Light emitting element and display device comprising the same

Abstract

A light-emitting element and a display device including the same are provided. The display device comprises a first substrate, a first electrode and a second electrode spaced apart from each other and disposed on the first substrate, a first insulating layer disposed on the first electrode and the second electrode, a plurality of light-emitting elements with both ends disposed on the first insulating layer and on the first electrode and the second electrode, a first connecting electrode disposed on the first electrode and in contact with one end of the light-emitting element, a second connecting electrode disposed on the second electrode and in contact with the other end of the light-emitting element, a second insulating layer disposed on the first light-emitting element, the first connecting electrode and the second connecting electrode, and a third connecting electrode disposed on the second insulating layer and in contact with the light-emitting element through an opening formed in the second insulating layer that partially exposes the light-emitting element.

Description

Technology Field

[0001] The present invention relates to a light-emitting element and a display device including the same. Background Technology

[0002] The importance of display devices is increasing along with the development of multimedia. In response to this, various types of display devices, such as Organic Light Emitting Displays (OLEDs) and Liquid Crystal Displays (LCDs), are being used.

[0003] A device for displaying images of a display device includes a display panel such as an organic light-emitting display panel or a liquid crystal display panel. Among these, as a light-emitting display panel, it may include a light-emitting element; for example, in the case of a light-emitting diode (LED), there are organic light-emitting diodes that use organic materials as light-emitting materials and inorganic light-emitting diodes that use inorganic materials as light-emitting materials. The problem to be solved

[0004] The problem that the present invention aims to solve is to provide a display device capable of emitting light regardless of the orientation direction of the light-emitting elements.

[0005] The problem that the present invention aims to solve is to provide a light-emitting element capable of allowing current to flow in a specific direction.

[0006] The problems of the present invention are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0007] A display device according to one embodiment for solving the above problem comprises a first substrate, a first electrode and a second electrode spaced apart from each other and disposed on the first substrate, a first insulating layer disposed on the first electrode and the second electrode, a plurality of light-emitting elements with both ends disposed on the first insulating layer and on the first electrode and the second electrode, a first connecting electrode disposed on the first electrode and in contact with one end of the light-emitting element, a second connecting electrode disposed on the second electrode and in contact with the other end of the light-emitting element, a first light-emitting element, a second insulating layer disposed on the first connecting electrode and the second connecting electrode, and a third connecting electrode disposed on the second insulating layer and in contact with the light-emitting element through an opening formed in the second insulating layer that partially exposes the light-emitting element.

[0008] The first connecting electrode contacts one end surface of the light-emitting element, the second connecting electrode contacts the other end surface of the light-emitting element, and the third connecting electrode may contact the side surface of the light-emitting element.

[0009] The light-emitting element may include a first light-emitting element in which a first end is placed on the first electrode and a second end is placed on the second electrode, and a second light-emitting element in which a first end is placed on the second electrode and a second end is placed on the first electrode.

[0010] The light-emitting element comprises a plurality of semiconductor layers and an insulating film surrounding the semiconductor layers, and the third connecting electrode can contact the semiconductor layer from the side of the light-emitting element.

[0011] The light-emitting element comprises a first semiconductor layer, a second semiconductor layer disposed on the first semiconductor layer, a light-emitting layer disposed between the first semiconductor layer and the second semiconductor layer, and a third semiconductor layer disposed on the opposite side of the first semiconductor layer facing the light-emitting layer, and the third connecting electrode can contact the first semiconductor layer.

[0012] The light-emitting element may further include a fourth semiconductor layer disposed between the portion where the first semiconductor layer contacts the third connecting electrode and the end surface where the third semiconductor layer is located.

[0013] The invention further includes a conductive layer disposed on the first substrate and a via layer disposed on the conductive layer, wherein the first electrode contacts a first conductive pattern of the conductive layer through a first electrode contact hole penetrating the via layer, and the first connecting electrode can contact the first electrode through a first contact portion penetrating the first insulating layer.

[0014] The second connecting electrode may contact the second conductive pattern of the conductive layer through a second contact portion penetrating the via layer and the first insulating layer, and the third connecting electrode may contact the voltage wiring of the conductive layer through a third contact portion penetrating the via layer, the first insulating layer, and the second insulating layer.

[0015] The second electrode may contact the voltage wiring of the conductive layer through a second electrode contact hole penetrating the via layer, the second connecting electrode may contact the first electrode through a fourth contact portion penetrating the first insulating layer, and the third connecting electrode may contact the second electrode through a fifth contact portion penetrating the first insulating layer and the second insulating layer.

[0016] The apparatus further includes a fourth connecting electrode disposed on the first electrode between the first insulating layer and the second insulating layer and in contact with the light-emitting element, a fifth connecting electrode disposed on the second electrode between the first insulating layer and the second insulating layer and in contact with the light-emitting element, and a sixth connecting electrode disposed on the second insulating layer and in contact with the light-emitting element, wherein the fourth connecting electrode may be spaced apart from the first connecting electrode, the fifth connecting electrode may be spaced apart from the second connecting electrode, and the sixth connecting electrode may be spaced apart from the third connecting electrode.

[0017] The third connecting electrode is arranged to overlap with the light-emitting elements to which the fourth connecting electrode and the fifth connecting electrode contact, and the sixth connecting electrode is arranged to overlap with the light-emitting elements to which the first connecting electrode and the second connecting electrode contact, and can contact the fourth connecting electrode and the fifth connecting electrode through sixth contact portions penetrating the second insulating layer.

[0018] The apparatus further comprises a third electrode and a fourth electrode spaced apart from each other and disposed on the first substrate, a fourth connecting electrode disposed on the third electrode, a fifth connecting electrode disposed on the fourth electrode, and a sixth connecting electrode disposed on the second insulating layer, wherein the light-emitting element comprises a first group of light-emitting elements disposed on the first electrode and the second electrode, and a second group of light-emitting elements disposed on the third electrode and the fourth electrode, wherein the third connecting electrode may be in contact with the second group of light-emitting elements and the sixth connecting electrode may be in contact with the first group of light-emitting elements.

[0019] The sixth connecting electrode further includes an electrode extension portion disposed across the second electrode, the third electrode, and the fourth electrode, and the electrode extension portion can contact the fourth connecting electrode and the fifth connecting electrode through a sixth contact portion penetrating the second insulating layer.

[0020] The device further includes a third insulating layer disposed between the light-emitting element and the second insulating layer, wherein a portion of the first connecting electrode and the second connecting electrode is disposed on the third insulating layer, and the opening can penetrate the third insulating layer to expose the light-emitting element.

[0021] The apparatus further includes a fourth insulating layer disposed between the second connecting electrode and the second insulating layer, wherein a portion of the first connecting electrode is disposed on the fourth insulating layer, and the opening can penetrate the fourth insulating layer to expose the light-emitting element.

[0022] A light-emitting element according to one embodiment for solving the above problem comprises a first semiconductor layer doped with n-type, a second semiconductor layer doped with p-type disposed on the first semiconductor layer, a light-emitting layer disposed between the first semiconductor layer and the second semiconductor layer, a third semiconductor layer disposed on the opposite side of one side of the first semiconductor layer facing the light-emitting layer and not doped with a dopant, and an insulating film disposed to surround at least the outer surface of the light-emitting layer.

[0023] The length of the third semiconductor layer may have a range of 20% or less of the length of the light-emitting element.

[0024] It may further include an electron blocking layer disposed within the third semiconductor layer.

[0025] It may further include an electron blocking layer disposed within the first semiconductor layer between the third semiconductor layer and the light-emitting layer.

[0026] The gap between the electron blocking layer and the third semiconductor layer may be smaller than the gap between the electron blocking layer and the light-emitting layer.

[0027] Specific details of other embodiments are included in the detailed description and drawings. Effects of the invention

[0028] A light-emitting element according to one embodiment includes an undoped semiconductor layer, allowing current to flow in a specific direction.

[0029] The display device includes a plurality of connecting electrodes connected to the light-emitting element and different semiconductor layers of the light-emitting element. The display device according to one embodiment can emit light regardless of the orientation direction of the light-emitting elements, and has the advantage of improving the yield of the manufacturing process by minimizing the number of light-emitting elements that do not emit light per unit area.

[0030] The effects according to the embodiments are not limited to those exemplified above, and a wider variety of effects are included in this specification. Brief explanation of the drawing

[0031] FIG. 1 is a schematic plan view of a display device according to one embodiment. FIG. 2 is a plan view showing one pixel of a display device according to one embodiment. Figure 3 is a plan view showing the first subpixel of Figure 2. Figure 4 is a cross-sectional view taken along the Q1-Q1' and Q2-Q2' lines of Figure 3. Figure 5 is a cross-sectional view taken along the line Q3-Q3' of Figure 3. FIG. 6 is a schematic diagram of a light-emitting element according to one embodiment. Figure 7 is a cross-sectional view of the light-emitting element of Figure 6. Figure 8 is a cross-sectional view taken along the line Q4-Q4' of Figure 3. FIG. 9 is a cross-sectional view showing the arrangement of light-emitting elements and a third connecting electrode of a display device according to another embodiment. FIG. 10 is a schematic diagram showing the flow of current for emitting light from light-emitting elements of a display device according to one embodiment. FIG. 11 is a plan view showing one subpixel of a display device according to another embodiment. Figure 12 is a cross-sectional view taken along the line Q5-Q5' of Figure 11. Figure 13 is a cross-sectional view taken along the line Q6-Q6' of Figure 11. FIG. 14 is a cross-sectional view of a light-emitting element according to another embodiment. FIG. 15 is a cross-sectional view of a light-emitting element according to another embodiment. FIG. 16 is a plan view showing one subpixel of a display device according to another embodiment. Figure 17 is a cross-sectional view taken along the line Q7-Q7' of Figure 16. FIG. 18 is a plan view showing one subpixel according to another embodiment of the display device of FIG. 16. FIG. 19 is a plan view showing one subpixel of a display device according to another embodiment. FIG. 20 is a cross-sectional view taken along the line Q8-Q8' of FIG. 19. FIG. 21 is a cross-sectional view taken along the Q9-Q9' and Q10-Q10' lines of FIG. 19. FIG. 22 is a plan view showing one subpixel according to another embodiment of the display device of FIG. 19. FIG. 23 is a plan view showing one subpixel of a display device according to another embodiment. FIG. 24 is a plan view showing one subpixel according to another embodiment of the display device of FIG. 23. FIG. 25 is a cross-sectional view showing a part of a display device according to another embodiment. FIG. 26 is a cross-sectional view showing a part of a display device according to another embodiment. FIG. 27 is a cross-sectional view showing a part of a display device according to another embodiment. FIG. 28 is a cross-sectional view of a light-emitting element according to another embodiment. FIG. 29 is a plan view showing a part of a display device including the light-emitting element of FIG. 28. Specific details for implementing the invention

[0032] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims.

[0033] Elements or layers referred to as "on" another element or layer include cases where another layer or element is interposed directly above or in the middle of another element. Likewise, "below," "left," and "right" refer to cases where they are interposed immediately adjacent to another element or where another layer or material is interposed in the middle. Throughout the specification, the same reference numerals refer to the same components.

[0034] Although terms such as "first," "second," etc., are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used merely to distinguish one component from another. Therefore, it goes without saying that the first component mentioned below may also be the second component within the technical scope of the present invention.

[0035] Hereinafter, embodiments will be described with reference to the attached drawings.

[0036] FIG. 1 is a schematic plan view of a display device according to one embodiment.

[0037] Referring to FIG. 1, the display device (10) displays a video or a still image. The display device (10) may refer to any electronic device that provides a display screen. For example, a television, laptop, monitor, billboard, Internet of Things, mobile phone, smartphone, tablet PC (Personal Computer), electronic watch, smart watch, watch phone, head-mounted display, mobile communication terminal, electronic notebook, electronic book, PMP (Portable Multimedia Player), navigation, game console, digital camera, camcorder, etc. that provide a display screen may be included in the display device (10).

[0038] The display device (10) includes a display panel that provides a display screen. Examples of display panels include an inorganic light-emitting diode display panel, an organic light-emitting diode display panel, a quantum dot light-emitting diode display panel, a plasma display panel, a field emission display panel, etc. In the following examples, an inorganic light-emitting diode display panel is used as an example of a display panel, but it is not limited thereto, and if the same technical concept is applicable, it can be applied to other display panels.

[0039] The shape of the display device (10) can be varied in many ways. For example, the display device (10) may have a shape such as a horizontally elongated rectangle, a vertically elongated rectangle, a square, a rectangle with rounded corners (vertices), other polygons, or a circle. The shape of the display area (DPA) of the display device (10) may also be similar to the overall shape of the display device (10). In FIG. 1, a display device (10) in the shape of a rectangle with a long length in the second direction (DR2) is illustrated.

[0040] The display device (10) may include a display area (DPA) and a non-display area (NDA). The display area (DPA) is an area where the screen can be displayed, and the non-display area (NDA) is an area where the screen is not displayed. The display area (DPA) may also be referred to as an active area, and the non-display area (NDA) as an inactive area. The display area (DPA) may generally occupy the center of the display device (10).

[0041] The display area (DPA) may include a plurality of pixels (PX). The plurality of pixels (PX) may be arranged in a matrix direction. The shape of each pixel (PX) may be a planar rectangle or a square, but is not limited thereto, and may be a rhombus shape with each side tilted toward one direction. Each pixel (PX) may be arranged alternately in a stripe type or a pentile type. Additionally, each of the pixels (PX) may include one or more light-emitting elements that emit light of a specific wavelength range to display a specific color.

[0042] A non-display area (NDA) may be placed around a display area (DPA). The non-display area (NDA) may surround the display area (DPA) in whole or in part. The display area (DPA) is rectangular in shape, and the non-display area (NDA) may be placed adjacent to the four sides of the display area (DPA). The non-display area (NDA) may form the bezel of the display device (10). In each non-display area (NDA), wiring or circuit drivers included in the display device (10) may be placed, or external devices may be mounted.

[0043] FIG. 2 is a plan view showing one pixel of a display device according to one embodiment.

[0044] Referring to FIG. 2, a plurality of pixels (PX) of a display device (10) may each include a plurality of subpixels (PXn, where n is 1 to 3). For example, a single pixel (PX) may include a first subpixel (PX1), a second subpixel (PX2), and a third subpixel (PX3). The first subpixel (PX1) may emit light of a first color, the second subpixel (PX2) may emit light of a second color, and the third subpixel (PX3) may emit light of a third color. As an example, the first color may be blue, the second color may be green, and the third color may be red. However, not limited thereto, each subpixel (PXn) may emit light of the same color, such as blue. Also, FIG. 2 illustrates that a single pixel (PX) includes three subpixels (PXn), but is not limited thereto, and a pixel (PX) may include a larger number of subpixels (PXn).

[0045] Each subpixel (PXn) of the display device (10) may include a light-emitting region (EMA) and a non-light-emitting region (not shown). The light-emitting region (EMA) is an area where a light-emitting element (ED) is placed and light of a specific wavelength range is emitted, and the non-light-emitting region may be an area where a light-emitting element (ED) is not placed and light emitted from the light-emitting element (ED) does not reach, so no light is emitted. The light-emitting region may include an area where a light-emitting element (ED) is placed, and may include an area adjacent to the light-emitting element (ED) where light emitted from the light-emitting element (ED) is emitted.

