is formed to when the soluble portion 45C of the red upper positive resist layer 45 is removed. Similarly, the green upper positive resist layer 55 and the blue upper positive resist layer 65 can be made sufficiently thick. Therefore, the thicknesses of the red light-emitting layer 35r, the green light-emitting layer 35g, and the blue light-emitting layer 35b can be easily controlled.

[0151] According to the method of the first embodiment, the red light-emitting layer 35r and the green light-emitting layer 35g are adhered to the substrate via the insoluble portions 41D and 51D of the red lower reversal resist layer 41 and the green lower reversal resist layer 51, respectively, during the development process using a strong developer. This reduces the likelihood of the red light-emitting layer 35r and the green light-emitting layer 35g peeling off from the substrate during the manufacturing process.

[0152] According to the method of the first embodiment, the main baking for thermally curing the red lower reversal resist layer 41 and the green lower reversal resist layer 51 can be performed in one step, as shown in Fig. 5. Alternatively, the main baking does not have to be performed. This reduces chemical or mechanical damage caused by heating or temperature changes due to the main baking.

[0153] [Embodiment 2] Other embodiments of the present invention will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0154] FIG. 35 is a schematic cross-sectional view showing an example of the configuration of the light emitting element layer 5 in the display device 2 according to the second embodiment.

[0155] An example of the light-emitting element layer 5 according to the second embodiment differs from the example of the light-emitting element layer 5 according to the first embodiment in that it includes a blue lower resin layer 34b between the hole transport layer 33 and the blue light-emitting layer 35b. In this case, the red lower resin layer 34r, the green lower resin layer 34g, and the blue lower resin layer 34b are collectively referred to as the "lower resin layer 34." In other words, the light-emitting element layer 5 according to the second embodiment differs from the light-emitting element layer 5 according to the first embodiment in that it includes lower resin layers 34 below all of the light-emitting layers 35.

[0156] (Manufacturing method) The configuration according to the second embodiment can be realized by performing the process P1 shown in FIG. 6 in the process of forming all the light-emitting layers.

[0157] Hereinafter, with reference to FIGS. 36 to 40, an example of the step of forming an example of the light emitting element layer 5 shown in FIG. 35 on a substrate (step S4, light emitting element forming step) will be described in detail.

[0158] 36 to 40 are each a schematic cross-sectional view showing an example of the step (step S4) of forming an example of the light-emitting element layer 5 shown in FIG. 35 on a substrate.

[0159] First, similarly to the above-described first embodiment, the flow shown in FIG. 5 is performed up to the step of performing the process including the formation of the green light-emitting layer 35g (step S26).

[0160] <Processing including formation of blue light-emitting layer> 6 and 36, a process including the formation of the blue light-emitting layer 35b is performed (step S27). In step S27, a process P1 shown in FIG.

[0161] 6 and 36, a reversal resist material is first applied to the entire surface of the hole transport layer 33 and the soluble portions 45C, 55C of the red upper positive resist layer 45 and the green upper positive resist layer 55, thereby forming a blue lower reversal resist layer 61 (third reversal resist) (step S41, part of the third light-emitting layer formation process). Subsequently, a blue light-emitting material layer 64 and a blue upper positive resist layer 65 are formed (steps S42 and S43, part of the third light-emitting layer formation process). In this way, a laminate (third laminate) is formed that includes the blue lower reversal resist layer 61, the blue light-emitting material layer 64, and the blue upper positive resist layer 65, in this order from the substrate side.

[0162] Next, the laminate is subjected to a first exposure to ultraviolet light using a first blue mask 67 (step S44, part of the third light-emitting layer forming step). As a result, the portions of the blue lower reversal resist layer 61 and the blue upper positive resist layer 65 that overlap the blue light-emitting layer 35b do not undergo a photochemical reaction and remain as insoluble portions 61A and 65A that are insoluble in the developer. On the other hand, the other portions undergo a photochemical reaction to become soluble portions 61B and 65B that are soluble in the developer.

[0163] 6 and 37, development is performed using a strong developer (step S45, part of the third light-emitting layer formation process). As a result, the soluble portions 61B, 65B of the blue lower reversal resist layer 61 and the blue upper positive resist layer 65, and the portion of the blue light-emitting material layer 64 between them, are removed. Meanwhile, the insoluble portions 61A, 65A of the blue lower reversal resist layer 61 and the blue upper positive resist layer 65, and the portion of the blue light-emitting material layer 64 between them, remain. This remaining portion of the blue light-emitting material layer 64 becomes the blue light-emitting layer 35b.

[0164] In this way, the above-described laminate is patterned using photolithography and re-insolubilization of the reversal resist, resulting in the formation of the blue light-emitting layer 35b.

[0165] 6 and 38, the patterned laminate is subjected to a second exposure to ultraviolet light using a second blue mask 68 (step S46, part of the third re-insolubilization step). As a result, the insoluble portions 61A and 56A of the blue lower reversal resist layer 61 and the blue upper positive resist layer 65 are photochemically reacted to become soluble portions 61C and 65C that are soluble in a developer.

