Light emitting device, pixel structure including the light emitting device and manufacturing method thereof

Abstract

The present invention relates to a light-emitting device, a pixel structure including the light-emitting device and a manufacturing method thereof. The light-emitting device includes: a first semiconductor layer; a second semiconductor layer, opposite to the first semiconductor layer; an active layer, arranged between the first semiconductor layer and the second semiconductor layer; a first insulating film, surrounding the outer surface of at least one of the first semiconductor layer, the second semiconductor layer and the active layer; and a second insulating film, surrounding the outer surface of the first insulating film.

Description

Technical Field

[0001] The present disclosure relates to a light emitting device, a pixel structure including the light emitting device, and a method for manufacturing the pixel structure. Background Art

[0002] Light emitting diodes (LEDs) can have relatively satisfactory durability even under poor environmental conditions and have excellent performance in terms of life span and brightness. Recently, research on technology for applying light emitting elements to various light emitting devices has become increasingly active.

[0003] As part of this research, technology is being developed to manufacture light-emitting elements with small sizes corresponding to the micrometer or nanometer scale using inorganic crystal structures (e.g., structures obtained by growing nitride-based semiconductors). For example, ultra-small light-emitting elements can be manufactured in a size small enough to form pixels of self-emissive display panels, etc.

[0004] The light-emitting element is directly grown on the electrode, or the light-emitting element is grown separately and independently and then arranged on the electrode, so that the light-emitting element is arranged between the electrodes. After the light-emitting element is arranged, the electrode and the light-emitting element are electrically combined via a separately provided combining electrode. As the size of the light-emitting element is reduced in nanometer units, when the electrical combination is performed, the possibility of failure is high due to the increase in process difficulty. Summary of the invention

[0005] Technical issues

[0006] Various embodiments of the present disclosure relate to a light-emitting element (or light-emitting device), including a pixel structure of the light-emitting element and a method for manufacturing the pixel structure, in which an organic insulating film is formed on the outer surface of the light-emitting element to be modified to be hydrophobic through a chemical reaction.

[0007] Other embodiments of the present disclosure relate to a method of manufacturing a pixel structure, in which after the light emitting element is arranged, the organic layer is selectively subjected to hydrophobic treatment only by surface treatment, thereby being able to form a bonding electrode only in a desired region.

[0008] Technical Solution

[0009] According to one aspect of the present disclosure, a light emitting device may include: a first semiconductor layer; a second semiconductor layer facing the first semiconductor layer; an active layer disposed between the first semiconductor layer and the second semiconductor layer; a first insulating film surrounding an outer surface of at least one of the first semiconductor layer, the second semiconductor layer and the active layer; and a second insulating film surrounding an outer surface of the first insulating film.

[0010] The second insulating film may include an organic polymer material.

[0011] The light emitting element may further include a hydrophobic layer provided on at least a portion of a surface of the second insulating film.

[0012] The second insulating film may include at least one of polypropylene (PP), polystyrene (PS), polymethyl methacrylate (PMMA), polyethylene (PE), polyamide (PA), polyester, and polytetrafluoroethylene (PTFE).

[0013] In addition, the light emitting element may further include at least one of a first electrode and a second electrode facing the first electrode. The first semiconductor layer may be disposed between the first electrode and the active layer, and the second semiconductor layer may be disposed between the second electrode and the active layer.

[0014] According to one aspect of the present disclosure, a pixel structure may include: a substrate; an electrode assembly, including a first electrode arranged on the substrate and a second electrode arranged on the same plane as the first electrode to be spaced apart from the first electrode; a light-emitting element arranged between the first electrode and the second electrode; and a combined electrode assembly, including a first combined electrode and a second combined electrode, the first combined electrode being formed on the first electrode to combine the first end of the light-emitting element with the first electrode, and the second combined electrode being formed on the second electrode to combine the second end of the light-emitting element with the second electrode, wherein the light-emitting element may include a first semiconductor layer; a second semiconductor layer facing the first semiconductor layer; an active layer disposed between the first semiconductor layer and the second semiconductor layer; a first insulating film surrounding the outer surface of at least one of the first semiconductor layer, the second semiconductor layer and the active layer; and a second insulating film surrounding the outer surface of the first insulating film.

[0015] The pixel structure may further include a first hydrophobic layer formed on the exposed surface of the second insulating film.

[0016] The pixel structure may further include an organic layer, which is disposed on the light emitting element.

[0017] The pixel structure may further include a second hydrophobic layer formed on a surface of the organic layer.

[0018] The pixel structure may further include a dam structure which is disposed outside the first electrode and the second electrode and includes an organic matter.

[0019] The pixel structure may further include a third hydrophobic layer formed on a surface of the dam structure.

[0020] The first bonding electrode and the second bonding electrode may be formed in a region where the first hydrophobic layer, the second hydrophobic layer, and the third hydrophobic layer are not formed.

[0021] The pixel structure may further include an insulating layer, which is disposed between the substrate and the light emitting element and includes an inorganic substance.

[0022] According to aspects of the present disclosure, a method for manufacturing a pixel structure may include: forming a first electrode and a second electrode on a substrate to have a predetermined interval between the first electrode and the second electrode; forming a dam structure outside the first electrode and the second electrode, the dam structure being formed of an organic matter; forming an insulating layer on the first electrode and the second electrode, the insulating layer being formed of an inorganic matter; arranging a light-emitting element between the first electrode and the second electrode; plasma-treating the substrate, the light-emitting element being arranged on the substrate; removing at least a portion of the insulating layer; and forming a first combining electrode and a second combining electrode that respectively combine the light-emitting element to the first electrode and the second electrode.

[0023] The light-emitting element may include a first semiconductor layer; a second semiconductor layer facing the first semiconductor layer; an active layer disposed between the first semiconductor layer and the second semiconductor layer; a first insulating film surrounding an outer surface of at least one of the first semiconductor layer, the second semiconductor layer and the active layer; and a second insulating film surrounding an outer surface of the first insulating film, wherein a first hydrophobic layer may be formed on an exposed surface of the second insulating film by plasma treatment.

[0024] The third hydrophobic layer may be formed on the surface of the dam structure by plasma treatment.

[0025] In the step of performing plasma treatment, a fluorine-containing gas is used.

[0026] The method may further include forming an organic layer on the light emitting element after the step of arranging the light emitting element.