[0046] Not limited thereto, the light-emitting region may also include a region where light emitted from a light-emitting element (ED) is reflected or refracted by another member and emitted. A plurality of light-emitting elements (EDs) are arranged in each subpixel (PXn), and a light-emitting region may be formed by including the region where they are arranged and an adjacent region.

[0047] In the drawings, the light-emitting regions (EMAs) of each subpixel (PXn) are illustrated as having substantially uniform areas, but are not limited thereto. In some embodiments, each light-emitting region (EMA) of each subpixel (PXn) may have different areas depending on the color or wavelength of light emitted from the light-emitting element (ED) placed in the corresponding subpixel.

[0048] Additionally, each subpixel (PXn) may further include a sub-region (SA) placed in a non-emissive region. The sub-region (SA) may be placed on one side of the first direction (DR1) of the emitting region (EMA) and may be placed between the emitting regions (EMA) of the subpixels (PXn) adjacent to the first direction (DR1). For example, a plurality of emitting regions (EMA) and sub-regions (SA) may be repeatedly arranged in the second direction (DR2), while the emitting regions (EMA) and sub-regions (SA) may be alternately arranged in the first direction (DR1). A first bank (BNL1) is placed between the sub-regions (SA) and the emitting regions (EMA), and the spacing between them may vary according to the width of the first bank (BNL1). A light-emitting element (ED) is not placed in the sub-region (SA) so that light is not emitted, but a portion of the electrode (RME) placed in each subpixel (PXn) may be placed therein. Electrodes (RME) placed in different subpixels (PXn) can be placed separately from each other in a sub-region (SA).

[0049] The first bank (BNL1) may be arranged in a grid pattern across the entire front of the display area (DPA), including portions extending in the first direction (DR1) and the second direction (DR2) on the plane. The first bank (BNL1) may be arranged across the boundaries of each subpixel (PXn) to distinguish neighboring subpixels (PXn). Additionally, the first bank (BNL1) may be arranged to surround the light-emitting area (EMA) and sub-area (SA) arranged for each subpixel (PXn) to distinguish them.

[0050] FIG. 3 is a plan view showing the first subpixel of FIG. 2. FIG. 4 is a cross-sectional view cut along the Q1-Q1' and Q2-Q2' lines of FIG. 3. FIG. 5 is a cross-sectional view cut along the Q3-Q3' line of FIG. 3. FIG. 3 shows a first subpixel (PX1) included in a pixel (PX), and FIG. 4 shows a cross-section across both ends of different light-emitting elements (ED; ED1, ED2) placed in the first subpixel (PX1). FIG. 5 shows a cross-section of contact portions (CT1, CT2, CT3) in which a plurality of connecting electrodes (CNE) are connected to an electrode (RME) or a lower conductive layer.

[0051] Referring to FIG. 3 to FIG. 5 in conjunction with FIG. 2, the display device (10) may include a first substrate (SUB) and a semiconductor layer, a plurality of conductive layers, and a plurality of insulating layers disposed on the first substrate (SUB). The semiconductor layer, the conductive layer, and the insulating layers may each constitute a circuit layer (CCL) and a display element layer of the display device (10).

[0052] The first substrate (SUB) may be an insulating substrate. The first substrate (SUB) may be made of an insulating material such as glass, quartz, or polymer resin. Additionally, the first substrate (SUB) may be a rigid substrate, but may also be a flexible substrate capable of bending, folding, rolling, etc.

[0053] The first conductive layer may be disposed on the first substrate (SUB). The first conductive layer includes a lower metal layer (BML), and the lower metal layer (BML) is disposed to overlap with the active layer (ACT1) of the first transistor (T1). The lower metal layer (BML) includes a light-blocking material to prevent light from being incident on the active layer (ACT1) of the first transistor. However, the lower metal layer (BML) may be omitted.

[0054] A buffer layer (BL) can be disposed on a lower metal layer (BML) and a first substrate (SUB). The buffer layer (BL) is formed on the first substrate (SUB) to protect the transistors of the pixel (PX) from moisture penetrating through the first substrate (SUB), which is susceptible to moisture permeability, and can perform a surface planarization function.

[0055] The semiconductor layer is disposed on the buffer layer (BL). The semiconductor layer may include the active layer (ACT1) of the first transistor (T1). The active layer (ACT1) may be disposed to partially overlap with the gate electrode (G1) of the second conductive layer described later.

[0056] The semiconductor layer may include polycrystalline silicon, single-crystal silicon, oxide semiconductors, etc. In another embodiment, the semiconductor layer may include polycrystalline silicon. The oxide semiconductor may be an oxide semiconductor containing indium (In). For example, the oxide semiconductor may be at least one of indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium oxide (IGO), indium zinc tin oxide (IZTO), indium gallium tin oxide (IGTO), indium gallium zinc oxide (IGZO), and indium gallium zinc tin oxide (IGZTO).

[0057] In the drawing, a first transistor (T1) is illustrated in the subpixel (PXn) of the display device (10), but the display device (10) is not limited thereto and may include a larger number of transistors.

[0058] The first gate insulating layer (GI) is placed on the semiconductor layer and the buffer layer (BL). The first gate insulating layer (GI) can serve as the gate insulating film of the first transistor (T1).

[0059] A second conductive layer is disposed on the first gate insulating layer (GI). The second conductive layer may include a gate electrode (G1) of the first transistor (T1). The gate electrode (G1) may be disposed to overlap the channel region of the active layer (ACT1) and the third direction (DR3), which is the thickness direction. Although not shown in the drawing, the second conductive layer may further include a capacitance electrode of a storage capacitor.

[0060] The first interlayer insulating layer (IL1) is disposed on the second conductive layer. The first interlayer insulating layer (IL1) functions as an insulating film between the second conductive layer and other layers disposed thereon, and can protect the second conductive layer.

[0061] The third conductive layer is disposed on the first interlayer insulating layer (IL1). The third conductive layer may include the first source electrode (S1) and the first drain electrode (D1) of the first transistor (T1).

[0062] The first source electrode (S1) and the first drain electrode (D1) of the first transistor (T1) can each contact the active layer (ACT1) through a contact hole penetrating the first interlayer insulating layer (IL1) and the first gate insulating layer (GI). Additionally, the first source electrode (S1) can contact the lower metal layer (BML) through another contact hole penetrating the first interlayer insulating layer (IL1), the first gate insulating layer (GI), and the buffer layer (BL). Although not shown in the drawing, the third conductive layer may further include a plurality of data lines or a capacitive electrode of a storage capacitor.

[0063] The second interlayer insulating layer (IL2) is disposed on the third conductive layer. The second interlayer insulating layer (IL2) functions as an insulating film between the third conductive layer and other layers disposed thereon, and can protect the third conductive layer.

[0064] The fourth conductive layer is disposed on the second interlayer insulating layer (IL2). The fourth conductive layer may include a first voltage line (VL1), a second voltage line (VL2), a first conductive pattern (CDP1), and a second conductive pattern (CDP2). A high potential voltage (or a first power supply voltage) delivered to the first transistor (T1) may be applied to the first voltage line (VL1), and a low potential voltage (or a second power supply voltage) delivered to the third connecting electrode (CNE3) may be applied to the second voltage line (VL2).

[0065] The first conductivity pattern (CDP1) and the second conductivity pattern (CDP2) can be electrically connected to the first transistor (T1). The first conductivity pattern (CDP1) can be connected to the first electrode (RME1) described later, and the second conductivity pattern (CDP2) can be connected to the second connection electrode (CNE2). The first transistor (T1) can transmit the first power supply voltage applied from the first voltage wiring (VL1) to the first electrode (RME1) and the second connection electrode (CNE2). However, it is not limited thereto, and in an embodiment where the second connection electrode (CNE2) is connected to the first electrode (RME1), the second conductivity pattern (CDP2) may be omitted.

[0066] The above-described buffer layer (BL), first gate insulating layer (GI), first interlayer insulating layer (IL1), and second interlayer insulating layer (IL2) may be composed of a plurality of inorganic layers stacked alternately. For example, the buffer layer (BL), first gate insulating layer (GI), first interlayer insulating layer (IL1), and second interlayer insulating layer (IL2) may be silicon oxide (SiO₂). x ), Silicon Nitride (SiN x), Silicon Oxynitride (SiO₂ x N y It may be formed into a double layer in which an inorganic layer comprising at least one of the above is stacked, or a multilayer in which the same is stacked alternately. However, it is not limited thereto, and the buffer layer (BL), the first gate insulating layer (GI), the first interlayer insulating layer (IL1), and the second interlayer insulating layer (IL2) may be formed into a single inorganic layer including the insulating material described above. In some embodiments, the first interlayer insulating layer (IL1) and the second interlayer insulating layer (IL2) may be made of an organic insulating material such as polyimide (PI).

[0067] The second, third, and fourth conductive layers may be formed as a single layer or multiple layers composed of any one of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu), or alloys thereof. However, they are not limited thereto.

[0068] A via layer (VIA) is disposed on the fourth conductive layer. The via layer (VIA) may include an organic insulating material, such as polyimide (PI), and may perform a surface planarization function.

[0069] On the via layer (VIA), a plurality of electrodes (RME; RME1, RME2), a first bank (BNL1), a plurality of light-emitting elements (ED1, ED2), and a plurality of connecting electrodes (CNE; CNE1, CNE2, CNE3) are disposed as display element layers. Additionally, a plurality of insulating layers (PAS1, PAS2) may be disposed on the via layer (VIA).

[0070] Multiple electrodes (RME) are arranged in each subpixel (PXn) with a shape extending in one direction. Multiple electrodes (RME) may have a shape extending in a first direction (DR1) and be arranged spaced apart from each other in a second direction (DR2) within each subpixel (PXn).

[0071] For example, a single subpixel (PXn) may include a plurality of electrodes (RME) that extend in a first direction (DR1) and are arranged across a light-emitting region (EMA) and a sub-region (SA). The electrodes (RME) of adjacent subpixels (PXn) in the first direction (DR1) may be separated from each other at a separation section (ROP) of the sub-region (SA). The plurality of electrodes (RME) may be formed into an electrode line extending in the first direction (DR1) during the manufacturing process of the display device (10) and utilized to generate an electric field within the subpixel (PXn) to align light-emitting elements (ED). The light-emitting elements (ED) may be aligned by receiving a dielectrophoretic force from the electric field generated on the electrode line, and the electrode line may be separated at the separation section (ROP) to form each electrode (RME).

[0072] Meanwhile, although the drawings illustrate a structure in which electrodes (RME) are spaced apart from each other in the separation portion (ROP) of the sub-region (SA), they are not limited thereto. In some embodiments, electrodes (RME) placed in each sub-pixel (PXn) may be spaced apart from each other in the separation portion (ROP) formed within the light-emitting region (EMA). In this case, the plurality of electrodes (RME) may be divided into one group of electrodes located on one side of the separation portion (ROP) and another group of electrodes located on the other side of the separation portion (ROP), based on the separation portion (ROP) of the light-emitting region (EMA).

[0073] According to one embodiment, the display device (10) may include a first electrode (RME1) and a second electrode (RME2) disposed in each subpixel (PXn). The first electrode (RME1) and the second electrode (RME2) may extend in a first direction (DR1) on a via layer (VIA) and may be spaced apart from each other in a second direction (DR2). The first electrode (RME1) and the second electrode (RME2) may have the same width as each other, but are not limited thereto.

[0074] The first electrode (RME1) may be a first type electrode connected to the fourth conductive layer below the via layer (VIA), and the second electrode (RME2) may be a second type electrode that is not connected. The first electrode (RME1) may be directly connected to the fourth conductive layer through a first electrode contact hole (CTD) formed in a portion overlapping with the first bank (BNL1). The first electrode (RME1) may contact the first conductive pattern (CDP1) through the first electrode contact hole (CTD) penetrating the via layer (VIA) below it. The first electrode (RME1) may be electrically connected to the first transistor (T1) through the first conductive pattern (CDP1) so that the first power supply voltage can be applied. Since the first electrode (RME1) is separated and arranged for each subpixel (PXn), the light-emitting elements (ED) of different subpixels (PXn) can emit light individually.

[0075] On the other hand, the second electrode (RME2) may remain in a floating state after alignment of the light-emitting elements (EDs) without being connected to the lower conductive layer. As described below, an electrical signal applied to the second voltage wiring (VL2) is transmitted to the third connecting electrode (CNE3), and the second connecting electrode (CNE2) placed on the second electrode (RME2) may be directly connected to the second conductive pattern (CDP2). The second electrode (RME2) is utilized in the alignment process of the light-emitting elements (EDs), and an electrical signal may not be applied during the operation of the display device (10). During the alignment process of the light-emitting elements (EDs), different electrical signals are applied to the first electrode (RME1) and the second electrode (RME2), respectively, whereas during the operation of the display device (10), the same electrical signal may be applied to the connecting electrode placed on the first electrode (RME1) and the connecting electrode placed on the second electrode (RME2). To this end, the first electrode (RME1) and the second electrode (RME2) are arranged in a separated state from each other during the manufacturing process of the display device (10), and the connecting electrode placed on the second electrode (RME2) can be directly connected to the conductive layer below the via layer (VIA).

[0076] However, this is not limited thereto, and in some embodiments, the second electrode (RME2) may also be a first type electrode connected to the lower conductive layer. Additionally, while the drawings illustrate the placement of two electrodes (RME) for each subpixel (PXn), this is not limited thereto. The display device (10) may include a greater number of electrodes, particularly second type electrodes, some of which may remain in a floating state and others may be electrically connected to connecting electrodes. This will be described later with reference to other embodiments.

[0077] Some of the plurality of electrodes (RME) may be electrically connected to a light-emitting element (ED). For example, the first electrode (RME1) may be connected to the light-emitting element (ED) through the first connecting electrode (CNE1) described below and may transmit an electrical signal applied from the fourth conductive layer to the light-emitting element (ED). An electrical signal for causing the light-emitting elements (ED) to emit light may be directly applied to the first electrode (RME1), and in an embodiment further comprising electrodes other than the first electrode (RME1) and the second electrode (RME2), the electrical signal may be transmitted to the other electrodes through the connecting electrode (CNE) and the light-emitting elements (ED).

[0078] Each of the plurality of electrodes (RME) may include a highly reflective conductive material. For example, the electrode (RME) may be a highly reflective material that includes a metal such as silver (Ag), copper (Cu), or aluminum (Al), or an alloy including aluminum (Al), nickel (Ni), or lanthanum (La). The electrode (RME) may reflect light emitted from the light-emitting element (ED) and traveling toward the side of the first bank (BNL1) toward the upper direction of each subpixel (PXn).

[0079] However, not limited thereto, each electrode (RME) may further include a transparent conductive material. For example, each electrode (RME) may include a material such as ITO, IZO, ITZO, etc. In some embodiments, each electrode (RME) may have a structure in which a transparent conductive material and a highly reflective metal layer are each stacked one or more times, or may be formed as a single layer including these. For example, each electrode (RME) may have a stacked structure such as ITO / Ag / ITO / , ITO / Ag / IZO, or ITO / Ag / ITZO / IZO.

