Light-emitting element and display device including the same

Abstract

A light-emitting element and a display device including the light-emitting element are provided. The light-emitting element includes: a first semiconductor layer doped to have a first polarity; a second semiconductor layer doped to have a second polarity different from the first polarity; an active layer disposed between the first semiconductor layer and the second semiconductor layer; and an insulating film disposed to surround at least an outer surface of the active layer and extending in a first direction in which the first semiconductor layer, the active layer, and the second semiconductor layer are stacked, wherein a thickness of a first portion of the insulating film surrounding the active layer is in a range of 10% to 16% of a diameter of the active layer.

Description

Technical Field

[0001] The present disclosure relates to a light-emitting element and a display device including the light-emitting element. Background Art

[0002] With the development of multimedia technology, the importance of display devices has been steadily increasing. In response thereto, various types of display devices have been used, such as organic light-emitting displays, liquid crystal displays (LCDs), and the like.

[0003] A display device is a device for displaying an image and includes a display panel such as an organic light-emitting display panel or a liquid crystal display panel. The light-emitting display panel may include a light-emitting element such as a light-emitting diode (LED), and examples of the light-emitting diode include an organic light-emitting diode (OLED) using an organic material as a fluorescent material and an inorganic light-emitting diode using an inorganic material as a fluorescent material.

[0004] An inorganic LED using an inorganic semiconductor as a fluorescent material is durable even in a high-temperature environment and has a higher blue light efficiency than an OLED. In addition, a transfer method using dielectrophoresis (DEP) has been developed for a manufacturing process that has been pointed out as a limitation of a conventional inorganic LED. Accordingly, continuous research has been conducted on inorganic LEDs having better durability and efficiency than OLEDs. Summary of the Invention

[0005] Technical Problem

[0006] Aspects of the present disclosure provide a light-emitting element including a thick electrode layer and a thick insulating film to protect an active layer.

[0007] Aspects of the present disclosure also provide a display device including the light-emitting element and having improved light-emitting reliability.

[0008] It should be noted that aspects of the present disclosure are not limited thereto, and from the following description, other aspects not mentioned herein will be apparent to those of ordinary skill in the art.

[0009] Technical Solution

[0010] According to an embodiment of the present disclosure, a light-emitting element includes: a first semiconductor layer doped to have a first polarity; a second semiconductor layer doped to have a second polarity different from the first polarity; an active layer disposed between the first semiconductor layer and the second semiconductor layer; and an insulating film disposed to at least surround an outer surface of the active layer and extending in a first direction in which the first semiconductor layer, the active layer, and the second semiconductor layer are stacked, wherein a thickness of a first portion of the insulating film surrounding the active layer is in a range of 10% to 16% of a diameter of the active layer.

[0011] The diameter of the active layer can be in the range of 500 nm to 600 nm, and the thickness of the first part of the insulating film can be in the range of 60 nm to 80 nm.

[0012] The insulating film may further include a second part, which is connected to the first part and is arranged to cover a partial area of the side surface of the second semiconductor layer, and the thickness of the second part may be smaller than that of the first part.

[0013] In the insulating film, the part surrounding the interface between the active layer and the second semiconductor layer may have a thickness of at least 20 nm.

[0014] The second part may have a curved outer surface such that its thickness decreases in the first direction.

[0015] The light-emitting element may further include an electrode layer provided on the second semiconductor layer, wherein the thickness of the electrode layer may be greater than that of the second semiconductor layer.

[0016] The electrode layer may have a thickness in the range of 20 nm to 200 nm.

[0017] The insulating film may be arranged to surround the side surface of the electrode layer.

[0018] The insulating film may be arranged to surround a part of the side surface of the electrode layer, and the electrode layer may have a top surface and a partially exposed side surface.

[0019] The insulating film may further include a third part, which is connected to the first part and surrounds a part of the side surface of the electrode layer, and the thickness of the third part may be smaller than that of the first part.

[0020] The third part may have a curved outer surface such that its thickness decreases in the first direction.

[0021] According to an embodiment of the present disclosure, a display device includes: a substrate; a first electrode and a second electrode, the first electrode being disposed on the substrate and the second electrode being spaced apart from the first electrode; at least one light-emitting element disposed between the first electrode and the second electrode and electrically connected to the first electrode and the second electrode; a first insulating layer disposed below the light-emitting element between the first electrode and the second electrode; and a second insulating layer disposed on the light-emitting element and exposing one end and the other end of the light-emitting element, wherein the light-emitting element includes: a first semiconductor layer doped to have a first polarity; a second semiconductor layer doped to have a second polarity different from the first polarity; an active layer disposed between the first semiconductor layer and the second semiconductor layer; and an insulating film disposed to at least surround an outer surface of the active layer and extending in a first direction in which the first semiconductor layer, the active layer, and the second semiconductor layer are stacked, wherein the insulating film includes a second portion in contact with the second insulating layer, a first portion surrounding one end of the light-emitting element including the active layer, and a third portion surrounding the other end of the light-emitting element, and a thickness of the second portion is greater than thicknesses of the first portion and the third portion.

[0022] The display device may further include a first contact electrode and a second contact electrode, the first contact electrode being in contact with the first electrode and one end of the light-emitting element, and the second contact electrode being in contact with the second electrode and the other end of the light-emitting element.

[0023] The light-emitting element may further include an electrode layer disposed on the second semiconductor layer and having a thickness greater than a thickness of the second semiconductor layer, the first contact electrode being in contact with the first portion of the insulating film and the electrode layer, and the second contact electrode being in contact with the third portion of the insulating film and the first semiconductor layer.

[0024] The first portion of the insulating film may be disposed to surround a part of a side surface of the electrode layer, and the electrode layer may have a top surface and a partially exposed side surface.

[0025] The first contact electrode may be in contact with the top surface and the partially exposed side surface of the electrode layer.

[0026] The first portion of the insulating film may have a curved outer surface such that its thickness decreases in the first direction.

[0027] In the first portion, a first thickness measured at an interface between the second semiconductor layer and the electrode layer and a second thickness measured at an interface between the second semiconductor layer and the active layer may satisfy the following equation (1):

[0028] [Equation 1]

[0029] Θc = arctan((W2' - W1') / D) ≤ 70°

[0030] Here, Θc is the inclination angle of the inclined outer surface of the first part of the insulating film, W1' is the first thickness measured at the interface between the electrode layer and the second semiconductor layer in the first part of the insulating film, W2' is the second thickness measured at the interface between the second semiconductor layer and the active layer in the first part of the insulating film, and D is the thickness of the second semiconductor layer.

[0031] The second thickness may be 20 nm or greater, and in the first part, the thickness of the portion surrounding the active layer may be 40 nm or greater.

[0032] The electrode layer may have a thickness in the range of 20 nm to 200 nm.

[0033] The thickness of the second part may be in the range of 10% to 16% of the diameter of the active layer.

[0034] The diameter of the active layer may be in the range of 500 nm to 600 nm, and the thickness of the second part of the insulating film may be in the range of 60 nm to 80 nm.

[0035] In the light-emitting element, a first diameter measured at the second part of the insulating film may be greater than a second diameter measured at the first part of the insulating film and a third diameter measured at the third part of the insulating film.

[0036] Details of other embodiments are included in the detailed description and the drawings.

[0037] Advantageous Effects

[0038] The light-emitting element according to one embodiment includes an electrode layer having a thickness greater than the thickness of the second semiconductor layer, and an insulating film in which the portion surrounding the active layer has a certain level or greater thickness. The light-emitting element can prevent the electrode layer from being removed during the manufacturing process, and can safely protect the active layer even if the insulating film is partially etched.

[0039] Therefore, a display device including the light-emitting element can improve the light-emitting efficiency and light-emitting reliability.

[0040] The effects according to the embodiments are not limited to the content of the above examples, and more various effects are included in the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is a schematic plan view of a display device according to one embodiment.

[0042] Figure 2 is a schematic plan view of a pixel of a display device according to one embodiment.

[0043] Figure 3 shows Figure 2Plan view of a sub-pixel of

[0044] Figure 4 is a cross-sectional view taken along Figure 3 the lines Xa-Xa', Xb-Xb' and Xc-Xc' of

[0045] Figure 5 is a schematic diagram of a light-emitting element according to an embodiment.

[0046] Figure 6 is a schematic cross-sectional view of a light-emitting element according to an embodiment.

[0047] Figure 7 is Figure 4 an enlarged view of part QA of

[0048] Figure 8 is a cross-sectional view showing a part of a display device according to an embodiment.

[0049] Figures 9 to 14 is a cross-sectional view showing the manufacturing process of a light-emitting element according to an embodiment.

[0050] Figures 15 to 19 is a cross-sectional view showing a part of the manufacturing process of a display device according to an embodiment.

[0051] Figure 20 is a schematic cross-sectional view of a light-emitting element according to an embodiment.

[0052] Figure 21 partially shows Figure 20 the manufacturing process of the light-emitting element of

[0053] Figure 22 is a cross-sectional view showing a part of a display device including Figure 20 the light-emitting element of

[0054] Figure 23 is a schematic cross-sectional view of a light-emitting element according to an embodiment.

[0055] Figure 24 is a cross-sectional view showing a part of a display device including Figure 23 the light-emitting element of

[0056] Figure 25 is a plan view of a sub-pixel of a display device according to an embodiment.

[0057] Figure 26 is a plan view of a pixel of a display device according to an embodiment. Detailed Description

[0058] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. However, the invention may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0059] It will also be understood that when a layer is referred to as being "on" another layer or substrate, it can be directly on the other layer or substrate, or an intervening layer may also be present. Throughout the specification, the same reference numerals denote the same components.

[0060] It will be understood that although the terms "first", "second", etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the teachings of the present invention, the first element discussed below may be referred to as the second element. Similarly, the second element may also be referred to as the first element.

[0061] Hereinafter, embodiments will be described with reference to the accompanying drawings.

[0062] Figure 1 is a schematic plan view of a display device according to an embodiment.

[0063] Reference Figure 1 , the display device 10 displays a moving image or a still image. The display device 10 may refer to any electronic device that provides a display screen. Examples of the display device 10 may include a television, a laptop computer, a monitor, a billboard, an Internet of Things device, a mobile phone, a smartphone, a tablet personal computer (PC), an electronic watch, a smart watch, a watch phone, a head-mounted display, a mobile communication terminal, an electronic notebook, an e-book, a portable multimedia player (PMP), a navigation device, a game console, a digital camera, a video camera, etc. that provide a display screen.

[0064] The display device 10 includes a display panel that provides a display screen. Examples of the display panel may include an LED display panel, an organic light-emitting display panel, a quantum dot light-emitting display panel, a plasma display panel, and a field emission display panel. In the following description, a case where an LED display panel is applied as the display panel will be exemplified, but the present disclosure is not limited thereto, and other display panels may be applied within the same scope of the technical spirit.

[0065] The shape of the display device 10 can be variously modified. For example, the display device 10 can have shapes such as a rectangular shape elongated in the horizontal direction, a rectangular shape elongated in the vertical direction, a square shape, a quadrilateral shape with rounded corners (vertices), other polygonal shapes, and a circular shape. The shape of the display area DA of the display device 10 can also be similar to the overall shape of the display device 10. In Figure 1 FIG. 1, a display area DA and a display device 10 having a rectangular shape elongated in the horizontal direction are shown.

[0066] The display device 10 can include a display area DA and a non-display area NDA. The display area DA is an area where an image can be displayed, and the non-display area NDA is an area where an image is not displayed. The display area DA can also be referred to as an active area, and the non-display area NDA can also be referred to as a non-active area.

[0067] The display area DA can substantially occupy the center of the display device 10. The display area DA can include a plurality of pixels PX. The plurality of pixels PX can be arranged in a matrix form. In a plan view, the shape of each pixel PX can be a rectangular shape or a square shape. However, the present disclosure is not limited thereto, and it can be a rhombus shape in which each side is inclined with respect to one direction. Each of the pixels PX can include one or more light-emitting elements 300 that emit light in a specific wavelength band to display a specific color (see Figure 2 ).

[0068] Figure 2 FIG. 2 is a schematic plan view of a pixel of a display device according to one embodiment. Figure 3 FIG. 3 is a plan view showing Figure 2 a sub-pixel of FIG. 2.

[0069] Referring to Figure 2 and Figure 3 , each of the pixels PX can include a first sub-pixel PX1, a second sub-pixel PX2, and a third sub-pixel PX3. The first sub-pixel PX1 can emit light of a first color, the second sub-pixel PX2 can emit light of a second color, and the third sub-pixel PX3 can emit light of a third color. The first color can be blue, the second color can be green, and the third color can be red. However, the present disclosure is not limited thereto, and the sub-pixel PXn (n is a positive integer) can emit light of the same color. In addition, although Figure 2 FIG. 2 shows that the pixel PX includes three sub-pixels PXn, the present disclosure is not limited thereto, and the pixel PX can include a larger number of sub-pixels PXn.

[0070] Each sub-pixel PXn of the display device 10 may include a region defined as an emission region EMA. The first sub-pixel PX1 may include a first emission region EMA1, the second sub-pixel PX2 may include a second emission region EMA2, and the third sub-pixel PX3 may include a third emission region EMA3. The emission region EMA may be defined as a region where a light-emitting element 300 included in the display device 10 is provided to emit light in a specific wavelength band. The light-emitting element 300 includes an active layer 330 (see Figure 5 ), and the active layer 330 may emit light in a specific wavelength band in a non-directional manner. The light emitted from the active layer 330 of the light-emitting element 300 may be radiated in the lateral direction of the light-emitting element 300 and in the directions at both ends of the light-emitting element 300. The emission region EMA of each sub-pixel PXn may include a region adjacent to the light-emitting element 300 where the light emitted from the light-emitting element 300 is radiated, and this region includes the region where the light-emitting element 300 is provided. In addition, without being limited thereto, the emission region EMA may further include a region where the light emitted from the light-emitting element 300 is reflected or refracted by another member and then emitted. A plurality of light-emitting elements 300 may be provided in the corresponding sub-pixels PXn, and the emission region EMA may be formed to include the region where the light-emitting element 300 is provided and the adjacent region thereto.

[0071] Although not shown in the drawings, each sub-pixel PXn of the display device 10 may include a non-emission region defined as a region other than the emission region EMA. The non-emission region may be a region where the light-emitting element 300 is not provided and a region where light is not emitted because the light emitted from the light-emitting element 300 does not reach.