[0027] The second hydrophobic layer may be formed on the surface of the organic layer by plasma treatment.

[0028] The steps of forming the first combined electrode and the second combined electrode may include: applying a metal paste on the plasma-treated substrate; and drying the metal paste, wherein the metal paste may be incompatible with the first hydrophobic layer, the second hydrophobic layer, and the third hydrophobic layer, and may be applied to an area where the first hydrophobic layer, the second hydrophobic layer, and the third hydrophobic layer are not formed.

[0029] Beneficial Effects

[0030] The light emitting element, the pixel structure including the light emitting element, and the method for manufacturing the pixel structure according to the present disclosure can reduce the failure rate when the electrode and the light emitting element are electrically connected in the manufacture of the pixel structure using the ultra-small light emitting element. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a perspective view of a light emitting element according to an embodiment of the present disclosure.

[0032] Figure 2a and Figure 2b is a plan view showing a pixel structure according to an embodiment of the present disclosure.

[0033] Figure 3a and Figure 3b It is along Figure 2a and Figure 2b A cross-sectional view of the pixel structure taken along line II'.

[0034] Figure 4a and Figure 4b is a plan view showing a pixel structure according to another embodiment of the present disclosure.

[0035] Figure 5a and Figure 5b It is along Figure 4a and Figure 4b A cross-sectional view of the pixel structure taken along line II-II'.

[0036] Figure 6a to Figure 6g is a diagram for explaining a method of manufacturing a pixel structure according to an embodiment of the present disclosure.

[0037] Figure 7 is a diagram conceptually illustrating a display device including a pixel structure according to an embodiment of the present disclosure.

[0038] Figure 8 and Fig. 9 It is along Figure 7 A cross-sectional view of the display device taken along line III-III'. DETAILED DESCRIPTION

[0039] Since the present disclosure allows various changes and many embodiments, specific embodiments will be shown in the drawings and described in detail in the written description. However, this is not intended to limit the present disclosure to a specific mode of practice, and it will be understood that all changes, equivalents and substitutions that do not depart from the spirit and technical scope of the present disclosure are included in the present disclosure.

[0040] Throughout the present disclosure, the same reference numerals indicate the same parts throughout the various figures and embodiments of the present disclosure. For clarity, the size of the elements in the accompanying drawings may be exaggerated. It will be understood that, although the terms "first", "second", etc. may be used to describe various elements here, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, without departing from the teachings of the present disclosure, the first element discussed below may be referred to as the second element. Similarly, the second element may also be referred to as the first element. In the present disclosure, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form.

[0041] It will also be understood that when the terms "comprise", "include", etc. are used in this specification, it indicates the presence of the stated features, integers, steps, operations, elements, components and / or combinations thereof, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof. In addition, when a first component such as a layer, film, region or plate is disposed on a second component, the first component may not only be directly on the second component, but a third component may be placed between them. In addition, when it is indicated that a first component such as a layer, film, region or plate is formed on a second component, the surface of the second component on which the first component is formed is not limited to the upper surface of the second component, but may also include other surfaces such as the side surface or lower surface of the second component. Conversely, when a first component such as a layer, film, region or plate is below a second component, the first component may not only be directly below the second component, but a third component may be placed between them.

[0042] Hereinafter, a light emitting element, a pixel structure including the light emitting element, and a method of manufacturing the pixel structure according to an embodiment of the present disclosure will be described with reference to the accompanying drawings.

[0043] Figure 1 is a perspective view of a light emitting element according to an embodiment of the present disclosure.

[0044] The light emitting element 10 is an LED element that can emit light, and can be formed into, for example, a rod-like shape and a strip-like shape extending in the longitudinal direction (ie, having an aspect ratio greater than 1), such as a cylindrical shape and a prismatic shape. Figure 1 As shown in , the nano-small light emitting element 10 according to the embodiment of the present disclosure may include a first electrode layer 110, a second electrode layer 120, a first semiconductor layer 130, a second semiconductor layer 140, and an active layer 150 disposed between the first semiconductor layer 130 and the second semiconductor layer 140. For example, the first electrode layer 110, the first semiconductor layer 130, the active layer 150, the second semiconductor layer 140, and the second electrode layer 120 may be sequentially stacked in the longitudinal direction of the light emitting element 10. In addition, in the example, the length T of the nano-small light emitting element 10 may be in the range of 2 μm to 5 μm, but the present disclosure is not limited thereto.

[0045] Each of the first electrode layer 110 and the second electrode layer 120 may be an ohmic contact electrode. However, each of the first electrode layer 110 and the second electrode layer 120 is not limited thereto and may be a Schottky contact electrode. Each of the first electrode layer 110 and the second electrode layer 120 may include a conductive metal. For example, each of the first electrode layer 110 and the second electrode layer 120 may include one or more metal materials selected from the group consisting of aluminum, titanium, indium, gold, and silver. As an example, the materials included in the first electrode layer 110 and the second electrode layer 120 may be the same as each other. As another example, the materials included in the first electrode layer 110 and the second electrode layer 120 may be different from each other.

[0046] The first electrode layer 110 as an ohmic contact electrode may not be an essential component. In this case, the first semiconductor layer 130 may be directly coupled to the first electrode 31 of the pixel structure 1 to be described later. In addition, the second electrode layer 120 as an ohmic contact electrode may not be an essential component. In this case, the second semiconductor layer 140 may be directly coupled to the second electrode 32 of the pixel structure 1 to be described later.

[0047] The first semiconductor layer 130 according to an embodiment of the present disclosure may be a hole transport layer and include, for example, a p-type semiconductor layer. For example, when the light emitting element 10 is a blue light emitting element, the p-type semiconductor layer may be a layer having a composition formula In x Al y Ga 1-x-y The semiconductor material of N (0≤x≤1, 0≤y≤1, 0≤x+y≤1) can be selected from any one of, for example, InAlGaN, GaN, AlGaN, InGaN, AlN and InN, and can be doped with a second conductive dopant (for example, Mg).

