Transparent electrode having nano particles, and method of forming the same

Abstract

The present invention relates to a transparent electrode and a method for manufacturing the same. The transparent electrode may comprise conductive nanoparticles stacked on a base layer. A monomolecular ligand may be located on the surface of each conductive nanoparticle. Accordingly, the transparent electrode can be easily formed on various types of device substrates.

Description

Technology Field

[0001] The present invention relates to a transparent electrode comprising conductive nanoparticles stacked on a base layer and a method for manufacturing the same. Background Technology

[0002] Generally, transparent electrodes are used in various electronic devices. For example, organic electroluminescent displays, liquid crystal displays, and touch panels may include transparent electrodes. The transparent electrode may include a transparent conductive material. For example, the transparent electrode may include a transparent metal oxide.

[0003] The above transparent electrode can be formed by a vacuum sputtering method. For example, a method for manufacturing the above transparent electrode may include a step of depositing a transparent conductive material on a device substrate by a vacuum sputtering method. However, since the above vacuum sputtering method uses only 15% to 30% of the target source, manufacturing costs may increase. In addition, the above vacuum sputtering method may not result in the transparent conductive material being deposited uniformly on a device substrate having curvature.

[0004] To solve the problems of the vacuum sputtering method described above, a sol-gel method for forming a transparent electrode in a solution state may be used. However, since the sol-gel method is performed at a high temperature of 500°C or higher, damage to surrounding devices may occur due to the process of forming the transparent electrode. Furthermore, in the sol-gel method, the sol-gel precursor solution must be fixed on the corresponding area during the process. Therefore, the size and shape of the device substrate on which the transparent electrode is to be formed are restricted in the sol-gel method. The problem to be solved

[0005] The problem that the present invention aims to solve is to provide a transparent electrode capable of increasing process efficiency and a method for manufacturing the same.

[0006] Another problem that the present invention aims to solve is to provide a transparent electrode that can be formed on various types of device substrates without degradation of electrical characteristics, and a method for manufacturing the same.

[0007] The problems that the present invention aims to solve are not limited to those mentioned above. Problems not mentioned herein will be clearly understood by a person skilled in the art from the description below. means of solving the problem

[0008] A transparent electrode according to the technical concept of the present invention for achieving the above-mentioned problem comprises a base layer. Conductive nanoparticles are stacked on the base layer. A monomeric ligand is located on the surface of each conductive nanoparticle. The monomeric ligand comprises a monomeric material.

[0009] Conductive nanoparticles can include transparent metal oxides.

[0010] The monomeric material may be a monomeric material containing an amine group.

[0011] The monomeric ligand may include at least one selected from the group consisting of hydrazine, tris(2-aminoethyl)amine, and diethylenetriamine.

[0012] The base layer may contain a polymer material.

[0013] Polymeric materials may include polyethylenimine.

[0014] Ground ligands can be located on the surface of the base layer. Each ground ligand can bind to one of the conductive nanoparticles.

[0015] Base ligands can contain the same material as the base layer.

[0016] Conductive nanoparticles can have a multilayer structure. The first distance between adjacent conductive nanoparticles in each layer can be the same.

[0017] The second distance between two adjacent layers of conductive nanoparticles can be smaller than the first distance.

[0018] A method for manufacturing a transparent electrode according to the technical concept of the present invention for achieving the above-mentioned problem comprises the steps of: forming a base layer; forming a first pre-nano particle layer composed of conductive nanoparticles having a polymer ligand located on its surface on the base layer; forming a first nanoparticle layer by substituting the polymer ligand in the first pre-nano particle layer with a monomer ligand; forming a second pre-nano particle layer composed of conductive nanoparticles having a polymer ligand located on its surface on the first nanoparticle layer; and forming a second nanoparticle layer by substituting the polymer ligand in the second pre-nano particle layer with a monomer ligand. The polymer ligand comprises a polymer material. The monomer ligand comprises a monomer material.