[0166] 6 and 39, the patterned laminate is subjected to reversal baking (step S47, part of the third reinsolubilization step). As a result, the soluble portions 61C of the blue lower reversal resist layer 61 are decarboxylated to become reinsoluble portions 61D that are insoluble in the developer. Meanwhile, the soluble portions 65C of the blue upper positive resist layer 65 remain as soluble portions 65C.

[0167] As described above, in step S27, the blue light-emitting layer 35b is formed in a state where it is sandwiched and protected between the insoluble portion 61D of the lower blue reversal resist layer 61 and the soluble portion 65C of the upper blue positive resist layer 65.

[0168] Thereafter, a weak development step (step S28 in FIG. 5, positive resist removal step) and subsequent steps are carried out in the same manner as in the above-described embodiment 1. In this way, the light emitting element layer 5 shown in FIG. 30 is formed.

[0169] (Action and effect) According to the method of the second embodiment, the blue light-emitting material layer 64 is formed on the blue lower reversal resist layer 61 as shown in FIG. 36, and the unnecessary portion of the blue light-emitting material layer 64 (i.e., the portion that does not become the blue light-emitting layer 35b) is removed together with the soluble portion 61B of the blue lower reversal resist layer 61 as shown in FIG. 37.

[0170] Therefore, the method according to the present embodiment 2 can reduce the amount of the light-emitting material of the blue light-emitting layer 35b that is mixed as residue in areas other than the formation area of the blue light-emitting layer 35b, compared to the method according to the above-described embodiment 1. Specifically, the method can reduce the amount of the light-emitting material of the blue light-emitting layer 35b that is mixed as residue on the side surfaces of the red light-emitting layer 35r and the green light-emitting layer 35g, the side surfaces of the red lower resin layer 34r and the green lower resin layer 34g, and the upper surface of the hole-transport layer 33.

[0171] According to the method of the second embodiment, in the step of developing using a strong developer, the blue light-emitting layer 35b adheres to the substrate via the insoluble portion 61D of the blue lower reversal resist layer 61. This further reduces peeling of the blue light-emitting layer 35b from the substrate during the manufacturing process.

[0172] [Embodiment 3] Other embodiments of the present invention will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0173] FIG. 41 is a schematic cross-sectional view showing an example of the configuration of the light emitting element layer 5 in the display device 2 according to the third embodiment.

[0174] An example of the light-emitting element layer 5 according to this embodiment 3 differs from the example of the light-emitting element layer 5 according to the above-described embodiment 1 in that it includes a lower resin layer 34 below all of the light-emitting layers 35 and a red upper resin layer 36r between the red light-emitting layer 35r and the electron transport layer 37.

[0175] (Manufacturing method 1) Hereinafter, with reference to FIGS. 42 to 44, an example of a step of forming an example of the light emitting element layer 5 shown in FIG. 41 on a substrate (step S4, light emitting element forming step) will be described in detail.

[0176] The configuration according to the second embodiment can be realized by performing step S25 last among steps S25 to S27 shown in Fig. 4, and having step S25 execute process P3 shown in Fig. 42. Note that steps S26 and S27 execute process P1 shown in Fig. 6.

[0177] Fig. 42 is a schematic flow diagram showing a process (process P3) performed to form the light emitting element layer 5 shown in Fig. 41. Fig. 43 is a schematic cross-sectional view showing process P3 shown in Fig. 42. Fig. 44 is a schematic cross-sectional view showing process P3 shown in Fig. 42 and process P4 shown in Fig. 45 described later.

[0178] First, as in the modified example of the first embodiment described above, the process is carried out up to the step of performing a process including forming the blue light-emitting layer 35b (step S27, first light-emitting layer forming step) and the step of performing a process including forming the green light-emitting layer 35g (step S26, second light-emitting layer forming step).

[0179] Next, a process including the formation of a red light-emitting layer 35r (step S25) is performed. Here, as shown in FIGS. 42 and 43, a positive resist material is applied to the entire surface of the hole transport layer 33 to form a red lower positive resist layer 42 (step S48, part of the third light-emitting layer forming step). Subsequently, a red light-emitting material layer 44 and a red upper positive resist layer 45 are formed over the entire surface (steps S42 and S43, part of the third light-emitting layer forming step).

[0180] In this way, a laminate (third laminate) is formed, which includes the red light emitting material layer 44 (third light emitting material layer) laminated between the red lower positive resist layer 42 and the red upper positive resist layer 45 (two positive resist layers). At this time, each of the red lower positive resist layer 42 and the red upper positive resist layer 45 is insoluble in a developer.

[0181] Next, the laminate is exposed to ultraviolet light using a red first mask 47 (step S49, part of the third light-emitting layer forming process). This process P3 differs from processes P1 (see FIG. 6) and P2 (see FIG. 7) in that exposure is performed only once.

[0182] As a result, the portions of the red lower positive resist layer 42 and the red upper positive resist layer 45 that overlap the red light-emitting layer 35r do not undergo a photochemical reaction and remain as insoluble portions 42A and 45A that are insoluble in the developer, whereas the other portions undergo a photochemical reaction to become soluble portions 42B and 45B that are soluble in the developer.