[0080] A first insulating layer (PAS1) is disposed on a via layer (VIA) and a plurality of electrodes (RME). The first insulating layer (PAS1) is disposed to completely cover the plurality of electrodes (RME), and can protect them while simultaneously insulating them from one another. Additionally, the first insulating layer (PAS1) can prevent a light-emitting element (ED) disposed thereon from being damaged by direct contact with other components.

[0081] In an exemplary embodiment, the first insulating layer (PAS1) may have a step formed such that a portion of its upper surface is recessed between electrodes (RME) spaced apart in the second direction (DR2). A light-emitting element (ED) may be disposed on the upper surface of the first insulating layer (PAS1) where the step is formed, and a space may be formed between the light-emitting element (ED) and the first insulating layer (PAS1). However, it is not limited thereto.

[0082] A plurality of contact portions (e.g., a first contact portion (CT1) to a third contact portion (CT3)) may be formed in the first insulating layer (PAS1) that expose a portion of the upper surface of each electrode (RME) or penetrate to the via layer (VIA). The plurality of contact portions penetrate the first insulating layer (PAS1), and the connecting electrodes (CNE) described later may come into contact with the electrode (RME) or the fourth conductive layer below the via layer (VIA) through the contact portions.

[0083] The first bank (BNL1) may be placed on the first insulating layer (PAS1). The first bank (BNL1) may be arranged in a grid pattern including a portion extending in the first direction (DR1) and the second direction (DR2) in the plan view, and may be placed across the boundaries of each subpixel (PXn) to distinguish neighboring subpixels (PXn). Additionally, the first bank (BNL1) may be arranged to surround the light-emitting region (EMA) and sub-region (SA) placed for each subpixel (PXn) to distinguish them.

[0084] The first bank (BNL1) can have a certain height and can prevent ink from overflowing into adjacent subpixels (PXn) during the inkjet printing process in the manufacturing process of the display device (10). The first bank (BNL1) can prevent inks in which different light-emitting elements (EDs) are dispersed for each other subpixel (PXn) from mixing with each other.

[0085] A plurality of light-emitting elements (EDs) may be disposed on a first insulating layer (PAS1). A light-emitting element (ED) may include a plurality of layers disposed in a direction parallel to the upper surface of a first substrate (SUB). A light-emitting element (ED) of a display device (10) may be disposed such that one extended direction is parallel to the first substrate (SUB), and a plurality of semiconductor layers included in the light-emitting element (ED) may be disposed sequentially along a direction parallel to the upper surface of the first substrate (SUB). However, it is not limited thereto. In some cases, if the light-emitting element (ED) has a different structure, a plurality of layers may be disposed in a direction perpendicular to the first substrate (SUB).

[0086] A plurality of light-emitting elements (EDs) may be spaced apart from each other along a first direction (DR1) in which each electrode (RME) is extended and may be aligned substantially parallel to each other. The light-emitting elements (EDs) may have a shape that extends in one direction, and may be arranged so that the direction in which each electrode (RME) is extended and the direction in which the light-emitting element (ED) is extended are substantially perpendicular. However, they are not limited thereto, and the light-emitting elements (EDs) may be arranged obliquely to the direction in which each electrode (RME) is extended.

[0087] A light-emitting element (ED) may include a plurality of semiconductor layers and may come into contact with connecting electrodes (CNE1, CNE2, CNE3) described later. Since an insulating film ('38' in FIG. 6) is not formed on the extended one-way end surface of the light-emitting element (ED) and a portion of the semiconductor layer is exposed, the exposed semiconductor layer may come into contact with the connecting electrode (CNE). Additionally, in a display device (10) according to one embodiment, a portion of the insulating film (38) located on the side of the light-emitting element (ED) may be removed, and a portion of the connecting electrode (CNE) may be connected on the side of the light-emitting element (ED). Each light-emitting element (ED) may be electrically connected to the conductive layer below the first electrode (RME1) or via layer (VIA) through the connecting electrode (CNE), and may emit light of a specific wavelength range when an electrical signal is applied.

[0088] The light-emitting elements (EDs) placed in each subpixel (PXn) can emit light of different wavelengths depending on the material forming the semiconductor layer. However, they are not limited thereto, and the light-emitting elements (EDs) placed in each subpixel (PXn) can emit light of the same color. Additionally, the light-emitting elements (EDs) may be oriented such that one end faces a specific direction by means of an electric field generated on the electrode (RME), by including semiconductor layers doped with different conductivity types.

[0089] A light-emitting element (ED) may have an extended length longer than the gap between a first electrode (RME1) and a second electrode (RME2), and may be arranged so that both ends are placed on the first electrode (RME1) and the second electrode (RME2), respectively. According to one embodiment, a display device (10) may include a plurality of light-emitting elements (ED; ED1, ED2) in which the directions of one end are different. The light-emitting elements (ED) may include a plurality of semiconductor layers, and a first end and a second end opposite thereto may be defined based on one semiconductor layer. The light-emitting element (ED) may be arranged so that the first end and the second end are placed on the first electrode (RME1) and the second electrode (RME2), respectively, and may be distinguished into different light-emitting elements (ED1, ED2) depending on the electrode (RME1, RME2) on which the first end is placed. For example, the light-emitting element (ED) may include a first light-emitting element (ED1) in which a first end is placed on a first electrode (RME1) and a second end is placed on a second electrode (RME2), and a second light-emitting element (ED2) in which a first end is placed on a second electrode (RME2) and a second end is placed on the first electrode (RME1). However, it is not limited thereto, and a plurality of light-emitting elements (ED) may be arranged such that only one end is placed on the electrodes (RME1, RME2) according to the orientation between the first electrode (RME1) and the second electrode (RME2).

[0090] The first light-emitting element (ED1) and the second light-emitting element (ED2) can each have their two ends connected to different connecting electrodes. The first end of the first light-emitting element (ED1) can be connected to a connecting electrode placed on the first electrode (RME1), and the first end of the second light-emitting element (ED2) can be connected to a connecting electrode placed on the second electrode (RME2). As described below, the connecting electrodes placed on each electrode (RME1, RME2) are electrically connected to the first transistor (T1), and the first light-emitting element (ED1) and the second light-emitting element (ED2) can be electrically connected to the first transistor (T1) through the connecting electrodes regardless of the direction in which the first end faces.

[0091] The manufacturing process of the display device (10) includes an alignment process for placing light-emitting elements (EDs) on electrodes (RME1, RME2). The light-emitting elements (EDs) include a plurality of semiconductor layers doped with different conductivity types and can be placed on the electrodes (RME) while changing their orientation direction and position by an electric field generated on the electrodes (RME1, RME2). The orientation direction of the light-emitting element (ED) is defined as the direction in which a specific end faces depending on the position of the semiconductor layer, but the orientation direction of the plurality of light-emitting elements (EDs) placed on the electrodes (RME) may not be constant. For example, the orientation direction of the plurality of light-emitting elements (EDs), such as the first light-emitting element (ED1) and the second light-emitting element (ED2), may differ from each other. If only the connecting electrode (CNE) placed on one electrode is connected to the light-emitting elements (ED), and only some of the light-emitting elements (ED) (e.g., the first light-emitting element (ED1)) have their first ends electrically connected to the first transistor (T1), then some of the light-emitting elements (ED) (e.g., the second light-emitting element (ED2)) may not emit light.

[0092] A display device (10) according to one embodiment may include a circuit layer (CCL) capable of emitting light regardless of the orientation direction of the light-emitting elements (ED), a connecting electrode (CNE), and a connecting structure of the light-emitting elements (ED). The first electrode (RME1) and the second electrode (RME2) are utilized in the alignment process of the light-emitting elements (ED), and when the light-emitting elements (ED) emit light, an electrical signal applied to the circuit layer (CCL) can be transmitted to the light-emitting elements (ED) through different connecting electrodes (CNE). The arrangement of the connecting electrodes (CNE) and the connection with the light-emitting elements (ED) will be described later.

[0093] A second insulating layer (PAS2) is disposed on a plurality of light-emitting elements (ED). The second insulating layer (PAS2) is disposed entirely on the first insulating layer (PAS1) and can be disposed to cover the light-emitting elements (ED) and the first bank (BNL1) disposed on the first insulating layer (PAS1). The second insulating layer (PAS2) is disposed to cover the first connecting electrode (CNE1) and the second connecting electrode (CNE2) described later, and can protect them while simultaneously insulating them from one another. Additionally, the second insulating layer (PAS2) can mutually insulate the first connecting electrode (CNE1) and the second connecting electrode (CNE2) from the third connecting electrode (CNE3) disposed on the second insulating layer (PAS2).

[0094] According to one embodiment, the second insulating layer (PAS2) may be made of a transparent insulating material. The display device (10) includes a second insulating layer (PAS2) that covers light-emitting elements (ED; ED1, ED2) and mutually insulates a plurality of connecting electrodes (CNE). The second insulating layer (PAS2) may be made of a transparent material so that light emitted from the light-emitting elements (ED) can be emitted in the upper direction of the via layer (VIA).

[0095] In the second insulating layer (PAS2), an opening (OP) that exposes a portion of the side of the light-emitting elements (ED) below it, and a third contact portion (CT3) that penetrates the first insulating layer (PAS1) and the via layer (VIA) together may be formed. The third connecting electrode (CNE3) described later may be disposed on the second insulating layer (PAS2) and connected to the light-emitting elements (ED) and the conductive layer below the via layer (VIA) through the opening (OP) and the third contact portion (CT3).

[0096] A plurality of connecting electrodes (CNE) are disposed on light-emitting elements (ED). The connecting electrodes (CNE) may include a first connecting electrode (CNE1) and a second connecting electrode (CNE2) disposed on each electrode (RME1, RME2) and disposed between a first insulating layer (PAS1) and a second insulating layer (PAS2), and a third connecting electrode (CNE3) disposed to overlap with the light-emitting elements (ED) on the second insulating layer (PAS2).

[0097] A plurality of connecting electrodes (CNE) may be arranged across a light-emitting region (EMA) and a sub-region (SA), including a portion extending in a first direction (DR1). A first connecting electrode (CNE1) may be placed on a first electrode (RME1) and extend in the first direction (DR1), and a second connecting electrode (CNE2) may be placed on a second electrode (RME2) and extend in the first direction (DR1). A third connecting electrode (CNE3) may be arranged to overlap with light-emitting elements (ED) in a space separated from the first electrode (RME1) and the second electrode (RME2) and extend in the first direction (DR1). A plurality of connecting electrodes (CNE) may be arranged on a first bank (BNL1) placed between the light-emitting region (EMA) and the sub-region (SA), and may form a linear pattern for each sub-pixel (PXn). Additionally, connecting electrodes (CNE) disposed on the same layer similar to electrodes (RME) may be spaced apart from each other in a second direction (DR2). The first connecting electrode (CNE1) and the second connecting electrode (CNE2) may be spaced apart in a second direction (DR2) on the light-emitting elements (ED).

[0098] In one embodiment, the width of the first connecting electrode (CNE1) and the second connecting electrode (CNE2) is the same as the width of the third connecting electrode (CNE3), and the width of the third connecting electrode (CNE3) may be greater than the gap between the first electrode (RME1) and the second electrode (RME2). The third connecting electrode (CNE3) may overlap with the light-emitting elements (ED), and both sides may overlap with the first electrode (RME1) and the second electrode (RME2) in the thickness direction, respectively. In the plan view, the gap between the first connecting electrode (CNE1) and the second connecting electrode (CNE2) in the second direction (DR2) may be smaller than the gap between the electrodes (RME1, RME2), and the third connecting electrode (CNE3) may overlap with the first connecting electrode (CNE1) and the second connecting electrode (CNE2) in the thickness direction. However, the third connecting electrode (CNE3) may be placed on the second insulating layer (PAS2) and may not be directly connected to the first connecting electrode (CNE1) and the second connecting electrode (CNE2) below it.

[0099] Meanwhile, the drawings illustrate that the connecting electrodes (CNE) are placed directly on the light-emitting element (ED) and that the connecting electrodes (CNE) placed under the second insulating layer (PAS2) are formed in substantially the same layer, but are not limited thereto. In some embodiments, other insulating layers may be further disposed between the light-emitting element (ED) and the connecting electrodes (CNE), and between the connecting electrodes (CNE), so that some of the connecting electrodes (CNE) are placed on the same layer and others are placed on different layers.

[0100] The portion of the connecting electrode (CNE) placed in the light-emitting region (EMA) may come into contact with the light-emitting elements (ED). For example, the first connecting electrode (CNE1) may come into contact with the first end of the first light-emitting elements (ED1) and the second end of the second light-emitting elements (ED2), and the second connecting electrode (CNE2) may come into contact with the second end of the first light-emitting elements (ED1) and the first end of the second light-emitting elements (ED2). The third connecting electrode (CNE3) may come into contact with the side of the first light-emitting element (ED1) and the second light-emitting element (ED2).

[0101] According to one embodiment, the second insulating layer (PAS2) includes an opening (OP) that exposes the sides of the light-emitting elements (EDs), and the third connecting electrode (CNE3) may contact the sides of the light-emitting elements (EDs) exposed through the opening (OP). The opening (OP) may be positioned to overlap with the light-emitting elements (EDs) in the second insulating layer (PAS2). Although not shown in the drawing, the opening (OP) may have a shape that extends in a first direction (DR1) with a certain width between the first electrode (RME1) and the second electrode (RME2). The opening (OP) may expose the sides of the light-emitting elements (EDs) but may not expose the first connecting electrode (CNE1) and the second connecting electrode (CNE2) located below the second insulating layer (PAS2). For example, the width of the opening (OP) may be smaller than the gap between the first connecting electrode (CNE1) and the second connecting electrode (CNE2), and the second insulating layer (PAS2) may cover the first connecting electrode (CNE1) and the second connecting electrode (CNE2). The third connecting electrode (CNE3) extends along the opening (OP) in a first direction (DR1) and may be positioned to partially wrap the sides of the exposed light-emitting elements (ED).

[0102] Meanwhile, the connecting electrodes (CNE) of the display device (10) can be classified into different types of connecting electrodes depending on whether they are connected to the electrode (RME). For example, the connecting electrode (CNE) may include a first connecting electrode (CNE1) as a first type connecting electrode that is directly connected to the electrode (RME) through a contact portion formed in the first insulating layer (PAS1). Additionally, it may include a second connecting electrode (CNE2) and a third connecting electrode (CNE3) as a second type connecting electrode that is connected to the lower conductive layer through a contact portion penetrating the lower via layer (VIA).

[0103] The first connecting electrode (CNE1) may be positioned to overlap with the first electrode (RME1) on the first insulating layer (PAS1). The first connecting electrode (CNE1) may contact the first electrode (RME1) through a first contact portion (CT1) that penetrates the first insulating layer (PAS1) and exposes the upper surface of the first electrode (RME1). The second connecting electrode (CNE2) may be positioned to overlap with the second electrode (RME2) on the first insulating layer (PAS1). However, the second connecting electrode (CNE2) may not contact the second electrode (RME2) but may contact the second conductive pattern (CDP2) through a second contact portion (CT2) that penetrates the first insulating layer (PAS1) and the via layer (VIA) and exposes the second conductive pattern (CDP2) of the fourth conductive layer.