[0019] The steps of forming a first nanoparticle layer and forming a second nanoparticle layer may include the step of immersing a base layer in a dispersion in which an amine group-containing monomer material is dispersed.

[0020] A method for manufacturing a transparent electrode according to the technical concept of the present invention may further include the step of heat-treating a first nanoparticle layer and a second nanoparticle layer.

[0021] The heat treatment process can be performed at 300°C to 400°C.

[0022] A base layer can be formed on a device substrate. The step of forming the base layer may include the step of immersing the device substrate in a dispersion in which a polymer material is dispersed.

[0023] The base layer can be formed from polymeric ligands and other materials.

[0024] The step of forming a base layer may include the step of forming base ligands that bind to conductive nanoparticles of a first pre-nanoparticle layer on the surface of the base layer using a polymer material.

[0025] The device substrate can have curvature. Effects of the invention

[0026] A transparent electrode and a method for manufacturing the same according to the technical concept of the present invention may comprise conductive nanoparticles stacked on a base layer and a monomolecular ligand located on the surface of each conductive nanoparticle. Accordingly, the transparent electrode and the method for manufacturing the same according to the technical concept of the present invention can be easily formed on various types of device substrates without degradation of electrical properties. Therefore, process efficiency can be improved in the transparent electrode and the method for manufacturing the same according to the technical concept of the present invention. Brief explanation of the drawing

[0027] FIG. 1a is a schematic diagram showing a transparent electrode according to an embodiment of the present invention. Figure 1b is an enlarged view of the P region of Figure 1a. FIGS. 2a and 3a to 6a are drawings sequentially illustrating a method for manufacturing a transparent electrode according to an embodiment of the present invention. Figure 2b is an enlarged view of the R1 region of Figure 2a. Figure 3b is an enlarged view of the R2 region of Figure 3a. Figure 4b is an enlarged view of the R3 area of ​​Figure 4a. Figure 5b is an enlarged view of the R4 area of ​​Figure 5a. Figure 6b is an enlarged view of the R5 region of Figure 6a. Figure 7 is a graph showing the transmittance of a transparent electrode according to the number of nanoparticle layers stacked on a device substrate. Figure 8 is a graph showing the sheet resistance of a transparent electrode according to the heat treatment temperature. Figures 9 and 10 are graphs showing the electrical properties according to the ligands located on the surface of each conductive nanoparticle. FIGS. 11 to 14 are drawings showing an electronic device using a transparent electrode according to an embodiment of the present invention. Specific details for implementing the invention

[0028] Detailed information regarding the above-mentioned objectives, technical configuration, and resulting effects of the present invention will be more clearly understood through the following detailed description with reference to the drawings illustrating embodiments of the present invention. Here, since the embodiments of the present invention are provided to ensure that the technical concept of the present invention is sufficiently conveyed to those skilled in the art, the present invention may be embodied in other forms so as not to be limited to the embodiments described below.

[0029] Additionally, parts indicated by the same reference number throughout the specification refer to the same components, and the length and thickness of layers or regions in the drawings may be exaggerated for convenience. Furthermore, where it is stated that a first component is "on" a second component, this includes not only the case where the first component is located on the upper side in direct contact with the second component, but also the case where a third component is located between the first component and the second component.

[0030] Here, the terms first, second, etc. are used to describe various components and to distinguish one component from another. However, within the scope of the technical concept of the present invention, the first component and the second component may be named arbitrarily for the convenience of those skilled in the art.

[0031] The terms used in the specification of the present invention are used merely to describe specific embodiments and are not intended to limit the invention. For example, a component expressed in the singular includes a plurality of components unless the context clearly implies only the singular. Furthermore, in the specification of the present invention, terms such as "comprising" or "having" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0032] Additionally, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in the specification of the present invention.