[0048] The second semiconductor layer 140 according to an embodiment of the present disclosure may be an electron transport layer and include, for example, an n-type semiconductor layer. For example, when the light emitting element 10 is a blue light emitting element, the n-type semiconductor layer may be a layer having a composition formula of In x Al y Ga 1-x-y The semiconductor material of N (0≤x≤1, 0≤y≤1, 0≤x+y≤1) can be selected from any one of, for example, InAlGaN, GaN, AlGaN, InGaN, AlN, and InN, and can be doped with a first conductive dopant (for example, Si, Ge, Sn, etc.). In addition, the light emitting element 10 is not limited to a blue light emitting element, and can include different kinds of III-V semiconductor materials as the n-type semiconductor layer when the emission color is different.

[0049] The active layer 150 as a light emitting layer may be disposed between the first semiconductor layer 130 and the second semiconductor layer 140, and may be formed, for example, as a single quantum well structure or a multi-quantum well structure. For example, a cladding layer (not shown) doped with a conductive dopant may be disposed above the active layer 150 and / or below the active layer 150. The cladding layer (not shown) doped with a conductive dopant may be formed as an AlGaN layer or an InAlGaN layer. In addition, the active layer 150 may be formed using a material such as AlGaN or AlInGaN.

[0050] When an electric field is applied to the active layer 150, light may be generated by the recombination of electron-hole pairs. The position of the active layer 150 may be changed differently depending on the type of the light-emitting element. In an embodiment, the active layer 150 may be disposed at a position such that the ratio of the length between the first electrode layer 110 and the first semiconductor layer 130 to the length between the second electrode layer 120 and the second semiconductor layer 140 is 1:20. In addition, the light-emitting element 10 is not limited to a blue light-emitting element, and different types of III-V semiconductor materials may be included in the active layer 150 when the emission color is different.

[0051] Although it has been described that the first semiconductor layer 130, the second semiconductor layer 140 and the active layer 150 may be included in the light emitting element 10, the technical spirit of the present disclosure is not limited thereto. For example, the light emitting element 10 may further include a separate fluorescent layer, an active layer, a semiconductor layer and / or an electrode layer above and / or below the first semiconductor layer 130 and the second semiconductor layer 140.

[0052] The light-emitting element 10 may further include a first insulating film 160 covering the outer surface of the active layer 150. For example, the first insulating film 160 may cover the side surface of the active layer 150. Therefore, it is possible to prevent an electrical short circuit that may occur when the active layer 150 contacts the first electrode 31 or the second electrode 32 of the pixel structure 1. In addition, the first insulating film 160 may protect the outer surface of the light-emitting element 10 including the active layer 150 to prevent the light-emitting efficiency from deteriorating. In various embodiments of the present disclosure, the first insulating film 160 may be an inorganic layer. For example, the first insulating film 160 may include a layer made of SiO 2 、Si 3 N 4 、Al 2 O 3 and TiO 2 At least one insulating material selected from the group consisting of, but not limited to, In other words, various materials having insulating properties may be used.

[0053] In various embodiments of the present disclosure, the light emitting element 10 may further include a second insulating film 170 covering the outer surface of the first insulating film 160. In various embodiments of the present disclosure, the second insulating film 170 may be an organic layer. For example, the second insulating film 170 may be made of a material such as polypropylene (PP), polystyrene (PS), polymethyl methacrylate (PMMA), polyethylene (PE), polyamide (PA), polyester, or polytetrafluoroethylene (PTFE). However, the technical spirit of the present disclosure is not limited thereto. The second insulating film 170 is a material that can be at least partially converted into hydrophobicity by reacting with fluorine, and may be made of an organic polymer material including a polymer.

[0054] Figure 2a and Figure 2b is a plan view showing a pixel structure according to an embodiment of the present disclosure, Figure 3a and Figure 3b It is along Figure 2a and Figure 2b A cross-sectional view of the pixel structure taken along line II'.

[0055] Reference Figure 2a , the pixel structure 1 may include an electrode assembly 30, a light emitting element 10, and a combined electrode assembly 40 combining the electrode assembly 30 and the light emitting element 10. In addition, the pixel structure 1 may further include a dam structure 70 disposed outside the electrode assembly 30. The pixel structure 1 may be provided with a plurality of electrode assemblies 30 and a plurality of combined electrode assemblies 40. A plurality of pixel structures 1 may be provided on a display device 1000 of the present disclosure to be described later.

[0056] Reference Figure 2a and Figure 3a , the first electrode 31 and the second electrode 32 constituting the electrode assembly 30 may be formed on the substrate 5 to be on the same plane and to be spaced apart from each other by a predetermined distance.

[0057] The substrate 5 may be any one of a glass substrate, a crystal substrate, a sapphire substrate, a plastic substrate, and a flexible polymer film that can be bent, but the present disclosure is not limited thereto.

[0058] like Figure 3a As shown in , each of the first electrode 31 and the second electrode 32 can be formed in a rectangular shape. However, the technical spirit of the present disclosure is not limited thereto. Each of the first electrode 31 and the second electrode 32 can have various shapes, such as a trapezoid, a semicircle, a semi-ellipse, and a circle inclined at a predetermined angle. In various embodiments of the present disclosure, one of the first electrode 31 and the second electrode 32 can be an anode electrode, and the other can be a cathode electrode.

[0059] The first electrode 31 and the second electrode 32 perform the function of arranging (or aligning) the light emitting element 10 in the manufacturing process of the pixel structure 1, and perform the function of applying an electrical signal to the light emitting element 10 in the completed pixel structure 1. The specific arrangement (or alignment) function of the first electrode 31 and the second electrode 32 will be described in detail below with reference to the method for manufacturing the pixel structure 1.

[0060] The first electrode 31 and the second electrode 32 may be made of a conductive material having a predetermined reflectivity. The conductive material may include a metal such as Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, or an alloy thereof, a conductive oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), or indium tin zinc oxide (ITZO), and a conductive polymer such as PEDOT. In addition, each of the first electrode 31 and the second electrode 32 may have a single-layer structure, but is not limited thereto, and may have a multilayer structure formed by stacking two or more materials of metals, alloys, conductive oxides, and conductive polymers.

[0061] Each of the first electrode 31 and the second electrode 32 can make light emitted from both ends of the light emitting element 10 travel in a direction (eg, a front direction) in which an image is displayed.