[0183] Next, as shown in Figures 42 and 44, strong development is performed (step S45, part of the third light-emitting layer forming step). As a result, the soluble portions 42B, 45B of the red lower positive resist layer 42 and the red upper positive resist layer 45, and the portion of the red light-emitting material layer 44 therebetween, are removed. On the other hand, the insoluble portions 42A, 45A of the red lower positive resist layer 42 and the red upper positive resist layer 45, and the portion of the red light-emitting material layer 44 therebetween, remain. This remaining portion of the red light-emitting material layer 44 becomes the red light-emitting layer 35r.

[0184] As described above, in step S25, the red light-emitting layer 35r is formed in a state where it is sandwiched between the insoluble portions 42A and 45A of the red lower positive resist layer 42 and the red upper positive resist layer 45 and is protected.

[0185] Thereafter, similarly to the first embodiment, a weak development step (step S28 in FIG. 5) and subsequent steps are performed. The insoluble portions 42A, 45A of the red lower positive resist layer 42 and the red upper positive resist layer 45 become the red lower resin layer 34r and the red upper resin layer 36r, respectively, either as they are or after main baking. In this manner, the light-emitting element layer 5 shown in FIG. 41 is formed.

[0186] This method also makes it possible to reduce the amount of the light-emitting material of each light-emitting layer 35 that is mixed as residue in areas other than the area where the light-emitting layer 35 is formed.

[0187] (Manufacturing method 2) Hereinafter, another example of the step of forming the example of the light emitting element layer 5 shown in FIG. 41 on a substrate (step S4, light emitting element forming step) will be described in detail with reference to FIGS.

[0188] The configuration according to the second embodiment can be realized by performing step S25 of steps S25 to S27 shown in Fig. 5 by executing process P4 shown in Fig. 45. Here, steps S26 and S27 execute process P1 shown in Fig. 6. Furthermore, since process P4 uses a negative resist material, the order in which steps S25 to S27 (see Fig. 5) are performed can be interchanged.

[0189] Fig. 45 is a schematic flow diagram showing another process (process P4) performed to form the light emitting element layer 5 shown in Fig. 41. Fig. 46 is a schematic cross-sectional view showing process P4 shown in Fig. 45.

[0190] First, as in the modified example of the first embodiment described above, the process is carried out up to the step of performing a process including forming the blue light-emitting layer 35b (step S27, first light-emitting layer forming step) and the step of performing a process including forming the green light-emitting layer 35g (step S26, second light-emitting layer forming step).

[0191] Next, a process including the formation of the red light-emitting layer 35r is performed (step S25). Here, as shown in FIGS. 45 and 46, a negative resist material is applied to the entire surface of the hole transport layer 33 to form a red lower negative resist layer 43 (step S450, part of the third light-emitting layer forming process). Subsequently, a red light-emitting material layer 44 is formed to form a red upper negative resist layer 46 (step S51, part of the third light-emitting layer forming process). In this specification, the term "negative resist material" refers to a material including a negative photoresist.

[0192] In this way, a laminate (third laminate) is formed, which includes the red light emitting material layer 44 (third light emitting material layer) laminated between the red lower negative resist layer 43 and the red upper negative resist layer 46 (two negative resist layers). At this time, each of the red lower negative resist layer 43 and the red upper negative resist layer 46 is soluble in a developer.

[0193] Next, the laminate is exposed to ultraviolet light using a red second mask 48 (step S52, part of the third light-emitting layer forming step). Process P4 differs from processes P1 (see FIG. 6) and P2 (see FIG. 7) in that exposure is performed only once.

[0194] As a result, the portions of the red lower negative resist layer 43 and the red upper negative resist layer 46 that overlap the red light-emitting layer 35r undergo a photochemical reaction to become insoluble portions 43A and 46A that are insoluble in the developer, whereas the other portions do not undergo a photochemical reaction and remain soluble portions 43B and 46B that are soluble in the developer.

[0195] Next, as shown in Figures 45 and 44, strong development is performed (step S45, part of the third light-emitting layer forming step). As a result, the soluble portions 43B, 46B of the red lower negative resist layer 43 and the red upper negative resist layer 46, and the portion of the red light-emitting material layer 44 therebetween, are removed. On the other hand, the insoluble portions 43A, 46A of the red lower negative resist layer 43 and the red upper negative resist layer 46, and the portion of the red light-emitting material layer 44 therebetween, remain. This remaining portion of the red light-emitting material layer 44 becomes the red light-emitting layer 35r.

[0196] As described above, in step S25, the red light-emitting layer 35r is formed in a state where it is sandwiched between the insoluble portions 43A, 46A of the red lower negative resist layer 43 and the red upper negative resist layer 46 and protected.

[0197] Thereafter, similarly to the first embodiment, a weak development step (step S28 in FIG. 5) and subsequent steps are performed. The insoluble portions 43A, 46A of the red lower negative resist layer 43 and the red upper negative resist layer 46 become the red lower resin layer 34r and the red upper resin layer 36r, respectively, either as they are or after main baking. In this manner, the light-emitting element layer 5 shown in FIG. 41 is formed.