[0072] Each sub-pixel PXn of the display device 10 may include a plurality of electrodes 210 and 220, a light-emitting element 300, a plurality of contact electrodes 260, and a plurality of outer dikes 430. Although not shown in Figure 2 and Figure 3 , the display device 10 may further include a plurality of inner dikes 410 and 420 (see Figure 4 ) and a plurality of insulating layers 510, 520, and 530 (see Figure 4 ).

[0073] The plurality of electrodes 210 and 220 may include a first electrode 210 and a second electrode 220. The first electrode 210 and the second electrode 220 may include respective electrode main portions 210S and 220S arranged to extend in a first direction DR1 and at least one respective electrode branch portion 210B and 220B branched from the respective electrode main portions 210S and 220S and extending in a second direction DR2 intersecting the first direction DR1.

[0074] The first electrode 210 may include a first electrode main body portion 210S extending in a first direction DR1, and at least one first electrode branch portion 210B branching from the first electrode main body portion 210S and extending in a second direction DR2.

[0075] The first electrode main body portion 210S of any one sub-pixel PXn may be arranged such that both ends of each first electrode main body portion 210S terminate with a gap between the corresponding sub-pixels PXn, and each first electrode main body portion 210S may be arranged on substantially the same straight line as the first electrode main body portions 210S of the sub-pixels PXn adjacent to it in the same row (e.g., in the first direction DR1). Since the first electrode main body portions 210S provided in the corresponding sub-pixels PXn are arranged such that their both ends are spaced apart from each other, different electrical signals can be applied to the first electrode branch portions 210B.

[0076] The first electrode branch portion 210B may branch from at least a part of the first electrode main body portion 210S and extend in the second direction DR2, and may be terminated while being spaced apart from a second electrode main body portion 220S arranged to face the first electrode main body portion 210S.

[0077] The second electrode 220 may include: a second electrode main body portion 220S extending in the first direction DR1 and arranged to face the first electrode main body portion 210S while being spaced apart from the first electrode main body portion 210S in the second direction DR2; and a second electrode branch portion 220B branching from the second electrode main body portion 220S and extending in the second direction DR2. The second electrode main body portion 220S may be connected to the second electrode main body portion 220S of another sub-pixel PXn adjacent to it in the first direction DR1 at the other end. That is, different from the first electrode main body portion 210S, the second electrode main body portion 220S may extend across the corresponding sub-pixels PXn in the first direction DR1. The second electrode main body portion 220S extending across the corresponding sub-pixels PXn may be connected to the outside of the display area DA where the corresponding pixel PX or sub-pixel PXn is placed, or connected to an extension portion extending from the non-display area NDA in one direction.

[0078] The second electrode branch portion 220B may be arranged to face the first electrode branch portion 210B with a gap therebetween, and may be terminated while being spaced apart from the first electrode main body portion 210S. The second electrode branch portion 220B may be connected to the second electrode main body portion 220S, and one end of the second electrode branch portion 220B in the extending direction may be arranged within the sub-pixel PXn while being spaced apart from the first electrode main body portion 210S.

[0079] The first electrode 210 and the second electrode 220 can be electrically connected to the conductive layer of the circuit element layer PAL (see Figure 4 ) of the display device 10 through contact holes (e.g., the first electrode contact hole CNTD and the second electrode contact hole CNTS), respectively. In the drawings, it is shown that the first electrode contact hole CNTD is formed at each first electrode main part 210S of each sub-pixel PXn, while only one second electrode contact hole CNTS is formed at a single second electrode main part 220S extending across the corresponding sub-pixel PXn. However, the present disclosure is not limited thereto, and in some cases, even the second electrode contact hole CNTS can be formed for each sub-pixel PXn.

[0080] The electrodes 210 and 220 can be electrically connected to the light-emitting element 300 and can receive a preset voltage applied thereto to allow the light-emitting element 300 to emit light in a specific wavelength band. In addition, at least a part of each of the electrodes 210 and 220 can be used to form an electric field within the sub-pixel PXn to align the light-emitting element 300.

[0081] In an embodiment, the first electrode 210 can be a pixel electrode separated for each sub-pixel PXn, and the second electrode 220 can be a common electrode connected along the corresponding sub-pixels PXn to be shared by them. One of the first electrode 210 and the second electrode 220 can be the anode electrode of the light-emitting element 300, and the other can be the cathode electrode of the light-emitting element 300. However, the present disclosure is not limited thereto, and the opposite case can also be possible.

[0082] In the drawings, it is shown that two first electrode branches 210B are provided in each sub-pixel PXn, and one second electrode branch 220B is provided therebetween. However, the layout of the first electrode branches 210B and the second electrode branches 220B is not limited thereto. In some cases, the first electrode 210 and the second electrode 220 can have a shape that does not have electrode main parts 210S and 220S and extends in the second direction DR2. In addition, the first electrode 210 and the second electrode 220 do not have to have a shape extending in one direction, and they can have various layouts. For example, the first electrode 210 and the second electrode 220 can have a partially curved or bent shape, and one electrode can be arranged to surround the other electrode. The layout and shape of the first electrode 210 and the second electrode 220 are not particularly limited as long as at least some of their parts face each other and there is a gap therebetween to create a space where the light-emitting element 300 can be arranged.

[0083] The outer bank portion 430 may be provided at the boundary between the sub-pixels PXn. Each outer bank portion 430 may extend in the second direction DR2 to be provided at the boundary between adjacent sub-pixels PXn arranged in the first direction DR1. The main portions 210S of the first electrodes may terminate such that their corresponding ends are spaced apart from each other, and the outer bank portion 430 is therebetween. However, the present disclosure is not limited thereto, and the outer bank portion 430 may extend in the first direction DR1 to be provided at the boundary between adjacent sub-pixels PXn arranged in the second direction DR2. The outer bank portion 430 may include the same material as the inner bank portions 410 and 420 to be described later, and these outer bank portions 430 and inner bank portions 410 and 420 may be formed simultaneously in one process.

[0084] The light-emitting element 300 may be provided between the first electrode 210 and the second electrode 220. The light-emitting element 300 may be electrically connected to the first electrode 210 at one end thereof and to the second electrode 220 at the other end thereof. The light-emitting element 300 may be electrically connected to each of the first electrode 210 and the second electrode 220 through the contact electrode 260.

[0085] A plurality of light-emitting elements 300 may be spaced apart from each other and aligned substantially parallel to each other. The spacing between the light-emitting elements 300 is not particularly limited. In some cases, a plurality of light-emitting elements 300 may be provided adjacent to each other to form a group, and other plurality of light-emitting elements 300 may be arranged, and the other plurality of light-emitting elements 300 are simultaneously spaced apart from each other at regular distances to form another group. That is, the light-emitting elements 300 may be arranged at different densities, but they may still be aligned in one direction. Further, in an embodiment, the light-emitting element 300 may have a shape extending in one direction, and for example, the extending direction of the electrodes such as the first electrode branch portion 210B and the second electrode branch portion 220B may be substantially perpendicular to the extending direction of the light-emitting element 300. However, the present disclosure is not limited thereto, and the light-emitting element 300 may be provided diagonally with respect to the extending direction of the first electrode branch portion 210B and the second electrode branch portion 220B, rather than perpendicular to the extending direction of the first electrode branch portion 210B and the second electrode branch portion 220B.

[0086] The light-emitting element 300 according to one embodiment may have an active layer 330 including different materials, and thus may emit light in different wavelength bands to the outside. The display device 10 according to one embodiment may include the light-emitting element 300 that emits light in different wavelength bands. The light-emitting element 300 of the first sub-pixel PX1 may include an active layer 330 that emits first light having a central wavelength band of a first wavelength, the light-emitting element 300 of the second sub-pixel PX2 may include an active layer 330 that emits second light having a central wavelength band of a second wavelength, and the light-emitting element 300 of the third sub-pixel PX3 may include an active layer 330 that emits third light having a central wavelength band of a third wavelength.

[0087] Therefore, the first light may be emitted from the first sub-pixel PX1, the second light may be emitted from the second sub-pixel PX2, and the third light may be emitted from the third sub-pixel PX3. In some embodiments, the first light may be blue light having a central wavelength band of 450 nm to 495 nm, the second light may be green light having a central wavelength band of 495 nm to 570 nm, and the third light may be red light having a central wavelength band of 620 nm to 752 nm.

[0088] However, the present disclosure is not limited thereto. In some cases, the first sub-pixel PX1, the second sub-pixel PX2, and the third sub-pixel PX3 may include the same type of light-emitting element 300 to emit light of substantially the same color.

[0089] Meanwhile, the light-emitting element 300 according to one embodiment may include a semiconductor core and an insulating film 380 surrounding the semiconductor core (see Figure 5 ). The semiconductor core may include a plurality of semiconductor layers 310 and 320 (see Figure 5 ) and an active layer 330 disposed therebetween (see Figure 5 ). The light-emitting element 300 may have one end electrically connected to the first electrode 210 and the other end electrically connected to the second electrode 220 to receive an electrical signal, and the light-emitting element 300 that has received the electrical signal may generate light in the active layer 330 and emit it to the outside. The insulating film 380 surrounding the semiconductor core of the light-emitting element 300 may be disposed to at least surround the outer surface of the active layer 330 and protect it. The light-emitting element 300 according to one embodiment may include an insulating film 380 having a thickness of a certain level or greater, so as to prevent the active layer 330 of the light-emitting element 300 from being damaged during the manufacturing process of the light-emitting element 300 and the manufacturing process of the display device 10, and improve the reliability of the element.

[0090] In addition, the semiconductor core of the light-emitting element 300 may further include an electrode layer 370 disposed on the second semiconductor layer 320 (see Figure 5), and the light-emitting element 300 may be electrically connected to the first electrode 210 or the second electrode 220 through the electrode layer 370. Here, the light-emitting element 300 according to one embodiment may include an electrode layer 370 having a thickness equal to or greater than a certain level to prevent the electrode layer 370 of the light-emitting element 300 from being removed during the manufacturing process of the light-emitting element 300, thereby improving the element efficiency. A detailed description thereof will be given later with reference to other drawings.

[0091] The plurality of contact electrodes 260 may have a shape in which at least a part of their regions extends in one direction. Each of the plurality of contact electrodes 260 may be in contact with the light-emitting element 300 and the electrodes 210 and 220, and the light-emitting element 300 may receive electrical signals from the first electrode 210 and the second electrode 220 through the contact electrodes 260.

[0092] The contact electrode 260 may include a first contact electrode 261 and a second contact electrode 262. The first contact electrode 261 and the second contact electrode 262 may be respectively disposed on the first electrode branch portion 210B and the second electrode branch portion 220B.

[0093] The first contact electrode 261 may be disposed on the first electrode 210 or the first electrode branch portion 210B, and may extend in the second direction DR2 to contact one end of the light-emitting element 300. The second contact electrode 262 may be spaced apart from the first contact electrode 261 in the first direction DR1, and may be disposed on the second electrode 220 or the second electrode branch portion 220B, and extend in the second direction DR2 to contact the other end of the light-emitting element 300. The first contact electrode 261 and the second contact electrode 262 may be in contact with the first electrode 210 and the second electrode 220 exposed through the opening of the second insulating layer 520. The light-emitting element 300 may be electrically connected to the first electrode 210 and the second electrode 220 through the first contact electrode 261 and the second contact electrode 262.

[0094] In some embodiments, the widths of the first contact electrode 261 and the second contact electrode 262 measured in one direction may be respectively greater than the widths of the first electrode 210 and the second electrode 220 measured in one direction or the widths of the first electrode branch portion 210B and the second electrode branch portion 220B measured in one direction. The first contact electrode 261 and the second contact electrode 262 may be disposed to cover the sides of the first electrode 210 and the second electrode 220 or the sides of the first electrode branch portion 210B and the second electrode branch portion 220B. However, the present disclosure is not limited thereto, and in some cases, the first contact electrode 261 and the second contact electrode 262 may be disposed to cover only one side of the first electrode branch portion 210B and the second electrode branch portion 220B.

[0095] Although two first contact electrodes 261 and one second contact electrode 262 are shown in the drawings as being provided in one sub-pixel PXn, the present disclosure is not limited thereto. The number of the first contact electrodes 261 and the second contact electrode 262 may vary according to the number of the first electrodes 210 and the second electrodes 220 provided in each sub-pixel PXn or the number of the first electrode branches 210B and the second electrode branches 220B.

[0096] Meanwhile, although not shown in Figure 2 and Figure 3 the display device 10 may further include a circuit element layer PAL located below the electrodes 210 and 220 and a plurality of insulating layers (e.g., 510, 520, and 530) provided thereon. Hereinafter, the stacked structure of the display device 10 will be described in detail with reference to Figure 4 FIGs.

[0097] Figure 4 FIGs. Figure 3 are cross-sectional views taken along lines Xa-Xa', Xb-Xb', and Xc-Xc' of

[0098] Figure 4 Only the cross-section of the first sub-pixel PX1 is shown, but the same can be applied to other pixels PX or sub-pixels PXn. Figure 4 FIG.

[0099] shows a cross-section passing through one end and the other end of the light-emitting element 300 provided in the first sub-pixel PX1. Figure 2 and Figure 3 With reference to Figure 4 FIGs.

[0100] Specifically, the substrate 110 may be an insulating substrate. The substrate 110 may be made of an insulating material such as glass, quartz, or a polymer resin. In addition, the substrate 110 may be a rigid substrate, but may also be a flexible substrate that can be bent, folded, or curled.

[0101] The light-blocking layer BML may be disposed on the substrate 110. The light-blocking layer BML may include a first light-blocking layer BML1 and a second light-blocking layer BML2. The first light-blocking layer BML1 may be electrically connected to a first source electrode 123 of the first transistor 120, which will be described later. The second light-blocking layer BML2 may be electrically connected to a second source electrode 143 of the second transistor 140.

[0102] The first light-blocking layer BML1 and the second light-blocking layer BML2 are arranged to overlap with a first active material layer 126 of the first transistor 120 and a second active material layer 146 of the second transistor 140, respectively. The first light-blocking layer BML1 and the second light-blocking layer BML2 may include a material that blocks light, and thus can prevent light from reaching the first active material layer 126 and the second active material layer 146. For example, the first light-blocking layer BML1 and the second light-blocking layer BML2 may be formed of an opaque metal material that blocks light transmission. However, the present disclosure is not limited thereto, and in some cases, the light-blocking layer BML may be omitted.