[0062] In an embodiment, a component for driving the pixel structure 1 as a passive matrix or an active matrix may also be provided between the first electrode 31, the second electrode 32 and the substrate 5. For example, when the pixel structure 1 is driven as an active matrix, a signal line may be provided between the first electrode 31, the second electrode 32 and the substrate 5. The signal line may include a scan line and a data line. A thin film transistor may be coupled to the signal line and include a gate electrode, a semiconductor pattern, a source electrode, and a drain electrode. The drain electrode may be coupled to one of the first electrode 31 and the second electrode 32, and a data signal of the data line may be applied to any one of the reflective electrodes through the thin film transistor. Here, the signal line, the insulating layer and / or the thin film transistor may be naturally provided in various numbers and shapes. This will be referred to later. Figures 7 to 9 Describe this.

[0063] The light emitting element 10 is disposed between the first electrode 31 and the second electrode 32. In the embodiment, the light emitting element 10 has a length shorter than the distance between the first electrode 31 and the second electrode 32. Since the length of the light emitting element 10 is shorter than the distance between the first electrode 31 and the second electrode 32, both ends of the light emitting element 10 may not be in direct contact with the first electrode 31 and the second electrode 32 at the same time. In this way, since both ends of the light emitting element 10 may not be in direct contact with the first electrode 31 and the second electrode 32, in the manufacturing process of the pixel structure 1, even if a high voltage is applied to the first electrode 31 and the second electrode 32 to arrange the light emitting element 10, the pixel structure 1 may not apply a high voltage to the light emitting element 10. Therefore, damage to the ultra-small light element or damage to the first electrode 31 and the second electrode 32, which is a problem that occurs when a high voltage is applied to the light emitting element 10, can be prevented.

[0064] Referenced above Figure 1 The specific structure of the light emitting element 10 is described.

[0065] In various embodiments of the present disclosure, at least a portion of the second insulating film 170 of the light emitting element 10 may be modified to have hydrophobicity, thereby forming a hydrophobic layer 8 (referred to as a first hydrophobic layer).

[0066] The insulating layer 6 may be disposed below the light emitting element 10. The insulating layer 6 is formed of an inorganic layer such as silicon oxide, silicon nitride or metal oxide and has hydrophilicity. The insulating layer 6 may be formed during a process for arranging the light emitting element 10. This will be described in detail below with reference to a method for manufacturing the pixel structure 1.

[0067] The bonding electrode assembly 40 has a first bonding electrode 41 bonding the light emitting element 10 and the first electrode 31, and a second bonding electrode 42 stably bonding the light emitting element 10 and the second electrode 32. The first bonding electrode 41 contacts the first electrode 31 and the first electrode layer 110 of the nano-small light emitting element 10, and bonds the first electrode 31 and the first electrode layer 110 of the nano-small light emitting element 10, while the second bonding electrode 42 contacts the second electrode 32 and the second electrode layer 120 of the nano-small light emitting element 10, and bonds the second electrode 32 and the second electrode layer 120 of the nano-small light emitting element 10.

[0068] The first and second bonding electrodes 41 and 42 may be made of a transparent conductive material so that light emitted from each of the light emitting elements 10 and reflected in the front direction by the first and second electrodes 31 and 32 travels without loss. For example, the transparent conductive material may include ITO, IZO, ITZO, etc.

[0069] The dam structure 70 may be disposed outside the first electrode 31 and the second electrode 32. The dam structure 70 may be formed to be higher than the height of the first electrode 31 and the second electrode 32. In the process of manufacturing the pixel structure 1, the dam structure 70 may prevent a solution containing a plurality of light emitting elements 10 or a metal paste 200 for forming the bonding electrode assembly 40 from moving to an undesired area.

[0070] The dam structure 70 may be made of an organic substance as a material capable of maintaining a predetermined thickness. For example, the dam structure 70 may be made of polyimide, but is not limited thereto.

[0071] In various embodiments of the present disclosure, a hydrophobic layer 8 (referred to as a third hydrophobic layer 8) may be formed over the dam structure 70. The hydrophobic layer 8 may be formed by treating the surface of the pixel structure 1 during a process and then chemically modifying a portion of the surface of the dam structure 70.

[0072] The surface treatment may be a plasma treatment that introduces a fluorine-containing gas (e.g., C x F x A type of gas) is applied to the surface of the pixel structure 1, and then a portion of the surface is chemically modified to have hydrophobicity. x F x The gas may be, for example, carbon tetrafluoride (CF 4 ). The fluorine contained in the gas may react with the organic polymer (CH 2 bond) to chemically react to modify organic matter into hydrophobic (CF 2 The hydrophobic layer 8 may be formed by selectively plasma-treating a portion of the surface of the second insulating film 170 and the dam structure 70 of the light emitting element 10 made of an organic polymer.

[0073] In various embodiments, at least one insulating layer and / or coating layer may be disposed on the first bonding electrode 41 and the second bonding electrode 42. The insulating layer and / or coating layer may be a planarization layer that reduces a height difference caused by the electrode assembly 30, the light emitting element 10, and the bonding electrode assembly 40 disposed thereunder. In addition, the insulating layer and / or coating layer may be an encapsulation layer to prevent oxygen and moisture from penetrating into the light emitting element 10.

[0074] In various embodiments of the present disclosure, the pixel structure 1 may include: Figure 2b and Figure 3b The partition wall assembly 20 is shown in FIG.

[0075] Reference Figure 2b and Figure 3b, the first partition wall 21 and the second partition wall 22 constituting the partition wall assembly 20 may be disposed on the substrate 5. The first partition wall 21 and the second partition wall 22 may be formed on the substrate 5 to be on the same plane and spaced apart from each other by a predetermined distance, and may be made of an insulating material.

[0076] like Figure 3b As shown in , each of the first partition wall 21 and the second partition wall 22 may have a trapezoidal shape in which its side surface is inclined at a predetermined angle. However, the technical spirit of the present disclosure is not limited thereto. Each of the first partition wall 21 and the second partition wall 22 may have various shapes, such as semicircular, semi-elliptical, circular or rectangular.

[0077] In this embodiment, the first electrode 31 and the second electrode 32 are respectively disposed on the first partition wall 21 and the second partition wall 22. The first electrode 31 and the second electrode 32 have shapes corresponding to the shapes of the first partition wall 21 and the second partition wall 22. In addition, since the first electrode 31 and the second electrode 32 have shapes corresponding to the shapes of the first partition wall 21 and the second partition wall 22, light emitted from both ends of each light emitting element 10 can be reflected by the first electrode 31 and the second electrode 32, and then further travel in the front direction. Therefore, the efficiency of light emitted from the light emitting element 10 can be enhanced. In this embodiment, the first partition wall 21 and the second partition wall 22 and the first electrode 31 and the second electrode 32 disposed on the first partition wall 21 and the second partition wall 22 can be used as a reflective member for improving the efficiency of light emitted from each light emitting element 10.

