Display device and manufacturing method thereof

Abstract

A display device and a manufacturing method thereof are provided. The display device includes: a first substrate; a first electrode and a second electrode spaced apart from each other on the first substrate; a plurality of light-emitting elements, at least a portion of which is arranged between the first electrode and the second electrode; a first contact electrode at least partially covering the first electrode and contacting one end of each of the plurality of light-emitting elements; and a second contact electrode spaced apart from the first contact electrode to at least partially cover the second electrode and contact the other end of each of the plurality of light-emitting elements, wherein the first contact electrode and the second contact electrode include a conductive polymer.

Description

Technical Field

[0001] The present invention relates to a display device and a method for manufacturing the same. Background Art

[0002] With the development of multimedia technology, 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] A display device is a device for displaying an image and includes a display panel such as an organic light-emitting display panel or a liquid crystal display panel. A light-emitting display panel may include a light-emitting element (e.g., a light-emitting diode (LED)). Examples of light-emitting diodes include organic light-emitting diodes (OLEDs) using organic materials as fluorescent materials and inorganic light-emitting diodes using inorganic materials as fluorescent materials. Summary of the Invention

[0004] Technical issues

[0005] To solve the above-mentioned problems, disclosed embodiments provide a display device including a light emitting element and a contact electrode electrically connected to the light emitting element and including a conductive polymer.

[0006] The disclosed embodiments also provide a method for manufacturing a display device, which can shorten the manufacturing time of the display device.

[0007] It should be noted that the disclosed aspects are not limited thereto, and other aspects not mentioned here will be apparent to those of ordinary skill in the art from the following description.

[0008] Technical Solution

[0009] According to a disclosed embodiment, a display device includes: a first substrate; a first electrode and a second electrode, which are arranged on the first substrate to be spaced apart from each other; a plurality of light-emitting elements, which are at least partially arranged between the first electrode and the second electrode; a first contact electrode, which at least partially covers the first electrode, and the first contact electrode is in contact with first ends of the plurality of light-emitting elements; and a second contact electrode, which is spaced apart from the first contact electrode and at least partially covers the second electrode, and the second contact electrode is in contact with second ends of the plurality of light-emitting elements, wherein the first contact electrode and the second contact electrode include a conductive polymer.

[0010] The conductive polymer may include PEDOT:PSS.

[0011] The first contact electrode and the second contact electrode may have a thickness of 150 nm to 250 nm.

[0012] The first contact electrode and the second contact electrode may be spaced apart from each other on the plurality of light emitting elements.

[0013] The display device may further include: a plurality of first embankments, arranged between the first electrode, the second electrode and the first substrate, a middle portion of the first embankment being thicker than the rest of the first embankment, wherein the first contact electrode and the second contact electrode may be arranged to at least partially overlap with the first embankment in a thickness direction.

[0014] The first and second contact electrodes may be disposed to overlap the first bank in a thickness direction, and portions of the first and second contact electrodes overlapping the thick portion of the first bank may be thicker than remaining portions of the first and second contact electrodes.

[0015] Portions of the first and second contact electrodes covering the first and second end portions of the plurality of light emitting elements may be thicker than remaining portions of the first and second contact electrodes.

[0016] The plurality of light emitting elements may include a first light emitting element and a second light emitting element, wherein both ends of the first light emitting element are in contact with the first contact electrode and the second contact electrode, and the second light emitting element is provided on the first light emitting element and both ends of the second light emitting element are in contact with the first contact electrode and the second contact electrode.

[0017] The display device may further include: a first insulating layer disposed on the first substrate, disposed between the first electrode and the second electrode, and configured to partially cover the first electrode and the second electrode, wherein the plurality of light emitting elements may be disposed on the first insulating layer.

[0018] The display device may further include: a second insulating layer disposed on the first substrate to cover the first and second electrodes, the plurality of light emitting elements, and the first and second contact electrodes.

[0019] The second insulating layer may directly contact portions of outer surfaces of the plurality of light emitting elements, the portions being spaced apart from the first contact electrode and the second contact electrode.

[0020] The display device may further include: a second bank disposed on the first substrate to surround a region where the plurality of light emitting elements are disposed, wherein a second insulating layer may also be disposed on the second bank.

[0021] According to a disclosed embodiment, a method for manufacturing a display device includes: preparing a target substrate and a first electrode and a second electrode disposed on the target substrate; ejecting an ink including a plurality of light-emitting elements, liquid crystal molecules, and a conductive polymer onto the target substrate; and forming a plurality of contact electrodes disposed on the first electrode and the second electrode by generating an electric field on the target substrate to orient the liquid crystal molecules and the plurality of light-emitting elements and to solidify the conductive polymer.

[0022] The plurality of light emitting elements and liquid crystal molecules may extend in one direction, and the step of forming the plurality of contact electrodes may include orienting the plurality of light emitting elements and liquid crystal molecules so that the direction in which the plurality of light emitting elements and liquid crystal molecules extend is parallel to the top surface of the target substrate.

[0023] The liquid crystal molecules may have positive dielectric anisotropy.

[0024] The conductive polymer can be oriented by an electric field so that its main chain portion is oriented in one direction and aggregated on the first electrode and the second electrode, and a plurality of light emitting elements can be fixed by the conductive polymer in such a manner that both ends thereof are oriented in one direction.

[0025] The conductive polymer may include PEDOT:PSS.

[0026] The step of curing the conductive polymer may be performed by applying light with a plurality of light emitting elements and liquid crystal molecules aligned in one direction.

[0027] The plurality of light emitting elements may include a first light emitting element and a second light emitting element, both ends of the first light emitting element being disposed on the first electrode and the second electrode, and the second light emitting element being disposed on the first light emitting element and both ends of the second light emitting element being disposed on the first electrode and the second electrode.

[0028] The plurality of contact electrodes may include a first contact electrode contacting the first ends of the plurality of light emitting elements and the first electrode, and a second contact electrode contacting the second ends of the plurality of light emitting elements and the second electrode and spaced apart from the first contact electrode.