[0103] A buffer layer 115 is disposed on the light-blocking layer BML and the substrate 110. The buffer layer 115 may be arranged to cover the entire surface of the substrate 110 (including the light-blocking layer BML). The buffer layer 115 can prevent the diffusion of impurity ions, prevent the penetration of moisture or external air, and perform a surface planarization function. In addition, the buffer layer 115 can be used to insulate the light-blocking layer BML from the first active material layer 126 and the second active material layer 146 from each other.

[0104] A semiconductor layer is disposed on the buffer layer 115. The semiconductor layer may include a first active material layer 126 of the first transistor 120, a second active material layer 146 of the second transistor 140, and an auxiliary layer 163. The semiconductor layer may include polysilicon, single-crystalline silicon, an oxide semiconductor, etc.

[0105] The first active material layer 126 may include a first doped region 126a, a second doped region 126b, and a first channel region 126c. The first channel region 126c may be disposed between the first doped region 126a and the second doped region 126b. The second active material layer 146 may include a third doped region 146a, a fourth doped region 146b, and a second channel region 146c. The second channel region 146c may be disposed between the third doped region 146a and the fourth doped region 146b. The first active material layer 126 and the second active material layer 146 may include polysilicon. The polysilicon may be formed by crystallizing amorphous silicon. Examples of the crystallization method may include rapid thermal annealing (RTA), solid phase crystallization (SPC), excimer laser annealing (ELA), metal-induced lateral crystallization (MILC), and sequential lateral solidification (SLS), but are not limited thereto. As another example, the first active material layer 126 and the second active material layer 146 may include single crystal silicon, low temperature polysilicon, amorphous silicon, etc. The first doped region 126a, the second doped region 126b, the third doped region 146a, and the fourth doped region 146b may be some regions of the first active material layer 126 and the second active material layer 146 doped with impurities. However, the present disclosure is not limited thereto.

[0106] However, the first active material layer 126 and the second active material layer 146 are not necessarily limited to the above. In an embodiment, the first active material layer 126 and the second active material layer 146 may include an oxide semiconductor. In this case, the first doped region 126a and the third doped region 146a may be a first conductive region, and the second doped region 126b and the fourth doped region 146b may be a second conductive region. When the first active material layer 126 and the second active material layer 146 include an oxide semiconductor, the oxide semiconductor may be an oxide semiconductor containing indium (In). In some embodiments, the oxide semiconductor may be 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 tin oxide (IGZTO), etc. However, the present disclosure is not limited thereto.

[0107] The first gate insulating film 150 is disposed on the semiconductor layer. The first gate insulating film 150 may be disposed to cover the entire surface of the buffer layer 115 (including the semiconductor layer). The first gate insulating film 150 may be used as the gate insulating film of the first transistor 120 and the second transistor 140.

[0108] The first conductive layer is disposed on the first gate insulating film 150. The first conductive layer may include a first gate electrode 121 disposed on the first active material layer 126 of the first transistor 120, a second gate electrode 141 disposed on the second active material layer 146 of the second transistor 140, and a wiring pattern 161 disposed on the auxiliary layer 163 on the first gate insulating film 150. The first gate electrode 121 may overlap with the first channel region 126c of the first active material layer 126, and the second gate electrode 141 may overlap with the second channel region 146c of the second active material layer 146.

[0109] The interlayer insulating film 170 is disposed on the first conductive layer. The interlayer insulating film 170 may serve as an insulating film between the first conductive layer and other layers disposed thereon. In addition, the interlayer insulating film 170 may include an organic insulating material and may also perform a surface planarization function.

[0110] The second conductive layer is disposed on the interlayer insulating film 170. The second conductive layer includes a first source electrode 123 and a first drain electrode 124 of the first transistor 120, a second source electrode 143 and a second drain electrode 144 of the second transistor 140, and a power supply electrode 162 disposed on the wiring pattern 161.

[0111] The first source electrode 123 and the first drain electrode 124 may respectively contact the first doped region 126a and the second doped region 126b of the first active material layer 126 through contact holes formed through the interlayer insulating film 170 and the first gate insulating film 150. The second source electrode 143 and the second drain electrode 144 may respectively contact the third doped region 146a and the fourth doped region 146b of the second active material layer 146 through contact holes formed through the interlayer insulating film 170 and the first gate insulating film 150. In addition, the first source electrode 123 and the second source electrode 143 may be electrically connected to the first light blocking layer BML1 and the second light blocking layer BML2 respectively through other contact holes.

[0112] The passivation film 180 may be disposed on the second conductive layer. The passivation film 180 may be disposed to cover the second conductive layer and may be disposed on the entire interlayer insulating film 170. That is, the passivation film 180 may be disposed to cover the first source electrode 123, the first drain electrode 124, the second source electrode 143, and the second drain electrode 144.

[0113] The conductive wiring layer may be provided on the passivation film 180. The conductive wiring layer may include a first conductive wiring 191 and a second conductive wiring 192, and they may be electrically connected to the first source electrode 123 of the first transistor 120 and the power supply electrode 162, respectively. The conductive wiring layer may also be electrically connected to the first electrode 210 and the second electrode 220 of the emission layer EML, and may transmit the electrical signals applied from the first transistor 120 and the power supply electrode 162 to the electrodes 210 and 220.

[0114] The first insulating layer 510 is provided on the conductive wiring layer. The first insulating layer 510 contains an organic insulating material and may perform a surface flattening function.

[0115] A plurality of inner dikes 410 and 420, an outer dike 430 (see Figure 3 ), a plurality of electrodes 210 and 220, and the light-emitting element 300 may be provided on the first insulating layer 510.

[0116] As described above, the outer dike 430 may extend in the first direction DR1 or the second direction DR2 to be provided at the boundary between the sub-pixels PXn. That is, the outer dike 430 may define the boundary of each sub-pixel PXn.

[0117] Although not shown, when manufacturing the display device 10, when using an inkjet printing device to eject the ink in which the light-emitting element 300 is dispersed, the outer dike 430 may function to prevent the ink from crossing the boundary of the sub-pixel PXn. The outer dike 430 may separate the inks in which different light-emitting elements 300 are dispersed for different sub-pixels PXn so as not to mix with each other. However, the present disclosure is not limited thereto.

[0118] A plurality of inner dikes 410 and 420 may be provided to be spaced apart from each other in each sub-pixel PXn. The plurality of inner dikes 410 and 420 may include a first inner dike 410 and a second inner dike 420 provided adjacent to the center of each sub-pixel PXn.

[0119] The first inner dike 410 and the second inner dike 420 are provided to face each other. The first electrode 210 may be provided on the first inner dike 410, and the second electrode 220 may be provided on the second inner dike 420. Referring to Figure 3 and Figure 4 , it can be understood that the first electrode branch 210B is provided on the first inner dike 410, and the second electrode branch 220B is provided on the second inner dike 420.

[0120] Similar to the first electrode 210 and the second electrode 220, the first inner bank 410 and the second inner bank 420 can be arranged to extend in the second direction DR2 in each sub-pixel PXn. Although not shown in the drawings, the first inner bank 410 and the second inner bank 420 can extend in the second direction DR2 toward the sub-pixels PXn adjacent in the second direction DR2. However, the present disclosure is not limited thereto, and the first inner bank 410 and the second inner bank 420 can be separately provided in each sub-pixel PXn, thereby forming a pattern on the entire surface of the display device 10.

[0121] Each of the first inner bank 410 and the second inner bank 420 can have a structure in which at least a part of it protrudes above the first insulating layer 510. Each of the first inner bank 410 and the second inner bank 420 can be provided with a protrusion above the plane of the light-emitting element 300, and at least a part of the protrusion can have a slope. The shape of the protrusions of the first inner bank 410 and the second inner bank 420 is not particularly limited. Since the inner banks 410 and 420 protrude with respect to the first insulating layer 510 and have inclined side surfaces, the light emitted from the light-emitting element 300 can be reflected by the inclined side surfaces of the inner banks 410 and 420. As will be described later, when the electrodes 210 and 220 provided on the inner banks 410 and 420 include materials having a high reflectivity, the light emitted from the light-emitting element 300 can be reflected by the electrodes 210 and 220 located on the inclined side surfaces of the inner banks 410 and 420 and travel in the upward direction of the first insulating layer 510.

[0122] In other words, the outer bank 430 can define adjacent sub-pixels PXn and perform the function of preventing ink from overflowing into adjacent sub-pixels PXn during the inkjet process, while the inner banks 410 and 420 can have a protruding structure in each sub-pixel PXn and perform the function of a reflection partition wall for reflecting the light emitted from the light-emitting element 300 in the upward direction of the first insulating layer 510. However, the present disclosure is not limited thereto. Meanwhile, the plurality of inner banks 410 and 420 and the outer bank 430 can include, but are not limited to, polyimide (PI).

[0123] The plurality of electrodes 210 and 220 can be respectively provided on the first insulating layer 510 and the inner banks 410 and 420. As described above, the electrodes 210 and 220 respectively include electrode main bodies 210S and 220S and electrode branches 210B and 220B. Figure 3 The line Xa-Xa' is a line crossing the first electrode main body 210S, Figure 3 The line Xb-Xb' is a line crossing the first electrode branch 210B and the second electrode branch 220B, and Figure 3 The line Xc-Xc' is a line crossing the second electrode main body 220S. That is, provided byFigure 4 The first electrode 210 in the region indicated by the line Xa-Xa' can be understood as the first electrode main body part 210S; provided in Figure 4 The first electrode 210 and the second electrode 220 in the region indicated by the line Xb-Xb' can be respectively understood as the first electrode branch part 210B and the second electrode branch part 220B; and provided in Figure 4 The second electrode 220 in the region indicated by the line Xc-Xc' can be understood as the second electrode main body part 220S. The first electrode main body part 210S and the first electrode branch part 210B can form the first electrode 210, and the second electrode main body part 220S and the second electrode branch part 220B can form the second electrode 220.

[0124] Some regions of the first electrode 210 and the second electrode 220 can be provided on the first insulating layer 510, and some other regions thereof can be respectively provided on the first inner dike part 410 and the second inner dike part 420. That is, the widths of the first electrode 210 and the second electrode 220 can be greater than the widths of the inner dike parts 410 and 420. Portions of the bottom surfaces of the first electrode 210 and the second electrode 220 can be in contact with the first insulating layer 510, and other portions thereof can be in contact with the inner dike parts 410 and 420.

[0125] Although not shown in the drawings, the first electrode main body part 210S of the first electrode 210 extending in the first direction DR1 and the second electrode main body part 220S of the second electrode 220 extending in the first direction DR1 can respectively partially overlap with the first inner dike part 410 and the second inner dike part 420. However, the present disclosure is not limited thereto, and the first electrode main body part 210S and the second electrode main body part 220S may respectively not overlap with the first inner dike part 410 and the second inner dike part 420.

[0126] The first electrode contact hole CNTD can be formed in the first electrode main body part 210S of the first electrode 210 to penetrate the first insulating layer 510 and expose a part of the first conductive wiring 191. The first electrode 210 can be in contact with the first conductive wiring 191 through the first electrode contact hole CNTD, and the first electrode 210 can be electrically connected to the first source electrode 123 of the first transistor 120 to receive an electrical signal.

[0127] The second electrode contact hole CNTS can be formed in the second electrode main body part 220S of the second electrode 220 to penetrate the first insulating layer 510 and expose a part of the second conductive wiring 192. The second electrode 220 can be in contact with the second conductive wiring 192 through the second electrode contact hole CNTS, and the second electrode 220 can be electrically connected to the power supply electrode 162 to receive an electrical signal.

[0128] Some regions of the first electrode 210 and the second electrode 220 (e.g., the first electrode branch portion 210B and the second electrode branch portion 220B) may be configured to cover the first inner dike portion 410 and the second inner dike portion 420, respectively. The first electrode 210 and the second electrode 220 may face each other with a gap therebetween, and a plurality of light-emitting elements 300 may be disposed therebetween.

[0129] Each of the electrodes 210 and 220 may include a transparent conductive material. For example, each of the electrodes 210 and 220 may include a material such as indium tin oxide (ITO), indium zinc oxide (IZO), and indium tin zinc oxide (ITZO), but is not limited thereto. In some embodiments, each of the electrodes 210 and 220 may include a conductive material having a high reflectivity. For example, each of the electrodes 210 and 220 may include a metal as a material having a high reflectivity, such as silver (Ag), copper (Cu), or aluminum (Al). In this case, light incident on each of the electrodes 210 and 220 may be reflected to radiate in the upward direction of each sub-pixel PXn.

[0130] In addition, each of the electrodes 210 and 220 may have a structure in which at least one transparent conductive material and at least one metal layer having a high reflectivity are stacked, or may be formed as one layer including them. In an embodiment, each of the electrodes 210 and 220 may have a stacked structure of ITO / silver (Ag) / ITO / IZO, or may be made of an alloy including aluminum (Al), nickel (Ni), and lanthanum (La). However, the present disclosure is not limited thereto.

[0131] The second insulating layer 520 is disposed on the first insulating layer 510, the first electrode 210, and the second electrode 220. The second insulating layer 520 is disposed to partially cover the first electrode 210 and the second electrode 220. The second insulating layer 520 may be disposed to cover most of the top surfaces of the first electrode 210 and the second electrode 220, and openings (not shown) exposing portions of the first electrode 210 and the second electrode 220 may be formed in the second insulating layer 520. The openings of the second insulating layer 520 may be positioned to expose relatively flat top surfaces of the first electrode 210 and the second electrode 220.

[0132] In an embodiment, the second insulating layer 520 may be formed to have a step such that a part of its top surface is recessed between the first electrode 210 and the second electrode 220. In some embodiments, the second insulating layer 520 may include an inorganic insulating material, and a part of the top surface of the second insulating layer 520 provided to cover the first electrode 210 and the second electrode 220 may be recessed through the step formed by the electrodes 210 and 220. A light-emitting element 300 provided on the second insulating layer 520 between the first electrode 210 and the second electrode 220 may form an empty space with respect to the recessed top surface of the second insulating layer 520. The light-emitting element 300 may be provided to be partially spaced apart from the top surface of the second insulating layer 520, and there may be a gap therebetween, and the gap may be filled with a material forming a third insulating layer 530 to be described later.