[0078] Figure 4a and Figure 4b is a plan view showing a pixel structure according to another embodiment of the present disclosure, Figure 5a and Figure 5b It is along Figure 4a and Figure 4b A cross-sectional view of the pixel structure taken along line II-II'.

[0079] Reference Figure 4a and Figure 5a ,and Figure 2a and Figure 3a Compared with the embodiment of the present invention, the pixel structure 1 may further include an organic layer 9 formed on the light emitting element 10. The organic layer 9 may be made of an organic material such as polypropylene (PP), polystyrene (PS), polymethyl methacrylate (PMMA), polyethylene (PE), polyamide (PA), polyester or polytetrafluoroethylene (PTFE). Therefore, a portion of the surface of the organic layer 9 may be converted into hydrophobicity by the above-mentioned surface treatment to form a hydrophobic layer 8 (referred to as a second hydrophobic layer).

[0080] The organic layer 9 forms the hydrophobic layer 8, thereby preventing the metal paste 200 used to form the combined electrode assembly 40 from passing through the light-emitting element 10 and combining across the left and right sides of the light-emitting element 10 in the process of manufacturing the pixel structure 1. In other words, the metal paste 200 used to form the combined electrode assembly 40 can be completely separated into the left and right sides of the light-emitting element 10 by the organic layer 9 formed on the light-emitting element 10 and the hydrophobic layer 8 formed on the organic layer 9 by modification of the organic layer 9.

[0081] In an embodiment, the organic layer 9 may be formed to be shorter than the length of the light emitting element 10. Therefore, both sides of the light emitting element 10, in detail, both sides of the second insulating film 170 of the light emitting element 10 may be exposed to the outside of the organic layer 9. As described above, the light emitting element 10 may be arranged between the first electrode 31 and the second electrode 32, and the organic layer 9 may be formed on the light emitting element 10 between the first electrode 31 and the second electrode 32, and formed to extend parallel to the first electrode 31 and the second electrode 32.

[0082] Figure 4b and Figure 5b An example is shown in which the partition wall component 20 is provided on the substrate 5 and the organic layer 9 is also formed on the light emitting element 10. The detailed description of the components of this embodiment is as described with reference to Figure 2b , Figure 3b , Figure 4a and Figure 5a as described.

[0083] Figure 6a to Figure 6g is a diagram for explaining a method of manufacturing a pixel structure according to an embodiment of the present disclosure. Figure 6a to Figure 6g There is shown a method of manufacturing the pixel structure according to the embodiment without the partition wall member 20. However, the following manufacturing method can also be applied to the method of manufacturing the pixel structure according to the embodiment with the partition wall member 20.

[0084] Reference Figure 6a , the first electrode 31 and the second electrode 32 may be formed on the substrate 5 so that the first electrode 31 and the second electrode 32 are spaced apart from each other at a preset interval. In addition, a dam structure 70 may be formed outside the first electrode 31 and the second electrode 32. The dam structure 70 may be made of an organic substance as a material capable of maintaining a predetermined thickness. For example, the dam structure 70 may be formed of polyimide, but the present disclosure is not limited thereto.

[0085] In various embodiments, the dam structure 70 may be provided before forming the first electrode 31 and the second electrode 32 or after forming the first electrode 31 and the second electrode 32 .

[0086] Reference Figure 6b, the insulating layer 6 may be applied to the entire surface of the substrate 5 on which the first electrode 31 and the second electrode 32 are formed. The insulating layer 6 may be formed of an inorganic layer such as silicon oxide, silicon nitride, or metal oxide.

[0087] Reference Figure 6c , the light emitting element 10 is introduced and arranged on the substrate 5 on which the insulating layer 6 is disposed. In an embodiment, a solution containing a plurality of light emitting elements 10 may be applied to the substrate 5. Here, the dam structure 70 may prevent the applied solution from overflowing the area of ​​the pixel structure 1. The solvent of the solution may include at least one of acetone, water, isopropyl alcohol (IPA) and toluene, but is not limited thereto. The solvent may be variously changed with a volatile material.

[0088] After applying the solution, a voltage may be applied so that an electric field is formed between the first electrode 31 and the second electrode 32. The light emitting element 10 may be arranged between the first electrode 31 and the second electrode 32 by the electric field formed between the first electrode 31 and the second electrode 32. For example, both ends of the light emitting element 10 may be arranged to face the first electrode 31 and the second electrode 32, respectively.

[0089] The solvent of the solution may be eliminated in a state where the light emitting elements 10 are arranged. For example, the solvent may be removed by evaporation.

[0090] In various embodiments of the present disclosure, Figure 6c As shown at the bottom of the substrate 5, an organic layer 9 may also be formed on the light emitting element 10. The organic layer 9 may be an organic material that may be modified at a portion of its surface to have hydrophobicity by a surface treatment described later, such as polypropylene (PP), polystyrene (PS), polymethyl methacrylate (PMMA), polyethylene (PE), polyamide (PA), polyester, or polytetrafluoroethylene (PTFE), etc. The organic layer 9 may be formed on the light emitting element 10 by a method such as masking after the organic material is coated on the substrate 5 on which the light emitting element 10 is arranged and then dried.

[0091] Reference Figure 6d The top of the substrate 5 on which the light emitting element 10 is arranged may be subjected to surface treatment. x F x The gas is applied to the substrate 5 on which the light emitting element 10 is arranged. The gas applied to the substrate 5 chemically reacts with the organic polymer, thereby modifying the organic matter formed by the organic polymer to have hydrophobicity. Figure 6dIn the embodiment, since the second insulating film 170 and the dam structure 70 formed on the outermost surface of the light emitting element 10 are formed of an organic substance, a portion of the surface may be modified to have hydrophobicity by surface treatment, thereby forming a hydrophobic layer 8. At the same time, since the insulating layer 6 covering the remaining area except the light emitting element 10 and the dam structure 70 is formed of an inorganic layer, it may not react with the gas applied to the substrate 5.

