Display device

Abstract

A display device is provided. The display device includes: a first substrate; a first electrode and a second electrode arranged to be spaced apart from each other on the first substrate; a plurality of light-emitting elements arranged on the first electrode and the second electrode; a plurality of contact electrodes arranged on the first electrode or the second electrode and in contact with the light-emitting elements, wherein the contact electrodes include a first contact electrode arranged on the first electrode, a second contact electrode arranged on the second electrode, a third contact electrode facing the first contact electrode in the second direction, and a fourth contact electrode facing the second contact electrode in the second direction, and include an electrode connecting portion connected to the third contact electrode and the fourth contact electrode and arranged to surround the second contact electrode.

Description

Technical Field

[0001] The disclosure relates to a display device. Background Art

[0002] As multimedia technology develops, the importance of display devices has gradually increased. In response to this, various types of display devices such as organic light emitting displays, liquid crystal displays (LCDs), etc. have been used.

[0003] The 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 (e.g., a light-emitting diode (LED)), examples of which 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. Summary of the invention

[0004] Technical issues

[0005] The disclosed aspects provide a display device having reduced light emitting failure of each sub-pixel and improved brightness per unit area.

[0006] It should be noted that the disclosed aspects are not limited thereto, and other aspects not mentioned herein will be apparent to those of ordinary skill in the art from the following description.

[0007] Technical Solution

[0008] According to the disclosed embodiments, the display device includes: a first substrate; a first electrode and a second electrode, extending along a first direction on the first substrate and spaced apart from each other in a second direction; a plurality of light-emitting elements, arranged on the first electrode and the second electrode; and a plurality of contact electrodes, arranged on the first electrode or the second electrode and contacting the light-emitting elements, wherein the contact electrodes include: a first contact electrode, arranged on the first electrode; a second contact electrode, arranged on the second electrode; a third contact electrode, spaced apart from the second contact electrode in the first direction and facing the first contact electrode in the second direction; and a fourth contact electrode, spaced apart from the first contact electrode in the first direction and facing the second contact electrode in the second direction, and the display device also includes an electrode connecting portion connected to the third contact electrode and the fourth contact electrode and surrounding the second contact electrode.

[0009] The electrode connecting portion may be integrated with the third contact electrode and the fourth contact electrode.

[0010] The display device may further include a first insulating layer, which is disposed on the first substrate to cover the first electrode and the second electrode and includes a first opening exposing a portion of the upper surface of the first electrode and a second opening exposing a portion of the upper surface of the second electrode, wherein the light-emitting element may be disposed on the first insulating layer.

[0011] The display device may further include a second insulating layer disposed on the first insulating layer and the light emitting elements and exposing both ends of each light emitting element and a portion of the first insulating layer on which the contact electrode is disposed.

[0012] The first contact electrode, the second contact electrode, the third contact electrode, and the fourth contact electrode may be directly disposed on the first insulating layer, and at least a portion of the electrode connection portion may be disposed on the second insulating layer.

[0013] The display device may further include a third insulating layer covering the first contact electrode and the second contact electrode, wherein at least a portion of each of the third contact electrode, the fourth contact electrode, and the electrode connecting portion may be disposed on the third insulating layer.

[0014] The light emitting element may include: a first light emitting element having one end in contact with the first contact electrode and the other end in contact with the third contact electrode; and a second light emitting element having one end in contact with the fourth contact electrode and the other end in contact with the second contact electrode.

[0015] The light emitting element may further include a third light emitting element having both ends not in contact with the contact electrode.

[0016] The first contact electrode may cover the first opening to contact the first electrode, the second contact electrode may cover the second opening to contact the second electrode, and third and fourth contact electrodes may be disposed on the first insulating layer not to contact the first and second electrodes.

[0017] The electrode connecting portion may include: a first extension portion extending in a first direction and connected to a third contact electrode; and a second extension portion extending in a second direction and having one side connected to the first extension portion and another side connected to a fourth contact electrode, wherein the first extension portion may be spaced apart from a long side of an outer side of the second contact electrode, and the second extension portion may be spaced apart from a short side of an outer side of the second contact electrode.

[0018] A distance between the long side of the second contact electrode and the first extension portion of the electrode-connecting portion may be equal to or smaller than a distance between the second contact electrode and the fourth contact electrode.

[0019] The first extension portion of the electrode connecting portion may partially overlap the second electrode in the thickness direction.

[0020] Each of the contact electrodes may include a first portion and a second portion having a width smaller than that of the first portion, and a distance between the second portions between the contact electrodes facing each other in the second direction may be greater than a distance between the first portions.

[0021] According to the disclosed embodiment, the display device includes: a first substrate; a first electrode and a second electrode, which extend along a first direction on the first substrate and are spaced apart from each other in a second direction; a first insulating layer, which is disposed on the first substrate and includes an opening exposing a portion of the first electrode or the second electrode; a plurality of light-emitting elements, which are disposed on the first insulating layer and have two ends respectively disposed on the first electrode and the second electrode; a plurality of first-type contact electrodes, which are disposed on the first electrode or the second electrode and contact the light-emitting elements and the first electrode or the second electrode; and a second-type contact electrode, which contacts the light-emitting elements and does not contact the first electrode and the second electrode, wherein the second-type contact electrode includes: a plurality of contact portions, which are disposed on the first electrode or the second electrode but spaced apart from the first-type contact electrode; and an electrode connecting portion, which connects the contact portions, wherein the electrode connecting portion is spaced apart from and surrounds the outer side of any one of the first-type contact electrodes.

[0022] The first type contact electrode may include: a first contact electrode, which is arranged on the first electrode and contacts the first electrode through a first opening that exposes a portion of the upper surface of the first electrode; and a second contact electrode, which is arranged on the second electrode and contacts the second electrode through a second opening that exposes a portion of the upper surface of the second electrode, and the second type contact electrode includes: a first contact portion, which is arranged on the second electrode and is spaced apart from the second contact electrode; a second contact portion, which is arranged on the first electrode and is spaced apart from the first contact electrode; and a first electrode connecting portion, which connects the first contact portion and the second contact portion.

[0023] The first electrode connection portion may surround an outer side of the second contact electrode.

[0024] The light emitting element may include: a first light emitting element having one end in contact with the first contact electrode and the other end in contact with the first contact portion; and a second light emitting element having one end in contact with the second contact portion and the other end in contact with the second contact electrode.

[0025] The first contact portion may face the first contact electrode, the second contact portion may be spaced apart from the first contact electrode in the first direction, the first electrode connecting portion may surround the outer side of the first contact electrode, and the second type contact electrode may further include: a third contact portion, disposed between the second contact electrode and the first contact portion to face the second contact portion; a fourth contact portion, spaced apart from the second contact portion in the first direction to face the second contact electrode; and a second electrode connecting portion, connecting the third contact portion and the fourth contact portion and surrounding the outer side of the second contact electrode.

[0026] The display device may further include a second insulating layer disposed on the first insulating layer and the light emitting elements and exposing both ends of each light emitting element and a portion of the first insulating layer on which a contact electrode is disposed, wherein the contact portions of the first type contact electrode and the second type contact electrode may be disposed on the same layer.

[0027] The electrode connection portion of the second type contact electrode may be directly disposed on the second insulating layer.

[0028] Details of other embodiments are included in the detailed description and accompanying drawings.

[0029] Technical Effects

[0030] In the display device according to the embodiment, some of the multiple light-emitting elements in each sub-pixel are connected in series with each other. Therefore, the brightness of each unit sub-pixel can be improved, and the light-emitting failure of each sub-pixel can be reduced. In addition, the placement of the electrode connecting portion is designed to ensure that there is a sufficient area in which the light-emitting element of each sub-pixel is arranged and the light-emitting element is connected in series. Therefore, even if the area occupied by each sub-pixel is small, the brightness can be improved while maintaining the size of each sub-pixel.

[0031] The effects according to the embodiments are not limited to the above-exemplified contents, and more various effects are included in the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a schematic plan view of a display device according to an embodiment.

[0033] Figure 2 is a plan view of a pixel of a display device according to an embodiment.

[0034] Figure 3 yes Figure 2 A plan view of a sub-pixel.

[0035] Figure 4 It is along Figure 3 A cross-sectional view taken along line Q1-Q1' and line Q2-Q2'.

[0036] Figure 5 It is along Figure 3 A cross-sectional view taken along line Q3-Q3'.

[0037] Figure 6 It is along Figure 3 A cross-sectional view taken along line Q4-Q4' and line Q5-Q5'.

[0038] Figure 7 It is along Figure 3 A cross-sectional view taken along line Q6-Q6'.

[0039] Figure 8 is a schematic diagram of a light emitting element according to an embodiment.

[0040] Fig. 9 is a plan view of a sub-pixel of a display device according to another embodiment.

[0041] Fig.10 It is along Fig. 9 A cross-sectional view taken along line Q7-Q7'.

[0042] Fig.11 is a plan view of a sub-pixel of a display device according to another embodiment.

[0043] Fig.12 is a plan view of a sub-pixel of a display device according to another embodiment.

[0044] Fig.13 It is along Fig.12 A cross-sectional view taken along line Q8-Q8'.

[0045] Fig.14 is a plan view of a sub-pixel of a display device according to another embodiment.

[0046] Fig.15 It is along Fig.14 A cross-sectional view taken along line Q9-Q9'.

[0047] Fig.16 A contact electrode of a display device according to another embodiment is schematically shown. DETAILED DESCRIPTION

[0048] The 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 implemented in different forms and should not be construed as limited to the embodiments set forth herein. On the contrary, 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.

[0049] 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 intervening layers may also be present. Throughout the specification, the same reference numerals refer to the same components.

[0050] 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 element. For example, without departing from the teachings of the invention, the first element discussed below may be named as the second element. Similarly, the second element may also be named as the first element.

[0051] Hereinafter, embodiments will be described with reference to the accompanying drawings.

[0052] Figure 1 is a plan view of a display device according to an embodiment.

[0053] 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 notebook computer, a monitor, a billboard, an Internet of Things (IoT) device, a mobile phone, a smart phone, 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 electronic book, a portable multimedia player (PMP), a navigation device, a game console, a digital camera, and a video camera, all of which provide a display screen.

[0054] The display device 10 includes a display panel that provides a display screen. Examples of the display panel include an inorganic light emitting diode 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. A case where an inorganic light emitting diode display panel is applied as an example of a display panel will be described below, but the disclosure is not limited to this case, and other display panels may also be applied as long as the same technical spirit is applicable.

[0055] The shape of the display device 10 may be variously modified. For example, the display device 10 may have various shapes such as a horizontally long rectangle, a vertically long rectangle, a square, a quadrilateral with rounded corners (vertices), other polygons, or a circle. The shape of the display area DPA of the display device 10 may also be similar to the overall shape of the display device 10. Figure 1 , each of the display device 10 and the display area DPA is shaped like a horizontally long rectangle, but the disclosure is not limited thereto.

[0056] The display device 10 may include a display area DPA and a non-display area NDA. The display area DPA may be an area where a picture may be displayed, and the non-display area NDA may be an area where a picture is not displayed. The display area DPA may also be referred to as an active area, and the non-display area NDA may also be referred to as a non-active area. The display area DA may generally occupy the center of the display device 10.