[0104] As described above, since the first electrode (RME1) is connected to the first conductivity pattern (CDP1), the first connecting electrode (CNE1) and the second connecting electrode (CNE2) can be electrically connected to the first transistor (T1) through different conductivity patterns (CDP1, CDP2), respectively. The first power supply voltage applied to the first voltage wiring (VL1) and the first transistor (T1) can be transmitted to the first connecting electrode (CNE1) and the second connecting electrode (CNE2), respectively, through the first conductivity pattern (CDP1) and the second conductivity pattern (CDP2). The first power supply voltage is applied to the first end of the first light-emitting element (ED1) through the first connecting electrode (CNE1), and the first power supply voltage is applied to the first end of the second light-emitting element (ED2) through the second connecting electrode (CNE2). That is, the display device (10) can apply a first power supply voltage to the first end of the light-emitting elements (ED) regardless of the orientation direction of the plurality of light-emitting elements (ED). The flow of the first power supply voltage applied to the second end of the light-emitting elements (ED) can be blocked by one semiconductor layer of the light-emitting elements (ED). Accordingly, among the first power supply voltages applied to the first connecting electrode (CNE1) and the second connecting electrode (CNE2), only the voltage applied to the first end of the light-emitting elements (ED) can be transmitted through the light-emitting elements (ED).

[0105] The third connecting electrode (CNE3) is positioned to overlap with the light-emitting elements (ED) on the second insulating layer (PAS2) and can contact the side of the light-emitting elements (ED) exposed through the opening (OP) of the second insulating layer (PAS2). Unlike other connecting electrodes, the third connecting electrode (CNE3) overlaps only partially with the electrodes (RME1, RME2) and can contact the second voltage wiring (VL2) of the fourth conductive layer through a third contact portion (CT3) penetrating the second insulating layer (PAS2), the first insulating layer (PAS1), and the via layer (VIA). The second power supply voltage applied to the second voltage wiring (VL2) is transmitted to the third connecting electrode (CNE3), and the second power supply voltage can be applied to the side of the first light-emitting element (ED1) and the second light-emitting element (ED2), respectively. Even if multiple light-emitting elements (EDs) are arranged in random orientation directions, the side exposed by the opening (OP) of the second insulating layer (PAS2) may be a specific part regardless of the type of light-emitting element (ED). The light-emitting elements (EDs) can receive a second power supply voltage applied to the third connecting electrode (CNE3) through the exposed side, and the current flowing through the light-emitting elements (EDs) can flow along the first end and side of the light-emitting elements (EDs). The first light-emitting elements (ED1) and the second light-emitting elements (ED2) can each have current delivered from the first connecting electrode (CNE1) and the second connecting electrode (CNE2) flow to the same third connecting electrode (CNE3), and they can be connected in parallel.

[0106] The first connecting electrode (CNE1), which is a first type connecting electrode, can transmit an electrical signal applied to the first electrode (RME1) to the light-emitting element (ED), and the second connecting electrode (CNE2) and the third connecting electrode (CNE3), which are second type connecting electrodes, can transmit an electrical signal applied to the conductive layer under the via layer (VIA) directly to the light-emitting element (ED).

[0107] Meanwhile, a plurality of contact portions (CT1, CT2, CT3) may be arranged so as not to overlap with the light-emitting elements (ED) in the second direction (DR2). Each contact portion (CT1, CT2, CT3) may be formed spaced apart from the area where the plurality of light-emitting elements (ED) are arranged in the first direction (DR1). In one embodiment, the plurality of contact portions (CT1, CT2, CT3) may be formed in a sub-region (SA) where the light-emitting elements (ED) are not arranged. As the contact portions (CT1, CT2, CT3) are arranged in the sub-region (SA), the refracting of light emitted from the light-emitting elements (ED) at the contact portions (CT1, CT2, CT3) and the inability to emit light can be minimized. Additionally, during the manufacturing process of the display device (10), the light-emitting elements (ED) can be prevented from clumping near the contact portions by the contact portions (CT1, CT2, CT3) that expose the upper surface of the electrode (RME).

[0108] Connecting electrodes (CNEs) may include a conductive material. For example, they may include ITO, IZO, ITZO, aluminum (Al), etc. As an example, the connecting electrode (CNE) may include a transparent conductive material, and light emitted from the light-emitting element (ED) may pass through the connecting electrode (CNE) and proceed toward the electrodes (RME). However, it is not limited thereto.

[0109] Although not shown in the drawing, an insulating layer covering the plurality of connecting electrodes (CNE) may be further disposed thereon. The insulating layer may be disposed entirely on the first substrate (SUB) and function to protect the components disposed thereon from the external environment.

[0110] Each of the above-described first insulating layer (PAS1) and second insulating layer (PAS2) may include an inorganic insulating material or an organic insulating material. However, it is not limited thereto.

[0111] A display device (10) according to one embodiment can emit light regardless of the orientation direction of the light-emitting elements (EDs) through connecting electrodes (CNEs), even if it includes light-emitting elements (EDs) with different orientation directions. The display device (10) has the advantage of improving the manufacturing process yield by increasing the light emission rate of the light-emitting elements (EDs) arranged per unit area.

[0112] FIG. 6 is a schematic diagram of a light-emitting element according to one embodiment. FIG. 7 is a cross-sectional view of the light-emitting element of FIG. 6. FIG. 7 shows a cross-section of the light-emitting element (ED) cut along the length.

[0113] Referring to FIGS. 6 and 7, the light-emitting element (ED) may be a light-emitting diode, and specifically, the light-emitting element (ED) may be an inorganic light-emitting diode made of inorganic material having a size in the nanometer to micrometer range. The light-emitting element (ED) may be aligned between two electrodes that form polarity when an electric field is formed in a specific direction between the two electrodes facing each other.

[0114] A light-emitting element (ED) according to one embodiment may have a shape that extends in one direction. The light-emitting element (ED) may have a shape such as a cylinder, a rod, a wire, or a tube. However, the shape of the light-emitting element (ED) is not limited thereto, and the light-emitting element (ED) may have various shapes, such as a polygonal prism shape like a cube, a rectangular prism, or a hexagonal prism, or a shape that extends in one direction but has a partially inclined outer surface.

[0115] The light-emitting element (ED) may include a semiconductor layer doped with any conductivity type (e.g., p-type or n-type) impurity. The semiconductor layer may emit light of a specific wavelength range when an electrical signal applied from an external power source is transmitted. The light-emitting element (ED) may include a first semiconductor layer (31), a second semiconductor layer (32), a third semiconductor layer (33), a light-emitting layer (36), an electrode layer (37), and an insulating film (38).

[0116] The first semiconductor layer (31) may be an n-type semiconductor. The first semiconductor layer (31) may include a semiconductor material having the chemical formula AlxGayIn1-x-yN (0≤x≤1, 0≤y≤1, 0≤x+y≤1). For example, the first semiconductor layer (31) may be one or more of n-type doped AlGaInN, GaN, AlGaN, InGaN, AlN, and InN. The n-type dopant doped in the first semiconductor layer (31) may be Si, Ge, Sn, etc.

[0117] The second semiconductor layer (32) is disposed on the first semiconductor layer (31) with the light-emitting layer (36) in between. The second semiconductor layer (32) may be a p-type semiconductor, and the second semiconductor layer (32) may include a semiconductor material having the chemical formula AlxGayIn1-x-yN (0≤x≤1, 0≤y≤1, 0≤x+y≤1). For example, the second semiconductor layer (32) may be one or more of p-type doped AlGaInN, GaN, AlGaN, InGaN, AlN, and InN. The p-type dopant doped in the second semiconductor layer (32) may be Mg, Zn, Ca, Se, Ba, etc.

[0118] Meanwhile, the drawing shows the first semiconductor layer (31) and the second semiconductor layer (32) as being composed of a single layer, but is not limited thereto. Depending on the material of the light-emitting layer (36), the first semiconductor layer (31) and the second semiconductor layer (32) may further include a larger number of layers, such as a clad layer or a TSBR (Tensile strain barrier reducing) layer.

[0119] The light-emitting layer (36) is disposed between the first semiconductor layer (31) and the second semiconductor layer (32). The light-emitting layer (36) may include a material having a single or multiple quantum well structure. If the light-emitting layer (36) includes a material having a multiple quantum well structure, it may have a structure in which a quantum layer and a well layer are alternately stacked in multiple layers. The light-emitting layer (36) can emit light by the coupling of electron-hole pairs according to an electric signal applied through the first semiconductor layer (31) and the second semiconductor layer (32). The light-emitting layer (36) may include materials such as AlGaN, AlGaInN, etc. In particular, if the light-emitting layer (36) has a structure in which quantum layers and well layers are alternately stacked in a multiple quantum well structure, the quantum layer may include materials such as AlGaN or AlGaInN, and the well layer may include materials such as GaN or AlInN.

[0120] The light-emitting layer (36) may have a structure in which semiconductor materials with large band gap energy and semiconductor materials with small band gap energy are alternately stacked, and may include different group 3 to group 5 semiconductor materials depending on the wavelength range of the light emitted. The light emitted by the light-emitting layer (36) is not limited to light in the blue wavelength range, and may emit light in the red or green wavelength range depending on the case.

[0121] The third semiconductor layer (33) may be an undoped semiconductor. The third semiconductor layer (33) may include substantially the same semiconductor material as the first semiconductor layer (31), but unlike the first semiconductor layer (31), it may not be doped as an n-type. For example, the third semiconductor layer (33) may be one or more of undoped AlGaInN, GaN, AlGaN, InGaN, AlN, and InN.

[0122] In one embodiment, the third semiconductor layer (33) may be disposed on the opposite side of the surface facing the light-emitting layer (36) of the first semiconductor layer (31). The third semiconductor layer (33) may be disposed on the lower surface of the first semiconductor layer (31) in the drawing and may be a portion exposed on one end surface of the light-emitting element (ED). Both ends of the light-emitting element (ED) may be portions where the second semiconductor layer (32) and the third semiconductor layer (33) are disposed, respectively, and the first power supply voltage applied through the first connecting electrode (CNE1) or the second connecting electrode (CNE2) may be transmitted to the second semiconductor layer (32) or the third semiconductor layer (33) of the light-emitting element (ED). Unlike the second semiconductor layer (32), the third semiconductor layer (33) includes a semiconductor material that is not doped with a dopant, so current may not flow due to the first power supply voltage. Accordingly, even if a first power supply voltage is applied from both ends of the light-emitting element (ED), current can flow in one direction only through a specific end.

[0123] Meanwhile, the length (LD_U) of the third semiconductor layer (33) may have a range of 20% or less of the length (LD) of the light-emitting element (ED). If the length (LD_U) of the third semiconductor layer (33) is too short, current from the first power supply voltage applied to the third semiconductor layer (33) may leak, and if the length (LD_U) is too long, a connection failure between the light-emitting element (ED) and the connecting electrodes (CNE) may occur. In particular, if the part where the third connecting electrode (CNE3) is connected to the light-emitting element (ED) is the third semiconductor layer (33), current from the second power supply voltage may not flow, and the light-emitting elements (ED) may not emit light. The third semiconductor layer (33) may have a length that can block the current flowing to the light-emitting element (ED) while considering the connection with the third connecting electrode (CNE3). For example, the third semiconductor layer (33) may have a length (LD_U) of 1 μm or less. However, it is not limited to this.

[0124] The electrode layer (37) may be an ohmic contact electrode. However, it is not limited thereto and may be a Schottky connection electrode. The light-emitting element (ED) may include at least one electrode layer (37). The light-emitting element (ED) may include one or more electrode layers (37), but is not limited thereto and the electrode layer (37) may be omitted.

[0125] The electrode layer (37) can reduce the resistance between the light-emitting element (ED) and the electrode or connecting electrode when the light-emitting element (ED) in the display device (10) is electrically connected to the electrode or connecting electrode. The electrode layer (37) may include a conductive metal. For example, the electrode layer (37) may include at least one of aluminum (Al), titanium (Ti), indium (In), gold (Au), silver (Ag), ITO, IZO, and ITZO.

[0126] The insulating film (38) is arranged to surround the outer surface of the plurality of semiconductor layers and electrode layers described above. For example, the insulating film (38) may be arranged to surround the outer surface of at least the light-emitting layer (36), but may be formed so that both ends in the longitudinal direction of the light-emitting element (ED) are exposed. Additionally, the insulating film (38) may be formed with a rounded upper surface in cross-section in an area adjacent to at least one end of the light-emitting element (ED).

[0127] The insulating film (38) is made of materials having insulating properties, for example, silicon oxide (SiO₂). x ), silicon nitride (SiN x ), silicon oxynitride (SiO₂ x N y ), aluminum nitride (AlN x ), aluminum oxide (AlO x It may include ) etc. In the drawing, the insulating film (38) is exemplified as being formed as a single layer, but is not limited thereto, and in some embodiments, the insulating film (38) may be formed as a multilayer structure in which a plurality of layers are stacked.

[0128] The insulating film (38) can perform the function of protecting the above members. The insulating film (38) can prevent an electrical short circuit that may occur in the light-emitting layer (36) when in direct contact with the electrode through which an electrical signal is transmitted to the light-emitting element (ED). In addition, the insulating film (38) can prevent a decrease in the light-emitting efficiency of the light-emitting element (ED).

[0129] Additionally, the outer surface of the insulating film (38) may be surface-treated. The light-emitting element (ED) may be sprayed onto the electrode and aligned in a dispersed state within a predetermined ink. Here, in order for the light-emitting element (ED) to remain dispersed without aggregating with other adjacent light-emitting elements (ED) within the ink, the surface of the insulating film (38) may be treated to be hydrophobic or hydrophilic.

[0130] Meanwhile, the side of the light-emitting element (ED) exposed through the opening (OP) of the second insulating layer (PAS2) in the display device (10) may be a portion where the first semiconductor layer (31) is disposed. The opening (OP) may penetrate a portion of the insulating film (38) of the light-emitting element (ED) along with the second insulating layer (PAS2), and may directly expose the first semiconductor layer (31). In one embodiment, the third connecting electrode (CNE3) of the display device (10) may directly contact the first semiconductor layer (31) exposed on the side of the light-emitting element (ED).

[0131] FIG. 8 is a cross-sectional view taken along the line Q4-Q4' of FIG. 3. FIG. 8 illustrates a cross-section in which the center of a plurality of light-emitting elements (ED) between the electrodes (RME) is traversed in a first direction (DR1) in which an opening (OP) is extended.

[0132] Referring to FIG. 8, the second insulating layer (PAS2) may include an opening (OP) that covers a plurality of light-emitting elements (ED) but exposes a portion of the side. In the process of forming the opening (OP), the insulating film (38) of the light-emitting elements (ED) may also be partially removed along with the second insulating layer (PAS2). Since the second insulating layer (PAS2) may include an inorganic insulating material similar to the insulating film (38) of the light-emitting elements (ED), a portion of the insulating film (38) may also be removed during the process of forming the opening (OP). Accordingly, the opening (OP) may directly expose the first semiconductor layer (31) of the light-emitting elements (ED). A portion of the third connecting electrode (CNE3) disposed within the opening (OP) may be in direct contact with the first semiconductor layer (31) of the light-emitting elements (ED), and a second power supply voltage may be transmitted to the first semiconductor layer (31) of the light-emitting elements (ED) through the third connecting electrode (CNE3).