[0198] This method also makes it possible to reduce the amount of the light-emitting material of each light-emitting layer 35 that is mixed as residue in areas other than the area where the light-emitting layer 35 is formed.

[0199] (Action and effect) The method according to the third embodiment can further reduce the amount of the light-emitting material of each light-emitting layer that gets mixed as residue into the formation region of another light-emitting layer, compared to the method according to the first embodiment described above.

[0200] [Embodiment 4] Other embodiments of the present invention will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0201] FIG. 47 is a schematic cross-sectional view showing an example of the configuration of the light emitting element layer 5 in the display device 2 according to the fourth embodiment.

[0202] An example of the light-emitting element layer 5 according to this embodiment 4 differs from the example of the light-emitting element layer 5 according to the above-described embodiment 1 in that, instead of a hole transport layer 33 formed over the entire surface, it includes a red hole transport layer 33r, a green hole transport layer 33g, and a blue hole transport layer 33b, each of which is patterned.

[0203] (Manufacturing method) Hereinafter, with reference to FIGS. 48 to 53, an example of a step of forming an example of the light emitting element layer 5 shown in FIG. 47 on a substrate (step S4, light emitting element forming step) will be described in detail.

[0204] 48 to 53 are cross-sectional views showing an example of a step (step S4, light-emitting element forming step) of forming an example of the light-emitting element layer 5 shown in FIG. 47 on a substrate.

[0205] First, the steps up to the step of forming the hole injection layer (step S23) in the flow shown in FIG. 46 are carried out in the same manner as in the first embodiment.

[0206] <Processing Including Formation of Red Light-Emitting Layer and Red Hole-Transporting Layer> Next, as shown in Fig. 48, a process including the formation of a red light-emitting layer 35r and a red hole transport layer 33r is performed (step S60). In step S60, process P5 shown in Fig. 49 is executed. Process P5 shown in Fig. 49 differs from process P1 shown in Fig. 6 in that it includes a step of forming a hole transport material layer (step S63).

[0207] 49 and 51, first, a red lower reversal resist layer 41 is formed over the entire surface (step S41). Next, a red hole transport material layer 71 (carrier transport material layer) is formed over the entire surface by vapor-depositing a hole transport material (material for the carrier transport layer) over the entire surface on the red lower reversal resist layer 41, or by applying a material containing a hole transport material over the entire surface (step S63). Next, a red light-emitting material layer 44 and a red upper positive resist layer 45 are formed over the entire surface (steps S42 and S43).

[0208] In this way, a laminate (first laminate) including the red lower reversal resist layer 41, the red hole transport material layer 71, the red light emitting material layer 44, and the red upper positive resist layer 45 in this order from the substrate side is formed.

[0209] 49, steps S44 and S45 are performed in the same manner as in the above-described embodiment 1. As a result, the red hole transport material layer 71 is patterned together with the red light-emitting material layer 44, and the remaining portion of the red hole transport material layer 71 becomes the red hole transport layer 33r.

[0210] Subsequently, steps S46 and S47 are performed in the same manner as in the above-described embodiment 1. As a result, the red light-emitting layer 35r and the red hole transport layer 33r are formed in a state where they are sandwiched and protected between the re-insoluble portion 41D of the red lower reversal resist layer 41 and the soluble portion 45C of the red upper positive resist layer 45.

[0211] <Processing Including Formation of Green Light-Emitting Layer and Green Hole-Transporting Layer> Next, as shown in Fig. 48, a process including the formation of the green light-emitting layer 35g and the green hole transport layer 33g is performed (step S61). In step S61, a process P5 shown in Fig. 49 is executed.

[0212] 49 and 52, first, a green lower reversal resist layer 51 is formed over the entire surface (step S41). Subsequently, a green hole transport material layer 72 is formed over the entire surface by vapor-depositing a hole transport material on the green lower reversal resist layer 51 or by applying a material containing a hole transport material over the entire surface (step S63). Subsequently, a green light-emitting material layer 54 and a green upper positive resist layer 55 are formed over the entire surface (steps S42 and S43).

[0213] In this way, a laminate is formed which includes the green lower reversal resist layer 51, the green hole transport material layer 72, the green light emitting material layer 54, and the green upper positive resist layer 55 in this order from the substrate side.

[0214] 49, steps S44 and S45 are performed in the same manner as in the above-described embodiment 1. As a result, the green hole transport material layer 72 is patterned together with the green light-emitting material layer 54, and the remaining portion of the green hole transport material layer 72 becomes the green hole transport layer 33g.

[0215] Subsequently, steps S46 and S47 are performed in the same manner as in the above-described embodiment 1. As a result, the green light-emitting layer 35g and the green hole-transporting layer 33g are formed in a state where they are sandwiched and protected between the insoluble portion 51D of the green lower reversal resist layer 51 and the soluble portion 55C of the green upper positive resist layer 55.

[0216] <Processing Including Formation of Blue Light-Emitting Layer and Blue Hole-Transporting Layer> Next, as shown in Fig. 48, a process including forming a blue light-emitting layer 35b and a blue hole transport layer 33b is performed (step S62). In step S62, a process P6 shown in Fig. 50 is executed. A process P3 shown in Fig. 50 differs from the process P2 shown in Fig. 7 in that it includes a step of forming a hole transport material layer (step S62).