[0057] The display area DPA may include a plurality of pixels PX. The pixels PX may be arranged in a matrix form. Each of the pixels PX may be a rectangle or a square in a plan view. However, the disclosure is not limited thereto, and each of the pixels PX may also have a rhombus planar shape with each side inclined relative to a certain direction. The pixels PX may be arranged in stripes or In addition, each of the pixels PX may include one or more light emitting elements 30 (see Figure 2 ).

[0058] The non-display area NDA may be positioned around the display area DPA. The non-display area NDA may completely or partially surround the display area DPA. The display area DPA may be rectangular, and the non-display area NDA may be disposed adjacent to four sides of the display area DPA. The non-display area NDA may form a frame of the display device 10. A wiring or circuit driver included in the display device 10 may be positioned in each non-display area NDA, and / or an external device may be installed in each non-display area NDA.

[0059] Figure 2 is a plan view of a pixel of a display device according to an embodiment.

[0060] Reference Figure 2 , each of the pixels PX may include a plurality of sub-pixels PXn (where n is an integer from 1 to 3). For example, one pixel PX may include a first sub-pixel PX1, a second sub-pixel PX2, and a third sub-pixel PX3. The first sub-pixel PX1 may emit light of a first color, the second sub-pixel PX2 may emit light of a second color, and the third sub-pixel PX3 may emit light of a third color. For example, the first color may be blue, the second color may be green, and the third color may be red. However, the disclosure is not limited thereto, and the sub-pixels PXn may also emit light of the same color. In addition, although in Figure 2 One pixel PX includes three sub-pixels PXn, but the disclosure is not limited thereto, and the pixel PX may also include additional sub-pixels PXn.

[0061] Each sub-pixel PXn of the display device 10 may include an emission area EMA and a non-emission area. The emission area EMA may be an area in which the light emitting element 30 is set to emit light of a specific wavelength band. The non-emission area may be an area in which the light emitting element 30 is not set and no light is output therefrom because the light emitted from the light emitting element 30 does not reach the area. The emission area may include an area in which the light emitting element 30 is positioned and in which the light emitted from the light emitting element 30 is output to an area adjacent to the light emitting element 30.

[0062] However, the disclosure is not limited thereto, and the emission region may also include a region in which light emitted from the light emitting element 30 is output after being reflected or refracted by other components. A plurality of light emitting elements 30 may be disposed in each sub-pixel PXn, and a region in which the light emitting element 30 is located and a region adjacent to the region may form an emission region.

[0063] In addition, each sub-pixel PXn may include a cutout region CBA disposed in a non-emission region. The cutout region CBA may be disposed on one side of the emission region EMA in the second direction DR2. The cutout region CBA may be disposed between the emission regions EMA of the sub-pixels PXn adjacent along the second direction DR2. A plurality of emission regions EMA and a plurality of cutout regions CBA may be arranged in the display region DPA of the display device 10. For example, the emission region EMA and the cutout region CBA may be repeatedly arranged in the first direction DR1, but may be alternately arranged in the second direction DR2. In addition, the distance between the cutout regions CBA in the first direction DR1 may be smaller than the distance between the emission regions EMA in the first direction DR1. The second bank BNL2 may be disposed between the cutout region CBA and the emission region EMA, and the distance between the cutout region CBA and the emission region EMA may vary according to the width of the second bank BNL2. Since the light emitting element 30 is not disposed in the cutout region CBA, no light is emitted from the cutout region CBA. However, portions of the electrodes 21 and 22 disposed in each sub-pixel PXn may be disposed in the cutout region CBA. The electrodes 21 and 22 disposed in each sub-pixel PXn may be separated from the electrodes 21 and 22 of the adjacent sub-pixel PXn in the cutout area CBA.

[0064] Figure 3 yes Figure 2 A plan view of a sub-pixel. Figure 4 It is along Figure 3 A cross-sectional view taken along line Q1-Q1' and line Q2-Q2'. Figure 5 It is along Figure 3 A cross-sectional view taken along line Q3-Q3'. Figure 6 It is along Figure 3 A cross-sectional view taken along line Q4-Q4' and line Q5-Q5'.

[0065] Figure 3 2 shows the arrangement of the electrodes 21 and 22, the light emitting element 30, and the contact electrode CNE in the first sub-pixel PX1. Figures 4 to 6 A cross section of the contact electrode CNE according to the arrangement and shape of the contact electrode CNE is shown. Figure 4 and Figure 6 A cross section spanning one end and the other end of the light emitting element 30 ( 30A and 30B) provided in the first sub-pixel PX1 is shown.

[0066] Combination Figure 2 Reference Figures 3 to 6 The display device 10 may include a first substrate 11 and a semiconductor layer, a plurality of conductive layers, and a plurality of insulating layers disposed on the first substrate 11. The semiconductor layer, the conductive layer, and the insulating layer may constitute a circuit layer and a light emitting element layer of the display device 10.

[0067] Specifically, the first substrate 11 may be an insulating substrate. The first substrate 11 may be made of an insulating material such as glass, quartz or polymer resin. In addition, the first substrate 11 may be a rigid substrate, but may also be a flexible substrate that can be bent, folded, curled, etc.

[0068] The light blocking layer BML may be disposed on the first substrate 11. The light blocking layer BML overlaps the active layer ACT of the first transistor T1 of the display device 10. The light blocking layer BML may include a light blocking material to prevent light from being incident on the active layer ACT of the first transistor. For example, the light blocking layer BML may be made of an opaque metal material that blocks the transmission of light. However, the disclosure is not limited thereto. In some cases, the light blocking layer BML may be omitted.

[0069] The buffer layer 12 may be disposed on the entire surface of the light blocking layer BML and the first substrate 11. The buffer layer 12 may be formed on the first substrate 11 to protect the first transistor T1 of the pixel PX from moisture introduced through the first substrate 11, and may perform a surface planarization function, and the first substrate 11 is susceptible to moisture penetration. The buffer layer 12 may be composed of a plurality of inorganic layers alternately stacked. For example, the buffer layer 12 may be a layer in which a plurality of inorganic layers including silicon oxide (SiO x ), silicon nitride (SiN x ) and silicon oxynitride (SiON) or may be a single layer including the above materials.

[0070] The semiconductor layer is disposed on the buffer layer 12. The semiconductor layer may include an active layer ACT of the first transistor T1. The active layer ACT may partially overlap a gate electrode GE of a first gate conductive layer to be described later.

[0071] Although only the first transistor T1 among the transistors included in each sub-pixel PXn of the display device 10 is shown in the drawings, the disclosure is not limited thereto. The display device 10 may include more transistors. For example, by including one or more transistors in addition to the first transistor T1 in each sub-pixel PXn, the display device 10 may include two or three transistors.

[0072] The semiconductor layer may include polycrystalline silicon, monocrystalline silicon, an oxide semiconductor, etc. When the semiconductor layer includes an oxide semiconductor, each active layer ACT may include a plurality of conductive regions ACT_a and ACT_b and a channel region ACT_c therebetween. The oxide semiconductor may be an oxide semiconductor containing indium (In). For example, 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 oxide (IGZO), or indium gallium zinc tin oxide (IGZTO).

[0073] In another embodiment, the semiconductor layer may include polycrystalline silicon. Polycrystalline silicon may be formed by crystallizing amorphous silicon. In this case, each conductive region of the active layer ACT may be a doped region doped with impurities.

[0074] The first gate insulating layer 13 is disposed on the semiconductor layer and the buffer layer 12. The first gate insulating layer 13 may be used as a gate insulating film of each transistor. The first gate insulating layer 13 may be a layer including an inorganic material (e.g., silicon oxide (SiO x ), silicon nitride (SiN x ) and silicon oxynitride (SiON), or may be a double layer or a multilayer in which the above materials are stacked.

[0075] The first gate conductive layer is disposed on the first gate insulating layer 13. The first gate conductive layer may include a gate electrode GE of the first transistor T1 and a first capacitive electrode CSE1 of a storage capacitor. The gate electrode GE may overlap with a channel region ACT_c of the active layer ACT in a thickness direction. The first capacitive electrode CSE1 may overlap with a second capacitive electrode CSE2 to be described later in a thickness direction. In an embodiment, the first capacitive electrode CSE1 may be integrally connected to the gate electrode GE. The first capacitive electrode CSE1 may overlap with the second capacitive electrode CSE2 in a thickness direction, and a storage capacitor may be formed between the first capacitive electrode CSE1 and the second capacitive electrode CSE2.

[0076] The first gate conductive layer may be, but is not limited to, a single layer or multiple layers made of any one or more of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), copper (Cu), and alloys thereof.

[0077] The first protective layer 15 is disposed on the first gate conductive layer. The first protective layer 15 may cover the first gate conductive layer to protect the first gate conductive layer. The first protective layer 15 may include an inorganic material (eg, silicon oxide (SiO x ), silicon nitride (SiN x) and silicon oxynitride (SiON), or may be a double layer or a multilayer in which the above materials are stacked.

[0078] The first data conductive layer is disposed on the first protective layer 15. The first data conductive layer may include first and second source / drain electrodes SD1 and SD2 of the first transistor T1, a data line DTL, and a second capacitive electrode CSE2.

[0079] Source / drain electrodes SD1 and SD2 of the first transistor T1 may respectively contact doping regions ACT_a and ACT_b of the active layer ACT through contact holes penetrating the first protective layer 15 and the first gate insulating layer 13. In addition, the second source / drain electrode SD2 of the first transistor T1 may be electrically connected to the light blocking layer BML through another contact hole.

[0080] The data line DTL may transmit a data signal to other transistors (not shown) included in the display device 10. Although not shown in the drawings, the data line DTL may be connected to source / drain electrodes of other transistors to transmit a signal sent to the data line DTL.

[0081] The second capacitive electrode CSE2 overlaps the first capacitive electrode CSE1 in the thickness direction. In an embodiment, the second capacitive electrode CSE2 may be integrally connected to the second source / drain electrode SD2.

[0082] The first data conductive layer may be, but is not limited to, a single layer or multiple layers made of any one or more of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), copper (Cu), and alloys thereof.

[0083] The first interlayer insulating layer 17 is disposed on the first data conductive layer. The first interlayer insulating layer 17 may be used as an insulating film between the first data conductive layer and other layers on the first data conductive layer. In addition, the first interlayer insulating layer 17 may cover the first data conductive layer and protect the first data conductive layer. The first interlayer insulating layer 17 may be an inorganic material (e.g., silicon oxide (SiO x ), silicon nitride (SiN x ) and silicon oxynitride (SiON), or may be a double layer or a multilayer in which the above materials are stacked.

[0084] The second data conductive layer is disposed on the first interlayer insulating layer 17. The second data conductive layer may include a first voltage wiring VL1, a second voltage wiring VL2, and a first conductive pattern CDP. A high potential voltage (or a first power supply voltage) supplied to the first transistor T1 may be applied to the first voltage wiring VL1, and a low potential voltage (or a second power supply voltage) supplied to the second electrode 22 may be applied to the second voltage wiring VL2. In addition, during the manufacturing process of the display device 10, an alignment signal required to align the light emitting element 30 may be transmitted to the second voltage wiring VL2.