[0133] However, the present disclosure is not limited thereto. The second insulating layer 520 may include a flat top surface such that the light-emitting element 300 is provided thereon. The top surface may extend in one direction toward the first electrode 210 and the second electrode 220, and may terminate on the inclined side surfaces of the first electrode 210 and the second electrode 220. That is, the second insulating layer 520 may be provided in a region where the electrodes 210 and 220 overlap the inclined side surfaces of the first inner dike portion 410 and the second inner dike portion 420, respectively. A contact electrode 260 to be described later may contact the exposed regions of the first electrode 210 and the second electrode 220, and may smoothly contact one end of the light-emitting element 300 on the flat top surface of the second insulating layer 520.

[0134] The second insulating layer 520 may protect the first electrode 210 and the second electrode 220 while insulating them from each other. In addition, it is possible to prevent the light-emitting element 300 provided on the second insulating layer 520 from being damaged due to direct contact with other components. However, the shape and structure of the second insulating layer 520 are not limited thereto.

[0135] The light-emitting element 300 may be provided on the second insulating layer 520 between the electrodes 210 and 220. For example, at least one light-emitting element 300 may be provided on the second insulating layer 520 provided between the electrode branch portions 210B and 220B. However, the present disclosure is not limited thereto, and although not shown in the drawings, at least some of the light-emitting elements 300 provided in each sub-pixel PXn may be placed in a region other than the region between the electrode branch portions 210B and 220B. In addition, the light-emitting element 300 may be provided such that some of its regions overlap the electrodes 210 and 220. The light-emitting element 300 may be provided at the ends where the first electrode branch portion 210B and the second electrode branch portion 220B face each other.

[0136] In the light-emitting element 300, a plurality of layers may be provided in a direction parallel to the first insulating layer 510. The light-emitting element 300 of the display device 10 according to one embodiment may have a shape extending in one direction, and may have a structure in which a plurality of semiconductor layers are sequentially arranged in one direction. In the light-emitting element 300, the first semiconductor layer 310, the active layer 330, the second semiconductor layer 320, and the electrode layer 370 may be sequentially provided along one direction, and their outer surfaces may be surrounded by the insulating film 380. The light-emitting element 300 provided in the display device 10 may be arranged such that one extending direction is parallel to the first insulating layer 510, and the plurality of semiconductor layers included in the light-emitting element 300 may be sequentially arranged in a direction parallel to the top surface of the first insulating layer 510. However, the present disclosure is not limited thereto. In some cases, when the light-emitting element 300 has a different structure, a plurality of layers may be arranged in a direction perpendicular to the first insulating layer 510.

[0137] In addition, one end of the light-emitting element 300 may be in contact with the first contact electrode 261, and the other end thereof may be in contact with the second contact electrode 262. According to one embodiment, since the end surface of the light-emitting element 300 in one direction along which the light-emitting element 300 extends is exposed without the insulating film 380 being formed thereon, the light-emitting element 300 may be in contact with the first contact electrode 261 and the second contact electrode 262 to be described later in the exposed area. However, the present disclosure is not limited thereto. In some cases, in the light-emitting element 300, at least some regions of the insulating film 380 may be removed, and the insulating film 380 may be removed to partially expose both end side surfaces of the light-emitting element 300. During the manufacturing process of the display device 10, in the step of forming the third insulating layer 530 covering the outer surface of the light-emitting element 300, the insulating film 380 may be partially removed. The exposed side surfaces of the light-emitting element 300 may be in contact with the first contact electrode 261 and the second contact electrode 262. However, the present disclosure is not limited thereto.

[0138] The third insulating layer 530 may be partially disposed on the light-emitting element 300 disposed between the first electrode 210 and the second electrode 220. The third insulating layer 530 may be disposed to partially surround the outer surface of the light-emitting element 300 to protect the light-emitting element 300, and may perform a function of fixing the light-emitting element 300 during the manufacturing process of the display device 10. According to an embodiment, the third insulating layer 530 may be disposed on the light-emitting element 300, and one end and the other end of the light-emitting element 300 may be exposed. The exposed one end and the other end of the light-emitting element 300 may be in contact with the contact electrodes 260, such that an electrical signal may be received from the electrodes 210 and 220. The shape of the third insulating layer 530 may be formed by using a patterning process of a material for forming the third insulating layer 530 by using a conventional mask process. The mask for forming the third insulating layer 530 may have a width smaller than the length of the light-emitting element 300, and the material for forming the third insulating layer 530 may be patterned such that both ends of the light-emitting element 300 are exposed. However, the present disclosure is not limited thereto.

[0139] In addition, in an embodiment, a part of the material of the third insulating layer 530 may be disposed between the bottom surface of the light-emitting element 300 and the second insulating layer 520. The third insulating layer 530 may be formed to fill a space formed between the second insulating layer 520 and the light-emitting element 300 during the manufacturing process of the display device 10. Accordingly, the third insulating layer 530 may be formed to surround the outer surface of the light-emitting element 300. However, the present disclosure is not limited thereto.

[0140] In a plan view, the third insulating layer 530 may extend in the second direction DR2 between the first electrode branch portion 210B and the second electrode branch portion 220B. For example, in a plan view, the third insulating layer 530 may have an island shape or a linear shape on the first insulating layer 510.

[0141] The first contact electrode 261 is disposed on the first electrode 210 and the third insulating layer 530, and the second contact electrode 262 is disposed on the second electrode 220 and the third insulating layer 530. The third insulating layer 530 may be disposed between the first contact electrode 261 and the second contact electrode 262, and may insulate them from each other to prevent direct contact between the first contact electrode 261 and the second contact electrode 262.

[0142] As described above, the first contact electrode 261 and the second contact electrode 262 may be in contact with at least one end of the light-emitting element 300, and the first contact electrode 261 and the second contact electrode 262 may be electrically connected to the first electrode 210 or the second electrode 220 to receive an electrical signal.

[0143] The first contact electrode 261 may contact the exposed area of the first electrode 210 on the first inner dike portion 410, and the second contact electrode 262 may contact the exposed area of the second electrode 220 on the second inner dike portion 420. The first contact electrode 261 and the second contact electrode 262 may transmit the electrical signals transmitted from the electrodes 210 and 220 to the light-emitting element 300, respectively.

[0144] The contact electrode 260 may include a conductive material. For example, they may include ITO, IZO, ITZO, aluminum (Al), etc. However, the present disclosure is not limited thereto.

[0145] The passivation layer 550 may be disposed on the contact electrode 260 and the third insulating layer 530. The passivation layer 550 may serve to protect the components disposed on the first insulating layer 510 from the external environment.

[0146] Each of the first insulating layer 510, the second insulating layer 520, the third insulating layer 530, and the passivation layer 550 described above may include an inorganic insulating material or an organic insulating material. In an embodiment, the first insulating layer 510, the second insulating layer 520, the third insulating layer 530, and the passivation layer 550 may include an inorganic insulating material such as silicon oxide (SiO x ), silicon nitride (SiN x ), silicon oxynitride (SiO x N y ), aluminum oxide (Al 2 O 3 ), aluminum nitride (AlN), etc. The first insulating layer 510, the second insulating layer 520, the third insulating layer 530, and the passivation layer 550 may include an organic insulating material such as acrylic resin, epoxy resin, phenolic resin, polyamide resin, polyimide resin, unsaturated polyester resin, polyphenylene resin, polyphenylene sulfide resin, benzocyclobutene, cardo resin, silicone resin, silsesquioxane resin, polymethyl methacrylate, polycarbonate, and polymethyl methacrylate-polycarbonate synthetic resin. However, the present disclosure is not limited thereto.

[0147] Meanwhile, the display device 10 according to an embodiment may include a light-emitting element 300 including an electrode layer 370 and an insulating film 380 each having a thickness equal to or greater than a certain level. The light-emitting element 300 according to an embodiment may prevent the active layer 330 from being damaged or the electrode layer 370 from being removed during the manufacturing process of the light-emitting element 300 and the manufacturing process of the display device 10, and may improve the light-emitting efficiency and light-emitting reliability of the light-emitting element 300. Hereinafter, the light-emitting element 300 according to an embodiment will be described in detail with reference to other drawings.

[0148] Figure 5 Schematic diagram of a light-emitting element according to an embodiment. Figure 6 Schematic cross-section of a light-emitting element according to an embodiment.

[0149] The light-emitting element 300 may be a light-emitting diode. In particular, the light-emitting element 300 may be an inorganic light-emitting diode having a micron or nanometer size and made of an inorganic material. When an electric field is formed in a specific direction between two electrodes facing each other, the inorganic light-emitting diode may be aligned between the two electrodes having polarity. The light-emitting element 300 may be aligned between the two electrodes by the electric field generated between the electrodes.

[0150] The light-emitting element 300 according to an embodiment may have a shape extending in one direction. The light-emitting element 300 may have a shape such as a rod, a wire, a tube, etc. In an embodiment, the light-emitting element 300 may have a cylindrical shape or a rod shape. However, the shape of the light-emitting element 300 is not limited thereto, and the light-emitting element 300 may have a polygonal prism shape such as a regular cube, a rectangular parallelepiped, and a hexagonal prism, or may have various shapes such as a shape extending in one direction and having a partially inclined outer surface. The plurality of semiconductor layers included in the light-emitting element 300 described later may have a structure in which they are sequentially arranged or stacked along one direction.

[0151] The light-emitting element 300 may include a semiconductor layer doped with impurities of any conductivity type (e.g., p-type or n-type). The semiconductor layer may emit light in a specific wavelength band by receiving an electric signal applied from an external power source.

[0152] The light-emitting element 300 according to an embodiment may emit light in a specific wavelength band. In an embodiment, the active layer 330 may emit blue light having a central wavelength band ranging from 450 nm to 495 nm. However, it should be understood that the central wavelength band of the blue light is not limited to the above range, but includes all wavelength ranges that can be considered blue in the related art. In addition, the light emitted from the active layer 330 of the light-emitting element 300 is not limited thereto, and may be green light having a central wavelength band ranging from 495 nm to 570 nm, or red light having a central wavelength band ranging from 620 nm to 752 nm. Hereinafter, the description will be provided based on the assumption that the light-emitting element 300 emits blue light, for example.

[0153] Reference Figure 5 and Figure 6, the light-emitting element 300 may include a semiconductor core and an insulating film 380 surrounding the semiconductor core, and the semiconductor core of the light-emitting element 300 may include a first semiconductor layer 310, a second semiconductor layer 320, and an active layer 330. In addition, the light-emitting element 300 according to one embodiment may further include an electrode layer 370 disposed on one surface of the first semiconductor layer 310 or the second semiconductor layer 320.

[0154] The first semiconductor layer 310 may be an n-type semiconductor. For example, when the light-emitting element 300 emits light in a blue wavelength band, the first semiconductor layer 310 may include a semiconductor material having the chemical formula Al x Ga y In 1-x-y N (0≤x≤1, 0≤y≤1, 0≤x + y≤1). For example, it may be any one or more of n-type doped AlGaInN, GaN, AlGaN, InGaN, AlN, and InN. The first semiconductor layer 310 may be doped with an n-type dopant. For example, the n-type dopant may be Si, Ge, Se, Sn, etc. In an embodiment, the first semiconductor layer 310 may be n-GaN doped with n-type Si. The length of the first semiconductor layer 310 may have a range of 1.5 μm to 5 μm, but is not limited thereto.

[0155] The second semiconductor layer 320 is disposed on the active layer 330 which will be described later. The second semiconductor layer 320 may be a p-type semiconductor. For example, when the light-emitting element 300 emits light in a blue wavelength band or a green wavelength band, the second semiconductor layer 320 may include a semiconductor material having the chemical formula Al x Ga y In 1-x-y N (0≤x≤1, 0≤y≤1, 0≤x + y≤1). For example, it may be any one or more of p-type doped AlGaInN, GaN, AlGaN, InGaN, AlN, and InN. The second semiconductor layer 320 may be doped with a p-type dopant. For example, the p-type dopant may be Mg, Zn, Ca, Ba, etc. In an embodiment, the second semiconductor layer 320 may be p-GaN doped with p-type Mg. The length of the second semiconductor layer 320 may have a range of 0.05 μm to 0.10 μm, but is not limited thereto.

[0156] Meanwhile, although the first semiconductor layer 310 and the second semiconductor layer 320 are shown as single layers in the drawings, the present disclosure is not limited thereto. According to some embodiments, depending on the material of the active layer 330, the first semiconductor layer 310 and the second semiconductor layer 320 may further include a greater number of layers, such as a cladding layer or a tensile strain barrier reduction (TSBR) layer. A description thereof will be given later with reference to other drawings.

[0157] The active layer 330 is disposed between the first semiconductor layer 310 and the second semiconductor layer 320. The active layer 330 may include a material having a single quantum well structure or a multi - quantum well structure. When the active layer 330 includes a material having a multi - quantum well structure, a plurality of quantum layers and well layers may be alternately stacked. The active layer 330 can emit light by coupling electron - hole pairs according to an electrical signal applied through the first semiconductor layer 310 and the second semiconductor layer 320. For example, when the active layer 330 emits light in the blue wavelength band, it may include materials such as AlGaN or AlGaInN. In particular, when the active layer 330 has a structure in which quantum layers and well layers are alternately stacked in a multi - 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. In an embodiment, as described above, the active layer 330 includes AlGaInN as the quantum layer and AlInN as the well layer, and the active layer 330 can emit blue light having a central wavelength band of 450 nm to 495 nm.

[0158] However, the present disclosure is not limited thereto, and the active layer 330 may have a structure in which a semiconductor material having a large bandgap and a semiconductor material having a small bandgap are alternately stacked, and may include other group - III to group - V semiconductor materials according to the wavelength band of the emitted light. The light emitted by the active layer 330 is not limited to light in the blue wavelength band, but in some cases, the active layer 330 may also emit light in the red wavelength band or the green wavelength band. The length of the active layer 330 may range from 0.05 μm to 0.10 μm, but is not limited thereto.

[0159] Meanwhile, the light emitted from the active layer 330 can be emitted in the longitudinal direction to both side surfaces and the outer surface of the light - emitting element 300. The directivity of the light emitted from the active layer 330 is not limited to one direction.

[0160] The electrode layer 370 may be an ohmic contact electrode. However, the present disclosure is not limited thereto, and they may be Schottky contact electrodes. The light - emitting element 300 may include at least one electrode layer 370. Although Figure 6 the light - emitting element 300 is shown including one electrode layer 370, the present disclosure is not limited thereto. In some cases, the light - emitting element 300 may include a larger number of electrode layers 370, or the electrode layer 370 may be omitted. Even if the number of electrode layers 370 is different or other structures are also included, the following description of the light - emitting element 300 can be applied equally.