[0217] 50 and 53, first, a hole transport material is vapor-deposited or a material containing a hole transport material is applied to the entire surface of the hole injection layer 31 and the soluble portions 45C, 55C of the red upper positive resist layer 45 and the green upper positive resist layer 55, thereby forming a blue hole transport material layer 73 (step S63). Subsequently, a blue light-emitting material layer 64 and a blue upper positive resist layer 65 are formed (steps S42, S43).

[0218] In this way, a laminate is formed which includes the blue hole transport material layer 73, the blue light emitting material layer 64, and the blue upper positive resist layer 65 in this order from the substrate side.

[0219] 50, steps S44 and S45 are performed in the same manner as in the above-described embodiment 1. As a result, the blue hole transport material layer 73 is patterned together with the blue light-emitting material layer 64, and the remaining portion of the blue hole transport material layer 73 becomes the blue hole transport layer 33b.

[0220] Next, step S46 is performed in the same manner as in the above-described embodiment 1. As a result, the blue light-emitting layer 35b and the blue hole transport layer 33b are formed in a state in which they are covered and protected by the soluble portion 65C of the blue upper positive resist layer 65.

[0221] Thereafter, the step of weak development (Step S28 in FIG. 5) and subsequent steps are carried out in the same manner as in the above-described Embodiment 1. In this way, the light emitting element layer 5 shown in FIG. 47 is formed.

[0222] (Action and effect) According to the method of the fourth embodiment, it is possible to pattern not only the red light-emitting layer 35r but also the red hole transport layer 33r corresponding to the red light-emitting layer 35r. Therefore, it is possible to form a red hole transport layer 33r suitable for the red light-emitting layer. Furthermore, it is possible to reduce the inclusion of the hole transport material of the red hole transport layer 33r as residue in areas other than the formation area of the red hole transport layer 33r. The same applies to the green hole transport layer 33g and the blue hole transport layer 33b.

[0223] The scope of the fourth embodiment is not limited to this, and includes various modifications, such as an example in which a layer other than the hole transport layer is patterned together with the light-emitting layer, an example in which a layer such as the hole transport layer is patterned together with the light-emitting layer in the above-mentioned second and third embodiments, and an example in which a layer such as the hole transport layer is patterned together with the light-emitting layer for only one or some of the multiple light-emitting layers.

[0224] 〔summary〕 A method for manufacturing a light-emitting device according to aspect 1 of the present invention is a method for manufacturing a light-emitting device comprising a light-emitting element forming step of forming a first light-emitting element including a first light-emitting layer on a substrate, wherein the light-emitting element forming step comprises a first light-emitting layer forming step of forming the first light-emitting layer by patterning a first laminate obtained by laminating a first reversal resist, a first light-emitting material layer including a light-emitting material of the first light-emitting layer, and a first positive resist in this order from the substrate side.

[0225] A method for manufacturing a light-emitting device according to aspect 2 of the present invention may be a method according to aspect 1 above, wherein the first light-emitting layer formation process comprises a stack formation process for depositing each layer of the first stack, a stack exposure process for exposing a portion of the first stack following the stack formation process, and a development process for removing the exposed first reversal resist, thereby removing the exposed portion of the first stack following the stack exposure process.

[0226] A method for manufacturing a light-emitting device according to aspect 3 of the present invention may be the method according to aspect 1 or 2 above, wherein the light-emitting element forming step further comprises, following the first light-emitting layer forming step, a first re-insolubilization step of solubilizing and insolubilizing the first reversal resist overlapping the first light-emitting layer.

[0227] A method for manufacturing a light-emitting device according to aspect 4 of the present invention may be a method according to aspect 3 above, wherein the first re-insolubilization step comprises a reversal resist exposure step of exposing the first reversal resist to light, and a heating step of heating the exposed first reversal resist following the reversal resist exposure step.

[0228] A method for manufacturing a light-emitting device according to a fifth aspect of the present invention may be the method according to the third or fourth aspect, wherein the light-emitting element forming step further comprises forming a second light-emitting element on the substrate, the second light-emitting element including a second light-emitting layer having a material different from that of the first light-emitting layer, and the light-emitting element forming step further comprises, after the first re-insolubilization step, patterning a second laminate obtained by laminating a second reversal resist, a second light-emitting material layer including a light-emitting material of the second light-emitting layer, and a second positive resist in this order from the substrate side, to form the second light-emitting layer.

[0229] A method for manufacturing a light-emitting device according to aspect 6 of the present invention may be the method according to aspect 5 above, wherein the light-emitting element forming step further includes a second re-insolubilization step of solubilizing and insolubilizing the second reversal resist overlapping the second light-emitting layer following the second light-emitting layer forming step.

[0230] A method for manufacturing a light-emitting device according to aspect 7 of the present invention may be the method according to aspect 6 above, wherein the light-emitting element formation process further includes a positive resist removal process, after the second re-insolubilization process, of removing the first positive resist and the second positive resist from the upper layers of the first light-emitting layer and the second light-emitting layer, respectively.