[0085] The first conductive pattern CDP may be connected to the second capacitive electrode CSE2 through a contact hole formed in the first interlayer insulating layer 17. The second capacitive electrode CSE2 may be integrated with the second source / drain electrode SD2 of the first transistor T1, and the first conductive pattern CDP may be electrically connected to the second source / drain electrode SD2. The first conductive pattern CDP may also contact the first electrode 21 to be described later, and the first transistor T1 may transmit the first power supply voltage received from the first voltage wiring VL1 to the first electrode 21 through the first conductive pattern CDP. Although the second data conductive layer includes one second voltage wiring VL2 and one first voltage wiring VL1 in the drawings, the disclosure is not limited thereto. The second data conductive layer may include more first voltage wirings VL1 and more second voltage wirings VL2.

[0086] The second data conductive layer may be, but is not limited to, a single layer or multiple layers made of any one or more of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), copper (Cu), and alloys thereof.

[0087] The first planarization layer 19 is disposed on the second data conductive layer. The first planarization layer 19 may include an organic insulating material (eg, an organic material such as polyimide (PI)), and may perform a surface planarization function.

[0088] A plurality of first banks BNL1, a plurality of electrodes 21 and 22, a light emitting element 30, a plurality of contact electrodes CNE1 to CNE4, and a second bank BNL2 are disposed on the first planarization layer 19. In addition, a plurality of insulating layers PAS1 to PAS4 may be disposed on the first planarization layer 19.

[0089] The first bank BNL1 may be directly disposed on the first planarization layer 19. The first bank BNL1 may extend in the second direction DR2 in each sub-pixel PXn, but may be disposed within the emission area EMA without extending to other sub-pixels PXn adjacent in the second direction DR2. In addition, the first banks BNL1 may be spaced apart from each other in the first direction DR1, and the light emitting element 30 may be disposed between the first banks BNL1. The first bank BNL1 may be disposed in each sub-pixel PXn to form a linear pattern in the display area DPA of the display device 10. The length of each first bank BNL1 measured in the second direction DR2 may be greater than the length of each of the contact electrodes CNE1 and CNE2 to be described later. However, the disclosure is not limited thereto. Although two first banks BNL1 are shown in the drawings, the disclosure is not limited thereto. The number of the first banks BNL1 may be increased according to the number of the electrodes 21 and 22 to be described later.

[0090] At least a portion of each of the first banks BNL1 may protrude from the upper surface of the first planarization layer 19. The protrusion of each of the first banks BNL1 may have an inclined side surface, and light emitted from the light emitting element 30 may travel toward above the first planarization layer 19 after being reflected by the electrodes 21 and 22 provided on the first banks BNL1. The first bank BNL1 may provide a region in which the light emitting element 30 is positioned while serving as a reflection barrier that reflects light emitted from the light emitting element 30 in an upward direction. The side surface of the first bank BNL1 may be inclined in a linear shape. However, the disclosure is not limited thereto, and the outer surface of the first bank BNL1 may also have a curved semicircular or semi-elliptical shape. The first bank BNL1 may include an organic insulating material such as polyimide (PI), but the disclosure is not limited thereto.

[0091] The electrodes 21 and 22 are disposed on the first bank BNL1 and the first planarization layer 19. The electrodes 21 and 22 may include a first electrode 21 and a second electrode 22. The first electrode 21 and the second electrode 22 may extend in the second direction DR2 and may be spaced apart from each other in the first direction DR1.

[0092] Each of the first electrode 21 and the second electrode 22 may extend in the second direction DR2 in each sub-pixel PXn, but may be separated from the other electrode 21 or 22 in the cutout area CBA. For example, the cutout area CBA may be disposed between the emission areas EMA of the sub-pixels PXn adjacent in the second direction DR2, and the first electrode 21 and the second electrode 22 may be separated from the other first electrode 21 and the other second electrode 22 disposed in the sub-pixels PXn adjacent in the second direction DR2 in the cutout area CBA. However, the disclosure is not limited thereto, and some of the electrodes 21 and 22 may not be separated for each sub-pixel PXn, but may extend beyond the sub-pixels PXn adjacent in the second direction DR2, or only one of the first electrode 21 and the second electrode 22 may be separated.

[0093] The first electrode 21 may be electrically connected to the first transistor T1 through the first contact hole CT1, and the second electrode 22 may be electrically connected to the second voltage wiring VL2 through the second contact hole CT2. For example, the first electrode 21 may contact the first conductive pattern CDP through the first contact hole CT1, and the first contact hole CT1 may penetrate the first planarization layer 19 in a portion of the second bank BNL2 extending along the first direction DR1. The second electrode 22 may also contact the second voltage wiring VL2 through the second contact hole CT2, and the second contact hole CT2 may penetrate the first planarization layer 19 in a portion of the second bank BNL2 extending along the first direction DR1. However, the disclosure is not limited thereto. In another embodiment, the first contact hole CT1 and the second contact hole CT2 may be disposed in the emission area EMA surrounded by the second bank BNL2 so as not to overlap with the second bank BNL2.

[0094] Although one first electrode 21 and one second electrode 22 are provided in each sub-pixel PXn in the drawings, the disclosure is not limited thereto, and more first electrodes 21 and more second electrodes 22 may be provided in each sub-pixel PXn. In addition, the first electrode 21 and the second electrode 22 provided in each sub-pixel PXn may not necessarily extend in one direction, and may be provided in various structures. For example, the first electrode 21 and the second electrode 22 may be partially bent or curved, or any one of the first electrode 21 and the second electrode 22 may surround the other electrode.

[0095] The first electrode 21 and the second electrode 22 may be respectively disposed on the first bank BNL1. The first electrode 21 and the second electrode 22 may be formed to have a width greater than the width of the first bank BNL1, respectively. For example, the first electrode 21 and the second electrode 22 may cover the outer surface of the first bank BNL1, respectively. The first electrode 21 and the second electrode 22 may be respectively disposed on the side surface of the first bank BNL1, and the distance between the first electrode 21 and the second electrode 22 may be smaller than the distance between the first bank BNL1. In addition, at least a portion of each of the first electrode 21 and the second electrode 22 may be directly disposed on the first planarization layer 19, so that at least a portion of each of the first electrode 21 and the second electrode 22 is located in the same plane. However, the disclosure is not limited thereto. In some cases, the widths of the electrodes 21 and 22 may be respectively smaller than the width of the first bank BNL1. However, each of the electrodes 21 and 22 may cover at least one side surface of the first bank BNL1 to reflect light emitted from the light emitting element 30.

[0096] Each of the electrodes 21 and 22 may include a transparent conductive material. For example, each of the electrodes 21 and 22 may include a material such as indium tin oxide (ITO), indium zinc oxide (IZO), or indium tin zinc oxide (ITZO). However, the disclosure is not limited thereto, and each of the electrodes 21 and 22 may include a conductive material having a high reflectivity. For example, each of the electrodes 21 and 22 may include a metal such as silver (Ag), copper (Cu), or aluminum (Al) as a material having a high reflectivity. In this case, each of the electrodes 21 and 22 may reflect light traveling toward the side surface of the first bank BNL1 after being emitted from the light emitting element 30 toward the top of each sub-pixel PXn.

[0097] However, the disclosure is not limited thereto, and each of the electrodes 21 and 22 may also have a structure in which a transparent conductive material and a metal layer having a high reflectivity are stacked in one or more layers, or may also be formed as a single layer including a transparent conductive material and a metal layer. For example, each of the electrodes 21 and 22 may have a stacked structure of ITO / Ag / ITO, ITO / Ag / IZO, or ITO / Ag / ITZO / IZO, or may be an alloy containing aluminum (Al), nickel (Ni), or lanthanum (La).

[0098] The electrodes 21 and 22 may be electrically connected to the light emitting element 30, and a predetermined voltage may be applied to the electrodes 21 and 22 so that the light emitting element 30 may emit light. For example, the electrodes 21 and 22 may be electrically connected to the light emitting element 30 through a contact electrode CNE to be described later, and a received electrical signal may be transmitted to the light emitting element 30 through the contact electrode CNE.

[0099] Any one of the first electrode 21 and the second electrode 22 may be electrically connected to the anode of the light emitting element 30, and the other may be electrically connected to the cathode of the light emitting element 30. However, the disclosure is not limited thereto, and the opposite may also be true.

[0100] In addition, each of the electrodes 21 and 22 can be used to form an electric field in each sub-pixel PXn so as to align the light emitting element 30. The light emitting element 30 can be arranged between the first electrode 21 and the second electrode 22 by the electric field formed on the first electrode 21 and the second electrode 22. The light emitting element 30 of the display device 10 can be ejected onto the electrodes 21 and 22 by an inkjet printing process. When the ink including the light emitting element 30 is ejected onto the electrodes 21 and 22, an alignment signal is transmitted to the electrodes 21 and 22 to generate an electric field. The light emitting element 30 dispersed in the ink can be aligned on the electrodes 21 and 22 by the dielectrophoretic force applied by the electric field generated on the electrodes 21 and 22.

[0101] The first insulating layer PAS1 is disposed on the first planarization layer 19. The first insulating layer PAS1 may cover the first bank BNL1, the first electrode 21, and the second electrode 22. In an embodiment, the first insulating layer PAS1 may include openings OP1 and OP2 partially exposing the first electrode 21 and the second electrode 22. The first insulating layer PAS1 may include a first opening OP1 exposing a portion of the upper surface of the first electrode 21 and a second opening OP2 exposing a portion of the upper surface of the second electrode 22. The first opening OP1 and the second opening OP2 may partially expose portions of the electrodes 21 and 22, respectively disposed on the upper surface of the first bank BNL1. Some of the contact electrodes CNE to be described later may contact the electrodes 21 and 22 exposed through the openings OP1 and OP2, respectively.

[0102] The first insulating layer PAS1 may be stepped so that a portion of an upper surface of the first insulating layer PAS1 is recessed between the first electrode 21 and the second electrode 22. For example, since the first insulating layer PAS1 covers the first electrode 21 and the second electrode 22, the upper surface of the first insulating layer PAS1 may be stepped according to the shape of the electrodes 21 and 22 disposed under the first insulating layer PAS1. However, the disclosure is not limited thereto. The first insulating layer PAS1 may protect the first electrode 21 and the second electrode 22 while insulating the first electrode 21 and the second electrode 22 from each other. In addition, the first insulating layer PAS1 may prevent the light emitting element 30 on the first insulating layer PAS1 from directly contacting other components, and thus prevent damage to the light emitting element 30 on the first insulating layer PAS1.

[0103] The second bank BNL2 may be disposed on the first insulating layer PAS1. The second bank BNL2 may include portions extending in the first direction DR1 and the second direction DR2 in a plan view and may be disposed in a lattice pattern throughout the entire display area DPA. The second bank BNL2 may be disposed at a boundary of each subpixel PXn to separate adjacent subpixels PXn.

[0104] In addition, the second bank BNL2 may surround the emission area EMA and the cutout area CBA disposed in each subpixel PXn to separate them. The first electrode 21 and the second electrode 22 may extend in the second direction DR2 to pass through a portion of the second bank BNL2 extending along the first direction DR1. A portion of the second bank BNL2 extending along the second direction DR2 may have a greater width between the emission areas EMA than between the cutout areas CBA. Therefore, the distance between the cutout areas CBA may be smaller than the distance between the emission areas EMA.

[0105] The second bank BNL2 may be formed to have a height greater than that of the first bank BNL1. The second bank BNL2 may prevent ink from overflowing to adjacent sub-pixels PXn in an inkjet printing process during a manufacturing process of the display device 10. Therefore, the second bank BNL2 may separate inks in which different light emitting elements 30 are dispersed for different sub-pixels PXn so as to prevent the inks from being mixed with each other. Similar to the first bank BNL1, the second bank BNL2 may include, but is not limited to, polyimide (PI).