[0029] Details of other embodiments are included in the detailed description and accompanying drawings.

[0030] Beneficial effects

[0031] According to an embodiment, a display device may include a contact electrode electrically connected to a plurality of electrodes and a light-emitting element and including a conductive polymer. The contact electrode may be formed of a transparent conductive material (e.g., a polymer), and light emitted from the light-emitting element may pass through the contact electrode and be reflected by the electrode, thereby emitting light emitted from the light-emitting element in an upward direction of the substrate.

[0032] Furthermore, a method for manufacturing a display device includes spraying ink containing dispersed liquid crystal molecules and a conductive polymer onto electrodes, and aligning light-emitting elements by generating an electric field on the electrodes. The light-emitting elements can be aligned in the ink along with the liquid crystal molecules, and the conductive polymer can secure the light-emitting elements. Consequently, the number of manufacturing processes for the display device can be reduced, and the alignment of the light-emitting elements can be further improved.

[0033] The effects according to the embodiment are not limited to the above-exemplified contents, and more various effects are included in the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a plan view of a display device according to a disclosed embodiment.

[0035] Figure 2 is a plan view of a pixel of a display device according to a disclosed embodiment.

[0036] Figure 3 It is along Figure 2 Cross-sectional views taken along lines IIIa-IIIa', IIIb-IIIb' and IIIc-IIIc'.

[0037] Figure 4 yes Figure 3 An enlarged cross-sectional view of portion A.

[0038] Figure 5 is a schematic diagram of a light emitting element according to a disclosed embodiment.

[0039] Figure 6 is a flowchart illustrating a method of manufacturing a display device according to a disclosed embodiment.

[0040] Figures 7 to 12 is a cross-sectional view illustrating a method of manufacturing a display device according to a disclosed embodiment.

[0041] Figure 13 FIG. 4 is a plan view of a sub-pixel of a display device according to another disclosed embodiment.

[0042] Figure 14 FIG. 4 is a plan view of a sub-pixel of a display device according to another disclosed embodiment.

[0043] Figure 15 FIG. 4 is a plan view of a sub-pixel of a display device according to another disclosed embodiment.

[0044] Figure 16 It is along Figure 15 A cross-sectional view taken along line VI-VI'.

[0045] Figure 17 FIG. 4 is a plan view of a sub-pixel of a display device according to another disclosed embodiment.

[0046] Figure 18 It is along Figure 17 A sectional view taken along line VIII-VIII'.

[0047] Figure 19 FIG. 4 is a plan view of a sub-pixel of a display device according to another disclosed embodiment.

[0048] Figure 20 FIG. 4 is a plan view of a sub-pixel of a display device according to another disclosed embodiment. DETAILED DESCRIPTION

[0049] 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 can be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0050] 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. Like reference numerals refer to like components throughout the specification.

[0051] It will be understood that although the terms "first," "second," etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, the first element discussed below can be referred to as the second element without departing from the teachings of the invention. Similarly, the second element can also be referred to as the first element.

[0052] Hereinafter, embodiments will be described with reference to the accompanying drawings.

[0053] Figure 1 is a plan view of a display device according to a disclosed embodiment.

[0054] Reference Figure 1 The display device 10 displays a moving image or a still image. The display device 10 may refer to almost any type of electronic device that provides a display image. Examples of the display device 10 may include a television (TV), a notebook computer, a monitor, a billboard, an Internet of Things (IoT) device, a mobile phone, a smartphone, a tablet personal computer (PC), an electronic watch, a smartwatch, a watch phone, a head-mounted display (HMD), a mobile communication terminal, an electronic notepad, an electronic book (e-book), a portable multimedia player (PMP), a navigation device, a game console, a digital camera, a video camera, and the like.

[0055] The display device 10 includes a display panel that provides a display image. Examples of the display panel of the display device 10 include an inorganic light-emitting diode (ILED) display panel, an organic light-emitting diode (OLED) display panel, a quantum dot light-emitting diode (QLED) display panel, a plasma display panel (PDP), a field emission display (FED) panel, and the like. The display panel of the display device 10 will be described below as, for example, an ILED display panel, but the disclosure is not limited thereto. That is, various other display panels are also applicable to the display panel of the display device 10.

[0056] The shape of the display device 10 may vary. For example, the display device 10 may have a square shape, a quadrilateral shape with rounded corners, a non-quadrilateral polygonal shape, a circular shape, a rectangular shape that extends longer in the horizontal direction than in the vertical direction, or a rectangular shape that extends longer in the vertical direction than in the horizontal direction. The shape of the display area DPA of the display device 10 may be similar to the shape of the display device 10. Figure 1 It is shown that both the display device 10 and the display area DPA have a rectangular shape extending relatively long in the horizontal direction.

[0057] 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 an image is displayed, and the non-display area NDA may be an area where no image is 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 an inactive area. The display area DPA may occupy a central portion of the display device 10.

[0058] The display area DPA may include a plurality of pixels PX. The pixels PX may be arranged in a row direction and a column direction. Each of the pixels PX may have a rectangular shape or a square shape in a plan view, but the disclosure is not limited thereto. Alternatively, each of the pixels PX may have a diamond shape having sides inclined relative to a specific direction. The pixels PX may be arranged in a stripe manner or a column direction. Each of the pixels PX may include one or more light emitting elements 30 that emit light in a specific wavelength range.

[0059] The non-display area NDA may be disposed around the display area DPA. The non-display area NDA may surround the entire display area DPA or a portion of the display area DPA. The display area DPA may have a rectangular shape, 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 line or circuit driver included in the display device 10 may be disposed in the non-display area NDA, or an external device may be installed in the non-display area NDA.

[0060] Figure 2 is a plan view of a pixel of a display device according to a disclosed embodiment.