[0161] In the display device 10 according to an embodiment, when the light-emitting element 300 is electrically connected to an electrode or a contact electrode, the electrode layer 370 may reduce the resistance between the light-emitting element 300 and the electrode or the contact electrode. The electrode layer 370 may include a conductive metal. For example, the electrode layer 370 may include at least one of aluminum (Al), titanium (Ti), indium (In), gold (Au), silver (Ag), indium tin oxide (ITO), indium zinc oxide (IZO), and indium tin zinc oxide (ITZO). In addition, the electrode layer 370 may include an n-type or p-type doped semiconductor material. The electrode layer 370 may include the same material or different materials, but is not limited thereto.

[0162] Meanwhile, in the light-emitting element 300, the electrode layer 370 may be partially etched during the manufacturing process. As will be described later, in the process of forming the insulating film 380, the electrode layer 370 may be partially etched to have a thickness less than the initial thickness. In the light-emitting element 300, the electrode layer 370 may have a thickness of a certain level or greater in order to prevent the electrode layer 370 from being etched and removed during the above process. In the light-emitting element 300 according to one embodiment, the thickness of the electrode layer 370 may be in the range of 20 nm to 200 nm, or in the range of 100 nm to 200 nm. When the electrode layer 370 has a thickness less than 20 nm, the electrode layer 370 may be etched and removed in the process of forming the insulating film 380, or a contact failure with the second semiconductor layer 320 may occur. On the other hand, when the thickness of the electrode layer 370 is greater than 200 nm, the light generated in the active layer 330 may be absorbed by the electrode layer 370, so that the optical characteristics of the light-emitting element 300 may deteriorate. To prevent this, the electrode layer 370 of the light-emitting element 300 may have a thickness of 20 nm or greater, preferably in the range of 100 nm to 200 nm.

[0163] Meanwhile, in the light-emitting element 300, the light generated in the active layer 330 may be emitted through two end surfaces (for example, the top surface of the electrode layer 370 or the bottom surface of the first semiconductor layer 310). Here, the transmittance of the light generated in the active layer 330 may vary according to the thickness of the electrode layer 370. However, the light-emitting element 300 according to one embodiment may include an electrode layer 370 having a thickness within the above range and having a transmittance of a certain level or higher. For example, when the active layer 330 generates blue light having a central wavelength band of about 450 nm, the electrode layer 370 may have a transmittance of 65% or greater, or 70% or greater, with respect to the light having a central wavelength band of about 450 nm. However, the present disclosure is not limited thereto.

[0164] In addition, in the light-emitting element 300, since the electrode layer 370 has a thickness within the above range, the change in transmittance with respect to the thickness can be minimized. That is, when the electrode layer 370 has a thickness of 20 nm to 200 nm, or 100 nm to 200 nm, the change in transmittance with respect to light having a center wavelength band of about 450 nm can be about 3% or about 1%. Therefore, in the light-emitting element 300, the thickness of the electrode layer 370 can be controlled to prevent the electrode layer 370 from being removed during the manufacturing process of the display device 10, and the emission characteristics and element efficiency can be improved due to a certain level or higher transmittance.

[0165] In addition, in some embodiments, the thickness of the electrode layer 370 of the light-emitting element 300 can be greater than the thickness of the second semiconductor layer 320. Due to the relatively large thickness of the electrode layer 370, the electrode layer 370 can be in smooth contact with the second semiconductor layer 320 or the first contact electrode 261. For this reason, in some cases, the electrode layer 370 of the light-emitting element 300 can be formed to be thicker than the second semiconductor layer 320. However, the present disclosure is not limited thereto.

[0166] The insulating film 380 is provided to surround the outer surfaces of the above-described semiconductor core and the electrode layer 370. In an embodiment, the insulating film 380 can be arranged to surround at least the outer surface of the active layer 330 and extend along the extending direction of the light-emitting element 300. The insulating film 380 can function as a protective member. For example, the insulating film 380 can be formed to surround the side surfaces of the members to expose both ends of the light-emitting element 300 in the longitudinal direction.

[0167] Although the insulating film 380 is shown in the drawings as extending in the longitudinal direction of the light-emitting element 300 to cover the regions of the side surfaces from the first semiconductor layer 310 to the electrode layer 370, the present disclosure is not limited thereto. The insulating film 380 can cover only the outer surfaces of some of the semiconductor layers including the active layer 330, or can cover only a part of the outer surface of the electrode layer 370 to partially expose the outer surface of each electrode layer 370. In addition, in a cross-sectional view, the insulating film 380 can have a top surface that is circular in a region adjacent to at least one end of the light-emitting element 300.

[0168] The insulating film 380 can include a material having insulating properties, such as silicon oxide (SiO x ), silicon nitride (SiN x ), silicon oxynitride (SiO x N y ), aluminum nitride (AlN), aluminum oxide (Al 2 O 3) etc. Therefore, it is possible to prevent an electrical short circuit that may occur when the active layer 330 is in direct contact with the electrodes through which an electrical signal is transmitted to the light-emitting element 300. In addition, since the insulating film 380 protects the outer surface of the light-emitting element 300 including the active layer 330, a reduction in luminous efficiency can be prevented.

[0169] In addition, in some embodiments, the insulating film 380 may have an outer surface that has been surface-treated. When manufacturing the display device 10, the light-emitting element 300 may be aligned by being ejected in a state of being dispersed in a predetermined ink onto the electrodes. Here, the surface of the insulating film 380 may be treated to be hydrophobic or hydrophilic so as to keep the light-emitting element 300 in a dispersed state without aggregating with other adjacent light-emitting elements 300 in the ink.

[0170] The light-emitting element 300 may have a length h of 1 μm to 10 μm or 2 μm to 6 μm, and preferably 3 μm to 5 μm. In addition, the diameter of the light-emitting element 300 may have a range of 300 nm to 700 nm, and the aspect ratio of the light-emitting element 300 may be 1.2 to 100. However, the present disclosure is not limited thereto, and the plurality of light-emitting elements 300 included in the display device 10 may have different diameters depending on the composition of the active layer 330. Preferably, the diameter of the light-emitting element 300 may be about 500 nm.

[0171] Meanwhile, the insulating film 380 may at least surround the active layer 330 to protect the semiconductor core of the light-emitting element 300. As described above, during the manufacturing process of the light-emitting element 300 and the manufacturing process of the display device 10, the insulating film 380 may be partially etched and have a reduced thickness. When the insulating film 380 has a reduced thickness, the insulating film 380 may be etched and removed during the manufacturing process, or the semiconductor core, particularly the active layer 330, may be damaged. To prevent this, the insulating film 380 of the light-emitting element 300 according to one embodiment may have a thickness equal to or greater than a certain level.

[0172] In a light-emitting element 300 according to an embodiment, the thickness of the insulating film 380 may be in the range of 10 nm to 1.0 μm, or in the range of 20 nm to 80 nm, preferably in the range of 60 nm to 80 nm. The insulating film 380 may have a thickness within the above range and may be provided to at least surround the outer surface of the active layer 330. Thus, even if the insulating film 380 is partially etched during the manufacturing process of the light-emitting element 300 and the manufacturing process of the display device 10, the insulating film 380 may remain on the outer surface of the active layer 330 and protect it. Meanwhile, in the drawings, the insulating film 380 is shown as being provided to surround the entire outer surface of the semiconductor core including the active layer 330 and to surround the side surfaces of the first semiconductor layer 310 and the electrode layer 370. However, the present disclosure is not limited thereto, and in the light-emitting element 300, the insulating film 380 may not be provided, and the outer surface of the semiconductor core may be partially exposed.

[0173] Since the insulating film 380 has a thickness within the above range, the diameter of the semiconductor core and the thickness of the insulating film 380 in the light-emitting element 300 may have a specific relationship. For example, in the light-emitting element 300, the thickness of the insulating film 380 may be in the range of 10% to 16% of the diameter of the semiconductor core. Since the insulating film 380 has a thickness within the above range, the semiconductor core, particularly the active layer 330, can be protected.

[0174] In addition, in some embodiments, the insulating film 380 may be provided along the outer surface of the semiconductor core, but may not have a uniform thickness. The insulating film 380 may have different thicknesses on the outer surfaces of the first semiconductor layer 310, the active layer 330, the second semiconductor layer 320, and the electrode layer 370. This may be because the insulating film 380 is etched during the manufacturing process of the light-emitting element 300 or is partially etched after the light-emitting element 300 is provided on the display device 10 to have different thicknesses according to the position.

[0175] Figure 7 is Figure 4 an enlarged view of a partial QA.

[0176] Figure 7 is an enlarged cross-sectional view showing the light-emitting element 300 provided between the first electrode 210 and the second electrode 220 in the display device 10. Refer to Figure 7, the light-emitting element 300 may be disposed on the second insulating layer 520 between the first electrode 210 and the second electrode 220. In a cross-sectional view, on the outer surface of the insulating film 380, the light-emitting element 300 may include one side surface as the lower surface and the other side surface as the upper surface. The one side surface may be in contact with the second insulating layer 520 and the third insulating layer 530 disposed on the lower side of the light-emitting element 300, and the other side surface may be in contact with the third insulating layer 530 and the contact electrode 260 disposed on the upper side of the light-emitting element 300.

[0177] One side surface as the lower surface of the light-emitting element 300 may be in contact with the second insulating layer 520 and may be in contact with the third insulating layer 530 in a space formed by partially recessing the second insulating layer 520 and filling it with the third insulating layer 530. During the manufacturing process of the display device 10, in a cross-sectional view, one side surface as the lower surface of the light-emitting element 300 may not be etched. Therefore, the contact surface between the second insulating layer 520 and the third insulating layer 530 may form a flat surface.

[0178] On the other hand, in the light-emitting element 300, in the etching process performed before the process of forming the contact electrode 260, the other side surface as the upper surface may be partially etched in a cross-sectional view. On the other side surface, except for the portion in contact with the third insulating layer 530, the insulating film 380 may be etched in the region in contact with the contact electrode 260. The display device 10 according to an embodiment may include a region where the thickness portion of the insulating film 380 of the light-emitting element 300 is different. The other side surface may include a first surface S1 in contact with the first contact electrode 261, a second surface S2 in contact with the second contact electrode 262, and a third surface S3 in contact with the third insulating layer 530. On the other side surface, the first surface S1 and the second surface S2 may be partially etched before the process of forming the contact electrode 260 so that the insulating film 380 may have a relatively small thickness, and the third surface S3 may be in contact with the third insulating layer 530 so that the insulating film 380 may not be etched. Therefore, the insulating film 380 may have a smaller thickness in the region where the first surface S1 and the second surface S2 are located than in the region where the third surface S3 is located.

[0179] The thickness of the insulating film 380 of the light-emitting element 300 may be the thickness of the region where the third surface S3 is located. That is, the insulating film 380 of the light-emitting element 300 of the display device 10 may have a thickness in the range of 60 nm to 80 nm in the region where the third surface S3 is located or in the region in contact with the third insulating layer 530. On the other hand, in the regions where the first surface S1 and the second surface S2 are located, or in the regions in contact with the first contact electrode 261 and the second contact electrode 262, the thickness may be in the range of 40 nm to 60 nm.

[0180] Therefore, the light-emitting element 300 disposed between the first electrode 210 and the second electrode 220 may have different diameters depending on the position. That is, the light-emitting element 300 may have different diameters measured in another direction perpendicular to one extending direction. For example, a first diameter Da of the light-emitting element 300 measured in another direction in the region where the third surface S3 is located may be greater than a second diameter Db measured in the region where the second surface S2 is located and a third diameter Dc measured in the region where the first surface S1 is located. The first diameter Da, the second diameter Db, and the third diameter Dc may have different values because the insulating film 380 is partially etched during the manufacturing process of the display device 10 or the manufacturing process of the light-emitting element 300.

[0181] In addition, in the light-emitting element 300, in the region where the first surface S1 is located, a third-first diameter Dc1 measured at the interface between the active layer 330 and the second semiconductor layer 320 and a third-second diameter Dc2 measured at the interface between the second semiconductor layer 320 and the electrode layer 370 may be further defined. Although the third-first diameter Dc1 and the third-second diameter Dc2 are shown to be equal in the drawings, the present disclosure is not limited thereto. In some embodiments, the third-first diameter Dc1 and the third-second diameter Dc2 may have different values, and the insulating film 380 may be formed to have an inclined outer surface in a cross-sectional view. The description thereof may refer to other embodiments.

[0182] The region where the first surface S1 of the insulating film 380 is located or the region in contact with the first contact electrode 261 may be a region surrounding the active layer 330 and have a thickness equal to or greater than a certain level. The insulating film 380 of the light-emitting element 300 according to one embodiment may have a thickness in the range of 60 nm to 80 nm, and at least some regions may have a thickness of 40 nm or greater and 60 nm or less. In the region where the first surface S1 of the insulating film 380 is located, particularly in the region surrounding the active layer 330, even if the insulating film 380 is partially etched during the manufacturing process, the insulating film 380 may have a thickness of 40 nm or greater, so that the active layer 330 of the light-emitting element 300 can be prevented from being exposed. Since the insulating film 380 is formed to have a thickness equal to or greater than a certain level during the manufacturing process of the light-emitting element 300, even if the insulating film 380 is partially etched, the light-emitting element 300 provided in the display device 10 can protect the active layer 330. Therefore, the light-emitting efficiency and light-emitting reliability of the light-emitting element 300 can be improved.

[0183] Meanwhile, the display device 10 may further include a larger number of insulating layers. According to one embodiment, the display device 10 may further include a fourth insulating layer 540 (see Figure 8 ) provided to protect the first contact electrode 261.

[0184] Figure 8 is a cross-sectional view showing a part of a display device according to one embodiment.

[0185] Reference Figure 8 , the display device 10 according to one embodiment may further include a fourth insulating layer 540 provided on the first contact electrode 261. The display device 10 according to the embodiment is different from the display device 10 of Figure 4 in that it further includes a fourth insulating layer 540, and at least a part of the second contact electrode 262 is provided on the fourth insulating layer 540. In the following description, redundant descriptions will be omitted while focusing on the differences.

[0186] Figure 8The display device 10 may include a fourth insulating layer 540 that is disposed on the first contact electrode 261 and electrically insulates the first contact electrode 261 and the second contact electrode 262 from each other. The fourth insulating layer 540 may be arranged to cover the first contact electrode 261 and not overlap with a partial region of the light-emitting element 300, such that the light-emitting element 300 is connected to the second contact electrode 262. The fourth insulating layer 540 may be in partial contact with the first contact electrode 261 and the third insulating layer 530 on the upper surface of the third insulating layer 530. The fourth insulating layer 540 may be disposed on the third insulating layer 530 to cover one end of the first contact electrode 261. Accordingly, the fourth insulating layer 540 may protect the first contact electrode 261 and electrically insulate it from the second contact electrode 262.