[0133] Regardless of the orientation direction, the portion of the light-emitting element (ED) exposed by the opening (OP) may be the first semiconductor layer (31). The length of the first semiconductor layer (31) of the light-emitting element (ED) may be longer than that of the light-emitting layer (36), the second semiconductor layer (32), and the third semiconductor layer (33), and the center of the light-emitting element (ED) placed on the electrodes (RME) may be located at the first semiconductor layer (31). Even if the first end of the first light-emitting element (ED1) and the second light-emitting element (ED2) are each facing a different direction, since the portion connected to the third connecting electrode (CNE3) is the first semiconductor layer (31), current can flow in a certain direction due to the power supply voltage.

[0134] Meanwhile, FIG. 8 illustrates an example where only a portion of the second insulating layer (PAS2) is removed to form an opening (OP). The portion of the second insulating layer (PAS2) where the opening (OP) is located may have a lower thickness than other portions, and the insulating film (38) covered by the second insulating layer (PAS2) may not be removed. That is, only a portion of the insulating film (38) located at the top of the cross-sectional view of the light-emitting element (ED) may be removed, and only a portion of the top of the first semiconductor layer (31) may be exposed. The third connecting electrode (CNE3) may be arranged to extend in the first direction (DR1) from the portion of the second insulating layer (PAS2) where the opening (OP) is located, covering the second insulating layer (PAS2) and a plurality of light-emitting elements (ED).

[0135] However, not limited thereto, the opening (OP) may be formed to completely penetrate the second insulating layer (PAS2), and the first semiconductor layer (31) may be exposed to the side portion in addition to the upper portion in the cross-sectional view.

[0136] FIG. 9 is a cross-sectional view showing the arrangement of light-emitting elements and a third connecting electrode of a display device according to another embodiment.

[0137] Referring to FIG. 9 in conjunction with FIG. 8, the opening (OP) can penetrate the second insulating layer (PAS2) to expose the first insulating layer (PAS1) below it, and the light-emitting element (ED) can have most of the insulating film (38) removed by the opening (OP). In the cross-sectional view, only the insulating film (38) located at the bottom of the semiconductor layer remains, and both the top and side portions of the first semiconductor layer (31) can be exposed. The third connecting electrode (CNE3) is positioned to surround the first semiconductor layer (31) exposed within the opening (OP) and can come into direct contact with the first insulating layer (PAS1) exposed by the opening (OP). The structure of the opening (OP) shown in FIG. 8 and FIG. 9 may vary depending on the conditions of the process of removing a portion of the second insulating layer (PAS2).

[0138] Meanwhile, the light-emitting element (ED) placed in the display device (10) may have a first semiconductor layer (31) connected to a third connecting electrode (CNE3), and the second semiconductor layer (32) and the third semiconductor layer (33) at both ends may be connected to the first connecting electrode (CNE1) or the second connecting electrode (CNE2), respectively. In one embodiment, the light-emitting element (ED) of the display device (10) may have a first end portion where the second semiconductor layer (32) is placed relative to the light-emitting layer (36), and a second end portion where the third semiconductor layer (33) is placed relative to the light-emitting layer (36). Since the third semiconductor layer (33) of the light-emitting element (ED) includes an undoped semiconductor material, current may not flow even when connected to the connecting electrode (CNE). Accordingly, even if the light-emitting element (ED) is connected to the connecting electrodes (CNE1, CNE2) at both ends, which are each connected to the first transistor (T1), current may flow only in a specific direction.

[0139] FIG. 10 is a schematic diagram showing the flow of current for emitting light from light-emitting elements of a display device according to one embodiment. FIG. 10 schematically illustrates the arrangement of electrodes (RME1, RME2) and connecting electrodes (CNE1, CNE2, CNE3) and light-emitting elements (ED).

[0140] Referring to FIG. 10, a display device (10) may have a first power supply voltage applied to a first connecting electrode (CNE1) and a second connecting electrode (CNE2), respectively, and a second power supply voltage applied to a third connecting electrode (CNE3). Current may flow through the light-emitting elements (ED) due to the first power supply voltage and the second power supply voltage, and the current may flow from the first connecting electrode (CNE1) and the second connecting electrode (CNE2) to the third connecting electrode (CNE3). The first power supply voltage is transmitted to the first or second end of the light-emitting elements (ED), and the current may flow to the first or second end of the light-emitting elements (ED). A first light-emitting element (ED1) has a first end positioned on a first electrode (RME1) so that current flows from the first connecting electrode (CNE1), and a second end positioned on a second electrode (RME2) so that current flows from the second connecting electrode (CNE2). On the other hand, a second light-emitting element (ED2) has a first end positioned on a second electrode (RME2) so that current flows from the second connecting electrode (CNE2), and a second end positioned on a first electrode (RME1) so that current flows from the first connecting electrode (CNE1). As described above, in the case where the portion where the second semiconductor layer (32) is disposed is defined as the first end and the portion where the third semiconductor layer (33) is disposed is defined as the second end, the current flowing through both ends of the light-emitting element (ED) can flow to the light-emitting layer (36) only through the second semiconductor layer (32), which is a p-type semiconductor layer, and the current can not flow through the third semiconductor layer (33), which is an undoped semiconductor layer. That is, the current flowing from the first connecting electrode (CNE1) of the first light-emitting element (ED1) can flow to the light-emitting layer (36), and the current flowing from the second connecting electrode (CNE2) of the second light-emitting element (ED2) can flow to the light-emitting layer (36).The current flowing through the light-emitting layer (36) can flow to the third connecting electrode (CNE3) through the first semiconductor layer (31) regardless of the first light-emitting element (ED1) and the second light-emitting element (ED2). Depending on the flow of current, the light-emitting elements (ED) can emit light of a specific wavelength range from the light-emitting layer (36).

[0141] A display device (10) according to one embodiment includes a light-emitting element (ED) through which current flows only through a specific end, and a plurality of connecting electrodes (CNE) connected to different semiconductor layers of the light-emitting element (ED). The display device (10) can emit light regardless of the orientation direction of the light-emitting elements (ED), and has the advantage of improving the yield of the manufacturing process by minimizing the number of light-emitting elements (ED) that cannot emit light per unit area.

[0142] Hereinafter, various embodiments of the display device (10) will be described with further reference to other drawings.

[0143] FIG. 11 is a plan view showing one subpixel of a display device according to another embodiment. FIG. 12 is a cross-sectional view taken along the line Q5-Q5' of FIG. 11. FIG. 13 is a cross-sectional view taken along the line Q6-Q6' of FIG. 11. FIG. 12 shows a portion where electrodes (RME1_1, RME2_1) and a lower conductive layer are connected across both ends of a light-emitting element (ED) of a display device (10_1), and FIG. 13 shows a cross-sectional view that crosses a plurality of contact portions (CT1, CT4, CT5).

[0144] Referring to FIGS. 11 to 13, in a display device (10_1) according to one embodiment, a second voltage wiring (VL2) is connected to a second electrode (RME2_1), and a third connecting electrode (CNE3_1) can be electrically connected to the second voltage wiring (VL2) through the second electrode (RME2_1). The second connecting electrode (CNE2_1) can be electrically connected to a first transistor (T1) through the first electrode (RME1_1), just like the first connecting electrode (CNE1_1). The display device (10_1) according to this embodiment differs from the embodiment of FIG. 3 in that the arrangement of connecting electrodes (CNE) for emitting light regardless of the orientation direction of the light-emitting elements (ED) is different.

[0145] The second electrode (RME2_1) may be a first type electrode connected to the lower fourth conductive layer in a manner similar to the first electrode (RME1_1). The second electrode (RME2_1) may be directly connected to the lower fourth conductive layer of the via layer (VIA) through a second electrode contact hole (CTS) formed in a portion overlapping with the first bank (BNL1). The second electrode (RME2_1) may contact the second voltage wiring (VL2) through a second electrode contact hole (CTS) penetrating the lower via layer (VIA). Since the second electrode (RME2_1) is disposed separately for each subpixel (PXn), the light-emitting elements (EDs) of different subpixels (PXn) can emit light individually.

[0146] The first connecting electrode (CNE1_1) can be connected to the first electrode (RME1_1) through the first contact portion (CT1) in the same manner as in the embodiment of FIG. 3. The second connecting electrode (CNE2_1) can be placed on the second electrode (RME2_1) and connected to the first electrode (RME1_1) in the same manner as the first connecting electrode (CNE1_1). According to one embodiment, the second connecting electrode (CNE2_1) is placed on the second electrode (RME2_1) and further includes a first electrode extension portion (CE1) placed in a sub-region (SA), and the first electrode extension portion (CE1) can be placed so as to be positioned on the first electrode (RME1_1). The second connecting electrode (CNE2_1) can be in contact with the first electrode (RME1_1) through a fourth contact portion (CT4) penetrating the first insulating layer (PAS1), and can be electrically connected to the first transistor (T1) through the first electrode (RME1_1). As the second connecting electrode (CNE2_1) is connected to the first electrode (RME1_1), the second conductive pattern (CDP2) of the fourth conductive layer can be omitted.

[0147] A first power supply voltage through a first voltage wire (VL1) can be applied to the second connecting electrode (CNE2_1), and a second power supply voltage through a second voltage wire (VL2) can be applied to the second electrode (RME2_1) below it. However, since a first insulating layer (PAS1) is placed between them, a short circuit between the electrodes may not occur even if different electrical signals are applied to the second electrode (RME2_1) and the second connecting electrode (CNE2_1), respectively.

[0148] The third connecting electrode (CNE3_1) is positioned to overlap with the region between the first electrode (RME1_1) and the second electrode (RME2_1) and can be connected to the second electrode (RME2_1). According to one embodiment, the third connecting electrode (CNE3_1) further includes a second electrode extension (CE2) that extends in a first direction (DR1) in the region between the first electrode (RME1_1) and the second electrode (RME2_1) and is positioned in a sub-region (SA), and the second electrode extension (CE2) can be positioned to be placed on the second electrode (RME2_1). The third connecting electrode (CNE3_1) can be in contact with the second electrode (RME2_1) through a fifth contact portion (CT5) that penetrates the first insulating layer (PAS1) and the second insulating layer (PAS2), and can be electrically connected to the second voltage wiring (VL2) through the second electrode (RME2_1). As the third connecting electrode (CNE3_1) is connected to the second electrode (RME2_1), the third contact portion (CT3) that penetrates the second insulating layer (PAS2), the first insulating layer (PAS1), and the via layer (VIA) may be omitted.

[0149] The display device (10_1) can have various modifications in the arrangement of connecting electrodes (CNE) and connections with electrodes (RME) to cause light to be emitted regardless of the orientation direction of the light-emitting elements (ED). In the display device (10_1) according to the present embodiment, since the second electrode (RME2_1) is electrically connected to the second voltage wiring (VL2), there is no electrode remaining in a floating state in each subpixel (PXn), and each electrode (RME) may be a first type electrode connected to the fourth conductive layer. The display device (10_1) has the advantage of being free from the problem of forming unwanted parasitic capacitance as the floating electrode placed in each subpixel (PXn) is omitted.

[0150] FIG. 14 is a cross-sectional view of a light-emitting element according to another embodiment.

[0151] Referring to FIG. 14, a light-emitting element (ED_1) according to one embodiment may further include a fourth semiconductor layer (34_1) inserted and disposed in a third semiconductor layer (33_1). The light-emitting element (ED_1) may prevent current from flowing to a second end by including a third semiconductor layer (33_1), which is an undoped semiconductor layer, and the light-emitting element (ED_1) disposed in a display device (10). To more effectively prevent current flow through the third semiconductor layer (33_1), the light-emitting element (ED_1) according to one embodiment may further include a fourth semiconductor layer (34_1) that performs the function of an electron-blocking layer (EBL). This embodiment differs from the embodiment of FIG. 7 in that the light-emitting element (ED_1) further includes a fourth semiconductor layer (34_1). The description of the first semiconductor layer (31_1), the second semiconductor layer (32_1), the light-emitting layer (36_1), the electrode layer (37_1), and the insulating film (38_1) is the same as described above, and the fourth semiconductor layer (34_1) will be described in detail below.

[0152] The fourth semiconductor layer (34_1) can prevent current applied through the third semiconductor layer (33_1), which is the second end of the light-emitting element (ED_1), from flowing into the first semiconductor layer (31_1). The fourth semiconductor layer (34_1) may include a semiconductor material that is not doped with a dopant, similar to the third semiconductor layer (33_1). For example, the fourth semiconductor layer (34_1) may be one or more of AlGaInN, GaN, AlGaN, InGaN, AlN, and InN. The fourth semiconductor layer (34_1) may include a material having a higher band gap energy than the first semiconductor layer (31_1) and the third semiconductor layer (33_1), thereby preventing electrons injected into the third semiconductor layer (33_1) from flowing into the first semiconductor layer (31_1).

[0153] In the drawings, the fourth semiconductor layer (34_1) is exemplified as being inserted and disposed within the third semiconductor layer (33_1) and spaced apart from the first semiconductor layer (31_1), but is not limited thereto. In some embodiments, the fourth semiconductor layer (34_1) may be disposed in other semiconductor layers, but may be disposed spaced apart from the light-emitting layer (36_1) between the light-emitting layer (36_1) and the third semiconductor layer (33_1).

[0154] FIG. 15 is a cross-sectional view of a light-emitting element according to another embodiment.

[0155] Referring to FIG. 15, in a light-emitting element (ED_2) according to one embodiment, a fourth semiconductor layer (34_2) may be inserted and disposed in the first semiconductor layer (31_2). The fourth semiconductor layer (34_2) acts as an electron blocking layer and can prevent electrons injected into the third semiconductor layer (33_2) from flowing through the first semiconductor layer (31_2) to the third connecting electrode (CNE3). The fourth semiconductor layer (34_2) may be disposed adjacent to the second end where the third semiconductor layer (33_2) is disposed. That is, the gap between the fourth semiconductor layer (34_2) and the third semiconductor layer (33_2) may be smaller than the gap between the fourth semiconductor layer (34_2) and the light-emitting layer (36_2).

[0156] If the portion where the third connecting electrode (CNE3) and the first semiconductor layer (31_2) are in contact is located between the fourth semiconductor layer (34_2) and the light-emitting layer (36_2) based on the portion where the light-emitting element (ED) and the third connecting electrode (CNE3) are in contact in the display device (10), then the fourth semiconductor layer (34_2) may be inserted and disposed within the first semiconductor layer (31_2). In the light-emitting element (ED_2) of FIG. 15, the fourth semiconductor layer (34_2) is inserted and disposed within the first semiconductor layer (31_2), and in the display device (10), the fourth semiconductor layer (34_2) may be disposed between the portion exposed by the opening (OP) of the first semiconductor layer (31_2) and the third semiconductor layer (33_2). However, this is not limited thereto, and the fourth semiconductor layer (34_2) may be disposed between the first semiconductor layer (31_2) and the third semiconductor layer (33_2).

[0157] In one embodiment, the light-emitting element (ED_2) may have a fourth semiconductor layer (34_2) that performs the function of an electron blocking layer spaced apart from the light-emitting layer (36_2) with a contact portion with the third connecting electrode (CNE3) in between. The fourth semiconductor layer (34_2) of the light-emitting element (ED_2) can prevent electrons injected into the third semiconductor layer (33_2) from flowing to the third connecting electrode (CNE3), and can prevent a short circuit caused by current leakage from the second end of the light-emitting element (ED_2) in the display device (10).