[0061] Reference Figure 2 , each of the plurality of pixels PX may include a plurality of sub-pixels PXn (where n is an integer from 1 to 3). For example, a 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. The first color light, the second color light, and the third color light may be blue light, green light, and red light, respectively, but the disclosure is not limited thereto. Alternatively, the sub-pixels PXn may all emit light of the same color. Figure 2 It is shown that the pixel PX may include three sub-pixels PXn, but the disclosure is not limited thereto. Alternatively, the pixel PX may include more than three sub-pixels PXn.

[0062] The sub-pixels PXn may include an area defined as an emission area EMA. The first sub-pixel PX1 may include a first emission area EMA1, the second sub-pixel PX2 may include a second emission area EMA2, and the third sub-pixel PX3 may include a third emission area EMA3. Each of the emission areas EMA may be defined as an area in which the light emitting element 30 is disposed to emit light of a specific wavelength band. The light emitting element 30 may include an active layer ( Figure 5 The active layer 36 can emit light of a specific wavelength band without any directionality. The light emitted by the active layer 36 of the light-emitting element 30 can be emitted from both sides of each of the light-emitting elements 30. Each of the emission areas EMA includes an area where the light-emitting element 30 is provided, and may also include an area around the light-emitting element 30 that outputs the light emitted by the light-emitting element 30.

[0063] However, the disclosure is not limited thereto. Each of the emission areas EMA may include an area that outputs light emitted by the light emitting element 30 and then reflected or refracted from other elements. The light emitting element 30 may be provided in each of the sub-pixels PXn, and the area provided with the light emitting element 30 and the surrounding area of ​​the light emitting element 30 may form the emission area EMA.

[0064] Although not specifically shown, each of the sub-pixels PXn of the display device 10 may include a non-emission region defined as a region other than the emission region EMA. The non-emission region may be a region where the light emitting element 30 is not provided and may not output light because light emitted by the light emitting element 30 does not reach it.

[0065] Figure 3 It is along Figure 2Cross-sectional views taken along lines IIIa-IIIa', IIIb-IIIb' and IIIc-IIIc'. Figure 3 Shown Figure 2 However, it can also be directly applied to other pixels PX or other sub-pixels PXn. Figure 3 A cross-sectional view taken from one end to the other end of the light emitting element 30 in the first sub-pixel PX1 is shown.

[0066] Reference Figure 3 And further refer to Figure 2 The display device 10 may include a circuit element layer and a display element layer disposed on a first substrate 11. A semiconductor layer, a plurality of conductive layers, and a plurality of insulating layers may be disposed on the first substrate 11, and may form a circuit element layer and a display element layer. The conductive layer may include a first gate conductive layer, a second gate conductive layer, a first data conductive layer, a second data conductive layer, electrodes 21 and 22, and contact electrodes 26 and 27. The insulating layer may include a buffer layer 12, a first gate insulating layer 13, a first passivation layer 15, a first interlayer insulating layer 17, a second interlayer insulating layer 18, a first planarizing layer 19, a first insulating layer 51, and a second insulating layer 52.

[0067] Specifically, the first substrate 11 may be an insulating substrate. The first substrate 11 may be formed of an insulating material such as glass, quartz, or polymer resin. The first substrate 11 may be a rigid substrate, or may be a flexible substrate that is bendable, foldable, or rollable.

[0068] Light-blocking layers BML1 and BML2 may be disposed on the first substrate 11. The light-blocking layers BML1 and BML2 may include a first light-blocking layer BML1 and a second light-blocking layer BML2. The first light-blocking layer BML1 and the second light-blocking layer BML2 may be disposed so as to overlap at least the first active material layer DT_ACT of the drive transistor DT and the second active material layer ST_ACT of the switching transistor ST, respectively. The light-blocking layers BML1 and BML2 may include a material capable of blocking light and may prevent light from being incident on the first active material layer DT_ACT and the second active material layer ST_ACT. For example, the first light-blocking layer BML1 and the second light-blocking layer BML2 may be formed of an opaque metal material capable of blocking the transmission of light. However, the present disclosure is not limited thereto; alternatively, the light-blocking layers BML1 and BML2 may not be provided.

[0069] The buffer layer 12 may include light blocking layers BML1 and BML2 and may be provided on the entire surface of the first substrate 11. The buffer layer 12 may be formed on the first substrate 11 to protect the driving transistor DT and the switching transistor ST from moisture that may penetrate the first substrate 11 that is susceptible to moisture, and may perform a surface planarization function. The buffer layer 12 may include a plurality of inorganic layers stacked alternately. For example, the buffer layer 12 may be formed to include silicon oxide (SiO x ), silicon nitride (SiN x ) and silicon oxynitride (SiON) in a multilayer in which inorganic layers of at least one of the above-mentioned materials are alternately stacked.

[0070] The semiconductor layer is disposed on the buffer layer 12. The semiconductor layer may include a first active material layer DT_ACT of the driving transistor DT and a second active material layer ST_ACT of the switching transistor ST. The first active material layer DT_ACT of the driving transistor DT and the second active material layer ST_ACT of the switching transistor ST may be disposed to partially overlap the gate electrodes DT_G and ST_G of the first gate conductive layer.

[0071] In one embodiment, the semiconductor layer may include polycrystalline silicon, single crystal silicon, or an oxide semiconductor. Here, polycrystalline silicon may be formed by crystallizing amorphous silicon. When the semiconductor layer includes polycrystalline silicon, the first active material layer DT_ACT may include a first doped region DT_ACTa, a second doped region DT_ACTb, and a first channel region DT_ACTc. The first channel region DT_ACTc may be disposed between the first doped region DT_ACTa and the second doped region DT_ACTb. The second active material layer ST_ACT may include a third doped region ST_ACTa, a fourth doped region ST_ACTb, and a second channel region ST_ACTc. The second channel region ST_ACTc may be disposed between the third doped region ST_ACTa and the fourth doped region ST_ACTb. The first doped region DT_ACTa, the second doped region DT_ACTb, the third doped region ST_ACTa, and the fourth doped region ST_ACTb may be portions of the first active material layer DT_ACT or the second active material layer ST_ACT doped with impurities.