[0187] A side surface of the fourth insulating layer 540 in the direction in which the second contact electrode 262 is disposed may be aligned with a side surface of the third insulating layer 530. However, the present disclosure is not limited thereto. In some embodiments, similar to the second insulating layer 520, the fourth insulating layer 540 may include an inorganic insulating material.

[0188] The first contact electrode 261 may be disposed between the first electrode 210 and the fourth insulating layer 540, and the second contact electrode 262 may be disposed on the fourth insulating layer 540. The second contact electrode 262 may be in partial contact with the second insulating layer 520, the third insulating layer 530, the fourth insulating layer 540, the second electrode 220, and the light-emitting element 300. One end of the second contact electrode 262 in the direction in which the first electrode 210 is disposed may be disposed on the fourth insulating layer 540.

[0189] A passivation layer 550 may be disposed on the fourth insulating layer 540 and the second contact electrode 262 to protect them. Hereinafter, redundant descriptions will be omitted.

[0190] Hereinafter, a manufacturing process of the light-emitting element 300 according to an embodiment will be described.

[0191] Figures 9 to 14 is a cross-sectional view showing a manufacturing process of a light-emitting element according to an embodiment.

[0192] First, referring to Figure 9 , a lower substrate 1000 including a base substrate 1100 and a buffer material layer 1200 formed on the base substrate 1100 is prepared. The base substrate 1100 may include a transparent substrate, such as a sapphire (Al 2 O 3 ) substrate and a glass substrate. However, the present disclosure is not limited thereto, and it may be formed of a conductive substrate such as GaN, SiC, ZnO, Si, GaP, and GaAs. The following description is for the case where the base substrate 1100 is sapphire (Al2 O 3 )For the case of the substrate. Although not limited, the base substrate 1100 may have a thickness in the range of, for example, 400 μm to 1500 μm.

[0193] A plurality of semiconductor layers are formed on the base substrate 1100. The plurality of semiconductor layers grown by an epitaxial method can be formed by growing a seed crystal. Here, the semiconductor layer can be formed using one of electron beam deposition, physical vapor deposition (PVD), chemical vapor deposition (CVD), plasma laser deposition (PLD), dual-type thermal evaporation, sputtering, and metalorganic chemical vapor deposition (MOCVD), and preferably formed using metalorganic chemical vapor deposition (MOCVD). However, the present disclosure is not limited thereto.

[0194] Generally, the precursor material for forming the plurality of semiconductor layers can be selected to form a target material within a generally selectable range without any limitation. For example, the precursor material can be a metal precursor including an alkyl group such as methyl or ethyl. Examples of the precursor material can include, but are not limited to, trimethylgallium Ga(CH 3 ) 3 , trimethylaluminum Al(CH 3 ) 3 and triethyl phosphate (C 2 H 5 ) 3 PO 4 . Hereinafter, the description of the method and process conditions for forming the plurality of semiconductor layers is omitted, and the process sequence of the method for manufacturing the light-emitting element 300 and the layered structure of the light-emitting element 300 are described in detail.

[0195] A buffer material layer 1200 is formed on the base substrate 1100. Although one buffer material layer 1200 is shown deposited in the drawings, the present disclosure is not limited thereto, and a plurality of layers can be formed. The buffer material layer 1200 can be provided to reduce the difference in lattice constants between the first semiconductor 3100 and the base substrate 1100.

[0196] For example, the buffer material layer 1200 can include an undoped semiconductor and can be a material including substantially the same material as the first semiconductor layer 310 and neither n-type doped nor p-type doped. In an embodiment, the buffer material layer 1200 can be, but is not limited to, at least one of undoped AlGaInN, GaN, AlGaN, InGaN, AlN, and InN. The buffer material layer 1200 can also be omitted depending on the base substrate 1100. The following description will be given for an example in which a buffer material layer 1200 including an undoped semiconductor is formed on the base substrate 1100.

[0197] Next, asFigure 10 As shown, a semiconductor structure 3000 is formed on a lower substrate 1000. The semiconductor structure 3000 may include a first semiconductor 3100, an active layer 3300, a second semiconductor 3200, and an electrode material layer 3700. The plurality of material layers included in the semiconductor structure 3000 may be formed by performing a conventional process as described above, and the plurality of layers included in the semiconductor structure 3000 may correspond to the corresponding layers included in the light-emitting element 300 according to one embodiment. That is, the plurality of material layers may include the same materials as the first semiconductor layer 310, the active layer 330, the second semiconductor layer 320, and the electrode layer 370 of the light-emitting element 300.

[0198] Next, referring to Figure 11 , the semiconductor structure 3000 is etched to form semiconductor cores 3000' spaced apart from each other. The semiconductor structure 3000 may be etched by a conventional method. For example, the semiconductor structure 3000 may be etched by forming an etching mask layer thereon and etching the semiconductor structure 3000 along the etching mask layer in a direction perpendicular to the lower substrate 1000.

[0199] For example, the process of etching the semiconductor structure 3000 may be dry etching, wet etching, reactive ion etching (RIE), inductively coupled plasma reactive ion etching (ICP-RIE), etc. The dry etching method may be applicable to vertical etching because anisotropic etching can be performed. In the case of using the above etching techniques, it may be possible to use Cl 2 or O 2 as an etchant. However, the present disclosure is not limited thereto.

[0200] In some embodiments, etching the semiconductor structure 3000 may be performed using a combination of dry etching and wet etching. For example, it may be possible to perform etching in the depth direction using dry etching and then perform anisotropic etching using wet etching so that the etched sidewalls are placed in a plane perpendicular to the surface.

[0201] Next, an element bar ROD including an insulating film 380 partially surrounding the outer surface of the semiconductor core 3000' is formed (see Figure 13 ).

[0202] Referring to Figure 12 and Figure 13 , the insulating film 380 may be formed by forming an insulating coating film 3800 around the outer surface of the semiconductor core 3000' and then partially removing the insulating coating film 3800 to expose one end of the semiconductor core 3000' (e.g., the top surface of the electrode layer 370) (the first etching in Figure 12 ).

[0203] The insulating coating film 3800, which is an insulating material formed on the outer surface of the semiconductor core 3000', can be formed by a method of coating or immersing an insulating material on the outer surface of the vertically etched semiconductor core 3000'. However, the present disclosure is not limited thereto. For example, the insulating coating film 3800 can be formed using an atomic layer deposition (ALD) method.

[0204] The insulating coating film 3800 can also be formed on the side surface and the top surface of the semiconductor core 3000', and on the portions of the lower substrate 1000 that are exposed in the regions where the semiconductor cores 3000' are spaced apart from each other. Partial removal of the insulating coating film 3800 can be performed by etch-back or dry etching, which is anisotropic etching. In the drawings, the top surface of the insulating coating film 3800 is removed to expose the electrode layer 370, and in this process, the electrode layer 370 can also be partially removed. That is, in the light-emitting element 300, the thickness of the electrode layer 370 of the finally manufactured light-emitting element 300 can be smaller than the thickness of the electrode material layer 3700 formed during the manufacturing process. As described above, since the thickness of the electrode layer 370 of the light-emitting element 300 according to one embodiment can be 20 nm to 200 nm, or 100 nm to 200 nm, the thickness of the electrode material layer 3700 can be 200 nm or greater. However, the present disclosure is not limited thereto.

[0205] Although the top surface of the electrode layer 370 is shown as being exposed and the top surface of the insulating film 380 is flat in the drawings, the present disclosure is not limited thereto. In some embodiments, the insulating film 380 can be formed to have a partially curved outer surface in the region where it surrounds the electrode layer 370. In the process of partially removing the insulating coating film 3800, the side surface as well as the top surface of the insulating coating film 3800 can be partially removed, so that the insulating film 380 surrounding the plurality of layers can be formed to have a partially etched end surface. In particular, since the top surface of the insulating coating film 3800 is removed, the outer surface of the insulating film 380 adjacent to the electrode layer 370 in the light-emitting element 300 can be partially removed.

[0206] Finally, as Figure 14 shown, the light-emitting element 300 is manufactured by separating the element bar ROD on which the insulating film 380 is formed from the lower substrate 1000.

[0207] Through the above process, the light-emitting element 300 according to one embodiment can be manufactured. The light-emitting element 300 manufactured as described above can be disposed between the first electrode 210 and the second electrode 220, and a display device 10 can be manufactured by disposing a third insulating layer 530, a contact electrode 260, etc. thereon. Next, the manufacturing process of the display device 10 will be further described with reference to other drawings.

[0208] Figures 15 to 19A cross-sectional view showing a part of a manufacturing process of a display device according to an embodiment is provided.

[0209] First, referring to Figure 15 , a first insulating layer 510, a first inner dike portion 410 and a second inner dike portion 420 spaced apart from each other on the first insulating layer 510, a first electrode 210 and a second electrode 220 respectively disposed on the first inner dike portion 410 and the second inner dike portion 420, and a second insulating material layer 520' covering the first electrode 210 and the second electrode 220 are prepared. The second insulating material layer 520' may be partially patterned in a subsequent process to form the second insulating layer 520 of the display device 10. The above components may be formed by performing a conventional masking process to pattern metals, inorganic materials, or organic materials.

[0210] Next, an ink 900 including a light-emitting element 300 is ejected onto the first electrode 210 and the second electrode 220. The ink 900 may include a solvent 910 and the light-emitting element 300 dispersed in the solvent 910. The light-emitting element 300 may be ejected onto the electrodes 210 and 220 while being dispersed in the solvent 910, and may be aligned between the first electrode 210 and the second electrode 220 by an electrical signal applied in a subsequent process.

[0211] Next, referring to Figure 16 , an electrical signal may be applied to the first electrode 210 and the second electrode 220 to generate an electric field on the ink 900 including the light-emitting element 300. The light-emitting element 300 may receive a dielectrophoretic force caused by the electric field, and may be disposed between the first electrode 210 and the second electrode 220 while changing its orientation and position.

[0212] Next, referring to Figure 17 , the solvent 910 of the ink 900 is removed. Accordingly, the light-emitting element 300 is disposed between the first electrode 210 and the second electrode 220, and a plurality of light-emitting elements 300 disposed between the first electrode 210 and the second electrode 220 may be aligned in a specific orientation.

[0213] Next, referring to Figure 18 and Figure 19 , a third insulating material layer 530' is formed to cover the second insulating material layer 520' and the light-emitting element 300, and then is patterned to form the third insulating layer 530( Figure 18(second etching in). The third insulating material layer 530' may be partially patterned by an etching process (second etching) to form the third insulating layer 530. In the etching process (second etching) of the third insulating material layer 530', the outer surface of the light-emitting element 300 may be partially exposed, and at this time, the insulating film 380 may be partially etched. Therefore, the exposed portion of the insulating film 380 where the third insulating layer 530 is not provided (e.g., Figure 7 The regions where the first surface S1 and the second surface S2 are located) may have a thickness smaller than that of the third surface S3 which is the portion in contact with the third insulating layer 530.

[0214] Thereafter, although not shown in the drawings, the second insulating material layer 520' may be patterned to form the second insulating layer 520, and the first contact electrode 261, the second contact electrode 262, and the passivation layer 550 may be formed to manufacture the display device 10.

[0215] As described above, the light-emitting element 300 and the display device 10 according to one embodiment can be manufactured. The electrode layer 370 of the light-emitting element 300 may be partially etched during the manufacturing process of the light-emitting element 300 and have a reduced thickness, and the insulating film 380 of the light-emitting element 300 may be partially etched during the manufacturing process of the light-emitting element 300 and the manufacturing process of the display device 10 and have a reduced thickness. The light-emitting element 300 according to one embodiment may include the electrode layer 370 and the insulating film 380 each having a thickness of a certain level or more to protect the active layer 330 and allow smooth contact between the electrode layer 370 and the second semiconductor layer 320. Therefore, the light-emitting element 300 included in the display device 10 can ensure excellent luminous efficiency and luminous reliability.

[0216] Hereinafter, the light-emitting element 300 and the display device 10 according to various embodiments will be described.

[0217] Figure 20 is a schematic cross-sectional view of a light-emitting element according to one embodiment.

[0218] Referring to Figure 20 , in the light-emitting element 300_1 according to one embodiment, the insulating film 380_1 may have a partially inclined top surface or end surface and may include regions having different thicknesses. Figure 20 The light-emitting element 300_1 of Figure 6 is different from the light-emitting element 300 of Figure 6The electrode layer 370, the first semiconductor layer 310, the active layer 330, etc. are the same, and the differences will be mainly described.

[0219] According to an embodiment, the insulating film 380_1 may be provided to expose a part of the semiconductor core. For example, the side surface of the electrode layer 370_1 is exposed, and the end surface of the part of the insulating film 380_1 that exposes the electrode layer 370_1 may have a partially inclined shape. The outer surface of the electrode layer 370_1 may include a first exposed surface 370S1 and a second exposed surface 370S2 on its outer surface. The first exposed surface 370S1 is the other surface opposite to the surface in contact with the second semiconductor layer 320_1, and the second exposed surface 370S2 is exposed without the insulating film 380_1 being formed thereon. The first exposed surface 370S1 and the second exposed surface 370S2, which are the exposed surfaces without the insulating film 380_1 being formed thereon, may be exposed during the process of etching the insulating coating film 3800 in the manufacturing process of the light-emitting element 300_1. In Figure 6 the case of the light-emitting element 300, only the top surface of the electrode layer 370 is exposed during the process of etching the insulating coating film 3800. However, in Figure 20 the case of the light-emitting element 300_1, the second exposed surface 370S2 of the electrode layer 370_1 may also be exposed. At the same time, as shown in the figure, the side surface of the electrode layer 370_1 is not completely but partially exposed, so that a partial area thereof may be in contact with the insulating film 380_1. That is, the side surface of the electrode layer 370_1 may include a region in contact with the insulating film 380_1 and the second exposed surface 370S2 that is exposed without the insulating film 380_1 being formed thereon.