[0033] (Example)

[0034] FIG. 1a is a schematic diagram showing a transparent electrode according to an embodiment of the present invention. FIG. 1b is an enlarged view of region P of FIG. 1a.

[0035] Referring to FIGS. 1a and 1b, a transparent electrode (300) according to an embodiment of the present invention may include a base layer (310) and a conductive layer (320). The base layer (310) and the conductive layer (320) may be supported by the device substrate (100). For example, the device substrate (100) may include glass, quartz glass, a silicon wafer, or plastic. The base layer (310) may be located close to the device substrate (100). The conductive layer (320) may be located on the base layer (310). For example, the base layer (310) may be located between the device substrate (100) and the conductive layer (320).

[0036] The base layer (310) can fix the conductive layer (320) on the device substrate (100). For example, the base layer (310) may include a polymer material. The base layer (310) may include an amine group-containing material. For example, the base layer (310) may include polyethyleneimine (PEI).

[0037] Base ligands (310L) may be located on the surface of the base layer (310). The conductive layer (320) may be fixed on the base layer (310) by the base ligands (310L). The base ligands (310L) may be located uniformly. For example, the first distance (d1) between adjacent base ligands (310L) may be the same.

[0038] The above base ligands (310L) may include a polymeric material. The above base ligands (310L) may include the same material as the base layer (310). For example, the above base ligands (310L) may include an amine group-containing polymeric material such as polyethyleneimine (PEI).

[0039] The conductive layer (320) may include conductive nanoparticles (NP). The conductive nanoparticles (NP) may include a conductive material. The conductive nanoparticles (NP) may include a transparent material. For example, the conductive nanoparticles (NP) may include a transparent metal oxide such as ITO.

[0040] The conductive nanoparticles (NP) may be stacked on the base layer (310). For example, the conductive nanoparticles (NP) may have a multi-structure. The conductive nanoparticles (NP) in the layer closest to the device substrate (100) may be fixed to the base layer (310). For example, each base ligand (310L) may be bonded to one of the conductive nanoparticles (NP) in the layer closest to the device substrate (100). The conductive nanoparticles (NP) may be uniformly positioned in each layer. For example, the distance between adjacent conductive nanoparticles (NP) in each layer may be equal to the first distance (d1) between adjacent base ligands (310L). The conductive nanoparticles (NP) in two adjacent layers may be staggered relative to each other. For example, the conductive nanoparticles (NP) of each layer may be located between the conductive nanoparticles (NP) of adjacent layers.

[0041] A monomeric ligand (ML) may be located on the surface of each conductive nanoparticle (NP). For example, adjacent conductive nanoparticles (NP) may be connected through the monomeric ligand (ML). The monomeric ligand (ML) may include a monomeric material. The monomeric material may be an amine group-containing monomeric material. For example, the monomeric ligand (ML) may include at least one selected from the group consisting of hydrazine (Hyd), tris(2-aminoethyl)amine (TREN), and diethylenetriamine (DETA). Accordingly, in the transparent electrode (300) according to an embodiment of the present invention, the second distance (d2) between two adjacent layers of conductive nanoparticles (NP) may be smaller than the first distance (d1). Accordingly, electrical characteristics can be improved in the transparent electrode (300) according to the embodiment of the present invention.

[0042] FIGS. 2a to 6a are drawings sequentially illustrating a method for manufacturing a transparent electrode according to an embodiment of the present invention. FIG. 2b is an enlarged view of the R1 region of FIG. 2a. FIG. 3b is an enlarged view of the R2 region of FIG. 3a. FIG. 4b is an enlarged view of the R3 region of FIG. 4a. FIG. 5b is an enlarged view of the R4 region of FIG. 5a. FIG. 6b is an enlarged view of the R5 region of FIG. 6a.

[0043] Referring to FIGS. 1a to 6a and 1b to 6b, a method for forming a transparent electrode according to an embodiment of the present invention on a device substrate is described. First, as shown in FIGS. 2a and 2b, a method for manufacturing a transparent electrode according to an embodiment of the present invention may include the step of forming a base layer (310) on a device substrate (100).