[0231] A method for manufacturing a light-emitting device according to an eighth aspect of the present invention may be the method according to the sixth or seventh aspect, wherein the light-emitting element forming step further comprises forming a third light-emitting element on the substrate, the third light-emitting element including a third light-emitting layer having a material different from both the first light-emitting layer and the second light-emitting layer, and the light-emitting element forming step further comprises, after the second re-insolubilization step, patterning a third stack obtained by stacking a third light-emitting material layer including a light-emitting material of the third light-emitting layer and a third positive resist in this order from the substrate side to form the third light-emitting layer.

[0232] A method for manufacturing a light-emitting device according to a ninth aspect of the present invention may be the method according to the sixth aspect, wherein the light-emitting element forming step further forms a third light-emitting element including a third light-emitting layer having a material different from both the first light-emitting layer and the second light-emitting layer, and the light-emitting element forming step further includes a third light-emitting layer forming step, after the second re-insolubilization step, of forming the third light-emitting layer by patterning a third stack obtained by stacking a third reversal resist, a third light-emitting material layer including a light-emitting material of the third light-emitting layer, and a third positive resist in this order from the substrate side.

[0233] A method for manufacturing a light-emitting device according to aspect 10 of the present invention may be the method according to aspect 9 above, wherein the light-emitting element forming step further includes a third re-insolubilization step of solubilizing and insolubilizing the third reversal resist overlapping the third light-emitting layer following the third light-emitting layer forming step.

[0234] A method for manufacturing a light-emitting device according to aspect 11 of the present invention may be the method according to aspect 10 above, wherein the light-emitting element formation process further includes a positive resist removal process, after the third re-insolubilization process, of removing the first positive resist, the second positive resist, and the third positive resist from the upper layers of the first light-emitting layer, the second light-emitting layer, and the third light-emitting layer, respectively.

[0235] A method for manufacturing a light-emitting device according to aspect 12 of the present invention may be the method according to aspect 6 or 7 above, wherein the light-emitting element forming step further comprises forming a third light-emitting element on the substrate, the third light-emitting layer having a material different from both the first light-emitting layer and the second light-emitting layer, and the light-emitting element forming step further comprises, after the second re-insolubilization step, a third light-emitting layer forming step of forming the third light-emitting layer by patterning a third stack including a third light-emitting material layer containing the light-emitting material of the third light-emitting layer stacked between two layers of a third positive resist.

[0236] A method for manufacturing a light-emitting device according to aspect 13 of the present invention may be the method according to aspect 6 or 7 above, wherein in the light-emitting element forming step, a third light-emitting element including a third light-emitting layer having a material different from both the first light-emitting layer and the second light-emitting layer is formed on the substrate, and the light-emitting element forming step may further include a third light-emitting layer forming step of forming the third light-emitting layer by patterning a third stack including a third light-emitting material layer including the light-emitting material of the third light-emitting layer stacked between two layers of negative resist.

[0237] A method for manufacturing a light-emitting device according to aspect 14 of the present invention may be a method according to any one of aspects 1 to 13 above, wherein the first light-emitting element further comprises a lower electrode between the substrate and the first light-emitting layer, and a carrier transport layer between the lower electrode and the first light-emitting layer, and the first laminate further comprises a carrier transport material layer containing a material of the carrier transport layer laminated between the first reversal resist and the first light-emitting material layer, and the first light-emitting layer forming step further comprises patterning the carrier transport material layer to form the carrier transport layer.

[0238] A light-emitting device according to a fifteenth aspect of the present invention comprises a first light-emitting element on the substrate, the first light-emitting element comprising a substrate, a first lower electrode, a first light-emitting layer, and a first upper electrode, stacked in this order from the substrate side; and the first light-emitting element further comprising a photosensitive resin layer between the first lower electrode and the first light-emitting layer, the photosensitive resin layer comprising at least one compound selected from the group consisting of compounds represented by the following structural formulas (1) to (3).

[0239] [ka] Here, R1 and R2 each independently represent a substituted or unsubstituted hydrocarbon group.

[0240] A light-emitting device according to a sixteenth aspect of the present invention may have the configuration according to the fifteenth aspect, wherein the photosensitive resin layer further contains at least one selected from the group consisting of aromatic hydrocarbons having a hydroxyl group, 1-hydroxyethyl-2-alkylimidazoline, and shellac.

[0241] A light-emitting device according to a seventeenth aspect of the present invention has the configuration according to the fifteenth or sixteenth aspect, and may be configured such that the first light-emitting layer contains quantum dots as the light-emitting material.

[0242] A light-emitting device according to an eighteenth aspect of the present invention has the configuration according to any one of the fifteenth to seventeenth aspects, and may be configured such that the first light-emitting layer contains a positive photosensitive resin.

[0243] A light-emitting device according to aspect 19 of the present invention may have a configuration according to any one of aspects 15 to 18 above, wherein the first lower electrode is a cathode, the first upper electrode is an anode, and the first light-emitting element further includes an electron transport layer between the first lower electrode and the photosensitive resin layer, and the electron affinity of the photosensitive resin layer is smaller than the electron affinity of the electron transport layer and smaller than the electron affinity of the first light-emitting layer.