[0072] In another embodiment, the first active material layer DT_ACT and the second active material layer ST_ACT may include an oxide semiconductor. In this case, the doped region of each of the first active material layer DT_ACT and the second active material layer ST_ACT may be a conductor region. The oxide semiconductor may be an oxide semiconductor containing indium (In). In some embodiments, the oxide semiconductor may be indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium oxide (IGO), indium zinc tin oxide (IZTO), indium gallium tin oxide (IGTO), or indium gallium zinc tin oxide (IGZTO), but the disclosure is not limited thereto.

[0073] The first gate insulating layer 13 is provided on the semiconductor layer and the buffer layer 12. The first gate insulating layer 13 may be provided on the buffer layer 12 and on the semiconductor layer. The first gate insulating layer 13 may be used as a gate insulating film for the driving transistor DT and the switching transistor ST. The first gate insulating layer 13 may be formed to include an inorganic material (such as SiO x 、SiN x or SiON as an example), or is formed as a stack of these inorganic materials.

[0074] A first gate conductive layer is disposed on the first gate insulating layer 13. The first gate conductive layer may include a first gate electrode DT_G of the drive transistor DT and a second gate electrode ST_G of the switch transistor ST. The first gate electrode DT_G may be disposed so as to overlap the first channel region DT_ACTc of the first active material layer DT_ACT in the thickness direction, and the second gate electrode ST_G may be disposed so as to overlap the second channel region ST_ACTc of the second active material layer ST_ACT in the thickness direction.

[0075] The first gate conductive layer may be formed as a single layer or multiple layers including one of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), copper (Cu), and alloys thereof, but the disclosure is not limited thereto.

[0076] The first passivation layer 15 is provided on the first gate conductive layer. The first passivation layer 15 may be provided to cover and protect the first gate conductive layer. The first passivation layer 15 may be formed to include an inorganic material (such as SiO x 、SiN x or SiON as an example), or is formed as a stack of these inorganic materials.

[0077] The second gate conductive layer is disposed on the first passivation layer 15. The second gate conductive layer may include a first capacitor electrode CE1 of the storage capacitor, which is disposed to at least partially overlap the first gate electrode DT_G in the thickness direction. The first capacitor electrode CE1 may overlap the first gate electrode DT_G in the thickness direction, with the first passivation layer 15 interposed between the first capacitor electrode CE1 and the first gate electrode DT_G. The storage capacitor may be formed by the first capacitor electrode CE1 and the first gate electrode DT_G. The second gate conductive layer may be formed as a single layer or multiple layers including one of Mo, Al, Cr, Au, Ti, Ni, Nd, Cu, and alloys thereof, but the disclosure is not limited thereto.

[0078] The first interlayer insulating layer 17 is provided on the second gate conductive layer. The first interlayer insulating layer 17 may be used as an insulating film between the second gate conductive layer and a layer provided on the second gate conductive layer. The first interlayer insulating layer 17 may be formed to include an inorganic material (such as SiO x 、SiN x or SiON as an example), or is formed as a stack of these inorganic materials.

[0079] A first data conductive layer is disposed on the first interlayer insulating layer 17. The first data conductive layer may include first and second source / drain electrodes DT_SD1 and DT_SD2 of the driving transistor DT and first and second source / drain electrodes ST_SD1 and ST_SD2 of the switching transistor ST.

[0080] The first source / drain electrode DT_SD1 and the second source / drain electrode DT_SD2 of the driving transistor DT may contact the first doped region DT_ACTa and the second doped region DT_ACTb of the first active material layer DT_ACT through contact holes penetrating the first interlayer insulating layer 17, the first passivation layer 15, and the first gate insulating layer 13. The first source / drain electrode ST_SD1 and the second source / drain electrode ST_SD2 of the switching transistor ST may contact the third doped region ST_ACTa and the fourth doped region ST_ACTb of the second active material layer ST_ACT through contact holes penetrating the first interlayer insulating layer 17, the first passivation layer 15, and the first gate insulating layer 13. The first source / drain electrode DT_SD1 of the driving transistor DT and the first source / drain electrode ST_SD1 of the switching transistor ST may be electrically connected to the first light-blocking layer BML1 and the second light-blocking layer BML2, respectively, through other contact holes. If one of the first source / drain electrode DT_SD1 and the second source / drain electrode DT_SD2 of the driving transistor DT or one of the first source / drain electrode ST_SD1 and the second source / drain electrode ST_SD2 of the switching transistor ST is a source electrode, the other source / drain electrode may be a drain electrode, but the disclosure is not limited thereto. Alternatively, if one of the first source / drain electrode DT_SD1 and the second source / drain electrode DT_SD2 of the driving transistor DT or one of the first source / drain electrode ST_SD1 and the second source / drain electrode ST_SD2 of the switching transistor ST is a drain electrode, the other source / drain electrode may be a source electrode.

[0081] The first data conductive layer may be formed as a single layer or a multilayer including one of Mo, Al, Cr, Au, Ti, Ni, Nd, Cu, and alloys thereof, but the disclosure is not limited thereto.

[0082] The second interlayer insulating layer 18 is provided on the first data conductive layer. The second interlayer insulating layer 18 may be provided on the entire surface of the first interlayer insulating layer 17, cover the first data conductive layer, and protect the first data conductive layer. The second interlayer insulating layer 18 may be formed to include an inorganic material (such as SiO x 、SiN x or SiON as an example), or is formed as a stack of these inorganic materials.

[0083] The second data conductive layer is disposed on the second interlayer insulating layer 18. The second data conductive layer may include a first voltage line VL1, a second voltage line VL2, and a first conductive pattern CDP. A high potential voltage (or a first power supply voltage) supplied to the driving transistor DT may be applied to the first voltage line 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 line VL2. During the manufacture of the display device 10, an alignment signal for aligning the light-emitting element 30 may be applied to the second voltage line VL2.