[0106] The light emitting element 30 may be disposed on the first insulating layer PAS1. The light emitting elements 30 may be spaced apart from each other along the second direction DR2 along which each of the electrodes 21 and 22 extends, and may be substantially aligned parallel to each other. The light emitting element 30 may extend in a direction, and the direction along which the electrodes 21 and 22 extend and the direction along which the light emitting element 30 extends may be substantially perpendicular to each other. However, the disclosure is not limited thereto, and the light emitting element 30 may also extend in a direction that is not perpendicular to the direction along which the electrodes 21 and 22 extend but is inclined to the direction along which the electrodes 21 and 22 extend.

[0107] The light emitting element 30 disposed in the sub-pixel PXn may include a light emitting layer 36 including different materials (see Figure 8 ), to emit light of different wavelength bands. Therefore, the first color light, the second color light, and the third color light can be output from the first sub-pixel PX1, the second sub-pixel PX2, and the third sub-pixel PX3, respectively. However, the disclosure is not limited thereto, and the sub-pixels PXn may also include the same type of light emitting elements 30 to emit light of substantially the same color.

[0108] Both ends of each light emitting element 30 may be respectively disposed on the electrodes 21 and 22 between the first bank BNL1. The length of the light emitting element 30 may be longer than the distance between the first electrode 21 and the second electrode 22, and both ends of each light emitting element 30 may be respectively disposed on the first electrode 21 and the second electrode 22. For example, one end of each light emitting element 30 may be disposed on the first electrode 21, and the other end may be disposed on the second electrode 22.

[0109] Each of the light emitting elements 30 may include a plurality of layers positioned in a direction parallel to the upper surface of the first substrate 11 or the first planarization layer 19. The direction in which the light emitting element 30 extends may be parallel to the upper surface of the first planarization layer 19, and the semiconductor layers included in each of the light emitting elements 30 may be positioned sequentially along the direction parallel to the upper surface of the first planarization layer 19. However, the disclosure is not limited thereto. When each of the light emitting elements 30 has a different structure, the layers may also be positioned in a direction perpendicular to the upper surface of the first planarization layer 19.

[0110] Both ends of each light emitting element 30 may contact the contact electrode CNE, respectively. Figure 8 ) may not be formed on the end surface of each light emitting element 30 in the direction in which the light emitting element 30 extends, thereby exposing some of the semiconductor layer. Therefore, the exposed semiconductor layer may contact the contact electrode CNE. However, the disclosure is not limited thereto, and at least a portion of the insulating film 38 of each light emitting element 30 may be removed to partially expose the side surfaces of both ends of the semiconductor layer. The exposed side surface of the semiconductor layer may directly contact the contact electrode CNE.

[0111] According to the embodiment, the light emitting element 30 may include light emitting elements 30A and 30B having two ends contacting different contact electrodes CNE. The light emitting element 30 may include a first light emitting element 30A and a second light emitting element 30B which may be electrically connected through the contact electrodes CNE connected to each other. The first end of the first light emitting element 30A and the first end of the second light emitting element 30B may contact different contact electrodes CNE, and the second end of the first light emitting element 30A and the first end of the second light emitting element 30B may contact the contact electrodes CNE connected to each other. The first light emitting element 30A and the second light emitting element 30B may be connected in series to each other through the contact electrode CNE, and the brightness per unit area of ​​each sub-pixel PXn may be improved. This will be described in more detail later.

[0112] The second insulating layer PAS2 may be disposed on the light emitting element 30. The second insulating layer PAS2 may be partially disposed on the first insulating layer PAS1, the first electrode 21, the second electrode 22, and the light emitting element 30. For example, the second insulating layer PAS2 may be disposed on the entire surface of the first insulating layer PAS1 in a region surrounded by the second bank BNL2, except for the two ends of each light emitting element 30 and the portion of the upper surface of the electrodes 21 and 22 on which the contact electrode CNE is disposed. During the manufacturing process of the display device 10, the second insulating layer PAS2 may be placed to cover the light emitting element 30, the electrodes 21 and 22, and the first insulating layer PAS1, and then may be removed to expose the two ends of the light emitting element 30. A portion of the second insulating layer PAS2 may cover the light emitting element 30 while exposing the two ends of the light emitting element 30. A portion of the second insulating layer PAS2 disposed on the light emitting element 30 may extend along the second direction DR2 on the first insulating layer PAS1 in a plan view to form a linear or island pattern in each sub-pixel PXn. The second insulating layer PAS2 may protect the light emitting element 30 while anchoring the light emitting element 30 in the manufacturing process of the display device 10. In addition, in some embodiments, a portion of the second insulating layer PAS2 may fill the space between the light emitting element 30 and the first insulating layer PAS1.

[0113] In addition, the second insulating layer PAS2 may partially cover the outer side of each of the electrodes 21 and 22. The contact electrode CNE may be partially provided in a portion where the second insulating layer PAS2 is not provided. However, the disclosure is not limited thereto, and the second insulating layer PAS2 may also be provided only between the electrodes 21 and 22 to anchor the light emitting element 30, and may be removed in other regions.

[0114] A plurality of contact electrodes CNE and a third insulating layer PAS3 may be disposed on the second insulating layer PAS2.

[0115] The contact electrodes CNE may extend in one direction and may be disposed on the electrodes 21 and 22, respectively. The contact electrodes CNE may include a first contact electrode CNE1 and a fourth contact electrode CNE4 disposed on the first electrode 21 and a second contact electrode CNE2 and a third contact electrode CNE3 disposed on the second electrode 22. The contact electrodes CNE may be spaced apart from each other or may face each other. For example, the first contact electrode CNE1 and the fourth contact electrode CNE4 may be spaced apart from each other along the second direction DR2 on the first electrode 21, and the second contact electrode CNE2 and the third contact electrode CNE3 may be spaced apart from each other along the second direction DR2 on the second electrode 22. In addition, the first contact electrode CNE1 and the third contact electrode CNE3 may face each other in the first direction DR1, and the second contact electrode CNE2 and the fourth contact electrode CNE4 may also face each other in the first direction DR1. Each of the contact electrodes CNE may form a stripe pattern in the emission area EMA of each sub-pixel PXn.

[0116] Each of the contact electrodes CNE may contact the light emitting element 30. The first contact electrode CNE1 and the fourth contact electrode CNE4 may contact one end of each light emitting element 30, and the second contact electrode CNE2 and the third contact electrode CNE3 may contact the other end of each light emitting element 30. As described above, the semiconductor layer may be exposed on both end surfaces of each light emitting element 30 in the direction in which the light emitting element 30 extends, and the contact electrode CNE may be electrically connected to the semiconductor layer of each light emitting element 30 by contacting the semiconductor layer. The respective sides of the contact electrode CNE contacting both ends of the light emitting element 30 may be disposed on the second insulating layer PAS2.

[0117] The width of the contact electrode CNE measured in a certain direction may be smaller than the widths of the electrodes 21 and 22 respectively measured in the direction. The contact electrode CNE may contact one end and the other end of each light emitting element 30, respectively, and may partially cover the upper surfaces of the first electrode 21 and the second electrode 22. However, the disclosure is not limited thereto, and the contact electrode CNE may also be wider than the electrodes 21 and 22 to cover both sides of the electrodes 21 and 22.

[0118] The contact electrode CNE may include a transparent conductive material such as ITO, IZO, ITZO, or aluminum (Al). Light emitted from the light emitting element 30 may pass through the contact electrode CNE to travel toward the electrodes 21 and 22. However, the disclosure is not limited thereto.

[0119] According to an embodiment, the contact electrode CNE may include a first type contact electrode CNE#1 that contacts the electrodes 21 and 22 through the opening OP of the first insulating layer PAS1, and a second type contact electrode CNE#2 that does not contact the electrodes 21 and 22 and contacts only the light emitting element 30. In addition, the second type contact electrode CNE#2 may include a portion disposed on the electrodes 21 and 22 but does not contact the electrodes 21 and 22, and may further include an electrode connecting portion BE connecting the portion disposed on the electrodes 21 and 22. The first type contact electrode CNE#1 and the second type contact electrode CNE#2 may contact the light emitting element 30, but may be distinguished from each other according to whether they contact the electrodes 21 and 22 and whether they are connected to the electrode connecting portion BE.

[0120] For example, each of the first contact electrode CNE1 and the second contact electrode CNE2 may be a first type contact electrode CNE#1. The first contact electrode CNE1 may cover the first opening OP1 and contact the first electrode 21 through the first opening OP1, and the second contact electrode CNE2 may cover the second opening OP2 and contact the second electrode 22 through the second opening OP2. The first contact electrode CNE1 and the second contact electrode CNE2 may extend in one direction and may be disposed on the electrodes 21 and 22 and directly connected to the electrodes 21 and 22.

[0121] The second type contact electrode CNE#2 includes contact portions CP1 and CP2 respectively disposed on the electrodes 21 and 22 to contact the light emitting element 30 and an electrode connection portion BE connecting the contact portions CP1 and CP2 to each other. The third contact electrode CNE3 and the fourth contact electrode CNE4 may be the contact portions CP1 and CP2 of the second type contact electrode CNE#2. The third contact electrode CNE3 may be the first contact portion CP1 spaced apart from the second contact electrode CNE2 and facing the first contact electrode CNE1, and the fourth contact electrode CNE4 may be the second contact portion CP2 spaced apart from the first contact electrode CNE1 and facing the second contact electrode CNE2. The electrode connection portion BE may connect the first contact portion CP1 and the second contact portion CP2 or the third contact electrode CNE3 and the fourth contact electrode CNE4, and the third contact electrode CNE3 and the fourth contact electrode CNE4 may be electrically connected to each other through the electrode connection portion BE.

[0122] Each of the light emitting elements 30 may have one end disposed on the first electrode 21 and the other end disposed on the second electrode 22. Both ends of each light emitting element 30 may contact the first type contact electrode CNE#1 and the second type contact electrode CNE#2, respectively, and some of the light emitting elements 30 may be electrically connected to each other through the second type contact electrode CNE#2. According to an embodiment, the light emitting elements 30 may include a first light emitting element 30A and a second light emitting element 30B, the first light emitting element 30A having a first end in contact with the first contact electrode CNE1 and a second end in contact with the third contact electrode CNE3, and the second light emitting element 30B having a first end in contact with the fourth contact electrode CNE4 and a second end in contact with the second contact electrode CNE2.

[0123] The first end of the first light emitting element 30A and the second end of the second light emitting element 30B contact the first type contact electrode CNE#1, respectively. The first end of the first light emitting element 30A contacts the first contact electrode CNE1, and the second end of the second light emitting element 30B contacts the second contact electrode CNE2. The first end of the first light emitting element 30A and the second end of the second light emitting element 30B can be electrically connected to the electrodes 21 and 22, respectively, through the first type contact electrode CNE#1.