[0044] The base layer (310) may be formed with a uniform thickness over the entire surface of the device substrate (100). The base layer (310) may be formed from a polymer material. For example, the step of forming the base layer (310) may include the step of immersing the device substrate (100) in a first dispersion in which an amine group-containing polymer material, such as polyethyleneimine (PEI), is dispersed.

[0045] Base ligands (310L) may be located on the surface of the base layer (310). For example, the step of forming the base layer (310) may include the step of forming the base ligands (310L) on the surface of the base layer (310). The base ligands (310L) may be located uniformly. For example, the first distance (d1) between adjacent base ligands (310L) may be the same.

[0046] The above base ligands (310L) may include a polymer material. The above base ligands (310L) may include the same material as the base layer (310). For example, the above base ligands (310L) may include an amine group-containing polymer material such as polyethyleneimine (PEI). The above base ligands (310L) may be formed by the formation process of the base layer (310).

[0047] As illustrated in FIG. 3a and 3b, a method for manufacturing a transparent electrode according to an embodiment of the present invention may include the step of forming a first pre-nano particle layer (321a) on the base layer (310).

[0048] The first pre-nano layer (321a) may include conductive nanoparticles (NP) and polymer ligands (PL) located on the surface of each conductive nanoparticle (NP). The first pre-nano layers (321a) may be fixed to the base layer (310). For example, each conductive nanoparticle (NP) of the first pre-nano layer (321a) may be bonded to one of the base ligands (310L). The first pre-nano layer (321a) may be a single-layer structure. The conductive nanoparticles (NP) of the first pre-nano layer (321a) may be uniformly distributed. For example, the distance between adjacent conductive nanoparticles (NP) in the first pre-nano layer (321a) may be equal to the first distance (d1) between adjacent base ligands (310L).

[0049] The step of forming the first pre-nano particle layer (321a) may include the step of immersing the device substrate (100), on which the base layer (310) and the base ligands (310L) are formed, in a second dispersion in which the conductive nanoparticles (NP) are dispersed with a polymer ligand (PL) located on the surface. The polymer ligand (PL) may prevent the aggregation of the conductive nanoparticles (NP) within the first dispersion. The polymer ligand (PL) may include a polymer material. The polymer ligand (PL) may include a material different from the base layer (310) and the base ligands (310L). For example, the polymer ligand (PL) may include at least one of oleylamine and octanoic acid.

[0050] As illustrated in FIG. 4a and 4b, a method for manufacturing a transparent electrode according to an embodiment of the present invention may include the step of forming a first nanoparticle layer (321) using the first pre-nanoparticle layer (321a).

[0051] The step of forming the first nanoparticle layer (321) may include the step of substituting the polymer ligand (PL) with a monomer ligand (ML) in the first pre-nanoparticle layer (321a). For example, the step of forming the first nanoparticle layer (321) may include the step of immersing the device substrate (100) on which the first pre-nanoparticle layer (321a) is formed in a third dispersion in which the amine group-containing monomer material is dispersed.

[0052] The above-mentioned monomeric ligand (ML) may include a monomeric material. The monomeric material may be a monomeric material containing an amine group. For example, the monomeric ligand (ML) may include at least one selected from the group consisting of hydrazine (Hyd), tris(2-aminoethyl)amine (TREN), and diethylenetriamine (DETA). Adjacent nanoparticles (NP) of the first nanoparticle layer (321) may be connected through the monomeric ligand (ML). For example, the step of substituting the polymeric ligand (PL) with the monomeric ligand (ML) may include the step of connecting adjacent nanoparticles (NP) by the monomeric ligand (ML). The first nanoparticle layer (321) may be a single layer composed of conductive nanoparticles (NP) connected through the monomeric ligand (ML).