[0084] The first conductive pattern CDP can be electrically connected to the first source / drain electrode DT_SD1 of the drive transistor DT via a contact hole formed in the second interlayer insulating layer 18. The first conductive pattern CDP can contact the first electrode 21, which will be described later. The drive transistor DT can transmit a first power supply voltage from the first voltage line VL1 to the first electrode 21 via the first conductive pattern CDP. The second data conductive layer is shown as including one second voltage line VL2 and one first voltage line VL1, but the disclosure is not limited thereto. Alternatively, the second data conductive layer may include more than one first voltage line VL1 and more than one second voltage line VL2.

[0085] The second data conductive layer may be formed as a single layer or a multilayer including one of Mo, Al, Cr, Au, Ti, Ni, Nd, Cu, and alloys thereof, but the disclosure is not limited thereto.

[0086] The first planarization layer 19 is disposed on the second data conductive layer. The first planarization layer 19 may include an organic insulating material (specifically, an organic material such as polyimide (PI) as an example), and may perform a surface planarization function.

[0087] A plurality of first banks 40, a plurality of electrodes 21 and 22, a light emitting element 30, a second bank 45, and a plurality of contact electrodes 26 and 27 are disposed on the first planarization layer 19. A plurality of insulating layers 51 and 52 may be further disposed on the first planarization layer 19.

[0088] The first dam 40 may be directly disposed on the first planarization layer 19. The first dam 40 may extend in the second direction DR2 in each of the sub-pixels PXn and may be spaced apart and terminated at a boundary with an adjacent sub-pixel PXn in the second direction DR2 without extending into other sub-pixels PXn. Furthermore, the first dams 40 may be disposed spaced apart from each other in the first direction DR1 and facing each other. The first dams 40 may be spaced apart from each other to form an area in which the light-emitting element 30 is arranged between the first dams 40. The first dam 40 may be disposed in each of the sub-pixels PXn to form a linear pattern in the display area DPA of the display device 10. Figure 3Two first banks 40 are shown, but the disclosure is not limited thereto. More than two first banks 40 may be provided depending on the number of electrodes 21 and 22 to be described later.

[0089] The first bank 40 may at least partially protrude from the top surface of the first planarization layer 19. In one embodiment, the middle portion of the first bank 40 may be thicker than the rest of the first bank 40. The middle portion of the protruding portion of the first bank 40 may be relatively thick, and each of the protruding portions of the first bank 40 may have inclined side surfaces. Light emitted by the light-emitting element 30 may travel toward the inclined side surfaces of each of the first banks 40. The electrodes 21 and 22 disposed on the first bank 40 may include a material having a high reflectivity, and the light emitted by the light-emitting element 30 may be reflected by the electrodes 21 and 22 on the side surfaces of the first bank 40 to be emitted upwardly toward the first planarization layer 19. In other words, the first bank 40 not only provides a space for arranging the light-emitting element 30, but also serves as a reflective partition wall capable of reflecting light emitted by the light-emitting element 30 in an upward direction. The side surfaces of each of the first banks 40 may be linearly inclined, but the disclosure is not limited thereto. Alternatively, the side surfaces of each of the first banks 40 may have a curved semicircular or semi-elliptical shape. In one embodiment, the first bank 40 may include an organic insulating material (such as PI), but the disclosure is not limited thereto.

[0090] The electrodes 21 and 22 are disposed on the first bank 40 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 disposed to be spaced apart from and face each other in the first direction DR1. The first electrode 21 and the second electrode 22 may have a substantially similar shape to the first bank 40 and may be longer than the first bank 40 in the second direction DR2.

[0091] The first electrode 21 may extend in the second direction DR2 in each of the sub-pixels PXn and may be spaced apart from another first electrode 21 at a boundary between two adjacent sub-pixels PXn in the second direction DR2. In some embodiments, a second bank 45 may be provided along the boundary of each of the sub-pixels PXn, and the first electrodes 21 of each pair of adjacent sub-pixels PXn in the second direction DR2 may be spaced apart from each other by the second bank 45. The first electrode 21 may be electrically connected to the drive transistor DT. For example, at least a portion of the first electrode 21 may be provided to overlap with a portion of the second bank 45 extending in the first direction DR1 and may contact the first conductive pattern CDP via a first contact hole CT1 penetrating the first planarization layer 19. The first electrode 21 may be electrically connected to the first source / drain electrode DT_SD1 of the drive transistor DT via the first conductive pattern CDP.

[0092] The second electrode 22 may extend in the second direction DR2 beyond the boundary between adjacent sub-pixels PXn in the second direction DR2. In some embodiments, one second electrode 22 may be provided in a plurality of adjacent sub-pixels PXn in the second direction DR2. The second electrode 22 may partially overlap the second bank 45 at the boundary between adjacent sub-pixels PXn in the second direction DR2 and may be electrically connected to the second voltage line VL2 via a second contact hole CT2. For example, the second electrode 22 may be provided overlapping a portion of the second bank 45 extending in the first direction DR1 and may contact the second voltage line VL2 via a second contact hole CT2 penetrating the first planarization layer 19. The second electrode 22 is shown as being electrically connected to the second voltage line VL2 via a second contact hole CT2 provided at the boundary of each sub-pixel PXn, but the disclosure is not limited thereto. In some embodiments, one second contact hole CT2 may be provided in each sub-pixel PXn.

[0093] Each of the sub-pixels PXn is shown as including a first electrode 21 and a second electrode 22, but the disclosure is not limited thereto. Optionally, in some embodiments, more than one first electrode 21 and more than one second electrode 22 may be provided in each of the sub-pixels PXn. The first electrode 21 and the second electrode 22 provided in each of the sub-pixels PXn do not have to extend in one direction, but may be arranged in various layouts. For example, the first electrode 21 and the second electrode 22 may be partially bent or curved, and one of the first electrode 21 and the second electrode 22 may be provided to surround the other electrode. If a region in which the light-emitting element 30 is arranged is formed, at least a portion of the first electrode 21 and the second electrode 22 may be spaced apart from each other and face each other, and the structure and shape of the first electrode 21 and the second electrode 22 are not particularly limited.

[0094] 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, and an electrical signal applied to the electrodes 21 and 22 may be transmitted to the light emitting element 30 through the contact electrodes 26 and 27.