[0158] FIG. 16 is a plan view showing one subpixel of a display device according to another embodiment. FIG. 17 is a cross-sectional view taken along the line Q7-Q7' of FIG. 16. FIG. 17 illustrates a cross-section across both ends of light-emitting elements (ED) of different light-emitting element groups (ED#1, ED#2).

[0159] Referring to FIGS. 16 and 17, a display device (10_2) according to one embodiment may have each subpixel (PXn) having a larger number of connecting electrodes (CNE). Light-emitting elements (ED) placed in one subpixel (PXn) may be divided into different groups of light-emitting elements (ED#1, ED#2) according to the connected connecting electrodes (CNE), and the different groups of light-emitting elements (ED#1, ED#2) may be connected to each other through the connecting electrodes (CNE).

[0160] The connecting electrode (CNE) of the display device (10_1) may further include the fourth to sixth connecting electrodes (CNE4_2, CNE5_2, CNE6_2) in addition to the first to third connecting electrodes (CNE1_2, CNE2_2, CNE3_2).

[0161] The first connecting electrode (CNE1_2) and the second connecting electrode (CNE2_2) may be placed on the first electrode (RME1) and the second electrode (RME2), respectively, similar to the embodiment of FIG. 3. The first connecting electrode (CNE1_2) and the second connecting electrode (CNE2_2) may contact the first electrode (RME1) and the second conductive pattern (CDP2) through the first contact portion (CT1) and the second contact portion (CT2), respectively. The first connecting electrode (CNE1_2) and the second connecting electrode (CNE2_2) are placed between the first insulating layer (PAS1) and the second insulating layer (PAS2) and may contact some of the light-emitting elements (ED) placed in each subpixel (PXn) (e.g., light-emitting elements (ED) of the first light-emitting element group (ED#1)). Unlike the embodiment of FIG. 3, the first connecting electrode (CNE1_2) and the second connecting electrode (CNE2_2) have a relatively short length extended in the first direction (DR1) and may not come into contact with some light-emitting elements (EDs) (e.g., light-emitting elements (EDs) of the second light-emitting element group (ED#2)).

[0162] The fourth connecting electrode (CNE4_2) and the fifth connecting electrode (CNE5_2) may be disposed on the first electrode (RME1) and the second electrode (RME2), respectively. The fourth connecting electrode (CNE4_2) may be disposed spaced apart from the first connecting electrode (CNE1_2) in the first direction (DR1), and the fifth connecting electrode (CNE5_2) may be disposed spaced apart from the second connecting electrode (CNE2_2) in the first direction (DR1). Unlike the first connecting electrode (CNE1_2) and the second connecting electrode (CNE2_2), the fourth connecting electrode (CNE4_2) and the fifth connecting electrode (CNE5_2) may not be directly connected to the electrodes (RME1, RME2) or conductive layers below them. The fourth connecting electrode (CNE4_2) and the fifth connecting electrode (CNE5_2) are disposed between the first insulating layer (PAS1) and the second insulating layer (PAS2) and can come into contact with light-emitting elements (EDs) disposed in each subpixel (PXn) that do not come into contact with the first connecting electrode (CNE1_2) and the second connecting electrode (CNE2_2) (e.g., light-emitting elements (EDs) of the second light-emitting element group (ED#2)).

[0163] According to one embodiment, the display device (10_2) may include a first type connecting electrode directly connected to an electrode (RME) disposed below a first insulating layer (PAS1), a second type connecting electrode directly connected to a conductive layer disposed below a via layer (VIA), and a third type contact electrode that is not. The first connecting electrode (CNE1_2) and the second connecting electrode (CNE2_2) are the first type connecting electrode and the second type connecting electrode, respectively, and the fourth connecting electrode (CNE4_2) and the fifth connecting electrode (CNE5_2) may be third type connecting electrodes that are in contact only with light-emitting elements (EDs). The power supply voltage applied from the first voltage wiring (VL1) and the second voltage wiring (VL2) is not directly transmitted to them, but the power supply voltage may be transmitted from the light-emitting elements (EDs) or other types of connecting electrodes. The third type connecting electrode may provide a path through which current flows for the light-emitting elements (EDs) to emit light.

[0164] Additionally, according to one embodiment, the display device (10_2) may include a group of light-emitting elements (ED#1, ED#2) that are distinguished from one another according to the type of connecting electrode that contacts both ends of a subpixel (PXn). For example, in a subpixel (PXn), a first group of light-emitting elements (ED#1) that contacts a first connecting electrode (CNE1_2) and a second connecting electrode (CNE2_2) and a second group of light-emitting elements (ED#2) that contacts a fourth connecting electrode (CNE4_2) and a fifth connecting electrode (CNE5_2) may be disposed, with both ends of the first group of light-emitting elements (ED#1) placed on a first electrode (RME1) and a second electrode (RME2). The light-emitting elements (ED) of each group of light-emitting elements (ED#1, ED#2) may include a first light-emitting element (ED1) and a second light-emitting element (ED2) that are distinguished according to the direction in which the first end faces.

[0165] Each group of light-emitting elements (ED#1, ED#2) may consist of multiple light-emitting elements (ED) arranged relatively adjacently, and may have different relative positions within the light-emitting region (EMA). For example, in one subpixel (PXn), a first group of light-emitting elements (ED#1) may be arranged on one side of the first direction (DR1) with respect to the center of the light-emitting region (EMA), and a second group of light-emitting elements (ED#2) may be arranged on the other side of the first direction (DR1). The first group of light-emitting elements (ED#1) and the second group of light-emitting elements (ED#2) may be spaced apart from each other in the first direction (DR1). The spacing between the light-emitting elements (ED) of each group of light-emitting elements (ED#1, ED#2) may be smaller than the distance between the light-emitting elements (ED) of different groups of light-emitting elements (ED#1, ED#2). However, the light-emitting element group (ED#1, ED#2) may not be objectively distinguished as described above, and may be distinguished according to the relative position within the light-emitting region (EMA) and the type of connected connecting electrode (CNE).

[0166] As described above, the light-emitting elements (ED) of the first light-emitting element group (ED#1) and the second light-emitting element group (ED#2) are each connected at both ends to different connecting electrodes (CNE). Similarly, the light-emitting elements (ED) of different light-emitting element groups (ED#1, ED#2) may have different connecting electrodes disposed on the second insulating layer (PAS2).

[0167] The third connecting electrode (CNE3_2) is positioned to overlap with the light-emitting elements (ED) of the second light-emitting element group (ED#2) and can contact the second light-emitting element group (ED#2) exposed through an opening (OP) formed in the second insulating layer (PAS2). The third connecting electrode (CNE3_2) is positioned to extend to a sub-region (SA) of another sub-pixel (PXn) adjacent in the first direction (DR1) and can contact the second voltage wiring (VL2) through a third contact portion (CT3) formed in the sub-region (SA) of the other sub-pixel (PXn). The third connecting electrode (CNE3_2) may be a second type connecting electrode.

[0168] The sixth connecting electrode (CNE6_2) may be spaced apart from the third connecting electrode (CNE3_2) in the first direction (DR1) on the second insulating layer (PAS2). The sixth connecting electrode (CNE6_2) is positioned to overlap with the light-emitting elements (ED) of the first light-emitting element group (ED#1) and may come into contact with the first light-emitting element group (ED#1) exposed through an opening (OP) formed in the second insulating layer (PAS2). Unlike the third connecting electrode (CNE3_2), the sixth connecting electrode (CNE6_2) may be a third type connecting electrode that is not directly connected to the electrode or conductive layer below it. However, the sixth connecting electrode (CNE6_2) may further include a third electrode extension (CE3) that overlaps with the fourth connecting electrode (CNE4_2) and the fifth connecting electrode (CNE5_2) disposed below the first electrode (RME1) and the second electrode (RME2). The third electrode extension (CE3) may contact the fourth connecting electrode (CNE4_2) and the fifth connecting electrode (CNE5_2) through a plurality of sixth contact portions (CT6) that penetrate the second insulating layer (PAS2).

[0169] The current flowing through the first connecting electrode (CNE1_2) and the second connecting electrode (CNE2_2) can flow to the sixth connecting electrode (CNE6_2) through the light-emitting elements (ED) of the first light-emitting element group (ED#1). The current flows to the fourth connecting electrode (CNE4_2) and the fifth connecting electrode (CNE5_2) through the sixth connecting electrode (CNE6_2), and can flow to the third connecting electrode (CNE3_2) through the light-emitting elements (ED) of the second light-emitting element group (ED#2). The light-emitting elements (ED) of the first light-emitting element group (ED#1) and the light-emitting elements (ED) of the second light-emitting element group (ED#2) can be electrically connected to each other through the fourth to sixth connecting electrodes (CNE4_2, CNE5_2, CNE6_2), which are third type connecting electrodes, and the light-emitting elements (ED) placed in one subpixel (PXn) can be partially connected to each other in series.

[0170] In a display device (10_2) according to one embodiment, light-emitting elements disposed on the same layer can be divided into different light-emitting element groups (ED#1, ED#2), and these can be connected in series through a third type connecting electrode. The display device (10_2) includes light-emitting elements (ED) with different orientation directions, and the light-emitting elements (ED) can form a two-stage series-two-stage parallel connection through a plurality of connecting electrodes. The display device (10_2) according to this embodiment further includes light-emitting elements (ED) connected in series, so that the brightness per unit area can be improved.

[0171] FIG. 18 is a plan view showing one subpixel according to another embodiment of the display device of FIG. 16.

[0172] Referring to FIG. 18, a display device (10_2) according to one embodiment is similar to the embodiment of FIG. 11 in that a second electrode (RME2_2) is connected to a second voltage line (VL2) through a second electrode contact hole (CTS), and a second connecting electrode (CNE2_2) and a third connecting electrode (CNE3_2) can be connected to a first electrode (RME1_2) and a second electrode (RME2_2), respectively. The second connecting electrode (CNE2_2) is electrically connected to a first transistor (T1) through the first electrode (RME1_2), and the third connecting electrode (CNE3_2) can be electrically connected to a second voltage line (VL2) through the second electrode (RME2_2). This embodiment differs from the embodiment of FIG. 16 in that the connection structure of the second electrode (RME2_2) is the same as that of the embodiment of FIG. 11.

[0173] The second electrode (RME2_2) may be a first type electrode connected to the lower fourth conductive layer. The second electrode (RME2_2) may contact the second voltage wiring (VL2) of the via layer (VIA) through a second electrode contact hole (CTS) formed in a portion overlapping with the first bank (BNL1).

[0174] The second connecting electrode (CNE2_2) may be positioned on the second electrode (RME2_2) and placed on the first electrode (RME1_2) in a sub-region (SA). The second connecting electrode (CNE2_2) may contact the first electrode (RME1_2) through a fourth contact portion (CT4) penetrating the first insulating layer (PAS1), and may be electrically connected to the first transistor (T1) through the first electrode (RME1_2).

[0175] The third connecting electrode (CNE3_2) is positioned to overlap with the region between the first electrode (RME1_2) and the second electrode (RME2_2) and can be connected to the second electrode (RME2_2). The third connecting electrode (CNE3_2) can be positioned to lie on the second electrode (RME2_2) in the sub-region (SA). The third connecting electrode (CNE3_2) can contact the second electrode (RME2_2) through a fifth contact portion (CT5) that penetrates the first insulating layer (PAS1) and the second insulating layer (PAS2), and can be electrically connected to the second voltage wiring (VL2) through the second electrode (RME2_1).

[0176] FIG. 19 is a plan view showing one subpixel of a display device according to another embodiment. FIG. 20 is a cross-sectional view taken along the line Q8-Q8' of FIG. 19. FIG. 21 is a cross-sectional view taken along the lines Q9-Q9' and Q10-Q10' of FIG. 19. FIG. 20 shows a cross-section across both ends of light-emitting elements (ED) of different light-emitting element groups (ED#1, ED#2), and FIG. 21 shows a cross-section across a plurality of contact portions.

[0177] Referring to FIGS. 19 to 21, a display device (10_3) according to one embodiment may include a larger number of electrodes (RME) and connecting electrodes (CNE) for each subpixel (PXn). The number of light-emitting elements (ED) placed in one subpixel (PXn) may increase, thereby increasing the brightness per unit area. The display device (10_3) according to this embodiment differs from the embodiment of FIG. 16 in that the number of electrodes (RME) placed in each subpixel (PXn) is different.

[0178] The display device (10_3) may further include a third electrode (RME3_3) and a fourth electrode (RME4_3) in addition to the first electrode (RME1_3) and the second electrode (RME2_3). The third electrode (RME3_3) may be spaced apart from the second electrode (RME2_3) in the second direction (DR2), and the fourth electrode (RME4_3) may be spaced apart from the second electrode (RME2_3) in the second direction (DR2) with the third electrode (RME3_3) in between. The third electrode (RME3_3) may be spaced apart from the second electrode (RME2_3) in the second direction (DR2) and face it, and the fourth electrode (RME4_3) may be spaced apart from the third electrode (RME3_3) in the second direction (DR2) and face it. Similar to the first electrode (RME1_3) and the second electrode (RME2_3), the third electrode (RME3_3) and the fourth electrode (RME4_3) may also be extended in the first direction (DR1) and positioned across the light-emitting region (EMA) and the sub-region (SA), and may be spaced apart from the third electrode (RME3_3) and the fourth electrode (RME4_3) of another sub-pixel (PXn) adjacent in the first direction (DR1) at the separation portion (ROP). Similar to the second electrode (RME2_3), the third electrode (RME3_3) and the fourth electrode (RME4_3) may not be directly connected to the fourth conductive layer under the via layer (VIA). However, the third electrode (RME3_3) and the fourth electrode (RME4_3) may be third-type electrodes that contact the connecting electrode (CNE) described later.

[0179] A plurality of light-emitting elements (EDs) may be disposed on a first electrode (RME1_3), a second electrode (RME2_3), a third electrode (RME3_3), and a fourth electrode (RME4_3). The light-emitting elements (EDs) may be divided into a first group of light-emitting elements (ED#1) in which both ends are disposed on the first electrode (RME1_3) and the second electrode (RME2_3) on the first insulating layer (PAS1), and a second group of light-emitting elements (ED#2) in which both ends are disposed on the third electrode (RME3_3) and the fourth electrode (RME4_3) on the first insulating layer (PAS1). The light-emitting elements (EDs) of each group of light-emitting elements (ED#1, ED#2) may include a first light-emitting element (ED1) and a second light-emitting element (ED2) distinguished according to the direction in which the first end faces.

[0180] The first connecting electrode (CNE1_3) and the second connecting electrode (CNE2_3) may be placed on the first electrode (RME1_3) and the second electrode (RME2_3), respectively. Their placement may be substantially the same as the embodiment of FIG. 3. The first connecting electrode (CNE1_3) and the second connecting electrode (CNE2_3) may be in contact with both ends of the first light-emitting element group (ED#1).