[0220] The insulating film 380_1 may include a first part 380S1 and a second part 380S2. The insulating film 380_1 may be formed to expose the second exposed surface 370S2 of the electrode layer 370_1, and the first part 380S1 may be connected to the second exposed surface 370S2 and bent to have an inclined outer surface. That is, according to an embodiment, the thickness of the first part 380S1 of the insulating film 380_1 may decrease in one direction along which the light-emitting element 300_1 extends. The second part 380S2 may be connected to the first part 380S1 to form a flat outer surface. The first part 380S1 may be provided to surround the electrode layer 370_1 and a part of the second semiconductor layer 320_1, and the second part 380S2 may be provided to surround the active layer 330_1 and the first semiconductor layer 310_1. However, the present disclosure is not limited thereto, and the first part 380S1 having an inclined outer surface may be provided to surround a part of the active layer 330_1.

[0221] In the light-emitting element 300_1 of the present embodiment, the insulating film 380_1 may include portions having different thicknesses, such as a first portion 380S1 and a second portion 380S2. As described above, the insulating film 380_1 may have a thickness equal to or greater than a certain level to at least protect the active layer 330_1, and the second portion 380S2 of the insulating film 380_1, which is a portion surrounding the active layer 330_1, may have a greater thickness than the first portion 380S1 having an inclined outer surface.

[0222] According to one embodiment, in the insulating film 380_1 of the light-emitting element 300_1, a third thickness W3, which is the thickness of the second portion 380S2 surrounding the active layer 330_1, may be greater than the thickness of the first portion 380S1 having an inclined outer surface. In addition, at the first portion 380S1, a first thickness W1 measured at the interface between the electrode layer 370_1 and the second semiconductor layer 320_1 and a second thickness W2 measured at the interface between the second semiconductor layer 320_1 and the active layer 330_1 may be different from each other. Due to the inclined outer surface, the first thickness W1 of the portion of the first portion 380S1 adjacent to the exposed second exposed surface 370S2 of the electrode layer 370_1 may be smaller than the second thickness W2 of the portion adjacent to the second portion 380S2, and the third thickness W3 may be greater than the first thickness W1 and the second thickness W2. In an embodiment, in the insulating film 380_1, the third thickness W3 of the second portion 380S2 may be in the range of 60 nm to 80 nm, and the first thickness W1 and the second thickness W2 of the first portion 380S1 having an inclined outer surface may be smaller than the third thickness W3. However, the present disclosure is not limited thereto.

[0223] Such a shape of the light-emitting element 300_1 can be formed by simultaneously etching the upper surface of the insulating film 380_1 during the manufacturing process of the light-emitting element 300_1 when etching the insulating coating film 3800.

[0224] Figure 21 is a partial cross-sectional view Figure 20 of the manufacturing process of the light-emitting element shown.

[0225] Referring Figure 21 , in the manufacturing process of the light-emitting element 300_1, the insulating coating film 3800 may be partially removed to expose the top surface of the electrode layer 370_1. The process of partially removing the insulating coating film 3800 may be performed by a method of performing etching in a direction perpendicular to the lower substrate 1000. At this time, the side surface of the insulating coating film 3800 may be partially etched. In the light-emitting element 300_1 thus formed, the insulating film 380_1 may be etched to form the first portion 380S1 having an inclined outer surface.

[0226] Meanwhile, as described above, during the manufacturing process of the display device 10, the insulating film 380_1 of the light-emitting element 300_1 can be partially etched, and the insulating film 380_1 has a reduced thickness. In this case, the thickness relationship among the first thickness W1, the second thickness W2, and the third thickness W3 of the insulating film 380_1 can be changed.

[0227] Figure 22 is a cross-sectional view showing a part of a display device including Figure 20 a light-emitting element.

[0228] Figure 22 shows a cross-section through both ends of the light-emitting element 300_1 of the display device 10 including Figure 20 the light-emitting element 300_1. The difference between this embodiment and Figure 7 the embodiment of Figure 20 is that the light-emitting element 300 is Figure 22 the light-emitting element 300_1. That is, in

[0229] the embodiment of Figure 22 the insulating film 380_1 of the light-emitting element 300_1 includes a first portion 380S1 having an inclined outer surface, such that the shape of the first surface S1 where the first contact electrode 261 and the insulating film 380_1 contact each other can be changed. In the following description, redundant descriptions will be omitted while focusing on the differences.

[0230] Referring to Figure 22 , in the cross-sectional view, the light-emitting element 300_1 can include one side surface as the lower surface and the other side surface as the upper surface. This one side surface can contact the second insulating layer 520 and the third insulating layer 530. In the light-emitting element 300_1 according to one embodiment, the insulating film 380_1 includes a first portion 380S1 forming an inclined outer surface, and the electrode layer 370_1 includes an exposed second exposed surface 370S2. Therefore, one side surface of the light-emitting element 300_1 can be partially spaced apart from the second insulating layer 520. As shown in the figure, on one side surface of the light-emitting element 300_1, the first portion 380S1 of the insulating film 380_1 and the second exposed surface 370S2 of the electrode layer 370_1 can be spaced apart from the second insulating layer 520.

[0230] The other side surface of the light-emitting element 300_1 can contact the first contact electrode 261, the third insulating layer 530, and the second contact electrode 262. On the other side surface, in addition to the first surface S1 contacting the first contact electrode 261, the second surface S2 contacting the second contact electrode 262 and the third surface S3 contacting the third insulating layer 530 are Figure 7The second surface S2 and the third surface S3 of the embodiment are substantially the same. On the other hand, the first surface S1 can be positioned across the first portion 380S1 of the inclined outer surface forming the insulating film 380_1 and the second exposed surface 370S2 of the electrode layer 370_1. That is, according to one embodiment, the first contact electrode 261 can be in contact with the second exposed surface 370S2 of the electrode layer 370_1 and the first portion 380S1 of the insulating film 380_1, and the first surface S1 can be formed to be partially inclined or curved.

[0231] In addition, as described above, the display device 10 can include regions where the thickness portions of the insulating film 380 of the light-emitting element 300 are different. The insulating film 380_1 can have a smaller thickness in the region where the first surface S1 and the second surface S2 are located than in the region where the third surface S3 is located. In Figure 20 the light-emitting element 300_1, the insulating film 380_1 can have an inclined outer surface at the first portion 380S1, and a first thickness W1 measured at the interface between the electrode layer 370_1 and the second semiconductor layer 320_1 can be smaller than a second thickness W2 measured at the interface between the second semiconductor layer 320_1 and the active layer 330_1.

[0232] During the manufacturing process of the display device 10, the first portion 380S1 of the insulating film 380_1 can be partially etched so that the first thickness W1' and the second thickness W2' can be further reduced. On the other hand, in the insulating film 380_1, the region where the third surface S3 in contact with the third insulating layer 530 is located can not be etched so that the third thickness W3' measured in this region can be maintained at a constant level. That is, the third thickness W3' can be greater than the first thickness W1' and the second thickness W2'. In addition, due to the inclined outer surface of the first portion 380S1 of the insulating film 380_1 of the light-emitting element 300_1, the first thickness W1' can be smaller than the second thickness W2'.

[0233] Therefore, the light-emitting element 300_1 can have different diameters according to the position. For example, in the light-emitting element 300_1, a first diameter Da, which is the diameter measured in another direction in the region where the third surface S3 is located, can be greater than a second diameter Db measured in the region where the second surface S2 is located and a third diameter Dc measured in the region where the first surface S1 is located. In addition, in the light-emitting element 300_1, in the region where the first surface S1 is located, a third-first diameter Dc1 measured at the interface between the active layer 330_1 and the second semiconductor layer 320_1 can be greater than a third-second diameter Dc2 measured at the interface between the second semiconductor layer 320_1 and the electrode layer 370_1. However, the present disclosure is not limited thereto.

[0234] Meanwhile, according to one embodiment, at the first portion 380S1 of the insulating film 380_1, the first thickness W1' and the second thickness W2' may satisfy the following equation (1):

[0235] [Equation 1]

[0236] Θc = arctan((W2' - W1') / D) ≤ 70°

[0237] Wherein, Θc is the inclination angle of the inclined outer surface of the insulating film 380_1, W1' is the first thickness measured at the interface between the electrode layer 370_1 and the second semiconductor layer 320_1 in the insulating film 380_1, W2' is the second thickness measured at the interface between the second semiconductor layer 320_1 and the active layer 330_1 in the insulating film 380_1, and D is the thickness of the second semiconductor layer 320_1.

[0238] As described above, the insulating film 380_1 of the light-emitting element 300_1 has a thickness equal to or greater than a certain level to protect the active layer 330_1, and is disposed to at least surround the active layer 330_1. The insulating film 380_1 of the light-emitting element 300_1 provided in the display device 10 may be disposed to cover the active layer 330_1 and protect the active layer 330_1 even if the insulating film 380_1 is partially etched. As Figure 22 shown, in the light-emitting element 300_1, the insulating film 380_1 may include a first portion 380S1 in which an inclined outer surface is formed, and the active layer 330_1 may be positioned so as not to overlap with the first portion 380S1 of the insulating film 380_1.

[0239] Here, in order to protect the active layer 330_1 smoothly, the first portion 380S1 may have a minimum thickness in a region not overlapping with the active layer 330_1, and an inclination angle Θc of the inclined outer surface may be defined. In particular, the inclination angle Θc of the first portion 380S1 may be measured with respect to the second semiconductor layer 320_1 so that the insulating film 380_1 can protect the active layer 330_1. According to one embodiment, in the insulating film 380_1 of the light-emitting element 300_1 of the display device 10, the inclination angle Θc of the first portion 380S1 may be 70° or less, and the second thickness W2' may be 20 nm or more, and in the first portion 380S1, the thickness of the portion surrounding the active layer 330_1 may be 40 nm or more. The insulating film 380_1 of the light-emitting element 300_1 may have a thickness within the above range and may have a thickness sufficient to protect the active layer 330_1 even if the insulating film 380_1 is partially etched during the manufacturing process of the light-emitting element 300_1 to form the first portion 380S1 having an inclined outer surface. In particular, in the light-emitting element 300_1 provided in the display device 10, the thickness (second thickness W2') of the portion of the insulating film 380_1 surrounding the active layer 330_1 is in the range of 40 nm or more, and the inclination angle Θc with respect to the second semiconductor layer 320_1 is in the range of 70° or less, so that the light-emitting element 300_1 can prevent damage to the active layer 330_1. Therefore, the display device 10 may include the light-emitting element 300_1 and have improved light-emitting efficiency and light-emitting reliability.

[0240] Meanwhile, in the insulating film 380, the first thicknesses W1 and W1' measured at the interface between the second semiconductor layer 320 and the electrode layer 370 may be 0 nm or more. That is, in the light-emitting element 300 according to one embodiment, the insulating film 380 may not be provided at the interface between the electrode layer 370 and the second semiconductor layer 320.

[0241] Figure 23 is a schematic cross-sectional view of a light-emitting element according to one embodiment. Figure 24 is a cross-sectional view showing a part of a display device including Figure 23 the light-emitting element.

[0242] Reference Figure 23, in a light-emitting element 300_2 according to an embodiment, all side surfaces of the electrode layer 370_2 may be exposed, and side surfaces of the second semiconductor layer 320_2 may also be partially exposed. Accordingly, the electrode layer 370_2 may include a first exposed surface 370S1 and a second exposed surface 370S2, and the second semiconductor layer 320_2 may further include a third exposed surface 320S3. The insulating film 380_2 may include a first portion 380S1 connected to the third exposed surface 320S3 and having an inclined outer surface, and a second portion 380S2 connected to the first portion 380S1 and having a flat outer surface. The first portion 380S1 of the insulating film 380_2 may only partially overlap with the second semiconductor layer 320_2 to partially expose the second semiconductor layer 320_2. This embodiment is different from Figure 20 in that side surfaces of the second semiconductor layer 320_2 are further exposed. In the insulating film 380_2 of the light-emitting element 300_2, a second thickness W2, which is the thickness of the first portion 380S1, may be less than a third thickness W3, which is the thickness of the second portion 380S2, and the thickness measured at an interface between the electrode layer 370_2 and the second semiconductor layer 320_2 may be 0 nm. Descriptions of other components such as the first semiconductor layer 310_2 are the same as those described in the above reference Figure 20 embodiment, such that detailed descriptions thereof will be omitted.

[0243] Reference Figure 24 , in a cross-sectional view, the light-emitting element 300_2 may include one side surface as a lower surface and the other side surface as an upper surface. The one side surface may be in contact with the second insulating layer 520 and the third insulating layer 530. In a light-emitting element 300_2 according to an embodiment, the electrode layer 370_2 may include an exposed second exposed surface 370S2, and the second semiconductor layer 320_2 may include a partially exposed third exposed surface 320S3. Accordingly, one side surface of the light-emitting element 300_2 may be partially spaced apart from the second insulating layer 520. As shown in the figure, on one side surface of the light-emitting element 300_2, the first portion 380S1 of the insulating film 380_2, the second exposed surface 370S2 of the electrode layer 370_2, and the third exposed surface 320S3 of the second semiconductor layer 320_2 may be spaced apart from the second insulating layer 520.

[0244] The other side surface of the light-emitting element 300_2 may be in contact with the first contact electrode 261, the third insulating layer 530, and the second contact electrode 262. On the other side surface, in addition to a first surface S1 in contact with the first contact electrode 261, a second surface S2 in contact with the second contact electrode 262 and a third surface S3 in contact with the third insulating layer 530 are in contact with Figure 20The second surface S2 and the third surface S3 of the embodiment are substantially the same. On the other hand, the first surface S1 can be positioned to span the first portion 380S1 forming the inclined outer surface of the insulating film 380_2, the exposed second exposed surface 370S2 of the electrode layer 370_2, and the exposed third exposed surface 320S3 of the second semiconductor layer 320_2. That is, according to one embodiment, the first contact electrode 261 can be in contact with the third exposed surface 320S3 of the second semiconductor layer 320_2, the second exposed surface 370S2 of the electrode layer 370_2, and the first portion 380S1 of the insulating film 380_2, and the first surface S1 can be partially inclined or curved.

[0245] In addition, in Figure 23 the light-emitting element 300_2 of, the insulating film 380_2 has an inclined outer surface at the first portion 380S1, and the second semiconductor layer 320_2 is partially exposed such that the insulating film 380_2 is not disposed at the interface between the second semiconductor layer 320_2 and the electrode layer 370_2, and the second thickness W2 of the insulating film 380_2 can be defined at the interface between the second semiconductor layer 320_2 and the active layer 330_2.