[0095] In one embodiment, the first electrode 21 may be separated between multiple sub-pixels PXn, and the second electrode 22 may be connected in common throughout the multiple sub-pixels PXn. One of the first electrode 21 and the second electrode 22 may be electrically connected to the anode of the light-emitting element 30, while the other electrode may be electrically connected to the cathode of the light-emitting element 30. However, the disclosure is not limited to this. Alternatively, one of the first electrode 21 and the second electrode 22 may be electrically connected to the cathode of the light-emitting element 30, while the other electrode may be electrically connected to the anode of the light-emitting element 30. Alternatively, both the first electrode 21 and the second electrode 22 may be separated between multiple sub-pixels PXn.

[0096] The electrodes 21 and 22 can be used to generate an electric field in each of the sub-pixels PXn to align the light-emitting element 30. The light-emitting element 30 can be disposed 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. As will be described later, the light-emitting element 30 can be ejected onto the first electrode 21 and the second electrode 22 in a state dispersed in ink by inkjet printing, and in response to an alignment signal applied between the first electrode 21 and the second electrode 22, the light-emitting element 30 can be aligned between the first electrode 21 and the second electrode 22 by applying an electrophoretic force.

[0097] like Figure 3 As shown in FIG, the first electrode 21 and the second electrode 22 may be disposed on the first bank 40. The first electrode 21 and the second electrode 22 may be spaced apart from each other in the first direction DR1 and face each other, and a plurality of light emitting elements 30 may be disposed between the first electrode 21 and the second electrode 22. The light emitting element 30 may be disposed between the first electrode 21 and the second electrode 22 and electrically connected to the first electrode 21 and the second electrode 22 at the same time.

[0098] In some embodiments, the first electrode 21 and the second electrode 22 may be formed to have a greater width than the first bank 40. For example, the first electrode 21 and the second electrode 22 may be disposed to cover the outer surface of the first bank 40. The first electrode 21 and the second electrode 22 may be disposed on the side of the first bank 40, and the distance between the first electrode 21 and the second electrode 22 may be smaller than the distance between the first banks 40. In addition, at least portions of the first electrode 21 and the second electrode 22 may be disposed directly on the first planarization layer 19.

[0099] The electrodes 21 and 22 may include a transparent conductive material. For example, the electrodes 21 and 22 may include a material such as ITO, IZO, or ITZO, but the disclosure is not limited thereto. In some embodiments, the electrodes 21 and 22 may include a conductive material having a high reflectivity. For example, the electrodes 21 and 22 may include a material having a high reflectivity such as silver (Ag), copper (Cu), or aluminum (Al). In this example, the electrodes 21 and 22 may reflect the light emitted by the light emitting element 30 to travel toward the side of the first bank 40 in an upward direction of each of the sub-pixels PXn.

[0100] However, the disclosure is not limited thereto. Alternatively, the electrodes 21 and 22 may have a stack of one or more layers of a transparent conductive material and one or more layers of a high-reflectivity metal, or may be formed as a single layer including a transparent conductive material and a metal having a high reflectivity. In one embodiment, the electrodes 21 and 22 may have a stack of ITO / Ag / ITO, ITO / Ag / IZO, or ITO / Ag / ITZO / IZO, or may include an alloy of aluminum (Al), nickel (Ni), or lanthanum (La).

[0101] The first insulating layer 51 is provided on the first planarization layer 19, the first electrode 21, and the second electrode 22. The first insulating layer 51 may be provided to cover not only the first electrode 21 and the second electrode 22, but also the gap between the first electrode 21 and the second electrode 22. For example, the first insulating layer 51 may cover most of the top surfaces of the first electrode 21 and the second electrode 22, and may be provided to expose portions of the first electrode 21 and the second electrode 22. The first insulating layer 51 may be provided to expose portions of the top surfaces of the first electrode 21 and the second electrode 22, for example, on the first bank 40. The first insulating layer 51 may be formed on substantially the entire surface of the first planarization layer 19, and may include an opening (not shown) that partially exposes the first electrode 21 and the second electrode 22.

[0102] In one embodiment, the first insulating layer 51 may be stepped so that a portion of the top surface of the first insulating layer 51 may be recessed between the first electrode 21 and the second electrode 22. In some embodiments, the first insulating layer 51 may include an inorganic insulating material, and a portion of the top surface of the first insulating layer 51 provided to cover the first electrode 21 and the second electrode 22 may be recessed due to a height difference formed by the underlying elements. The light-emitting element 30 provided on the first insulating layer 51 between the first electrode 21 and the second electrode 22 may form an empty space with the recessed portion of the top surface of the first insulating layer 51. The light-emitting element 30 may be provided to be spaced apart from the top surface of the first insulating layer 51, and the space between the first insulating layer 51 and the light-emitting element 30 may be filled with a material of the contact electrodes 26 and 27 to be described later. However, the disclosure is not limited thereto. The first insulating layer 51 may form a flat surface on which the light-emitting element 30 is arranged.

[0103] The first insulating layer 51 can protect the first electrode 21 and the second electrode 22 and can insulate the first electrode 21 and the second electrode 22 from each other. In addition, the first insulating layer 51 can prevent the light-emitting element 30 disposed on the first insulating layer 51 from directly contacting other elements and being damaged by other elements. However, the shape and structure of the first insulating layer 51 are not particularly limited.

[0104] The second bank 45 may be disposed on the first insulating layer 51. In some embodiments, the second bank 45 may surround not only the region where the first bank 40 is disposed, but also the region where the light-emitting element 30 is disposed on the first insulating layer 51, and may be arranged along the boundary between sub-pixels PXn. The second bank 45 may be disposed to extend in the first direction DR1 and the second direction DR2, and thus may form a grid pattern across the entire surface of the display area DPA. The portion of the second bank 45 extending in the first direction DR1 may partially overlap the first and second electrodes 21 and 22, and the portion of the second bank 45 extending in the second direction DR2 may be spaced apart from the first bank 40 and the first and second electrodes 21 and 22.