[0053] As illustrated in FIG. 5a and 5b, a method for manufacturing a transparent electrode according to an embodiment of the present invention may include the step of forming a second pre-nano particle layer (322a) on the first nano particle layer (321).

[0054] The second pre-nano particle layer (322a) may be formed by the same method as the first pre-nano particle layer (321a). For example, the step of forming the second pre-nano particle layer (322a) may include the step of immersing the device substrate (100) on which the first nano particle layer (321) is formed in a fourth dispersion in which the conductive nanoparticles (NP) are dispersed with the polymer ligand (PL) located on the surface. The second pre-nano particle layer (322a) may include conductive nanoparticles (NP) and polymer ligands (PL) located on the surface of each conductive nanoparticle (NP).

[0055] The second pre-nano layer (322a) may be a single-layer structure composed of conductive nanoparticles (NPs) connected to the conductive nanoparticles (NPs) of the first nanoparticle layer (321). For example, the second pre-nano layer (322a) may be bonded to the first nanoparticle layer (321) by a monomolecular ligand (ML) located on the surface of each conductive nanoparticle (NP) of the first nanoparticle layer (321). Each conductive nanoparticle (NP) of the second pre-nano layer (322a) may be connected to one of the conductive nanoparticles (NPs) of the first nanoparticle layer (321) through the monomolecular ligand (ML).

[0056] The conductive nanoparticles (NPs) of the second pre-nanoparticle layer (322a) may be stacked on the conductive nanoparticles (NPs) of the first nanoparticle layer (321). For example, each conductive nanoparticle (NP) of the second pre-nanoparticle layer (322a) may be positioned between adjacent conductive nanoparticles (NPs) of the first nanoparticle layer (321). The conductive nanoparticles (NPs) of the second pre-nanoparticle layer (322a) may be positioned staggered with respect to the conductive nanoparticles (NPs) of the first nanoparticle layer (321). Generally, a monomolecular ligand (ML) made of a monomolecular material has a shorter length than a polymeric ligand (PL) made of a polymeric material. Accordingly, in the method for manufacturing a transparent electrode according to an embodiment of the present invention, the second distance (d2) between each conductive nanoparticle (NP) of the first nanoparticle layer (321) and the conductive nanoparticle (NP) of the adjacent second pre-nanoparticle layer (322a) may be smaller than the first distance (d1).

[0057] As illustrated in FIG. 6a and 6b, a method for manufacturing a transparent electrode according to an embodiment of the present invention may include the step of forming a second nanoparticle layer (322) using the second pre-nanoparticle layer (322a).

[0058] The step of forming the second nanoparticle layer (322) may include the step of substituting the polymer ligand (PL) with a monomer ligand (ML) in the second pre-nanoparticle layer (322a). The second nanoparticle layer (322) may be formed by the same method as the first nanoparticle layer (321). For example, the step of forming the second nanoparticle layer (322) may include the step of immersing the device substrate (100) on which the second pre-nanoparticle layer (322a) is formed in a fifth dispersion in which the amine group-containing monomer material is dispersed.

[0059] As illustrated in FIG. 1a and 1b, a method for manufacturing a transparent electrode according to an embodiment of the present invention may include the step of forming a conductive layer (320) using the first nanoparticle layer (321) and the second nanoparticle layer (322).

[0060] The conductive layer (320) may include the first nanoparticle layer (321) and the second nanoparticle layer (322). The conductive layer (320) may be a stacked structure of the conductive nanoparticles (NP). For example, the conductive layer (320) may be formed by repeating the steps of forming a preliminary nanoparticle layer on the device substrate (100) on which the second nanoparticle layer (322) is formed, and converting a polymer ligand to a monomer ligand in the preliminary nanoparticle layer.