[0124] The second end of the first light emitting element 30A and the first end of the second light emitting element 30B contact the second type contact electrode CNE#2. The second end of the first light emitting element 30A contacts the third contact electrode CNE3, and the first end of the second light emitting element 30B contacts the fourth contact electrode CNE4. Since the third contact electrode CNE3 and the fourth contact electrode CNE4 are connected to each other through the electrode connection portion BE, the second end of the first light emitting element 30A and the first end of the second light emitting element 30B can be electrically connected to each other through the second type contact electrode CNE#2. The first electrode 21 and the second electrode 22 can be electrically connected to the first transistor T1 and the second voltage wiring VL2 thereunder through the first contact hole CT1 and the second contact hole CT2, respectively, and can receive an electrical signal from the first transistor T1 and the second voltage wiring VL2. The electrical signal can flow through the first type contact electrode CNE#1, the first light emitting element 30A, the second light emitting element 30B, and the second type contact electrode CNE#2. Since the first light emitting element 30A and the second light emitting element 30B are electrically connected to each other through the second type contact electrode CNE#2, they can be connected to each other in series. When some light emitting elements 30 are provided in each sub-pixel PXn, if some of the light emitting elements 30 are connected in series with each other, the amount of light emitted from the light emitting elements 30 can be increased. In the display device 10, a plurality of light emitting elements 30 can be connected in series in each sub-pixel PXn to increase the brightness per unit sub-pixel. In addition, since the light emitting elements 30 are connected in series, even if some of the contact electrodes CNE are short-circuited, the light emitting elements 30 contacting other contact electrodes CNE can emit light. For example, when the first contact electrode CNE1 and the third contact electrode CNE3 contacting the first light emitting element 30A are directly connected to each other to be short-circuited, even if the first light emitting element 30A does not emit light, the second light emitting element 30B can emit light. The display device 10 can improve the brightness of each sub-pixel PXn while minimizing the light emitting failure in which the corresponding sub-pixel PXn does not completely emit light.

[0125] In an embodiment, the electrode connection portion BE and the contact portions CP1 and CP2 or the third contact electrode CNE3 and the fourth contact electrode CNE4 may be integrated with each other and disposed at the same layer, and the first type contact electrode CNE#1 and the second type contact electrode CNE#2 may be disposed at different layers. The first contact electrode CNE1 and the second contact electrode CNE2 of the first type contact electrode CNE#1 are formed in the same process but are spaced apart from each other. The third contact electrode CNE3, the fourth contact electrode CNE4 and the electrode connection portion BE of the second type contact electrode CNE#2 are formed in the same process to be connected to each other to form an integrated contact electrode. However, the disclosure is not limited thereto, and the electrode connection portion BE may also be formed in a separate process and connected to the contact portions CP1 and CP2.

[0126] The third insulating layer PAS3 may be disposed between the first type contact electrode CNE#1 and the second type contact electrode CNE#2. The third insulating layer PAS3 may also be disposed on the first type contact electrode CNE#1 and the second insulating layer PAS2 excluding the region where the contact portions CP1 and CP2 of the second type contact electrode CNE#2 are disposed. The second insulating layer PAS2 may be disposed on the entire surface of the first insulating layer PAS1 except for the portion where the contact electrode CNE is disposed on the electrodes 21 and 22, and the third insulating layer PAS3 may be disposed on the entire surface of the second insulating layer PAS2 except for the portion where the second type contact electrode CNE#2 is disposed on the electrodes 21 and 22. The third insulating layer PAS3 may insulate the first type contact electrode CNE#1 from the second type contact electrode CNE#2 so that the first type contact electrode CNE#1 and the second type contact electrode CNE#2 do not directly contact each other. That is, in an embodiment, the first type contact electrode CNE#1 and the second type contact electrode CNE#2 may be disposed on different layers. The first type contact electrode CNE#1 may be directly disposed on the second insulating layer PAS2, and the second type contact electrode CNE#2 may be directly disposed on the third insulating layer PAS3. However, the first type contact electrode CNE#1 and the second type contact electrode CNE#2 may also be directly disposed on the first insulating layer PAS1 in a region where the second insulating layer PAS2 and the third insulating layer PAS3 are not disposed and where both ends of the light emitting element 30 are exposed.

[0127] In addition, the second insulating layer PAS2 and the third insulating layer PAS3 may be disposed in a region where the light emitting element 30 is not disposed or between the electrodes 21 and 22 and the second bank BNL2, so that the electrode connection portion BE is disposed on the second insulating layer PAS2 or the third insulating layer PAS3. Since the electrode connection portion BE is disposed on the third insulating layer PAS3, it may be insulated from the first type contact electrode CNE#1 by the third insulating layer PAS3. However, the disclosure is not limited thereto, and the third insulating layer PAS3 may be omitted, and the second type contact electrode CNE#2 may be directly disposed on the second insulating layer PAS2.

[0128] In addition, according to an embodiment, the electrode connection portion BE of the second type contact electrode CNE#2 may be spaced apart from the outer side of the first type contact electrode CNE#1 and may surround the outer side. The electrode connection portion BE may include a first extension portion EP1 and a second extension portion EP2, the first extension portion EP1 extending in the second direction DR2 and connected to the third contact electrode CNE3, and the second extension portion EP2 extending in the first direction DR1 and having one side connected to the first extension portion EP1 and the other side connected to the fourth contact electrode CNE4. The first extension portion EP1 of the electrode connection portion BE may be spaced apart from the long side of the outer side of the second contact electrode CNE2, and the second extension portion EP2 may be spaced apart from the short side of the outer side of the second contact electrode CNE2. Therefore, the electrode connection portion BE may surround the outer side of the second contact electrode CNE2. The first extension portion EP1 of the electrode connection portion BE may not overlap with the second electrode 22.

[0129] The electrode connection portion BE of the second type contact electrode CNE#2 may connect the contact portions CP1 and CP2 or the third contact electrode CNE3 and the fourth contact electrode CNE4 via an area where the light emitting element 30 is not provided. The area where the contact electrodes CNE are spaced apart from each other is a portion of the emission area EMA of each sub-pixel PXn where the light emitting element 30 may be provided. Therefore, the electrode connection portion BE is placed so as not to cross the area where the contact electrodes CNE are spaced apart from each other. The electrode connection portion BE may surround the outside of the first type contact electrode CNE#1 and may be placed between the electrode 21 or 22 and the second bank BNL2. Since the electrode connection portion BE is only placed in an area where the light emitting element 30 is not provided, some of the light emitting elements 30 can be connected in series while maintaining the number of the light emitting elements 30 provided in each sub-pixel PXn. In the display device 10, the placement of the electrode connection portion BE is designed to ensure a sufficient area where the light emitting element 30 of each sub-pixel PXn is provided and to connect the light emitting elements 30 in series. Therefore, even if the area occupied by each sub-pixel PXn is small, the brightness can be improved while maintaining the size of each sub-pixel PXn.

[0130] According to an embodiment, the distances DC1 and DC2 between the electrode connection part BE and the first type contact electrode CNE#1 (for example, the second contact electrode CNE2) may be equal to or less than the distance between the contact electrodes CNE. The first type contact electrode CNE#1 and the second type contact electrode CNE#2 may not be directly connected to each other, but may be electrically connected to each other through the light emitting element 30. In one subpixel PXn, the electrode connection part BE surrounds the outer side of the second contact electrode CNE2 while being spaced apart from the second contact electrode CNE2 by a predetermined distance or more. The distance DC1 between the first extension part EP1 of the electrode connection part BE and the long side of the outer side of the second contact electrode CNE2 and the distance DC2 between the second extension part EP2 and the short side of the outer side of the second contact electrode CNE2 may be large enough to prevent them from directly contacting each other. The distances DC1 and DC2 may be equal to the distance between the contact parts CP1 and CP2 of the first type contact electrode CNE#1 and the second type contact electrode CNE#2, but may also be smaller within a range in which they may not be connected to each other.

[0131] The third insulating layer PAS3 may be provided between the first type contact electrode CNE#1 and the second type contact electrode CNE#2 to insulate them from each other. However, as described above, the third insulating layer PAS3 may also be omitted. In this case, the first type contact electrode CNE#1 and the second type contact electrode CNE#2 may be provided at the same layer, and the electrode connection portion BE may be spaced apart from the first type contact electrode CNE#1 by a predetermined distance (DC1 and DC2) within a range in which it is not directly connected to the first type contact electrode CNE#1.

[0132] Although two first-type contact electrodes CNE#1 and one second-type contact electrode CNE#2 are provided in one sub-pixel PXn in the drawings, the disclosure is not limited thereto. One first contact electrode CNE1 in contact with the first electrode 21 and one second contact electrode CNE2 in contact with the second electrode 22 may be provided as the first-type contact electrode CNE#1, but the second-type contact electrode CNE#2 may also include a greater number of contact portions CP1 and CP2 and an electrode connection portion BE. Therefore, the number of light-emitting elements 30 connected in series in each sub-pixel PXn may be increased, and the brightness of each sub-pixel PXn may also be improved.

[0133] The fourth insulating layer PAS4 may be disposed on the entire surface of the first substrate 11. The fourth insulating layer PAS4 may serve to protect components on the first substrate 11 from the external environment.

[0134] Each of the first insulating layer PAS1, the second insulating layer PAS2, the third insulating layer PAS3 and the fourth insulating layer PAS4 may include an inorganic insulating material or an organic insulating material. For example, the first insulating layer PAS1, the second insulating layer PAS2, the third insulating layer PAS3 and the fourth insulating layer PAS4 may include a silicon oxide (SiO x ), silicon nitride (SiN x ), silicon oxynitride (SiO x N y ), aluminum oxide (AlO x ) or aluminum nitride (AlN x ). Alternatively, the first insulating layer PAS1, the second insulating layer PAS2, the third insulating layer PAS3 and the fourth insulating layer PAS4 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, siloxane resin, silsesquioxane resin, polymethyl methacrylate, polycarbonate or polymethyl methacrylate-polycarbonate synthetic resin. However, the disclosure is not limited thereto.

[0135] The first type contact electrode CNE#1 may be spaced apart from the contact portion CP1 or CP2 of the second type contact electrode CNE#2 in the second direction DR2, or the first contact electrode CNE1 and the third contact electrode CNE3 may be spaced apart from the fourth contact electrode CNE4 and the second contact electrode CNE2 in the second direction DR2, and the light emitting element 30 may be disposed therebetween. These light emitting elements 30 may be disposed on the electrodes 21 and 22 without contacting the contact electrode CNE at both ends, and may remain as the light emitting element 30 that does not emit light in each sub-pixel PXn.

[0136] Figure 7 It is along Figure 3 A cross-sectional view taken along line Q6-Q6'.

[0137] Reference Figure 7, the light emitting element 30 according to the embodiment may further include a third light emitting element 30C having two ends that are not in contact with the contact electrode CNE. The two ends of the third light emitting element 30C may be disposed on the first electrode 21 and the second electrode 22, but the contact electrode CNE may not be disposed on the electrodes 21 and 22 on which the two ends of the third light emitting element 30C are disposed. The contact portions CP1 and CP2 of the first type contact electrode CNE#1 and the second type contact electrode CNE#2 may be spaced apart from each other along the second direction DR2 on the electrodes 21 and 22, and the light emitting element 30 may also be disposed in the region therebetween. The light emitting element includes a third light emitting element 30C that is not electrically connected to the contact electrode CNE, and the two ends of the third light emitting element 30C may be exposed by the second insulating layer PAS2 and the third insulating layer PAS3. The two ends of the third light emitting element 30C may directly contact the fourth insulating layer PAS4 disposed thereon. The display device 10 may include a third light emitting element 30C that does not emit light. However, even if each sub-pixel PXn includes some missing light-emitting elements 30 (such as the third light-emitting element 30C), sufficient brightness can be provided because the first light-emitting element 30A and the second light-emitting element 30B are connected in series. In addition, the third light-emitting element 30C can be surrounded by the second insulating layer PAS2, and its position can be anchored during the manufacturing process of the display device 10. Although the third light-emitting element 30C is not connected to the contact electrode CNE, it can not deviate from its position to act as a foreign body in the subsequent process, and the display device 10 can have sufficient brightness even if the display device 10 includes some missing light-emitting elements 30.