[0244] A light-emitting device according to aspect 20 of the present invention may have a configuration according to any one of aspects 15 to 18 above, wherein the first lower electrode is a cathode, the first upper electrode is an anode, and the first light-emitting element further includes an electron transport layer between the first lower electrode and the photosensitive resin layer, and the electron affinity of the photosensitive resin layer is smaller than the electron affinity of the electron transport layer and larger than the electron affinity of the first light-emitting layer.

[0245] A light-emitting device according to aspect 21 of the present invention may have a configuration according to any one of aspects 15 to 18 above, wherein the first lower-layer electrode is an anode, the first upper-layer electrode is a cathode, and the first light-emitting element further includes a hole transport layer between the first lower-layer electrode and the photosensitive resin layer, and the ionization energy of the photosensitive resin layer is greater than the ionization energy of the hole transport layer and greater than the ionization energy of the first light-emitting layer.

[0246] A light-emitting device according to aspect 22 of the present invention may have a configuration according to any one of aspects 15 to 18 above, wherein the first lower-layer electrode is an anode, the first upper-layer electrode is a cathode, and the first light-emitting element further includes a hole transport layer between the first lower-layer electrode and the photosensitive resin layer, and the ionization energy of the photosensitive resin layer is greater than the ionization energy of the hole transport layer and less than the ionization energy of the first light-emitting layer.

[0247] A light-emitting device according to a twenty-third aspect of the present invention has the configuration according to any one of the fifteenth to twenty-second aspects, and may be configured such that only the first light-emitting element includes the photosensitive resin layer.

[0248] A light-emitting device according to aspect 24 of the present invention may have a configuration according to any one of aspects 15 to 22 above, and further include a second light-emitting element on the substrate, the second light-emitting element including a second lower-layer electrode, a second light-emitting layer having a material different from that of the first light-emitting layer, and a second upper-layer electrode, stacked in this order from the substrate side, and the second light-emitting element may further include the photosensitive resin layer between the second lower-layer electrode and the second light-emitting layer.

[0249] A light-emitting device according to aspect 25 of the present invention may have the configuration according to aspect 24 above, further comprising a third light-emitting element on the substrate, the third light-emitting element including a third lower-layer electrode, a third light-emitting layer having a material different from both the first light-emitting layer and the second light-emitting layer, and a third upper-layer electrode, stacked in this order from the substrate side.

[0250] A light-emitting device according to aspect 26 of the present invention may have the configuration according to aspect 24 above, further comprising a third light-emitting element on the substrate, which includes a third lower-layer electrode, a third light-emitting layer having a material different from both the first light-emitting layer and the second light-emitting layer, and a third upper-layer electrode, stacked in this order from the substrate side, and wherein only the first light-emitting element and the second light-emitting element have the photosensitive resin layer.

[0251] A light-emitting device according to aspect 27 of the present invention may have the configuration according to aspect 25 or 26 above, wherein the first light-emitting element is a red light-emitting element including a red light-emitting layer as the first light-emitting layer, the second light-emitting element is a green light-emitting element including a green light-emitting layer as the second light-emitting layer, and the third light-emitting element is a blue light-emitting element including a blue light-emitting layer as the third light-emitting layer.

[0252] A light-emitting device according to aspect 28 of the present invention may have the configuration according to aspect 27 above, comprising a display area having a plurality of pixels and a frame area surrounding the display area, each of the plurality of pixels comprising the red light-emitting element, the green light-emitting element, and the blue light-emitting element, and the substrate comprising a thin-film transistor layer that drives the red light-emitting element, the green light-emitting element, and the blue light-emitting element, respectively.

[0253] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment. [Explanation of symbols]

[0254] 2. Display devices (light-emitting devices) 10 Lower film (substrate) 22 anode (lower layer electrode, first lower layer electrode, second lower layer electrode, third lower layer electrode, upper layer electrode, first upper layer electrode) 25 cathode (upper layer electrode, first upper layer electrode, second upper layer electrode, third upper layer electrode, lower layer electrode, first lower layer electrode) 33 Hole transport layer (carrier transport layer) 33r Red hole transport layer (carrier transport layer) 33g Green hole transport layer (carrier transport layer) 33b Blue hole transport layer (carrier transport layer) 34r Red lower resin layer (photosensitive resin layer) 34g Green lower resin layer (photosensitive resin layer) 34b Blue lower resin layer (photosensitive resin layer) 35r Red light-emitting layer (first light-emitting layer, third light-emitting layer) 35g Green light-emitting layer (second light-emitting layer) 35b Blue light-emitting layer (third light-emitting layer, first light-emitting layer) 37 Electron transport layer (carrier transport layer) 41 Red lower reversal resist layer (1st reversal resist, 3rd reversal resist) 42 Red lower positive resist layer (one layer of the third positive resist of the two layers) 43 Red lower negative resist layer (one layer of two negative resist layers) 44 Red light-emitting material layer (first light-emitting material layer, third light-emitting material) 45 Red upper positive resist layer (first positive resist, another layer of the second positive resist of the two layers) 46 Red upper negative resist layer (another layer of the two-layer negative resist) 51 Green lower reversal resist layer (second reversal resist) 54 Green light-emitting material layer (second light-emitting material layer) 55 Green upper positive resist layer (second positive resist) 61 Blue lower reversal resist layer (third reversal resist, first reversal resist) 64 Blue light-emitting material layer (third light-emitting material layer, first light-emitting material layer) 65 Blue upper positive resist layer (third positive resist, first positive resist) 70 Mother glass (substrate) 71 Red hole transport material layer (carrier transport material layer) 72 Green hole transport material layer (carrier transport material layer) 73 Blue hole transport material layer (carrier transport material layer) Pr red sub-pixel (first light-emitting element, red light-emitting element) Pg Green sub-pixel (second light-emitting element, green light-emitting element) Pb Blue sub-pixel (third light-emitting element, blue light-emitting element)