[0061] Consequently, the transparent electrode according to an embodiment of the present invention may include a conductive layer (320) formed by repeating the steps of forming a single layer of conductive nanoparticles (NP) having a polymer ligand (PL) on the surface on a base layer (310) having base ligands (310L) on the surface, and replacing the polymer ligand (Pl) with a monomer ligand (ML). Accordingly, the transparent electrode according to an embodiment of the present invention can be formed with a uniform thickness on a device substrate (100) of various shapes and sizes. That is, in the method for manufacturing a transparent electrode according to an embodiment of the present invention, the process of forming the transparent electrode can be simplified regardless of the shape and size of the device substrate (100). In addition, in the transparent electrode according to an embodiment of the present invention, the second distance (d2) between two adjacent layers of conductive nanoparticles (NP) can be relatively reduced by the process of replacing the polymer ligand (PL) located on the surface of each conductive nanoparticle (NP) with a monomer ligand (ML). Therefore, process efficiency and electrical characteristics can be improved in the transparent electrode according to the embodiment of the present invention.

[0062] Figure 7 is a graph showing the transmittance of a transparent electrode according to the number of nanoparticle layers stacked on a device substrate by the method for manufacturing a transparent electrode according to an embodiment of the present invention.

[0063] Referring to FIG. 7, it can be seen that, compared to a device substrate (D1) including quartz glass, the transmittance of the first transparent electrode (D2) with 10 stacked nanoparticle layers, the second transparent electrode (D3) with 20 stacked nanoparticle layers, the third transparent electrode (D4) with 30 stacked nanoparticle layers, and the fourth transparent electrode (D5) with 40 stacked nanoparticle layers is not significantly reduced within the visible region of 380 nm to 780 nm. Therefore, in the transparent electrode and the method for manufacturing the same according to the embodiment of the present invention, process efficiency can be improved without a decrease in transmittance.

[0064] FIG. 8 is a graph showing the sheet resistance according to the heat treatment temperature of the first nanoparticle layer and the second nanoparticle layer in the method for manufacturing a transparent electrode according to an embodiment of the present invention.

[0065] Referring to FIG. 8, it can be seen that the sheet resistance of the transparent electrode according to an embodiment of the present invention is reduced by a heat treatment process. Accordingly, the method for manufacturing the transparent electrode according to an embodiment of the present invention may further include a step of heat-treating the first nanoparticle layer and the second nanoparticle layer. Referring to FIG. 8, it can be seen that the sheet resistance of the transparent electrode according to an embodiment of the present invention does not change significantly during a heat treatment process at 300°C to 400°C. Therefore, in the method for manufacturing the transparent electrode according to an embodiment of the present invention, the heat treatment process may be performed at 300°C to 400°C.

[0066] FIG. 9 is a graph showing the conductivity according to the material of the ligand on the surface of conductive nanoparticles in a transparent electrode according to an embodiment of the present invention. FIG. 10 is a graph showing the sheet resistance according to the material of the ligand located on the surface of conductive nanoparticles in a transparent electrode according to an embodiment of the present invention.

[0067] Referring to FIGS. 9 and 10, it can be seen that the transparent electrode according to an embodiment of the present invention has relatively high electrical properties when the ligands located on the surface of the conductive nanoparticles include the monomeric materials hydrazine (Hyd) and tris(2-aminoethyl)amine (TREN). Accordingly, the transparent electrode according to an embodiment of the present invention and the method for manufacturing the same can improve electrical properties and process efficiency by forming a conductive layer by stacking conductive nanoparticles having monomeric ligands located on their surface.

[0068] A transparent electrode and a method for manufacturing the same according to an embodiment of the present invention are described as forming a base layer (310) and a conductive layer (320) on a device substrate (100) having a flat plane. However, since the base layer (310) and the conductive layer (320) according to an embodiment of the present invention are formed by an immersion process, they can be formed on device substrates (100) of various shapes. For example, as shown in FIG. 11, a transparent electrode and a method for manufacturing the same according to another embodiment of the present invention may include a base layer (310) that uniformly covers one side surface of a device substrate (100) having curvature, and a conductive layer (320) formed on the base layer (310) with a uniform thickness. Accordingly, the process efficiency of a transparent electrode and a method for manufacturing the same according to another embodiment of the present invention can be effectively improved.