[0138] The display device 10 according to the embodiment can improve the brightness per unit area by connecting some of the light emitting elements 30 in each sub-pixel PXn in series. In addition, since the electrode connection portion BE of the second-type contact electrode CNE#2 that connects the light emitting elements 30 in series is placed to pass through the area where the light emitting elements 30 are not provided, the light emitting elements 30 can be connected in series while maintaining the size of each sub-pixel PXn and the number of the light emitting elements 30.

[0139] Figure 8 is a schematic diagram of a light emitting element according to an embodiment.

[0140] The light emitting element 30 may be a light emitting diode. Specifically, the light emitting element 30 may be an inorganic light emitting diode having a size of micrometers or nanometers 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 in which polarity is formed. The light emitting element 30 may be aligned between the two electrodes by the electric field formed on the electrodes.

[0141] The light emitting element 30 according to the embodiment may extend in one direction. The light emitting element 30 may be shaped as a cylinder, a rod, a wire, a tube, etc. However, the shape of the light emitting element 30 is not limited thereto, and the light emitting element 30 may also have various shapes including polygonal prisms such as cubes, cuboids, or hexagonal prisms, and shapes extending in one direction and having partially inclined outer surfaces. A plurality of semiconductors included in the light emitting element 30 to be described later may be sequentially arranged or stacked along the one direction.

[0142] The light emitting element 30 may include a semiconductor layer doped with impurities of any conductivity type (eg, p-type or n-type). The semiconductor layer may receive an electrical signal from an external power source and emit light of a specific wavelength band.

[0143] Reference Figure 8 The light emitting element 30 may include a first semiconductor layer 31 , a second semiconductor layer 32 , a light emitting layer 36 , an electrode layer 37 and an insulating film 38 .

[0144] The first semiconductor layer 31 may be an n-type semiconductor. If the light emitting element 30 emits light in a blue wavelength band, the first semiconductor layer 31 may include an Al x Ga y In 1-x-y N (0≤x≤1, 0≤y≤1, 0≤x+y≤1). For example, the semiconductor material included in the first semiconductor layer 31 may be any one or more of n-type doped AlGaInN, GaN, AlGaN, InGaN, AlN and InN. The first semiconductor layer 31 may be doped with an n-type dopant, which may be Si, Ge or Sn. For example, the first semiconductor layer 31 may be n-GaN doped with n-type Si. The length of the first semiconductor layer 31 may be in the range of, but not limited to, 1.5 μm to 5 μm.

[0145] The second semiconductor layer 32 is disposed on the light emitting layer 36 to be described later. The second semiconductor layer 32 may be a p-type semiconductor. If the light emitting element 30 emits light of a blue or green wavelength band, the second semiconductor layer 32 may include Al x Ga y In 1-x-yN (0≤x≤1, 0≤y≤1, 0≤x+y≤1). For example, the semiconductor material included in the second semiconductor layer 32 may be any one or more of p-type doped AlGaInN, GaN, AlGaN, InGaN, AlN, and InN. The second semiconductor layer 32 may be doped with a p-dopant, which may be Mg, Zn, Ca, Sr, or Ba. For example, the second semiconductor layer 32 may be p-GaN doped with p-type Mg. The length of the second semiconductor layer 32 may be in the range of, but not limited to, 0.05 μm to 0.10 μm.

[0146] Although each of the first semiconductor layer 31 and the second semiconductor layer 32 is composed of one layer in the drawings, the disclosure is not limited thereto. Each of the first semiconductor layer 31 and the second semiconductor layer 32 may also include more layers, for example, a cladding layer or a tensile strain barrier reduction (TSBR) layer may be further included according to the material of the light emitting layer 36.

[0147] The light emitting layer 36 is disposed between the first semiconductor layer 31 and the second semiconductor layer 32. The light emitting layer 36 may include a material having a single quantum well structure or a multi-quantum well structure. When the light emitting layer 36 includes a material having a multi-quantum well structure, it may have a structure in which a plurality of quantum layers and a plurality of well layers are alternately stacked. The light emitting layer 36 may emit light by recombination of electron-hole pairs according to an electrical signal received through the first semiconductor layer 31 and the second semiconductor layer 32. If the light emitting layer 36 emits light of a blue wavelength band, it may include a material such as AlGaN or AlGaInN. Specifically, when the light emitting layer 36 has a multi-quantum well structure in which quantum layers and well layers are alternately stacked, the quantum layer may include a material such as AlGaN or AlGaInN, and the well layer may include a material such as GaN or AlInN. For example, the light emitting layer 36 may include AlGaInN as a quantum layer and AlInN as a well layer to emit blue light whose central wavelength band is in the range of 450nm to 495nm as described above.

[0148] However, the disclosure is not limited thereto, and the light emitting layer 36 may also have a structure in which a semiconductor material having a large energy band gap and a semiconductor material having a small energy band gap are alternately stacked, or may include different group III to group V semiconductor materials, according to the wavelength band of light emitted by the light emitting layer 36. The light emitted from the light emitting layer 36 is not limited to light of a blue wavelength band. In some cases, the light emitting layer 36 may emit light of a red or green wavelength band. The length of the light emitting layer 36 may be in the range of, but not limited to, 0.05 μm to 0.10 μm.

[0149] The light emitted from the light emitting layer 36 may be radiated not only through the outer surface of the light emitting element 30 in the longitudinal direction but also through both side surfaces. The direction of the light emitted from the light emitting layer 36 is not limited to one direction.

[0150] The electrode layer 37 may be an ohmic contact electrode. However, the disclosure is not limited thereto, and the electrode layer 37 may also be a Schottky contact electrode. The light emitting element 30 may include at least one electrode layer 37. Figure 8 3. The light emitting element 30 includes one electrode layer 37, but the disclosure is not limited thereto. In some cases, the light emitting element 30 may include an additional electrode layer 37, or the electrode layer 37 may be omitted. Even when the light emitting element 30 includes a different number of electrode layers 37 or further includes another structure, the following description of the light emitting element 30 may also be equally applicable.

[0151] When the light emitting element 30 is electrically connected to the electrode or contact electrode in the display device 10 according to the embodiment, the electrode layer 37 can reduce the resistance between the light emitting element 30 and the electrode or contact electrode. The electrode layer 37 may include a conductive metal. For example, the electrode layer 37 may include at least any 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 37 may include a semiconductor material doped with n-type or p-type. The electrode layer 37 may include the same material or different materials, but the disclosure is not limited thereto.

[0152] The insulating film 38 surrounds the outer surfaces of the semiconductor layer and the electrode layer. For example, the insulating film 38 may surround at least the outer surface of the light emitting layer 36 and extend in the direction along which the light emitting element 30 extends. The insulating film 38 may protect the above components. For example, the insulating film 38 may surround the side surfaces of the above components, but may expose both ends of the light emitting element 30 in the longitudinal direction.

[0153] In the figure, the insulating film 38 extends in the longitudinal direction of the light emitting element 30 to cover from the side surface of the first semiconductor layer 31 to the side surface of the electrode layer 37. However, the disclosure is not limited thereto, and the insulating film 38 may cover the outer surface of the light emitting layer 36 and only some semiconductor layers, or may cover only a portion of the outer surface of the electrode layer 37 to partially expose the outer surface of the electrode layer 37. In addition, the upper surface of the insulating film 38 may be circular in cross section in a region adjacent to at least one end of the light emitting element 30.

[0154] The thickness of the insulating film 38 may be, but is not limited to, in the range of 10 nm to 1.0 μm. The thickness of the insulating film 38 may be, for example, about 40 nm.

[0155] The insulating film 38 may include silicon oxide (SiOx ), silicon nitride (SiN x ), silicon oxynitride (SiO x N y ), aluminum nitride (AlN x ) or aluminum oxide (AlO x ). Therefore, it is possible to prevent an electrical short circuit that would occur when the light emitting layer 36 directly contacts an electrode that transmits an electrical signal to the light emitting element 30. In addition, since the insulating film 38 protects the outer surface of the light emitting element 30 including the light emitting layer 36, it is possible to prevent a decrease in light emitting efficiency.

[0156] In addition, the outer surface of the insulating film 38 may be processed. The light emitting elements 30 dispersed in a predetermined ink may be sprayed onto the electrode and then aligned. Here, the surface of the insulating film 38 may be hydrophobic or hydrophilic so that the light emitting elements 30 remain separated in the ink without agglomerating with other adjacent light emitting elements 30.

[0157] The length h of the light emitting element 30 may be in the range of 1 μm to 10 μm or 2 μm to 6 μm, and may be, for example, in the range of 3 μm to 5 μm. In addition, the diameter of the light emitting element 30 may be in the range of 30 nm to 700 nm, and the aspect ratio of the light emitting element 30 may be 1.2 to 100. However, the disclosure is not limited thereto, and the plurality of light emitting elements 30 included in the display device 10 may also have different diameters according to the difference in the composition of the light emitting layer 36. The diameter of the light emitting element 30 may be, for example, about 500 nm.

[0158] Hereinafter, other embodiments of the display device 10 will be described with reference to other drawings.

[0159] Fig. 9 is a plan view of a sub-pixel of a display device according to another embodiment. Fig.10 It is along Fig. 9 A cross-sectional view taken along line Q7-Q7'.

[0160] Reference Fig. 9 and Fig.10 , in the display device 10, the third insulating layer PAS3 may be omitted. The first-type contact electrode CNE#1 and the second-type contact electrode CNE#2 of the display device 10 may be directly disposed on the first insulating layer PAS1 or the second insulating layer PAS2, and may be disposed on the same layer. Figures 4 to 6 The embodiment of FIG. 1 is different in that the third insulating layer PAS3 is omitted. Hereinafter, any redundant description will be omitted and the differences will be mainly described.

[0161] In an embodiment, the third insulating layer PAS3 may be omitted, and the first type contact electrode CNE#1 and the second type contact electrode CNE#2 may be directly disposed on the first insulating layer PAS1 and the second insulating layer PAS2. A plurality of contact electrodes CNE may be formed simultaneously in the same process and may be disposed on the same layer. The contact portions CP1 and CP2 of the first type contact electrode CNE#1 and the second type contact electrode CNE#2 may be spaced apart from each other on the second insulating layer PAS2 disposed on the light emitting element 30. The first contact electrode CNE1_1 and the third contact electrode CNE3_1 and the second contact electrode CNE2_1 and the fourth contact electrode CNE4_1 are spaced apart from each other on the second insulating layer PAS2 and are not directly connected to each other. The electrode connection portion BE_1 is also directly disposed on the second insulating layer PAS2. The electrode connection portion BE_1 surrounds the outer side of the second contact electrode CNE2_1 among the first type contact electrode CNE#1, but is spaced apart from the outer side of the second contact electrode CNE2_1 by a predetermined distance. Therefore, the electrode connection portion BE_1 may not be directly connected to the second contact electrode CNE2_1.