[0246] During the manufacturing process of the display device 10, the first portion 380S1 of the insulating film 380_2 is partially etched such that the second thickness W2' can be further reduced. On the other hand, in the insulating film 380_2, the region where the third surface S3 in contact with the third insulating layer 530 is located is not etched such that the third thickness W3' as the thickness measured in this region can be maintained at a constant level. That is, the third thickness W3' can be greater than the second thickness W2'. However, the second thickness W2' can be in the range of at least 40 nm in order to protect the active layer 330_2 of the light-emitting element 300_2. Therefore, the light-emitting element 300_2 can prevent damage to the active layer 330_2, and the display device 10 can have improved light-emitting efficiency and light-emitting reliability.

[0247] Meanwhile, according to some embodiments, the first electrode 210 and the second electrode 220 may not have electrode main portions 210S and 220S extending in the first direction DR1.

[0248] Figure 25 is a plan view showing a sub-pixel of a display device according to one embodiment.

[0249] Reference Figure 25, in the display device 10_3, the first electrode 210_3 and the second electrode 220_3 may extend in one direction (i.e., in the second direction DR2). The first electrode 210_3 and the second electrode 220_3 may not have electrode main portions 210S and 220S extending in the first direction DR1. Figure 25 The display device 10_3 of Figure 3 differs from the display device 10 of

[0250] in that the electrode main portions 210S and 220S are omitted, and it further includes a second electrode 220_3. In the following description, redundant descriptions will be omitted while focusing on the differences. Figure 25 As shown in

[0251] in Figure 3 a plurality of first electrodes 210_3 and second electrodes 220_3 may extend in the second direction DR2 in each sub-pixel PXn. The outer bank portion 430 may also extend in the second direction DR2. The second electrode 220_3 and the outer bank portion 430 may extend to another sub-pixel PXn adjacent in the second direction DR2. Therefore, each of the sub-pixels PXn adjacent in the second direction DR2 may receive the same electrical signal from the second electrode 220_3. Figure 25 Different from the display device 10 of

[0252] in the display device 10_3 of Figure 25 a second electrode contact hole CNTS may be provided in each second electrode 220_3. The second electrode 220_3 may be electrically connected to the power electrode 162 of the circuit element layer PAL through the second electrode contact hole CNTS provided in each sub-pixel PXn. Although the second electrode contact hole CNTS is shown formed in each of the two second electrodes 220_3 in the drawings, the present disclosure is not limited thereto.

[0253] On the other hand, the first electrode 210_3 may extend in the second direction DR2 and terminate at the boundary of each sub-pixel PXn. Each of the sub-pixels PXn adjacent in the second direction DR2 may include first electrodes 210_3 spaced apart from each other, and they may receive different electrical signals through the first electrode contact hole CNTD. During the manufacturing process of the display device 10_3, the first electrode 210_3 may have a shape that extends in the second direction DR2 and terminates at the boundary between adjacent sub-pixels PXn. In Figure 25In the display device 10_3, some of the electrodes 210_3 and 220_3 can be set as floating electrodes without being electrically connected to the circuit element layer PAL through the electrode contact holes CNTD and CNTS. For example, among the plurality of electrodes 210_3 and 220_3, only the electrodes located outside can receive electrical signals through the electrode contact holes CNTD and CNTS, and the electrodes 210_3 and 220_3 disposed between them may not directly receive electrical signals. In this case, similar to the first electrode 210_3, a part of the second electrode 220_3 (for example, the second electrode 220_3 disposed between different first electrodes 210_3) can extend in the second direction DR2 and terminate at the boundary of each sub-pixel PXn without being disposed in another sub-pixel PXn. When some of the plurality of electrodes 210_3 and 220_3 are floating electrodes, the light-emitting elements 300_3 disposed between them can be partially connected in series and in parallel. The outer bank portion 430 can be disposed at the boundary of sub-pixels PXn adjacent in the first direction DR1 and can extend in the second direction DR2. Although not shown in the drawings, the outer bank portion 430 can be disposed at the boundary between sub-pixels PXn adjacent in the second direction DR2 and can extend in the first direction DR1. The description of the outer bank portion 430 is the same as that referred to above Figure 3 The description is the same. In addition, the first contact electrode 261_3 and the second contact electrode 262_3 included in the Figure 25 display device 10_3 are substantially the same as the first contact electrode 261 and the second contact electrode 262 of the Figure 3 display device 10.

[0254] Figure 25 It is shown that two first electrodes 210_3 and two second electrodes 220_3 are provided and they are alternately spaced apart from each other. However, the present disclosure is not limited thereto, and some electrodes can be omitted, or a larger number of electrodes can be provided in the display device 10_3.

[0255] Meanwhile, the first electrode 210 and the second electrode 220 of the display device 10 do not have to have a shape extending in one direction. The shapes of the first electrode 210 and the second electrode 220 of the display device 10 can be not particularly limited as long as they are placed separately from each other to provide a space therebetween in which the light-emitting element 300 is disposed.

[0256] Figure 26 is a plan view showing a pixel of a display device according to an embodiment.

[0257] Reference Figure 26, in the display device 10_4 according to the embodiment, at least some regions of the first electrode 210_4 and the second electrode 220_4 have a curved shape, and the curved region of the first electrode 210_4 can face the curved region of the second electrode 220_4 while being spaced apart from each other. Figure 26 The display device 10_4 of Figure 2 differs from the display device 10 in that the shapes of the first electrode 210_4 and the second electrode 220_4 are different from those of the first electrode 210 and the second electrode 220 of the display device 10. In the following description, redundant descriptions will be omitted while focusing on the differences.

[0258] Figure 26 The first electrode 210_4 of the display device 10_4 may include a plurality of holes HOL. For example, as shown in the figure, the first electrode 210_4 may include a first hole HOL1, a second hole HOL2, and a third hole HOL3 arranged in the second direction DR2. However, the embodiment is not limited thereto, and the first electrode 210_4 may include a larger number of holes HOL, a smaller number of holes HOL, or even a single hole HOL. Below, a description will be provided of an example in which the first electrode 210_4 includes the first hole HOL1, the second hole HOL2, and the third hole HOL3.

[0259] In the embodiment, the first hole HOL1, the second hole HOL2, and the third hole HOL3 may have a circular shape in a plan view. Accordingly, the first electrode 210_4 may have a curved region formed by the holes HOL, and in these curved regions, it faces the second electrode 220_4. However, this is merely exemplary, and the present disclosure is not limited thereto. The first hole HOL1, the second hole HOL2, and the third hole HOL3 are not particularly limited in shape as long as they can provide a space for accommodating the second electrode 220_4 therein. As an example, in a plan view, the hole HOL may have an elliptical shape, a polygonal shape such as a rectangle, etc.

[0260] The number of the second electrodes 220_4 may be plural, and the plural second electrodes 220_4 may be provided in each sub-pixel PXn. As an example, in each sub-pixel PXn, three second electrodes 220_4 may be provided in each sub-pixel PXn to correspond to the first hole HOL1, the second hole HOL2, and the third hole HOL3 of the first electrode 210_4. The second electrodes 220_4 may be respectively provided within the first hole HOL1, the second hole HOL2, and the third hole HOL3 surrounded by the first electrode 210_4.

[0261] In an embodiment, the hole HOL of the first electrode 210_4 may have a curved surface, and each second electrode 220_4 placed in the corresponding hole HOL of the first electrode 210_4 may also have a curved surface and be arranged to face the first electrode 210_4, with a gap between the second electrode 220_4 and the first electrode 210_4. As Figure 26 shown, the first electrode 210_4 may include holes HOL having a circular shape in a plan view, and the second electrode 220_4 may have a circular shape in a plan view. The curved surface of the region of the first electrode 210_4 where each hole HOL is formed may face the curved outer surface of a corresponding one of the second electrodes 220_4, with a gap therebetween. For example, the first electrode 210_4 may be arranged to surround the outer surface of the second electrode 220_4.

[0262] As described above, the light-emitting element 300_4 may be disposed between the first electrode 210_4 and the second electrode 220_4. The display device 10_4 according to the embodiment may include a second electrode 220_4 having a circular shape and a first electrode 210_4 arranged to surround the second electrode 220_4, and a plurality of light-emitting elements 300_4 may be arranged along the curved outer surface of the second electrode 220_4. As described above, since the light-emitting element 300_4 has a shape extending in one direction, the light-emitting elements 300_4 arranged along the curved outer surface of the second electrode 220_4 in each sub-pixel PXn may be arranged such that their extension directions point in different directions. Depending on the direction in which the extension direction of the light-emitting element 300_4 points, each sub-pixel PXn may have many different light-emitting directions. In the display device 10_4 according to the embodiment, by arranging the first electrode 210_4 and the second electrode 220_4 to have a curved shape, the light-emitting elements 300_4 disposed therebetween can be oriented in different directions, and the lateral visibility of the display device 10_4 can be improved.

[0263] At the end of the detailed description, those skilled in the art will understand that many variations and modifications can be made to the preferred embodiments without substantially departing from the principles of the present invention. Therefore, the preferred embodiments of the present invention disclosed are used only in a general and descriptive sense and not for the purpose of limitation.

Claims

1. A light-emitting element, comprising: a first semiconductor layer doped to have a first polarity; a second semiconductor layer doped to have a second polarity different from the first polarity; an active layer disposed between the first semiconductor layer and the second semiconductor layer; and an insulating film disposed to at least surround an outer surface of the active layer and extending in a first direction in which the first semiconductor layer, the active layer, and the second semiconductor layer are stacked, wherein a thickness of a first portion of the insulating film surrounding the active layer is in a range of 10% to 16% of a diameter of the active layer.

2. The light-emitting element according to claim 1, wherein the diameter of the active layer is in a range of 500 nm to 600 nm, and the thickness of the first portion of the insulating film is in a range of 60 nm to 80 nm.

3. The light-emitting element according to claim 2, wherein the insulating film further includes a second portion connected to the first portion and disposed to cover a partial region of a side surface of the second semiconductor layer, and the thickness of the second portion is less than the thickness of the first portion.

4. The light-emitting element according to claim 3, wherein in the insulating film, a portion surrounding an interface between the active layer and the second semiconductor layer has a thickness of at least 20 nm.

5. The light-emitting element according to claim 4, wherein the second portion has a curved outer surface such that the thickness of the second portion decreases in the first direction.

6. The light-emitting element according to claim 1, further comprising an electrode layer disposed on the second semiconductor layer, wherein the thickness of the electrode layer is greater than the thickness of the second semiconductor layer.

7. The light-emitting element according to claim 6, wherein the electrode layer has the thickness in a range of 20 nm to 200 nm.

8. The light-emitting element according to claim 6, wherein the insulating film is disposed to surround a side surface of the electrode layer.

9. The light-emitting element according to claim 6, wherein the insulating film is disposed to surround a part of a side surface of the electrode layer, and the electrode layer has a top surface and a partially exposed side surface.

10. The light-emitting element according to claim 9, wherein the insulating film further includes a third portion connected to the first portion and surrounding a part of the side surface of the electrode layer, and the thickness of the third portion is less than the thickness of the first portion.

11. The light-emitting element according to claim 10, wherein the third portion has a curved outer surface such that the thickness of the third portion decreases in the first direction.

12. A display device, comprising: a substrate; a first electrode and a second electrode, the first electrode being disposed on the substrate and the second electrode being spaced apart from the first electrode; at least one light-emitting element disposed between the first electrode and the second electrode and electrically connected to the first electrode and the second electrode; a first insulating layer disposed below the light-emitting element between the first electrode and the second electrode; and a second insulating layer disposed on the light-emitting element and exposing one end and the other end of the light-emitting element, wherein the light-emitting element includes: a first semiconductor layer doped to have a first polarity; a second semiconductor layer doped to have a second polarity different from the first polarity; an active layer disposed between the first semiconductor layer and the second semiconductor layer; and an insulating film disposed to at least surround an outer surface of the active layer and extending in a first direction in which the first semiconductor layer, the active layer, and the second semiconductor layer are stacked, wherein the insulating film includes a second portion in contact with the second insulating layer, a first portion surrounding the one end of the light-emitting element including the active layer, and a third portion surrounding the other end of the light-emitting element, the thickness of the second portion is greater than the thicknesses of the first portion and the third portion, and the thickness of the second portion of the insulating film is in a range of 10% to 16% of a diameter of the active layer.

13. The display device according to claim 12, further comprising a first contact electrode and a second contact electrode, the first contact electrode being in contact with the first electrode and the one end of the light-emitting element, and the second contact electrode being in contact with the second electrode and the other end of the light-emitting element.

14. The display device according to claim 13, wherein, the light-emitting element further includes an electrode layer disposed on the second semiconductor layer and having a thickness greater than a thickness of the second semiconductor layer, the first contact electrode being in contact with the first portion of the insulating film and the electrode layer, and the second contact electrode being in contact with the third portion of the insulating film and the first semiconductor layer.

15. The display device according to claim 14, wherein, the first portion of the insulating film is disposed to surround a part of a side surface of the electrode layer, and the electrode layer has a top surface and a partially exposed side surface.

16. The display device according to claim 15, wherein, the first contact electrode is in contact with the top surface and the partially exposed side surface of the electrode layer.

17. The display device according to claim 14, wherein, the first portion of the insulating film has a curved outer surface such that the thickness of the first portion decreases in the first direction.

18. The display device according to claim 17, wherein, in the first portion, a first thickness measured at an interface between the second semiconductor layer and the electrode layer and a second thickness measured at an interface between the second semiconductor layer and the active layer satisfy the following equation: Θc = arctan((W2' - W1') / D) ≤ 70° Wherein, Θc is the inclination angle of the inclined outer surface of the first portion of the insulating film, W1' is the first thickness measured at the interface between the electrode layer and the second semiconductor layer in the first portion of the insulating film, W2' is the second thickness measured at the interface between the second semiconductor layer and the active layer in the first portion of the insulating film, and D is the thickness of the second semiconductor layer.

19. The display device according to claim 18, wherein, the second thickness is 20 nm or greater, and in the first portion, the thickness of the portion surrounding the active layer is 40 nm or greater.

20. The display device according to claim 14, wherein, the electrode layer has the thickness in the range of 20 nm to 200 nm.

21. The display device according to claim 12, wherein, the diameter of the active layer is in the range of 500 nm to 600 nm, and the thickness of the second portion of the insulating film is in the range of 60 nm to 80 nm.

22. The display device according to claim 21, wherein, in the light-emitting element, a first diameter measured at the second portion of the insulating film is greater than a second diameter measured at the first portion of the insulating film and a third diameter measured at the third portion of the insulating film.

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