[0092] In the embodiment where the organic layer 9 is formed on the light emitting element 10, as shown in FIG. Figure 6d As shown at the bottom of , the hydrophobic layer 8 can be formed on the surface of the organic layer 9 by surface treatment. In an embodiment, when the organic layer 9 is formed to be shorter than the length of the light emitting element 10, both sides of the second insulating film 170 of the light emitting element 10 exposed to the outside of the organic layer 9 can be surface treated, thereby forming the hydrophobic layer 8.

[0093] Reference Figure 6e , at least a portion of the insulating layer 6 may be removed from the surface-treated substrate 5. Here, a portion of the insulating layer 6 formed below the light-emitting element 10 may not be removed. Figure 6e It is shown that the insulating layer 6 is removed from the region except for the lower portion of the light emitting element 10. However, the insulating layer 6 may not be removed from some regions (e.g., a portion on the first electrode 31 and the second electrode 32, and / or a region between each of the first electrode 31 and the second electrode 32 and the dam structure 70, etc.). For example, in the embodiment, as Figure 6e As shown in the middle part of , the insulating layer 6 may be removed only from the central portion of each of the first electrode 31 and the second electrode 32 , and the insulating layer 6 may not be removed from the remaining area.

[0094] Reference Figure 6f , a first bonding electrode 41 and a second bonding electrode 42 are formed to electrically bond the light emitting element 10 with the first electrode 31 and the second electrode 32 on the substrate 5 from which the insulating layer 6 is removed.

[0095] In various embodiments of the present disclosure, a metal paste 200 in a paste form made of a metal such as silver, aluminum, gold, or lead is applied to the substrate 5 from which the insulating layer 6 has been removed. In various embodiments, a metal paste 200 having a metal content of 50% to 70% may be used. The metal paste 200 may be applied in an inkjet or nozzle jet method. The metal paste 200 may be applied or dripped onto the substrate 5. In an embodiment, the metal paste 200 may be applied in a volume such that it does not overflow onto the light emitting element 10. As shown in FIG. Figure 6f As shown in the bottom of FIG. 5 , when the organic layer 9 is formed on the light emitting element 10, the metal paste 200 may be applied in a volume such that it does not overflow onto the organic layer 9. In an embodiment, 1 picoliter to 10 picoliters of the metal paste 200 may be applied to the substrate 5.

[0096] In the embodiment, the metal paste 200 can be generally applied to the area where the hydrophobic layer 8 is not formed. Even if the metal paste 200 is applied to the entire substrate 5 including the area where the hydrophobic layer 8 is formed, the metal paste 200 is not compatible with the hydrophobic layer 8, so that the metal paste can be more easily applied to the area where the hydrophobic layer 8 is not formed. Therefore, the metal paste 200 can be applied to the left and right sides of the light emitting element 10 separately between the dam structure 70.

[0097] Reference Figure 6g The metal paste 200 may be dried and formed into a compressed shape toward the first electrode 31, the second electrode 32, and the substrate 5 disposed thereunder. The metal paste 200 remaining between the light emitting element 10 and the dam structure 70 on the left forms a first bonding electrode 41 bonding the first electrode 31 and the light emitting element 10. In addition, the metal paste 200 remaining between the light emitting elements 10 forms a second bonding electrode 42 bonding the second electrode 32 and the light emitting element 10.

[0098] The present disclosure has the advantage that the combined electrode assembly 40 can be formed through a simpler process without a separate mask, thus reducing the complexity of the process and reducing the failure rate.

[0099] Figure 7 is a diagram conceptually illustrating a display device including a pixel structure according to an embodiment of the present disclosure.

[0100] Reference Figure 7 , the display device 1000 includes a plurality of pixel structures 1 according to the above-described embodiments and a driving circuit coupled to the plurality of pixel structures 1 .

[0101] A plurality of pixel structures 1 may be disposed in a display area DA of the display device 1000. A driving circuit may be disposed in a non-display area disposed outside the display area DA of the display device 1000. The driving circuit includes a data driving circuit 1100 and a gate driving circuit 1200. In an embodiment, the pixel structure 1 may constitute a pixel or a sub-pixel.

[0102] The data driving circuit 1100 includes a plurality of source driving ICs to drive the data lines DL. The gate driving circuit 1200 includes one or more gate driving ICs to supply scan pulses to the gate lines GL.

[0103] According to the method of driving a plurality of light emitting elements 10, the display device 1000 is classified into a passive matrix display device and an active matrix display device. For example, when the display device 1000 is implemented as an active matrix type, as in the above-mentioned embodiment, the pixel structure 1 may include a first transistor as a driving transistor for controlling the amount of current supplied to the light emitting element 10 and a second transistor as a switching transistor for transmitting a data voltage to the first transistor. Recently, active matrix display devices that selectively turn on each unit pixel according to resolution, contrast, and operating speed have become mainstream. However, the present disclosure is not limited thereto. Passive matrix display devices that turn on pixel groups may also use the electrode arrangement of the present disclosure.

[0104] Figure 8 and Fig. 9 It is along Figure 7 A cross-sectional view of the display device taken along line III-III'. Figure 8 and Fig. 9 1 is a diagram for explaining a pixel structure 1 when the display device 1000 is an active matrix type. Figure 8 and Fig. 9 An example in which one first electrode 31 and one second electrode 32 are disposed between the dam structure 70 is shown. However, the technical spirit of the present disclosure is not limited thereto. Figures 2a to 6g As described above, the pixel structure 1 of the display device 1000 may be configured to include one or more first electrodes 31 and one or more second electrodes 32 between the dam structure 70 .

[0105] Reference Figure 8 and Fig. 9 The pixel structure 1 includes a partition wall assembly 20, an electrode assembly 30, a light emitting element 10, and a bonding electrode assembly 40 disposed on a substrate 5. A dam structure 70 may be disposed outside the electrode assembly 30.

[0106] The first electrode 31 and the second electrode 32 may be disposed on the substrate 5. The first electrode 31 and the second electrode 32 may be disposed on the substrate 5 to be spaced apart from each other by a predetermined distance.

[0107] The substrate 5 may be any one of a glass substrate, a crystal substrate, a sapphire substrate, a plastic substrate, and a flexible polymer film that can be bent, but the present disclosure is not limited thereto.