[0162] In the display device 10, even if the third insulating layer PAS3 is omitted, the first-type contact electrode CNE#1 and the second-type contact electrode CNE#2 are spaced apart from each other by a predetermined distance. Specifically, since the electrode connection portion BE_1 surrounding any one of the first-type contact electrodes CNE#1 is spaced apart from the any one of the first-type contact electrodes CNE#1 by predetermined distances DC1 and DC2, they may not be directly connected to each other. The first light-emitting element 30A and the second light-emitting element 30B may be electrically connected in series through the second-type contact electrode CNE#2.

[0163] Fig.11 is a plan view of a sub-pixel of a display device according to another embodiment.

[0164] Reference Fig.11 In the display device 10 according to the embodiment, the distance DC1 between the first extension portion EP1_2 of the electrode connection portion BE_2 and the second contact electrode CNE2 may be smaller than the distance DC2 between the second extension portion EP2 and the second contact electrode CNE2. The first extension portion EP1_2 of the electrode connection portion BE_2 may overlap the outer side of the second electrode 22 in the thickness direction. Figure 3 The embodiment of the present invention is different in that the distance DC1 between the first extension portion EP1_2 of the electrode connection portion BE_2 and the second contact electrode CNE2 is smaller.

[0165] Since the third insulating layer PAS3 is disposed between the first-type contact electrode CNE#1 and the second-type contact electrode CNE#2 as described above, the first-type contact electrode CNE#1 and the second-type contact electrode CNE#2 may not be in direct contact with each other. The electrode connection portion BE_2 may surround the outer side of the second contact electrode CNE2, but may not directly contact the second contact electrode CNE2 even if the distances DC1 and DC2 therebetween become smaller. In addition, even if the third insulating layer PAS3 is omitted, the electrode connection portion BE_2 may be spaced apart from the second contact electrode CNE2 to the extent that it does not directly contact the second contact electrode CNE2. In the display device 10, since the electrode connection portion BE_2 bypasses the second contact electrode CNE2 at the minimum distance from the second contact electrode CNE2, the area occupied by the emission area EMA of each sub-pixel PXn may be further minimized. Thus, a larger number of sub-pixels PXn per unit area may be provided in the display device 10, and an ultra-high-resolution display device may be realized.

[0166] Fig.12 is a plan view of a sub-pixel of a display device according to another embodiment. Fig.13 It is along Fig.12 A cross-sectional view taken along line Q8-Q8'. Fig.13 FIG. 2 shows a cross section across both ends of the contact second-type contact electrode CNE#2 of the light emitting element 30. In addition, Fig.12 and Fig.13 FIG. 1 shows a diagram in which a larger number of second-type contact electrodes CNE#2 are provided in a region from which the third insulating layer PAS3 is omitted. Fig. 9 An embodiment of a display device 10.

[0167] Reference Fig.12 and Fig.13 , the display device 10 according to the embodiment may include a larger number of second-type contact electrodes CNE#2 to connect more light-emitting elements 30 in series in each sub-pixel PXn. Each sub-pixel PXn may also include a fourth light-emitting element 30D connected in series between the first light-emitting element 30A and the second light-emitting element 30B. In each sub-pixel PXn, the first light-emitting element 30A, the fourth light-emitting element 30D, and the second light-emitting element 30B may be connected in series to further improve the brightness of each sub-pixel PXn.

[0168] As in Fig.12In the embodiment of the present invention, the first-type contact electrode CNE#1 includes a first contact electrode CNE1_3 disposed on the first electrode 21 and a second contact electrode CNE2_3 disposed on the second electrode 22. The first contact electrode CNE1_3 and the second contact electrode CNE2_3 may contact the electrodes 21 and 22 through the openings OP1 and OP2 of the first insulating layer PAS1, respectively. The second-type contact electrode CNE#2 may include a third contact electrode CNE3_3, a fourth contact electrode CNE4_3, and a first electrode connecting portion BE1_3 connecting the third contact electrode CNE3_3 and the fourth contact electrode CNE4_3, and may also include a fifth contact electrode CNE5_3, a sixth contact electrode CNE6_3, and a second electrode connecting portion BE2_3 connecting the fifth contact electrode CNE5_3 and the sixth contact electrode CNE6_3. Since the arrangement of the first-type contact electrode CNE#1 is the same as that of the above reference electrode Fig. 9 The arrangement of the first type contact electrode CNE#1 described in the embodiment is the same, so the second type contact electrode CNE#2 will be described below.

[0169] The third contact electrode CNE3_3 is disposed on the second electrode 22 to face the first contact electrode CNE1_3. The fourth contact electrode CNE4_3 is disposed on the first electrode 21 and is spaced apart from the first contact electrode CNE1_3 in the second direction DR2. The arrangement of the third contact electrode CNE3_3 and the fourth contact electrode CNE4_3 may be similar to Figure 3 However, the first electrode connection portion BE1_3 connecting the third contact electrode CNE3_3 and the fourth contact electrode CNE4_3 may surround the outer wall of the first contact electrode CNE1_3 among the first type contact electrode CNE#1.

[0170] The fifth contact electrode CNE5_3 is disposed on the second electrode 22 between the third contact electrode CNE3_3 and the second contact electrode CNE2_3. The fifth contact electrode CNE5_3 may be spaced apart from each of the third contact electrode CNE3_3 and the second contact electrode CNE2_3 in the second direction DR2, and may face the fourth contact electrode CNE4_3 in the first direction DR1. The sixth contact electrode CNE6_3 is disposed on the first electrode 21 and spaced apart from the fourth contact electrode CNE4_3 in the second direction DR2. The sixth contact electrode CNE6_3 may face the second contact electrode CNE2_3 in the first direction DR1. The fifth contact electrode CNE5_3 may be the third contact portion CP3 of the second type contact electrode CNE#2, and the sixth contact electrode CNE6_3 may be the fourth contact portion CP4 of the second type contact electrode CNE#2. The second electrode connection portion BE2_3 connecting the fifth contact electrode CNE5_3 and the sixth contact electrode CNE6_3 may surround the outer wall of the second contact electrode CNE2_3 as the first type contact electrode CNE#1.

[0171] One end of each first light emitting element 30A contacts the first contact electrode CNE1_3, and the other end contacts the third contact electrode CNE3_3. One end of each second light emitting element 30B contacts the sixth contact electrode CNE6_3, and the other end contacts the second contact electrode CNE2_3. One end of each fourth light emitting element 30D contacts the fourth contact electrode CNE4_3, and the other end contacts the fifth contact electrode CNE5_3. The first light emitting element 30A and the fourth light emitting element 30D, as well as the fourth light emitting element 30D and the second light emitting element 30B can be connected in series with each other through the second type contact electrode CNE#2. In the display device 10 according to the current embodiment, the light emitting elements 30 of each sub-pixel PXn can be connected in series in multiple numbers, and the brightness of each sub-pixel PXn can also be improved.

[0172] The first electrode 21 and the second electrode 22 may not necessarily extend in one direction. In some embodiments, the electrodes 21 and 22 of the display device 10 may include portions extending with different widths and portions extending in different directions.

[0173] Fig.14 is a plan view of a sub-pixel of a display device according to another embodiment. Fig.15 It is along Fig.14 A cross-sectional view taken along line Q9-Q9'.

[0174] Reference Fig.14 and Fig.15, each of the electrodes 21_4 and 22_4 of the display device 10 according to the embodiment may include a widening portion RE-E extending in the second direction DR2 and having a width greater than that of other portions, a bent portion RE-B extending in a direction inclined from the first direction DR1 and the second direction DR2, and a connecting portion RE-C connecting the bent portion RE-B and the widening portion RE-E. Each of the electrodes 21_4 and 22_4 may generally extend in the second direction DR2, but may have a larger width in a portion, or may be bent in a direction inclined from the second direction DR2. The first electrode 21_4 and the second electrode 22_4 may be arranged in a symmetrical structure with respect to the region therebetween. Hereinafter, any redundant description will be omitted, and the shape of the first electrode 21_4 will be mainly described.

[0175] The first electrode 21_4 may include a widening portion RE-E having a width greater than that of other portions. The widening portion RE-E may be disposed on each first bank BNL1_4 in the emission area EMA of each subpixel PXn, and may extend in the second direction DR2. The light emitting element 30 may be disposed on the widening portion RE-E of the first electrode 21_4 and the second electrode 22_4. In addition, the contact electrode CNE may be disposed on the widening portion RE-E of each of the electrodes 21_4 and 22_4, but the width of the contact electrode CNE may be smaller than the width of the widening portion RE-E. The first type contact electrode CNE#1 may cover the openings OP1 and OP2 that partially expose the upper surfaces of the widening portions RE-E of the electrodes 21_4 and 22_4, and thus may contact the widening portion RE-E. The second type contact electrode CNE# 2 is spaced apart from the first type contact electrode CNE# 1 along the second direction DR2 on the widened portion RE-E, and the electrode connecting portion BE is spaced apart from the second contact electrode CNE2 on the widened portion RE-E of the second electrode 22_4 .

[0176] The connection portion RE-C may be respectively connected to both sides of each widening portion RE-E in the second direction DR2. The connection portion RE-C may be connected to each widening portion RE-E and may be disposed throughout the emission area EMA and the second bank BNL2_4 of each subpixel PXn.

[0177] The width of the connection portion RE-C may be smaller than the width of the widening portion RE-E. One side of each connection portion RE-C extending in the second direction DR2 may be colinearly connected to one side of the widening portion RE-E extending in the second direction DR2. For example, among both sides of each of the widening portion RE-E and the connection portion RE-C, one side of the widening portion RE-E positioned outside the center of the emission area EMA and one side of the connection portion RE-C positioned outside the center of the emission area EMA may extend and may be connected to each other. Therefore, the distance DE1 between the widening portions RE-E of the first electrode 21_4 and the second electrode 22_4 may be smaller than the distance DE2 between the connection portions RE-C.

[0178] The bent portion RE-B is connected to the connection portion RE-C. The bent portion RE-B connected to the connection portion RE-C may be bent in a direction inclined from the second direction DR2 (e.g., toward the center of each sub-pixel PXn). The shortest distance DE3 between the bent portion RE-B of the first electrode 21_4 and the second electrode 22_4 may be smaller than the distance DE2 between the connection portions RE-C. However, the shortest distance DE3 between the bent portions RE-B may be greater than the distance DE1 between the widening portions RE-E.

[0179] The length of the connection portion RE-C connected to the upper side of the widened portion RE-E of the first electrode 21_4 may be smaller than the length of the connection portion RE-C connected to the upper side of the widened portion RE-E of the second electrode 22_4. Therefore, the bent portion RE-B of the upper portion of the first electrode 21_4 and the bent portion RE-B of the upper portion of the second electrode 22_4 may be staggered with each other. On the other hand, the connection portions RE-C connected to the lower sides of the widened portions RE-E of the electrodes 21_4 and 22_4 may have the same length, and the bent portions RE-B of the lower portions may be arranged symmetrically with each other.

[0180] In addition, a segment portion RE-D remaining in the cutout area CBA after separating the electrode 21_4 may be formed at the end of each upper bent portion RE-B. The segment portion RE-D may be a portion remaining in the cutout area CBA after separating the electrode 21_4 or 22_4 of the sub-pixel PXn adjacent in the second direction DR2.