[0069] A transparent electrode and a method for manufacturing the same according to an embodiment of the present invention are described as having a base layer (310) in direct contact with a device substrate (100). However, in a transparent electrode and a method for manufacturing the same according to another embodiment of the present invention, various devices may be formed between the device substrate (100) and the base layer (310). For example, as shown in FIG. 11, the technical concept of the present invention may be applied to a display device (1000).

[0070] The above display device (1000) may include a light-emitting element (ED) located between a device substrate (1100) and an encapsulation substrate (1700). The light-emitting element (ED) may include a light-emitting layer (1400) located between a first electrode (1300) and a second electrode (1500). For example, the above display device (1000) applied to the technical concept of the present invention may be an organic electroluminescent display device that generates an image using light emitted from the light-emitting element (ED).

[0071] A plurality of insulating films may be stacked between the device substrate (1100) and the first electrode (1300). For example, a buffer film (1110), a gate insulating film (1120), an interlayer insulating film (1130), a lower protective film (1140), and an overcoat layer (1150) may be positioned in order between the device substrate (1100) and the first electrode (1300). At least one thin-film transistor (1200) may be positioned between the device substrate (1100) and the first electrode (1300). The thin-film transistor (1200) may include an active layer (1210), a gate electrode (1230), a source electrode (1250), and a drain electrode (1270). For example, the active layer (1210) may be located between the buffer film (1110) and the gate insulating film (1120), the gate electrode (1230) may be located between the gate insulating film (1120) and the interlayer insulating film (1130), and the source electrode (1250) and the drain electrode (1270) may be located between the interlayer insulating film (1130) and the lower protective film (1140). The source electrode (1250) may be connected to one end of the active layer (1210), and the drain electrode (1270) may be connected to the other end of the active layer (1210). The drain electrode (1270) may be spaced apart from the source electrode (1250). The step difference caused by the thin-film transistor (1200) may be removed by the overcoat layer (1150). An upper protective film (1170) and a sealing layer (1600) may be located between the second electrode (1500) and the sealing substrate (1700).

[0072] The first electrode (1300) and / or the second electrode (1500) may be transparent electrodes. For example, the first electrode (1300) may be a transparent electrode according to an embodiment of the present invention. The first electrode (1300) may have a stacked structure of a base layer (1310) and a conductive layer (1320). The conductive layer (1320) may be located between the base layer (1310) and the light-emitting layer (1400). Accordingly, the display device (1000) may be modified in various forms. For example, the device substrate (1100) and the encapsulation substrate (1700) may be flexible substrates.

[0073] The first electrode (1300) may be electrically connected to the thin-film transistor (1200). The first electrode (1300) may include an end located on the overcoat layer (1150). For example, a bank insulating film (1160) covering the end of the first electrode (1300) may be located on the overcoat layer (1150). The light-emitting layer (1140) and the second electrode (1150) may be formed on a portion of the first electrode (1300) exposed by the bank insulating film (1160). The light-emitting layer (1140) and the second electrode (1150) may extend onto the bank insulating film (1160). The display device (1000) may control the light-emitting element (ED) through a driving current applied to the first electrode (1300). That is, the first electrode (1300) may be formed on a portion of the device substrate (1100). For example, a method for manufacturing the first electrode (1300) may include the steps of forming the base layer (1310) and the conductive layer (1320) on the front surface of the overcoat layer (1150), and patterning the base layer (1310) and the conductive layer (1320) to form the first electrode (1300). Accordingly, the transparent electrode and the method for manufacturing the same according to an embodiment of the present invention may be applied to the display device (1000) in various forms.