[0105] The height of the second bank 45 can be greater than that of the first bank 40. Unlike the first bank 40, the second bank 45 can define adjacent sub-pixels PXn and can prevent ink from overflowing between adjacent sub-pixels PXn during inkjet printing for aligning the alignment light-emitting elements 30 during the manufacture of the display device 10. The second bank 45 can separate inks of groups having different light-emitting elements 30 without mixing them together. Similar to the first bank 40, the second bank 45 can include PI, but the disclosure is not limited thereto.

[0106] The light-emitting elements 30 may be disposed between the electrodes 21 and 22. In one embodiment, the light-emitting elements 30 may extend in one direction and may be disposed so as to be spaced apart from each other and aligned substantially parallel to each other. The distance between the light-emitting elements 30 is not particularly limited. Some of the light-emitting elements 30 may be disposed adjacent to each other to form a group, while some of the light-emitting elements 30 may be spaced apart from each other by a predetermined distance to form another group. Alternatively, the light-emitting elements 30 may be arranged at an uneven density. In addition, the direction along which the electrodes 21 and 22 extend may form a substantially right angle with the direction along which the light-emitting elements 30 extend. However, the disclosure is not limited thereto. Alternatively, the light-emitting elements 30 may extend obliquely relative to the direction along which the electrodes 21 and 22 extend.

[0107] The light emitting element 30 may include an active layer ( Figure 5 ” 36 ”), and thus can emit light of different wavelength bands to the outside. The display device 10 may include a light-emitting element 30 capable of emitting light of different wavelength bands. For example, the light-emitting element 30 of the first sub-pixel PX1 may include an active layer 36 that emits a first color light having a first wavelength as a center wavelength, the light-emitting element 30 of the second sub-pixel PX2 may include an active layer 36 that emits a second color light having a second wavelength as a center wavelength, and the light-emitting element 30 of the third sub-pixel PX3 may include an active layer 36 that emits a third color light having a third wavelength as a center wavelength.

[0108] Thus, the first subpixel PX1, the second subpixel PX2, and the third subpixel PX3 can emit a first color light, a second color light, and a third color light, respectively. In some embodiments, the first color light can be blue light having a center wavelength of 450 nm to 495 nm, the second color light can be green light having a center wavelength of 495 nm to 570 nm, and the third color light can be red light having a center wavelength of 620 nm to 752 nm. However, the disclosure is not limited thereto. Alternatively, the first subpixel PX1, the second subpixel PX2, and the third subpixel PX3 can include the same type of light-emitting element 30 and thus can all emit light of the same color.

[0109] The light-emitting elements 30 may be disposed on the first insulating layer 51 between the first banks 40 or between the electrodes 21 and 22. For example, at least one end of each of the light-emitting elements 30 may be disposed on the first electrode 21 or the second electrode 22. The length of the light-emitting element 30 may be greater than the distance between the first electrode 21 and the second electrode 22, and both ends of each of the light-emitting elements 30 may be disposed on the first electrode 21 and the second electrode 22. However, the disclosure is not limited thereto. Alternatively, only one end of each of the light-emitting elements 30 may be disposed on the electrodes 21 and 22, or both ends of each of the light-emitting elements 30 may not be disposed on the electrodes 21 and 22. Even if the light-emitting elements 30 are not disposed on the electrodes 21 and 22, both ends of each of the light-emitting elements 30 may be electrically connected to the electrodes 21 and 22 via the contact electrodes 26 and 27, which will be described later. In some embodiments, at least a portion of the light-emitting element 30 may be disposed between the first electrode 21 and the second electrode 22, and both ends of each of the light-emitting elements 30 may be electrically connected to the electrodes 21 and 22.

[0110] In addition, although not specifically shown, at least some of the light emitting elements 30 provided in each of the subpixels PXn may be provided in a region other than the region formed between the first embankments 40 (e.g., on the electrodes 21 and 22 or between the first embankment 40 and the second embankment 45).

[0111] In each of the light-emitting elements 30, a plurality of layers may be arranged in a direction perpendicular to the top surface of the first substrate 11 or the first planarization layer 19. The light-emitting element 30 may extend in one direction and may have a structure in which a plurality of semiconductor layers are sequentially arranged. The light-emitting element 30 may be arranged so that the direction in which the light-emitting element 30 of the display device 10 extends may be parallel to the first planarization layer 19, and the semiconductor layers included in each of the light-emitting elements 30 may be sequentially arranged in a direction parallel to the top surface of the first planarization layer 19. However, the disclosure is not limited thereto. In the case where the light-emitting element 30 may have a different structure, the layers of each of the light-emitting elements 30 may be arranged in a direction perpendicular to the first planarization layer 19.

[0112] In addition, both end portions of each of the light emitting elements 30 may be in contact with the contact electrodes 26 and 27. Since no insulating film ( Figure 538 ), and some of the semiconductor layer of each of the light-emitting elements 30 is exposed on both end surfaces in the extension direction of each of the light-emitting elements 30. Therefore, the exposed semiconductor layer can be in contact with the contact electrodes 26 and 27, but the disclosure is not limited to this. At least a portion of the insulating film 38 of each of the light-emitting elements 30 can be removed, and the side surfaces of the semiconductor layer of each of the light-emitting elements 30 can be partially exposed. The exposed side surfaces of the semiconductor layer of each of the light-emitting elements 30 can be in direct contact with the contact electrodes 26 and 27.

[0113] Contact electrodes 26 and 27 are provided on the electrodes 21 and 22 and the light emitting element 30. The contact electrodes 26 and 27 may include a first contact electrode 26 provided on the first electrode 21 and in contact with a first end portion of the light emitting element 30, and a second contact electrode 27 provided on the second electrode 22 and in contact with a second end portion of the light emitting element 30.