[0181] The first electrode 21_4 may have a contact portion RE-P disposed between the upper bent portion RE-B and the segment portion RE-D and having a relatively large width. The second electrode 22_4 may have a contact portion RE-P formed in the upper connection portion RE-C. In the contact portion RE-P, first and second contact holes CT1 and CT2 of the first and second electrodes 21_4 and 22_4 may be formed.

[0182] Fig.14 Examples and Figure 2The difference of the embodiment is that the first electrode 21_4 and the second electrode 22_4 include a widening portion RE-E, a connecting portion RE-C and a bent portion RE-B, and are symmetrically arranged relative to the center of each sub-pixel PXn. However, the disclosure is not limited thereto. In some cases, the first electrode 21_4 and the second electrode 22_4 may have different shapes.

[0183] In addition, each first bank BNL1_4 may have a larger width and may be disposed across the boundary between the sub-pixels PXn adjacent in the first direction DR1. The first bank BNL1_4 may be disposed in the emission area EMA of each sub-pixel PXn and across the boundary between the sub-pixels PXn. Therefore, a portion of the second bank BNL2_4 extending in the second direction DR2 may be partially disposed on the first bank BNL1-4. In one sub-pixel PXn, two first banks BNL1-4 may be partially disposed. The widened portion RE-E of the electrodes 21_4 and 22_4 may be disposed on the first bank BNL1_4, and the contact electrode CNE may contact the light emitting element 30 disposed between the first bank BNL1_4, and may be disposed on the widened portion RE-E of the electrodes 21_4 and 22_4.

[0184] The contact electrode CNE may be disposed on the inclined side surfaces of the electrodes 21 and 22 and the first bank BNL1 along the steps formed by them. Fig.14 When the contact electrode CNE is disposed on the widening portion RE-E of the electrodes 21_4 and 22_4 in the embodiment, the slope caused by the first bank BNL1-4 and the widening portion RE-E may be large at the upper corner or the lower corner of the widening portion RE-E. When the contact electrode CNE is disposed at the corner of the widening portion RE-E, the material forming the contact electrode CNE may be connected through a step formed by the first bank BNL1-4 and the electrode below the contact electrode CNE. To prevent this, in the display device 10, the width of the contact electrode CNE may be reduced at the corner of the widening portion RE-E.

[0185] Fig.16 A contact electrode of a display device according to another embodiment is schematically shown. Fig.16 yes Fig.14 FIG. 1 is an enlarged view of the first contact electrode CNE1_5 and the third contact electrode CNE3_5 having different shapes in the display device 10 .

[0186] Reference Fig.16, each contact electrode CNE may include a first portion P1 and a second portion P2 having a width smaller than that of the first portion P1. With respect to the distance between the contact electrodes CNE facing each other in the first direction DR1, a distance DC4 between the second portions P2 may be greater than a distance DC3 between the first portions P1. For example, each of the first contact electrode CNE1_5 and the third contact electrode CNE3_5 may include a first portion P1 having a relatively large width and a second portion P2 having a width smaller than that of the first portion P1. Each of the first contact electrode CNE1_5 and the third contact electrode CNE3_5 may have the same width as that of the first portion P1 as a whole, but a portion (or the second portion P2) disposed at a corner of the electrode 21 or 22 and on the first bank BNL1 may have a smaller width.

[0187] The first bank BNL1 may protrude from the upper surface of the first planarization layer 19, and each side of the first bank BNL1 may be inclined in cross section. When viewed in a plan view, the upper side and the lateral side of each first bank BNL1 may be inclined in cross section, and may be inclined more than other portions of each side at the corner where they meet. When viewed in a plan view, the widened portion RE-E of the electrodes 21 and 22 disposed on the first bank BNL1 may also further form a step at the corner where the upper side and the lateral side meet.

[0188] In the patterning process for forming the contact electrode CNE, the materials forming the contact electrode CNE must be spaced apart from each other by a certain distance. However, due to the step formed under the corner, the materials are not spaced apart from each other by a desired distance at the corner where the upper side and the lateral side of each widening portion RE-E meet. In this case, the materials of the contact electrodes CNE (e.g., the first contact electrode CNE1_5 and the third contact electrode CNE3_5) facing each other are partially connected to each other. In the display device 10, each of the contact electrodes CNE may be formed to have a small width in a portion where a large step is formed under the contact electrode CNE. Therefore, this can prevent different contact electrodes CNE from being directly connected to each other.

[0189] In an embodiment, regarding the distance between the contact electrodes CNE, the distance DC3 between the first portions P1 may be smaller than the distance DC4 between the second portions P2. For example, one side of the second portion P2 of each contact electrode CNE facing the other contact electrode CNE may be inclined so that the width of the contact electrode CNE decreases toward the upper side. That is, each contact electrode CNE may be chamfered in a portion where a large step is formed under the contact electrode CNE, and direct connection to another contact electrode CNE in the portion may be prevented.

[0190] In summarizing the detailed description, it will be appreciated by those skilled in the art that many changes and modifications may be made to the preferred embodiments without departing substantially from the principles of the invention. Therefore, the preferred embodiments of the disclosed invention are used only in a general and descriptive sense and not for the purpose of limitation.

Claims

1. A display device, comprising: first base; A first electrode and a second electrode extending along a first direction on the first substrate and spaced apart from each other in a second direction; A plurality of light emitting elements are arranged on the first electrode and the second electrode; as well as a plurality of contact electrodes, disposed on the first electrode or the second electrode and contacting the plurality of light emitting elements; The plurality of contact electrodes include: a first contact electrode disposed on the first electrode; a second contact electrode disposed on the second electrode; a third contact electrode spaced apart from the second contact electrode in the first direction and facing the first contact electrode in the second direction; and a fourth contact electrode spaced apart from the first contact electrode in the first direction and facing the second contact electrode in the second direction, and The display device further includes an electrode connecting portion connected to the third contact electrode and the fourth contact electrode and surrounding the second contact electrode.

2. The display device according to claim 1, wherein: The electrode connecting portion is integrated with the third contact electrode and the fourth contact electrode.

3. The display device according to claim 1, further comprising a first insulating layer, the first insulating layer being disposed on the first substrate to cover the first electrode and the second electrode and comprising a first opening exposing a portion of an upper surface of the first electrode and a second opening exposing a portion of an upper surface of the second electrode, in, The plurality of light emitting elements are disposed on the first insulating layer.

4. The display device according to claim 3, further comprising a second insulating layer, which is disposed on the first insulating layer and the plurality of light emitting elements and exposes both ends of each light emitting element and a portion of the first insulating layer on which the plurality of contact electrodes are disposed.

5. The display device according to claim 4, wherein: The first contact electrode, the second contact electrode, the third contact electrode and the fourth contact electrode are directly disposed on the first insulating layer, and At least a portion of the electrode connecting portion is disposed on the second insulating layer.

6. The display device according to claim 2, further comprising a third insulating layer covering the first contact electrode and the second contact electrode, in, At least a portion of each of the third contact electrode, the fourth contact electrode, and the electrode connecting portion is disposed on the third insulating layer.

7. The display device according to claim 1, wherein: The plurality of light emitting elements include: a first light emitting element having one end in contact with the first contact electrode and another end in contact with the third contact electrode; and a second light emitting element having one end in contact with the fourth contact electrode and another end in contact with the second contact electrode.

8. The display device according to claim 1, wherein: The plurality of light emitting elements further include a third light emitting element having both ends not in contact with the plurality of contact electrodes.

9. The display device according to claim 3, wherein: The first contact electrode covers the first opening to contact the first electrode, The second contact electrode covers the second opening to contact the second electrode, and The third contact electrode and the fourth contact electrode are disposed on the first insulating layer so as not to contact the first electrode and the second electrode.

10. The display device according to claim 1, wherein: The electrode connecting portion includes: a first extending portion extending in the first direction and connected to the third contact electrode; and a second extending portion extending in the second direction and having one side connected to the first extending portion and the other side connected to the fourth contact electrode, wherein the first extension portion is spaced apart from the outer long side of the second contact electrode, and The second extension portion is spaced apart from a short side of the outer side of the second contact electrode.

11. The display device according to claim 10, wherein: A distance between the long side of the second contact electrode and the first extension portion of the electrode connecting portion is equal to or smaller than a distance between the second contact electrode and the fourth contact electrode.

12. The display device according to claim 11, wherein: The first extension portion of the electrode connecting portion partially overlaps the second electrode in a thickness direction.

13. The display device according to claim 1, wherein: Each of the plurality of contact electrodes includes a first portion and a second portion having a width smaller than a width of the first portion, and A distance between the second portions between the plurality of contact electrodes facing each other in the second direction is greater than a distance between the first portions.

14. A display device, comprising: first base; A first electrode and a second electrode extending along a first direction on the first substrate and spaced apart from each other in a second direction; a first insulating layer disposed on the first substrate and comprising an opening exposing a portion of the first electrode or the second electrode; A plurality of light emitting elements are disposed on the first insulating layer and have two ends disposed on the first electrode and the second electrode respectively; a plurality of first-type contact electrodes, disposed on the first electrode or the second electrode and contacting the plurality of light-emitting elements and the first electrode or the second electrode; as well as a second-type contact electrode that contacts the plurality of light-emitting elements and does not contact the first electrode and the second electrode; The second-type contact electrode comprises: a plurality of contact portions, which are arranged on the first electrode or the second electrode but are separated from the plurality of first-type contact electrodes; and an electrode connecting portion, which connects the plurality of contact portions. The electrode connecting portion is spaced apart from an outer side of any one of the plurality of first-type contact electrodes and surrounds the outer side.

15. The display device according to claim 14, wherein: The plurality of first-type contact electrodes include: a first contact electrode disposed on the first electrode and contacting the first electrode through a first opening exposing a portion of an upper surface of the first electrode; and a second contact electrode disposed on the second electrode and contacting the second electrode through a second opening exposing a portion of an upper surface of the second electrode, and The second-type contact electrode includes: a first contact portion disposed on the second electrode and spaced apart from the second contact electrode; a second contact portion disposed on the first electrode and spaced apart from the first contact electrode; and a first electrode connecting portion connecting the first contact portion and the second contact portion.

16. The display device according to claim 15, wherein: The first electrode connecting portion surrounds an outer side of the second contact electrode.

17. The display device according to claim 16, wherein: The plurality of light emitting elements include a first light emitting element having one end in contact with the first contact electrode and another end in contact with the first contact portion; and a second light emitting element having one end in contact with the second contact portion and another end in contact with the second contact electrode.

18. The display device according to claim 15, wherein: The first contact portion faces the first contact electrode, The second contact portion is spaced apart from the first contact electrode in the first direction, The first electrode connecting portion surrounds the outer side of the first contact electrode, and The second-type contact electrode further includes: a third contact portion, which is arranged between the second contact electrode and the first contact portion to face the second contact portion; a fourth contact portion, which is spaced apart from the second contact portion in the first direction to face the second contact electrode; and a second electrode connecting portion, which connects the third contact portion and the fourth contact portion and surrounds the outer side of the second contact electrode.

19. The display device according to claim 14, further comprising a second insulating layer disposed on the first insulating layer and the plurality of light emitting elements and exposing both ends of each light emitting element and a portion of the first insulating layer on which the contact electrode is disposed, in, The plurality of first-type contact electrodes and the plurality of contact portions of the second-type contact electrodes are disposed on the same layer.

20. The display device according to claim 19, wherein: The electrode connecting portion of the second-type contact electrode is directly disposed on the second insulating layer.

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