[0108] Each of the first electrode 31 and the second electrode 32 may be formed in a rectangular shape. However, the technical spirit of the present disclosure is not limited thereto. Each of the first electrode 31 and the second electrode 32 may have various shapes, such as a trapezoid, a semicircle, a semi-ellipse, and a circle inclined at a predetermined angle. In various embodiments of the present disclosure, one of the first electrode 31 and the second electrode 32 may be an anode electrode, and the other may be a cathode electrode.

[0109] The light emitting element 10 is disposed between the first electrode 31 and the second electrode 32. Figure 1 The specific structure of the light emitting element 10 is described.

[0110] The insulating layer 6 may be provided under the light emitting element 10. The insulating layer 6 may be formed of an inorganic layer such as silicon oxide, silicon nitride, or metal oxide. The insulating layer 6 may be formed during a process for arranging the light emitting element 10.

[0111] The bonding electrode assembly 40 has a first bonding electrode 41 bonding the light emitting element 10 to the first electrode 31 and a second bonding electrode 42 stably bonding the light emitting element 10 to the second electrode 32. The first bonding electrode 41 contacts the first electrode layer 110 and the first electrode 31 of the nano-small light emitting element 10 and bonds the first electrode layer 110 and the first electrode 31 of the nano-small light emitting element 10, while the second bonding electrode 42 contacts the second electrode layer 120 and the second electrode 32 of the nano-small light emitting element 10 and bonds the second electrode layer 120 and the second electrode 32 of the nano-small light emitting element 10.

[0112] The dam structure 70 may be disposed outside the first electrode 31 and the second electrode 32. The dam structure 70 may be formed to be higher than the height of the first electrode 31 and the second electrode 32. In the process of manufacturing the pixel structure 1, the dam structure 70 may prevent a solution containing a plurality of light emitting elements 10 or a metal paste 200 for forming the bonding electrode assembly 40 from moving to an undesired area.

[0113] The dam structure 70 may be made of an organic substance as a material capable of maintaining a predetermined thickness. For example, the dam structure 70 may be formed of polyimide, but the present disclosure is not limited thereto.

[0114] In various embodiments of the present disclosure, the hydrophobic layer 8 may be formed over the light emitting element 10 and the dam structure 70. The hydrophobic layer 8 may be formed by treating the surface of the pixel structure 1 during the process and then chemically modifying a portion of the surface of the second insulating film 170 of the light emitting element 10 and the dam structure 70.

[0115] Although not shown in the drawings, in various embodiments, at least one insulating layer and / or coating layer may be disposed on the first bonding electrode 41 and the second bonding electrode 42. The insulating layer and / or coating layer may be a planarization layer that reduces a height difference caused by the partition wall assembly 20, the electrode assembly 30, the light emitting element 10, and the bonding electrode assembly 40 disposed thereunder. In addition, the insulating layer and / or coating layer may be an encapsulation layer to prevent oxygen and moisture from penetrating into the light emitting element 10.

[0116] Reference Fig. 9, the pixel structure 1 may further include an organic layer 9 formed on the light emitting element 10. The organic layer 9 may be made of an organic material such as polypropylene (PP), polystyrene (PS), polymethyl methacrylate (PMMA), polyethylene (PE), polyamide (PA), polyester or polytetrafluoroethylene (PTFE). Therefore, a portion of the surface of the organic layer 9 may be converted into hydrophobicity by the above-mentioned surface treatment to form a hydrophobic layer 8.

[0117] The first thin film transistor TFT1 is composed of a first active layer 311, a first gate electrode 312, a first drain electrode 313, and a first source electrode 314. The first gate insulating layer 302 may be disposed between the first gate electrode 312 and the first active layer 311 to insulate them from each other. The first gate electrode 312 is formed on the first gate insulating layer 302 to overlap a portion of the first active layer 311. The first thin film transistor TFT1 may be a driving thin film transistor disposed under the light emitting element 10 to drive the light emitting element 10.

[0118] The second thin film transistor TFT2 is composed of a second active layer 321, a second gate electrode 322, a second drain electrode 323, and a second source electrode 324. The first gate insulating layer 302 may be disposed between the second gate electrode 322 and the second active layer 321 to insulate them from each other. The second gate electrode 322 is formed on the first gate insulating layer 302 to overlap a portion of the second active layer 321.

[0119] The first active layer 311 and the second active layer 321 may be disposed on the buffer layer 301. The first active layer 311 and the second active layer 321 may use an inorganic semiconductor (such as amorphous silicon or polycrystalline silicon) or an organic semiconductor. In some embodiments, the first active layer 311 may be formed of an oxide semiconductor. For example, the oxide semiconductor may include oxides of materials selected from Group 12, Group 13, and Group 14 metal elements (such as zinc (Zn), indium (In), gallium (Ga), tin (Sn), cadmium (Cd), germanium (Ge), or hafnium (Hf)) and combinations thereof.

[0120] The first gate insulating layer 302 is disposed on the buffer layer 301 to cover the first active layer 311 and the second active layer 321. The second gate insulating layer 303 is formed to cover the first gate electrode 312 and the second gate electrode 322. The first gate electrode 312 and the second gate electrode 322 may include a single layer structure or a multilayer structure such as Au, Ag, Cu, Ni, Pt, Pd, Al, Mo, or Cr, or may include an alloy such as Al:Nd or Mo:W. The first gate insulating layer 302 and the second gate insulating layer 303 may include an inorganic layer such as silicon oxide, silicon nitride, or a metal oxide, and may be formed as a single layer or a multilayer.

[0121] An interlayer insulating layer 304 is formed on the second gate insulating layer 303. The interlayer insulating layer 304 may be formed of an inorganic layer such as silicon oxide or silicon nitride. The interlayer insulating layer 304 may include an organic layer.

[0122] The first drain electrode 313 and the first source electrode 314 are formed on the interlayer insulating layer 304. Each of the first drain electrode 313 and the first source electrode 314 contacts the first active layer 311 through a contact hole. In addition, the second drain electrode 323 and the second source electrode 324 are formed on the interlayer insulating layer 304, and each of the second drain electrode 323 and the second source electrode 324 contacts the second active layer 321 through a contact hole. The first drain electrode 313, the second drain electrode 323, the first source electrode 314, and the second source electrode 324 may include a metal, an alloy, a metal nitride, a conductive metal oxide, a transparent conductive material, etc.