Claims

1. A substrate; a first light-emitting element on the substrate, the first light-emitting element including a first lower-layer electrode, a first light-emitting layer, and a first upper-layer electrode stacked in this order from the substrate side; the first light-emitting element further includes a photosensitive resin layer between the first lower electrode and the first light-emitting layer, The photosensitive resin layer is The following structural formulas (1) to (3) 【Chemical 1】 (wherein R1 and R2 each independently represent a substituted or unsubstituted hydrocarbon group), the photosensitive resin layer further contains at least one selected from the group consisting of aromatic hydrocarbons having a hydroxyl group, 1-hydroxyethyl-2-alkylimidazoline, and shellac; A light-emitting device wherein the first light-emitting layer comprises quantum dots as a light-emitting material.

2. The light-emitting device of claim 1 , wherein the first light-emitting layer comprises a positive-tone photosensitive resin.

3. the first lower electrode is a cathode and the first upper electrode is an anode; the first light-emitting element further includes an electron transport layer between the first lower electrode and the photosensitive resin layer, 3. The light-emitting device according to claim 1, wherein the electron affinity of the photosensitive resin layer is smaller than the electron affinity of the electron transport layer and smaller than the electron affinity of the first light-emitting layer.

4. the first lower electrode is a cathode and the first upper electrode is an anode; the first light-emitting element further includes an electron transport layer between the first lower electrode and the photosensitive resin layer, 3. The light-emitting device according to claim 1, wherein the electron affinity of the photosensitive resin layer is smaller than that of the electron transport layer and larger than that of the first light-emitting layer.

5. the first lower electrode is an anode and the first upper electrode is a cathode; the first light-emitting element further includes a hole transport layer between the first lower electrode and the photosensitive resin layer, 3. The light-emitting device according to claim 1, wherein the ionization energy of the photosensitive resin layer is greater than the ionization energy of the hole transport layer and greater than the ionization energy of the first light-emitting layer.

6. the first lower electrode is an anode and the first upper electrode is a cathode; the first light-emitting element further includes a hole transport layer between the first lower electrode and the photosensitive resin layer, 3. The light-emitting device according to claim 1, wherein the ionization energy of the photosensitive resin layer is greater than the ionization energy of the hole transport layer and less than the ionization energy of the first light-emitting layer.

7. The light-emitting device according to claim 1 , wherein only the first light-emitting element comprises the photosensitive resin layer.

8. a second light-emitting element on the substrate, the second light-emitting element including a second lower-layer electrode, a second light-emitting layer having a material different from that of the first light-emitting layer, and a second upper-layer electrode, stacked in this order from the substrate side; The light-emitting device according to claim 1 , wherein the second light-emitting element further comprises the photosensitive resin layer between the second lower electrode and the second light-emitting layer.

9. 9. The light-emitting device of claim 8, further comprising a third light-emitting element on the substrate, the third light-emitting element including a third lower electrode, a third light-emitting layer having a material different from both the first light-emitting layer and the second light-emitting layer, and a third upper electrode, stacked in this order from the substrate side.

10. a third light-emitting element on the substrate, the third light-emitting element including a third lower-layer electrode, a third light-emitting layer made of a material different from both the first light-emitting layer and the second light-emitting layer, and a third upper-layer electrode, stacked in this order from the substrate side; The light-emitting device according to claim 8 , wherein only the first light-emitting element and the second light-emitting element are provided with the photosensitive resin layer.

11. the first light-emitting element is a red light-emitting element including a red light-emitting layer as the first light-emitting layer, the second light-emitting element is a green light-emitting element including a green light-emitting layer as the second light-emitting layer, The light-emitting device according to claim 9 or 10, wherein the third light-emitting element is a blue light-emitting element including a blue light-emitting layer as the third light-emitting layer.

12. a display area having a plurality of pixels and a frame area surrounding the display area; each of the plurality of pixels includes the red light emitting element, the green light emitting element, and the blue light emitting element; 12. The light-emitting device of claim 11, wherein the substrate comprises thin film transistor layers that drive the red light-emitting element, the green light-emitting element, and the blue light-emitting element, respectively.

Images