[0074] FIG. 12 is a simplified drawing of a touch panel (2000) to which the technical concept of the present invention is applied.

[0075] Referring to FIG. 12, the touch panel (2000) may include a first touch electrode group (2301) and a second touch electrode group (2302) located on a device substrate (2100). The first touch electrode group (2301) and the second touch electrode group (2302) may each include a plurality of touch electrodes connected in one direction. The second touch electrode group (2302) may connect touch electrodes in a direction perpendicular to the first touch electrode group (2301). The first touch electrode group (2301) and the second touch electrode group (2302) may include transparent touch electrodes. For example, the touch electrodes may be transparent electrodes to which the technical concept of the present invention is applied. Accordingly, the touch panel (2000) may have various forms. For example, the touch panel (2000) may be placed on a flexible display device. Accordingly, a touch panel (2000) to which the technical concept of the present invention is applied can be placed on a flexible display device having curvature without degradation of electrical characteristics.

[0076] FIG. 13 is a simplified diagram showing a light-emitting diode element (3000) to which the technical concept of the present invention is applied.

[0077] Referring to FIG. 13, the light-emitting diode device (3000) may include a device substrate (3100), a buffer film (3110), an n-type GaN layer (3120), an active layer (3130), a p-type GaN layer (3140), a first electrode pad (3210), a second electrode pad (3220), and a transparent electrode layer (3300). The buffer film (3110), the n-type GaN layer (3120), the active layer (3130), the p-type GaN layer (3140), and the first electrode pad (3210) may be stacked sequentially on the device substrate (3100). The second electrode (3220) may be located on a portion of the n-type GaN layer (3120). The active layer (3130) and the p-type GaN layer (3140) may be spaced apart from the second electrode (3220). The transparent electrode layer (3300) may be located between the p-type GaN layer (3140) and the first electrode pad (3210). The transparent electrode layer (3300) may be transparent. For example, the transparent electrode layer (3300) may be a transparent electrode to which the technical concept of the present invention is applied. Accordingly, the light-emitting diode device (3000) may include device substrates (3100) of various shapes and sizes. Therefore, the process efficiency of the light-emitting diode device (3000) may be improved. Explanation of the symbols

[0078] 100: Device substrate 310: Base layer 320: Conductive layer NP: Nanoparticle ML: Monomolecular ligand

Claims

Claim 1 A transparent electrode comprising: a first nanoparticle layer having transparent conductive nanoparticles located on a base layer and connected to the base layer through a base ligand having an amine group-containing polymer material; and a second nanoparticle layer having transparent conductive nanoparticles, connected and stacked to the conductive nanoparticles of the first nanoparticle layer by a monomer ligand having an amine group-containing monomer material, wherein the monomer ligand comprises at least one selected from the group consisting of hydrazine, tris(2-aminoethyl)amine, and diethylenetriamine, wherein the center-to-center distance between two adjacent conductive nanoparticles in the first nanoparticle layer connected to the base layer has a first distance, and the center-to-center distance between a conductive nanoparticle included in the second nanoparticle layer and a conductive nanoparticle included in the first nanoparticle layer has a second distance smaller than the first distance. Claim 2 In claim 1, the conductive nanoparticles are a transparent electrode comprising a transparent metal oxide. Claim 3 delete Claim 4 delete Claim 5 delete Claim 6 In claim 1, the polymer material is a transparent electrode comprising polyethylenimine. Claim 7 A transparent electrode according to claim 1, comprising base ligands located on the surface of the base layer, wherein each base ligand is coupled to one of the conductive nanoparticles. Claim 8 In claim 7, the above-mentioned base ligands comprise a transparent electrode having the same material as the base layer. Claim 9 delete Claim 10 delete Claim 11 delete Claim 12 delete Claim 13 delete Claim 14 delete Claim 15 delete Claim 16 delete Claim 17 delete Claim 18 delete

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