[0123] The structure of the thin film transistor TFT is not necessarily limited thereto, and various types of thin film transistors may be applied. For example, the thin film transistor TFT may be formed as a top gate structure, and may be formed as a bottom gate structure in which the first gate electrode 312 is disposed under the first active layer 311 .

[0124] The planarization layer 306 covers the first thin film transistor TFT1 and the second thin film transistor TFT2, and is disposed on the interlayer insulating layer 304. The planarization layer 306 may be used to eliminate the height difference of the layer and planarize the layer to increase the light emitting efficiency of the light emitting element 10 to be formed on the planarization layer. In addition, the planarization layer 306 may have a through hole that exposes a portion of the first drain electrode 313.

[0125] The planarization layer 306 may be formed of an insulating material. For example, the planarization layer 306 may be formed as a single layer structure or a multilayer structure of an inorganic substance, an organic substance, or an organic / inorganic composite, and may be formed by various deposition methods. In some embodiments, the planarization layer 306 may be formed of one or more materials among polyacrylate resins, epoxy resins, phenolic resins, polyamide resins, polyimide resins, unsaturated polyester resins, polyphenylene ether resins, polyphenylene sulfide resins, and benzocyclobutene (BCB).

[0126] However, the embodiments according to the present disclosure are not limited to the above structure. In some cases, either the planarization layer 306 or the interlayer insulating layer 304 may be omitted.

[0127] The first electrode 31 is an electrode provided over the interlayer insulating layer 304 to be electrically coupled to the light emitting element 10 .

[0128] The second electrode 32 is an electrode disposed above the interlayer insulating layer 304 to be electrically coupled to the light emitting element 10. The second electrode 32 may be electrically coupled to the power line. For example, a planarization layer 306 may be disposed below the power line to planarize the surface. However, the planarization layer 306 is not an essential component and may not be disposed as desired.

[0129] It will be understood by those skilled in the art that the present disclosure may be implemented in different specific forms without changing the technical ideas or essential features. Therefore, it should be understood that the exemplary embodiments are for illustrative purposes only and do not limit the limits of the present invention. It is intended that the limits of the present disclosure are defined by the appended claims, and that various modifications, additions and substitutions derived from the meaning, scope and equivalent concepts of the appended claims fall within the limits of the present disclosure.

Claims

1. A pixel structure, comprising: substrate; an electrode assembly, comprising a first electrode disposed on the substrate and a second electrode disposed on the same plane as the first electrode to be spaced apart from the first electrode; a light emitting device arranged between the first electrode and the second electrode; a combining electrode assembly, comprising a first combining electrode and a second combining electrode, wherein the first combining electrode is formed on the first electrode to combine the first end of the light emitting device with the first electrode, and the second combining electrode is formed on the second electrode to combine the second end of the light emitting device with the second electrode; A dam structure, disposed outside the first electrode and the second electrode; as well as A third hydrophobic layer is formed on the surface of the dam structure, Wherein, the light emitting device comprises: a first semiconductor layer; a second semiconductor layer, facing the first semiconductor layer; an active layer disposed between the first semiconductor layer and the second semiconductor layer; a first insulating film surrounding an outer surface of at least one of the first semiconductor layer, the second semiconductor layer, and the active layer; and a second insulating film surrounding an outer surface of the first insulating film, The pixel structure further includes: a first hydrophobic layer formed on the exposed surface of the second insulating film; an organic layer disposed on the light emitting device; and a second hydrophobic layer formed on the surface of the organic layer.

2. The pixel structure according to claim 1, wherein: The dam structure includes an organic material.

3. The pixel structure according to claim 2, wherein: The first coupling electrode and the second coupling electrode are formed in a region where the first hydrophobic layer, the second hydrophobic layer, and the third hydrophobic layer are not formed.

4. The pixel structure according to claim 1, further comprising: The insulating layer is disposed between the substrate and the light emitting device and includes an inorganic material.

5. The pixel structure according to claim 1, wherein: The second insulating film includes an organic polymer material.

6. The pixel structure according to claim 1, wherein: The second insulating film includes at least one of polypropylene (PP), polystyrene (PS), polymethyl methacrylate (PMMA), polyethylene (PE), polyamide (PA), polyester, and polytetrafluoroethylene (PTFE).

7. A method for manufacturing a pixel structure, the method comprising the following steps: forming a first electrode and a second electrode on a substrate to have a predetermined interval between the first electrode and the second electrode; forming a dam structure outside the first electrode and the second electrode, wherein the dam structure is formed of an organic material; forming an insulating layer on the first electrode and the second electrode, wherein the insulating layer is formed of an inorganic material; Arranging a light emitting device between the first electrode and the second electrode; performing plasma treatment on the substrate on which the light emitting device is arranged; removing at least a portion of the insulating layer; as well as A first bonding electrode bonding the light emitting device to the first electrode and a second bonding electrode bonding the light emitting device to the second electrode are formed.

8. The method according to claim 7, wherein: The light emitting device comprises: a first semiconductor layer; a second semiconductor layer, facing the first semiconductor layer; an active layer disposed between the first semiconductor layer and the second semiconductor layer; a first insulating film surrounding an outer surface of at least one of the first semiconductor layer, the second semiconductor layer, and the active layer; and a second insulating film surrounding an outer surface of the first insulating film, and Wherein, a first hydrophobic layer is formed on the exposed surface of the second insulating film by the plasma treatment.

9. The method according to claim 8, wherein: In the step of performing the plasma treatment, a fluorine-containing gas is used.

10. The method according to claim 9, further comprising: An organic layer is formed on the light emitting device after the step of arranging the light emitting device.

11. The method according to claim 10, wherein: A second hydrophobic layer is formed on the surface of the organic layer by the plasma treatment.

12. The method according to claim 11, wherein: A third hydrophobic layer is formed on the surface of the dam structure by the plasma treatment.

13. The method according to claim 12, wherein: The step of forming the first combined electrode and the second combined electrode comprises: applying a metal paste on the plasma treated substrate; and The metal paste is dried, The metal paste is incompatible with the first hydrophobic layer, the second hydrophobic layer, and the third hydrophobic layer, and is applied to a region where the first hydrophobic layer, the second hydrophobic layer, and the third hydrophobic layer are not formed.

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