[0181] The fourth connecting electrode (CNE4_3) and the fifth connecting electrode (CNE5_3) may be placed on the third electrode (RME3_3) and the fourth electrode (RME4_3), respectively. The third connecting electrode (CNE3_3) and the fourth connecting electrode (CNE4_3) may be in contact with both ends of the second light-emitting element group (ED#2). Their placement is similar to that of the first connecting electrode (CNE1_3) and the second connecting electrode (CNE2_3), but the connection with the electrode (RME) below them may be different. For example, the fourth connecting electrode (CNE4_3) may contact the third electrode (RME3_3) through a seventh contact portion (CT7) that penetrates the first insulating layer (PAS1) in the sub-region (SA), and the fifth connecting electrode (CNE5_3) may contact the fourth electrode (RME4_3) through an eighth contact portion (CT8) that penetrates the first insulating layer (PAS1) in the sub-region (SA). Unlike the second electrode (RME2_3), the third electrode (RME3_3) and the fourth electrode (RME4_3) may not be floated as they are connected to the connecting electrode above them.

[0182] The third connecting electrode (CNE3_3) is positioned to overlap with the light-emitting elements (ED) of the second light-emitting element group (ED#2) and can contact the second light-emitting element group (ED#2) exposed through an opening (OP) formed in the second insulating layer (PAS2). The third connecting electrode (CNE3_3) is positioned to extend to a sub-region (SA) and can contact the second voltage wiring (VL2) through a third contact portion (CT3) formed in the sub-region (SA).

[0183] The sixth connecting electrode (CNE6_3) may be spaced apart from the third connecting electrode (CNE3_3) in the second direction (DR2) on the second insulating layer (PAS2). The sixth connecting electrode (CNE6_3) is positioned to overlap with the light-emitting elements (ED) of the first light-emitting element group (ED#1) and may come into contact with the first light-emitting element group (ED#1) exposed through an opening (OP) formed in the second insulating layer (PAS2). Unlike the third connecting electrode (CNE3_3), the sixth connecting electrode (CNE6_3) may be a third type connecting electrode that is not directly connected to the electrode or conductive layer below it. However, the sixth connecting electrode (CNE6_3) may include a third electrode extension (CE3) that extends in the second direction (DR2) within the light-emitting region (EMA) and is positioned across the second electrode (RME2_3), the third electrode (RME3_3), and the fourth electrode (RME4_3). The third electrode extension (CE3) is positioned to overlap with the fourth connecting electrode (CNE4_3) and the fifth connecting electrode (CNE5_3), and may contact the fourth connecting electrode (CNE4_3) and the fifth connecting electrode (CNE5_3) through a plurality of sixth contact portions (CT6) that penetrate the second insulating layer (PAS2).

[0184] Similar to the embodiment of FIG. 16, the light-emitting elements (EDs) of the first light-emitting element group (ED#1) and the second light-emitting element group (ED#2) can be electrically connected through the sixth connecting electrode (CNE6_3), the fourth connecting electrode (CNE4_3), and the fifth connecting electrode (CNE5_3). The display device (10_3) according to the present embodiment may include a larger number of electrodes (RME) to accommodate more light-emitting elements (EDs), and the plurality of light-emitting elements (EDs) may form a two-stage series-two-stage parallel connection. The display device (10_3) may include more light-emitting elements (EDs) to improve brightness per unit area.

[0185] FIG. 22 is a plan view showing one subpixel according to another embodiment of the display device of FIG. 19.

[0186] Referring to FIG. 22, a display device (10_3) according to one embodiment is similar to the embodiment of FIG. 11 in that a second electrode (RME2_3) is connected to a second voltage line (VL2) through a second electrode contact hole (CTS), and a second connecting electrode (CNE2_3) and a third connecting electrode (CNE3_3) can be connected to a first electrode (RME1_3) and a second electrode (RME2_3), respectively. The second connecting electrode (CNE2_3) is electrically connected to a first transistor (T1) through the first electrode (RME1_3), and the third connecting electrode (CNE3_3) can be electrically connected to a second voltage line (VL2) through the second electrode (RME2_3). This embodiment differs from the embodiment of FIG. 19 in that the connection structure of the second electrode (RME2_3) is the same as that of the embodiment of FIG. 11. The arrangement and connection of the second electrode (RME2_3), the second connecting electrode (CNE2_3), and the third connecting electrode (CNE3_3) are substantially the same as described above with reference to FIGS. 11 and FIGS. 18, so a detailed description will be omitted.

[0187] FIG. 23 is a plan view showing one subpixel of a display device according to another embodiment.

[0188] Referring to FIG. 23, a display device (10_4) according to one embodiment includes a larger number of connecting electrodes (CNE) for each subpixel (PXn), so that the light-emitting elements (ED) of each subpixel (PXn) can form a 4-stage serial-2-stage parallel connection. This embodiment differs from the embodiment of FIG. 18 in that the number of connecting electrodes (CNE) placed in each subpixel (PXn) of the display device (10_4) and the serial connection between the light-emitting elements (ED) are different. Hereinafter, redundant content will be omitted, and the arrangement and connection of the light-emitting elements (ED) and connecting electrodes (CNE) will be described.

[0189] Compared to the embodiment of FIG. 19, the display device (10_4) according to one embodiment may have light-emitting elements (ED) placed on the first electrode (RME1_4) and the second electrode (RME2_4) divided into a first light-emitting element group (ED#1) and a third light-emitting element group (ED#3), and light-emitting elements (ED) placed on the third electrode (RME3_4) and the fourth electrode (RME4_4) divided into a second light-emitting element group (ED#2) and a fourth light-emitting element group (ED#4).

[0190] A plurality of connecting electrodes (CNE) may further include 7th to 12th connecting electrodes (CNE7_4, CNE8_4, CNE9_4, CNE10_4, CNE11_4, CNE12_4) in addition to 1st to 6th connecting electrodes (CNE1_4, CNE2_4, CNE3_4, CNE4_4, CNE5_4, CNE6_4). The arrangement and connection relationship of the 1st to 6th connecting electrodes (CNE1_4, CNE2_4, CNE3_4, CNE4_4, CNE5_4, CNE6_4) is substantially the same as that of the embodiment of FIG. 18. However, the length of the first to sixth connecting electrodes (CNE1_4, CNE2_4, CNE3_4, CNE4_4, CNE5_4, CNE6_4) extended in the first direction (DR1) may be shorter than that of the embodiment of FIG. 18 so as to contact only the light-emitting elements (ED) of the first light-emitting element group (ED#1) and the second light-emitting element group (ED#2). A detailed description of these is omitted.

[0191] The seventh connecting electrode (CNE7_4) is positioned to overlap with the first electrode (RME1_4) on the first insulating layer (PAS1). The seventh connecting electrode (CNE7_4) may be a third type connecting electrode that is spaced apart from the first connecting electrode (CNE1_4) in the first direction (DR1) and is not connected to the electrodes or conductive layer below it. The eighth connecting electrode (CNE8_4) is positioned to overlap with the second electrode (RME2_4) on the first insulating layer (PAS1). The eighth connecting electrode (CNE8_4) may be a third type connecting electrode that is spaced apart from the second connecting electrode (CNE2_4) in the first direction (DR1) and is not connected to the electrodes or conductive layer below it. The seventh connecting electrode (CNE7_4) and the eighth connecting electrode (CNE8_4) may each come into contact with both ends of the light-emitting elements (ED) of the third light-emitting element group (ED#3). In addition, the 7th connecting electrode (CNE7_4) and the 8th connecting electrode (CNE8_4) can be in contact through the 3rd electrode extension (CE3) and the 6th contact part (CT6) of the 6th connecting electrode (CNE6_4).

[0192] The ninth connecting electrode (CNE9_4) may be spaced apart from the sixth connecting electrode (CNE6_4) in the second direction (DR2) on the second insulating layer (PAS2). The ninth connecting electrode (CNE9_4) is positioned to overlap with the light-emitting elements (ED) of the third light-emitting element group (ED#3) and may come into contact with the third light-emitting element group (ED#3) exposed through an opening (OP) formed in the second insulating layer (PAS2). Unlike the third connecting electrode (CNE3_4), the ninth connecting electrode (CNE9_4) may be a third type connecting electrode that is not directly connected to the electrode or conductive layer below it. However, the ninth connecting electrode (CNE9_4) may include a fourth electrode extension (CE4) that extends in the second direction (DR2) within the light-emitting region (EMA) and is positioned across the second electrode (RME2_4), the third electrode (RME3_4), and the fourth electrode (RME4_4). The fourth electrode extension (CE4) is positioned to overlap with the tenth connecting electrode (CNE10_4) and the eleventh connecting electrode (CNE11_4) described later, and may contact the tenth connecting electrode (CNE10_4) and the eleventh connecting electrode (CNE11_4) through a plurality of ninth contact portions (CT9) penetrating the second insulating layer (PAS2).

[0193] The 10th connecting electrode (CNE10_4) is positioned to overlap with the 3rd electrode (RME3_4) on the 1st insulating layer (PAS1). The 10th connecting electrode (CNE10_4) may be a 3rd type connecting electrode that is spaced apart from the 4th connecting electrode (CNE4_4) in the 1st direction (DR1) and is not connected to the electrodes or conductive layer below it. The 11th connecting electrode (CNE11_4) is positioned to overlap with the 4th electrode (RME4_4) on the 1st insulating layer (PAS1). The 11th connecting electrode (CNE11_4) may be a 3rd type connecting electrode that is spaced apart from the 5th connecting electrode (CNE5_4) in the 1st direction (DR1) and is not connected to the electrodes or conductive layer below it. The 10th connecting electrode (CNE10_4) and the 11th connecting electrode (CNE11_4) can each come into contact with both ends of the light-emitting elements (ED) of the 4th light-emitting element group (ED#4). Additionally, the 10th connecting electrode (CNE10_4) and the 11th connecting electrode (CNE11_4) can come into contact through the 4th electrode extension (CE4) and the 9th contact part (CT9) of the 9th connecting electrode (CNE9_4).

[0194] The 12th connecting electrode (CNE12_4) may be spaced apart from the 3rd connecting electrode (CNE3_4) in the 2nd direction (DR2) on the 2nd insulating layer (PAS2). The 12th connecting electrode (CNE12_4) may be positioned to overlap with the light-emitting elements (ED) of the 4th light-emitting element group (ED#4) and may come into contact with the 4th light-emitting element group (ED#4) exposed through an opening (OP) formed in the 2nd insulating layer (PAS2). Unlike the 3rd connecting electrode (CNE3_4), the 12th connecting electrode (CNE12_4) may be a 3rd type connecting electrode that is not directly connected to the electrode or conductive layer below it. However, the 12th connecting electrode (CNE12_4) may include a 5th electrode extension (CE5), and the 5th electrode extension (CE5) may be positioned to overlap with the 4th connecting electrode (CNE4_4) and the 5th connecting electrode (CNE5_4). The fifth electrode extension (CE5) can contact the fourth connecting electrode (CNE4_4) and the fifth connecting electrode (CNE5_4) through a plurality of tenth contact portions (CT10) that penetrate the second insulating layer (PAS2).

[0195] In the display device (10_4), the light-emitting elements (ED) are divided into a larger number of light-emitting element groups (ED#1, ED#2, ED#3, ED#4) and can be connected in series with each other. Accordingly, the light-emitting elements (ED) in the display device (10_4) can form a 4-stage serial-2-stage parallel connection, so that the brightness of each subpixel (PXn) can be further enhanced.

[0196] FIG. 24 is a plan view showing one subpixel according to another embodiment of the display device of FIG. 23.

[0197] Referring to FIG. 24, a display device (10_4) according to one embodiment is similar to the embodiment of FIG. 11 in that a second electrode (RME2_4) is connected to a second voltage line (VL2) through a second electrode contact hole (CTS), and a second connecting electrode (CNE2_4) and a third connecting electrode (CNE3_4) can be connected to a first electrode (RME1_4) and a second electrode (RME2_4), respectively. The second connecting electrode (CNE2_4) is electrically connected to a first transistor (T1) through the first electrode (RME1_4), and the third connecting electrode (CNE3_4) can be electrically connected to a second voltage line (VL2) through the second electrode (RME2_4). This embodiment differs from the embodiment of FIG. 23 in that the connection structure of the second electrode (RME2_4) is the same as that of the embodiment of FIG. 11. The arrangement and connection of the second electrode (RME2_4), the second connecting electrode (CNE2_4), and the third connecting electrode (CNE3_4) are substantially the same as described above with reference to FIGS. 11 and 18, so a detailed description is omitted. FIG. 25 is a cross-sectional view showing a part of a display device according to another embodiment.

[0198] Referring to FIG. 25, a display device (10_5) according to one embodiment may further include an insulating layer that fixes the alignment position of light-emitting elements (EDs) during a manufacturing process. The display device (10_5) may further include a third insulating layer (PAS3_5) disposed on a plurality of light-emitting elements (EDs). The third insulating layer (PAS3_5) may be disposed to partially cover the light-emitting elements (EDs; ED1, ED2) prior to the process of forming a first connecting electrode (CNE1) and a second connecting electrode (CNE2). The third insulating layer (PAS3_5) can prevent the light-emitting elements (EDs) from detaching during the process of forming the connecting electrodes (CNEs).

[0199] The third insulating layer (PAS3_5) may be partially disposed on the first insulating layer (PAS1) and the light-emitting elements (ED). For example, the third insulating layer (PAS3_5) may be disposed to partially wrap the outer surface of a plurality of light-emitting elements (ED), and may be disposed so as not to cover both ends of the light-emitting elements (ED). The portion of the third insulating layer (PAS3_5) disposed on the light-emitting elements (ED) may be disposed to extend in a first direction (DR1) on the first insulating layer (PAS1) in a planar view, thereby forming a linear or island pattern within each subpixel (PXn). The third insulating layer (PAS3_5) can protect the light-emitting elements (ED; ED1, ED2) and at the same time fix the position of the light-emitting elements (ED) during the manufacturing process of the display device (10_5).

[0200] The first connecting electrode (CNE1_5) and the second connecting electrode (CNE2_5) may be spaced apart from each other on the third insulating layer (PAS3_5). The first connecting electrode (CNE1_5) may be in contact with the first end of the first light-emitting element (ED1) and the second end of the second light-emitting element (ED2), with a portion disposed on the third insulating layer (PAS3_5), and the second connecting electrode (CNE2_5) may be in contact with the second end of the first light-emitting element (ED1) and the first end of the second light-emitting element (ED2), with a portion disposed on the third insulating layer (PAS3_5). The first connecting electrode (CNE1_5) and the second connecting electrode (CNE2_5) may be spaced apart from each other in a second direction (DR2) on the portion of the third insulating layer (PAS3_5) that surrounds the light-emitting elements (ED).

[0201] The third connecting electrode (CNE3_5) can be positioned to overlap with the light-emitting elements (ED) on the second insulating layer (PAS2_5) and the third insulating layer (PAS3_5). An opening (OP) formed in the second insulating layer (PAS2_5) can penetrate the third insulating layer (PAS3_5) as well to expose the side of the light-emitting elements (ED), and the third connecting electrode (CNE3_5) can partially contact the side of the light-emitting elements (ED) exposed through the opening (OP).

[0202] FIG. 26 is a cross-sectional view showing a part of a display device according to another embodiment.

[0203] Referring to FIG. 26, in one embodiment, a display device (10_6) has a first connecting electrode (CNE1_6) and a second connecting electrode (CNE2_6) placed on different layers, and an insulating layer may be further placed between them. This embodiment differs from the embodiment of FIG. 25 in that the display device (10_6) includes more insulating layers.

[0204] The fourth insulating layer (PAS4_6) may be disposed on the first insulating layer (PAS1), the third insulating layer (PAS3_6), and the second connecting electrode (CNE2_6). The fourth insulating layer (PAS4_6) may be disposed entirely on the first insulating layer (PAS1) and the third insulating layer (PAS3_5), but may be disposed so that one end of the light-emitting elements (ED) on which the first connecting electrode (CNE1_6) is disposed is exposed. A portion of the first connecting electrode (CNE1_6) is disposed on the fourth insulating layer (PAS4_6), and the first connecting electrode (CNE1_6) and the second connecting electrode (CNE2_6) may be mutually insulated by the fourth insulating layer (PAS4_6).

[0205] The third connecting electrode (CNE3_6) may be positioned to overlap with light-emitting elements (EDs) on the second insulating layer (PAS2_6), the third insulating layer (PAS3_6), and the fourth insulating layer (PAS4_6). An opening (OP) formed in the second insulating layer (PAS2_6) may penetrate the third insulating layer (PAS3_6) and the fourth insulating layer (PAS4_6) to expose the sides of the light-emitting elements (EDs), and the third connecting electrode (CNE3_6) may partially contact the sides of the light-emitting elements (EDs) exposed through the opening (OP).

[0206] In the above embodiments, the first connecting electrode (CNE1) and the second connecting electrode (CNE2) may be formed in the same process, and the third connecting electrode (CNE3) may be formed in a different process. However, in the display device (10_6) according to the present embodiment, at least one insulating layer may be disposed between the first connecting electrode (CNE1_6) and the second connecting electrode (CNE2_6) and formed in a different process. For example, after disassembling the light-emitting elements (ED) and forming the third insulating layer (PAS3_6), the second connecting electrode (CNE2_6) is formed first, and then the fourth insulating layer (PAS4_6) and the first connecting electrode (CNE1_6) are formed sequentially. The display device (10_6) can prevent short-circuit problems caused by residue of connecting electrode materials in the manufacturing process by insulating each connecting electrode (CNE1_6, CNE2_6, CNE3_6) through an insulating layer (e.g., a second insulating layer (PAS2_6), a third insulating layer (PAS3_6) and a fourth insulating layer (PAS4_6)) from each other.

[0207] FIG. 27 is a cross-sectional view showing a part of a display device according to another embodiment.

[0208] Referring to FIG. 27, a display device (10_7) according to one embodiment may further include a plurality of second banks (BNL2) disposed between each electrode (RME; RME1, RME2) and a via layer (VIA). A portion of the plurality of electrodes (RME; RME1, RME2) disposed in a light-emitting region (EMA) may be disposed on the second bank (BNL2), and light-emitting elements (ED; ED1, ED2) may be disposed between the second banks (BNL2) that are spaced apart from each other. The display device (10_7) of this embodiment differs from the embodiment of FIG. 4 in that it further includes a second bank (BNL2) disposed below the electrode (RME).

[0209] The second bank (BNL2) may be placed directly on the via layer (VIA). The second bank (BNL2) may be placed extending from the center of the light-emitting region (EMA) in the first direction (DR1). In the display device (10_7), a plurality of second banks (BNL2) are placed in each subpixel (PXn), and they may be spaced apart from each other. For example, the second banks (BNL2) may be spaced apart from each other in the second direction (DR2) in each light-emitting region (EMA). The first electrode (RME1) and the second electrode (RME2) may each be placed on different second banks (BNL2).

[0210] The second bank (BNL2) may have a length extended in the first direction (DR1) that is smaller than the length in the first direction (DR1) of the area enclosed by the first bank (BNL1). That is, the second bank (BNL2) may be placed within the light-emitting area (EMA) of each subpixel (PXn) to form an island-shaped pattern that is extended in one direction with a relatively narrow width across the front of the display area (DPA).

[0211] The second bank (BNL2) may have a structure in which at least a portion protrudes with respect to the upper surface of the via layer (VIA). The protruding portion of the second bank (BNL2) may have an inclined side. However, not limited thereto, the second bank (BNL2) may have a shape of a semicircle or semi-ellipse with a curved outer surface. The second bank (BNL2) may include an organic insulating material such as polyimide (PI), but is not limited thereto.

[0212] In one embodiment, the width measured in the second direction (DR2) of the first electrode (RME1) and the second electrode (RME2) may be smaller than the second bank (BNL2).

[0213] The first electrode (RME1) and the second electrode (RME2) may be arranged to cover only one side of the second bank (BNL2). However, not limited thereto, the width of the electrodes (RME) measured in the second direction (DR2) may be larger than the second bank (BNL2), and the electrodes (RME) may cover both sides of the second bank (BNL2). A plurality of electrodes (RME) may be arranged to cover at least one side of the second bank (BNL2) to reflect light emitted from the light-emitting element (ED).

[0214] Additionally, the spacing between multiple electrodes (RME) in the second direction (DR2) may be narrower than the spacing between the second banks (BNL2). Even if the display device (10_7) includes additional second banks (BNL2), each electrode (RME) may have at least a portion of its area directly placed on the via layer (VIA) so that they can be placed on the same plane.

[0215] In one embodiment, the first electrode (RME1) and the second electrode (RME2) may be arranged to cover at least one side of the second bank (BNL2). The second bank (BNL2) may have a certain height and a side shape that is inclined or curved, and light-emitting elements (EDs) are arranged between the second bank (BNL2) that are spaced apart in a second direction (DR2). Light generated from the light-emitting elements (EDs) may be emitted in the direction of both ends of the light-emitting elements (EDs), and said light may travel toward the electrode (RME) placed on the side of the second bank (BNL2). As described above, the electrode (RME) may include a material with high reflectivity, and light emitted from the light-emitting elements (EDs) may be reflected from the electrode (RME) toward the upper direction of the via layer (VIA). The display device (10_8) may further include second banks (BNL2) placed between the via layer (VIA) and the electrode (RME) to improve the front light emission efficiency.

[0216] FIG. 28 is a cross-sectional view of a light-emitting element according to another embodiment. FIG. 29 is a plan view showing a part of a display device including the light-emitting element of FIG. 28.

[0217] Referring to FIGS. 28 and 29, a light-emitting element (ED_8) according to one embodiment may omit the third semiconductor layer (33) and include one first semiconductor layer (31), a plurality of light-emitting layers (36), a second semiconductor layer (32), and an electrode layer (37). In the light-emitting element (ED_8), the first semiconductor layer (31) may be disposed at the center in the longitudinal direction, and the light-emitting layer (36), the second semiconductor layer (32), and the electrode layer (37) may be sequentially disposed at each end in the longitudinal direction. The light-emitting element (ED_8) may have a shape that extends in one direction, and the plurality of semiconductor layers of the light-emitting element (ED_8) may have a symmetrical arrangement with respect to the first semiconductor layer (31). In the drawings, an example is shown in which an electrode layer (37) is disposed at each end of the light-emitting element (ED_8), but this is not limited thereto, and at least one electrode layer (37) may be omitted.

[0218] As in the embodiments of FIGS. 7 and FIGS. 10, a light-emitting element (ED) placed in a display device (10) has a third connecting electrode (CNE3) and a first semiconductor layer (31) connected at the center in the longitudinal direction, and both ends are connected to the first connecting electrode (CNE1) or the second connecting electrode (CNE2). The current flowing to the third connecting electrode (CNE3) flows through one end where the second semiconductor layer (32) or the electrode layer (37) is placed, emitting light from the light-emitting layer (36), and may not flow to the other end where the third semiconductor layer (33) is placed. However, as in the embodiment of FIG. 28, when the light-emitting element (ED_8) includes a plurality of light-emitting layers (36) and a second semiconductor layer (32) or an electrode layer (37) is disposed at each end relative to the first semiconductor layer (31), the current flowing to the first semiconductor layer (31) through the third connecting electrode (CNE3) flows to each end and can emit light from the light-emitting layer (36).

[0219] As illustrated in FIG. 29, a display device (10_8) according to one embodiment includes light-emitting elements (ED_8) comprising a plurality of light-emitting layers (36), and current can flow regardless of the orientation direction of the light-emitting elements (ED_8). In the light-emitting elements (ED_8), a first semiconductor layer (31) is connected to a third connecting electrode (CNE3), and each electrode layer (37) or second semiconductor layer (32) disposed at both ends can be connected to a first connecting electrode (CNE1) or a second connecting electrode (CNE2), respectively. Among the two ends of the light-emitting elements (ED_8), the first end disposed on the first electrode (RME1) can be connected to the first connecting electrode (CNE1), and the second end disposed on the second electrode (RME2) can be connected to the second connecting electrode (CNE2).

[0220] Unlike the embodiments of FIGS. 7 and FIG. 10, a second semiconductor layer (32), which is a p-type semiconductor layer, is disposed at both ends of the light-emitting element (ED_8), and a light-emitting layer (36) is disposed between it and the first semiconductor layer (31). Current flowing from the first connecting electrode (CNE1) and the second connecting electrode (CNE2) can flow to the first semiconductor layer (31) through the second semiconductor layer (32) and the light-emitting layer (36) of the light-emitting element (ED_8), respectively, and most of the light-emitting elements (ED_8) of the display device (10_8) can emit light. A display device (10_8) according to one embodiment includes light-emitting elements (ED_8) that include a plurality of light-emitting layers (36), so that light can be emitted regardless of the orientation direction of the light-emitting element (ED_8) and the direction of current flow, thereby increasing the amount of light emitted per unit area of ​​the subpixel (PXn).

[0221] Although embodiments of the present invention have been described above with reference to the attached drawings, those skilled in the art will understand that the present invention may be implemented in other specific forms without changing the technical concept or essential features thereof. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. Explanation of the symbols

[0222] 10: Display device RME: Electrode ED: Light-emitting element CNE: Connecting electrode

Claims

Claim 1 A display device comprising: a first substrate; a first electrode and a second electrode disposed on the first substrate and spaced apart from each other; a first insulating layer disposed on the first electrode and the second electrode; a plurality of light-emitting elements, each having both ends disposed on the first electrode and the second electrode on the first insulating layer; a first connecting electrode disposed on the first electrode and in contact with one end of the light-emitting element, and a second connecting electrode disposed on the second electrode and in contact with the other end of the light-emitting element; a second insulating layer disposed on the light-emitting element, the first connecting electrode, and the second connecting electrode; and a third connecting electrode disposed on the second insulating layer and in contact with the light-emitting element through an opening formed in the second insulating layer that partially exposes the light-emitting element. Claim 2 A display device according to claim 1, wherein the first connecting electrode contacts one end surface of the light-emitting element, the second connecting electrode contacts the other end surface of the light-emitting element, and the third connecting electrode contacts the side surface of the light-emitting element. Claim 3 In claim 2, the light-emitting element comprises a first light-emitting element having a first end placed on the first electrode and a second end placed on the second electrode, and a second light-emitting element having a first end placed on the second electrode and a second end placed on the first electrode. Claim 4 In claim 1, the light-emitting element comprises a plurality of semiconductor layers and an insulating film surrounding the semiconductor layers, and the third connecting electrode contacts the semiconductor layer on the side of the light-emitting element. Claim 5 In claim 4, the light-emitting element comprises a first semiconductor layer, a second semiconductor layer disposed on the first semiconductor layer, a light-emitting layer disposed between the first semiconductor layer and the second semiconductor layer, and a third semiconductor layer disposed on the opposite side of the first semiconductor layer facing the light-emitting layer, and the third connecting electrode is in contact with the first semiconductor layer. Claim 6 In claim 5, the light-emitting element further comprises a fourth semiconductor layer disposed between a portion where the first semiconductor layer contacts the third connecting electrode and a one-end surface where the third semiconductor layer is located. Claim 7 A display device according to claim 1, further comprising a conductive layer disposed on the first substrate and a via layer disposed on the conductive layer, wherein the first electrode contacts a first conductive pattern of the conductive layer through a first electrode contact hole penetrating the via layer, and the first connecting electrode contacts the first electrode through a first contact portion penetrating the first insulating layer. Claim 8 A display device according to claim 7, wherein the second connecting electrode contacts a second conductive pattern of the conductive layer through a second contact portion penetrating the via layer and the first insulating layer, and the third connecting electrode contacts a voltage wiring of the conductive layer through a third contact portion penetrating the via layer, the first insulating layer, and the second insulating layer. Claim 9 A display device according to claim 7, wherein the second electrode contacts the voltage wiring of the conductive layer through a second electrode contact hole penetrating the via layer, the second connecting electrode contacts the first electrode through a fourth contact portion penetrating the first insulating layer, and the third connecting electrode contacts the second electrode through a fifth contact portion penetrating the first insulating layer and the second insulating layer. Claim 10 A display device according to claim 1, further comprising: a fourth connecting electrode disposed on the first electrode between the first insulating layer and the second insulating layer and in contact with the light-emitting element; a fifth connecting electrode disposed on the second electrode between the first insulating layer and the second insulating layer and in contact with the light-emitting element; and a sixth connecting electrode disposed on the second insulating layer and in contact with the light-emitting element, wherein the fourth connecting electrode is spaced apart from the first connecting electrode, the fifth connecting electrode is spaced apart from the second connecting electrode, and the sixth connecting electrode is spaced apart from the third connecting electrode. Claim 11 A display device according to claim 10, wherein the third connecting electrode is arranged to overlap with the light-emitting elements to which the fourth connecting electrode and the fifth connecting electrode contact, and the sixth connecting electrode is arranged to overlap with the light-emitting elements to which the first connecting electrode and the second connecting electrode contact, and contacts the fourth connecting electrode and the fifth connecting electrode through sixth contact portions penetrating the second insulating layer. Claim 12 A display device according to claim 1, further comprising: a third electrode and a fourth electrode spaced apart from each other and disposed on the first substrate; a fourth connecting electrode disposed on the third electrode; a fifth connecting electrode disposed on the fourth electrode; and a sixth connecting electrode disposed on the second insulating layer, wherein the light-emitting element comprises a first group of light-emitting elements disposed on the first electrode and the second electrode, and a second group of light-emitting elements disposed on the third electrode and the fourth electrode, wherein the third connecting electrode is in contact with the second group of light-emitting elements and the sixth connecting electrode is in contact with the first group of light-emitting elements. Claim 13 In claim 12, the sixth connecting electrode further comprises an electrode extension portion disposed across the second electrode, the third electrode and the fourth electrode, and the electrode extension portion contacts the fourth connecting electrode and the fifth connecting electrode through a sixth contact portion penetrating the second insulating layer. Claim 14 A display device according to claim 1, further comprising a third insulating layer disposed between the light-emitting element and the second insulating layer, wherein a portion of the first connecting electrode and the second connecting electrode is disposed on the third insulating layer, and the opening penetrates the third insulating layer to expose the light-emitting element. Claim 15 A display device according to claim 14, further comprising a fourth insulating layer disposed between the second connecting electrode and the second insulating layer, wherein a portion of the first connecting electrode is disposed on the fourth insulating layer, and the opening penetrates the fourth insulating layer to expose the light-emitting element. Claim 16 delete Claim 17 delete Claim 18 delete Claim 19 delete Claim 20 delete

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