[0114] The first contact electrode 26 and the second contact electrode 27 may have a shape similar to the first bank 40. For example, the first contact electrode 26 and the second contact electrode 27 may extend in the second direction DR2 in each of the sub-pixels PXn and may be arranged to be spaced apart from each other and face each other in the first direction DR1. The first contact electrode 26 and the second contact electrode 27 may be spaced apart from each other and face each other in the region where the light-emitting element 30 is provided (for example, between the first electrode 21 and the second electrode 22). The contact electrodes 26 and 27 may be provided in each region surrounded by the second bank 45 so as to be spaced apart from the boundary between adjacent sub-pixels PXn. In some embodiments, the contact electrodes 26 and 27 may form a linear pattern in each of the sub-pixels PXn.

[0115] The first contact electrode 26 and the second contact electrode 27 may contact portions of the top surfaces of the first electrode 21 and the second electrode 22 that are exposed due to the absence of the first insulating layer 51 thereon. Furthermore, the contact electrodes 26 and 27 may contact both ends of each of the light-emitting elements 30. In some embodiments, the contact electrodes 26 and 27 may include a conductive material, and the light-emitting element 30 may be electrically connected to the electrodes 21 and 22 through the contact electrodes 26 and 27. As described above, the plurality of semiconductor layers may be partially exposed at both ends of each light-emitting element 30, and the contact electrodes 26 and 27 may be in direct contact with the exposed semiconductor layers. The first contact electrode 26 and the second contact electrode 27 may extend in the second direction DR2 and may be disposed around a portion of the outer surface of the light-emitting element 30 disposed between the electrodes 21 and 22.

[0116] In some embodiments, the width of the first contact electrode 26 and the second contact electrode 27 may be the same as or greater than the width of the first electrode 21 and the second electrode 22. The first contact electrode 26 and the second contact electrode 27 may be in contact with the first end portion and the second end portion of each of the light emitting elements 30, respectively, and may be disposed to cover both sides of each of the first electrode 21 and the second electrode 22. As described above, portions of the top surfaces of the first electrode 21 and the second electrode 22 may be exposed, and the first contact electrode 26 and the second contact electrode 27 may be in contact with the exposed portions of the top surfaces of the first electrode 21 and the second electrode 22. For example, the contact electrodes 26 and 27 may be in contact with portions of the first electrode 21 and the second electrode 22 on the first bank 40. In addition, as described above, Figure 3 As shown in FIG, at least portions of the first contact electrode 26 and the second contact electrode 27 may be disposed on the first insulating layer 51. However, the disclosure is not limited thereto. The widths of the first contact electrode 26 and the second contact electrode 27 may be smaller than the widths of the first electrode 21 and the second electrode 22, so that the first contact electrode 26 and the second contact electrode 27 may only cover the exposed portions of the top surfaces of the first electrode 21 and the second electrode 22.

[0117] One first contact electrode 26 and one second contact electrode 27 are shown as being provided in one subpixel PXn, but the disclosure is not limited thereto. The number of first and second contact electrodes 26 and 27 may vary depending on the number of first and second electrodes 21 and 22 in each subpixel PXn.

[0118] During the manufacture of the display device 10, after the light-emitting element 30 is arranged on the electrodes 21 and 22, a process may be required to fix the position of the light-emitting element 30. For example, in the case where the contact electrodes 26 and 27 are formed directly on the light-emitting element 30 and the electrodes 21 and 22, the position of the light-emitting element 30 may change during the deposition of the material for the contact electrodes 26 and 27. However, since the position of the light-emitting element 30 is fixed before the contact electrodes 26 and 27 are formed, the electrodes 21 and 22 and the light-emitting element 30 can be properly electrically connected. The contact electrodes 26 and 27 of the display device 10 can include a material that has conductivity and is capable of fixing the position of the light-emitting element 30 during the manufacture of the display device 10.

[0119] Contact electrodes 26 and 27 may include a transparent conductive polymer. When formed from a polymer, contact electrodes 26 and 27 can secure the alignment of light-emitting element 30 during manufacture of display device 10. Furthermore, because the material of contact electrodes 26 and 27 is conductive, they can electrically connect light-emitting element 30 to electrodes 21 and 22. Furthermore, because contact electrodes 26 and 27 include a transparent material, light emitted by light-emitting element 30 can pass through contact electrodes 26 and 27 and be output.

[0120] Examples of conductive polymers include, but are not limited to, polyethylenedioxythiophene (PEDOT), polyethylenedioxythiophene polystyrenesulfonate (PEDOT:PSS), poly(3-alkyl)thiophene (P3AT), poly(3-hexyl)thiophene (P3HT), polyaniline, polyacetylene, polyazulene, polyisothionaphthalene, polyisothionaphthalene, polythiophenylene ethylene, polythiophene, polyphenylene, polyphenylene sulfide, polyparaphenylene, polyparaphenylene ethylene, polyfuran, polypyrrole, and polyheptadiyne. In some embodiments, the conductive polymer included in contact electrodes 26 and 27 may be PEDOT:PSS. PEDOT:PSS includes polymer chains formed by PEDOT and charges formed in the side chain portion of PSS, and thus has conductivity. In addition, since PEDOT:PSS has transparency, contact electrodes 26 and 27 formed of PEDOT:PSS can constitute transparent conductive electrodes such as ITO. Light emitted from both end portions of each of the light emitting elements 30 may pass through the contact electrodes 26 and 27 and be reflected by the electrodes 21 and 22 , and thus may be emitted in an upward direction of the first substrate 11 .

[0121] Contact electrodes 26 and 27 may have a predetermined thickness. If contact electrodes 26 and 27 are thin, the light transmittance of contact electrodes 26 and 27 may be high, but the resistance of contact electrodes 26 and 27 may also be high. Conversely, if the thickness of contact electrodes 26 and 27 is increased in consideration of resistance, the light transmittance of contact electrodes 26 and 27 may be low. In one embodiment, contact electrodes 26 and 27 may have a thickness of 150 nm to 250 nm or approximately 200 nm. In this embodiment, contact electrodes 26 and 27 may have low resistance and high light transmittance.

[0122] Contact electrodes 26 and 27 can be formed by jetting ink comprising a conductive polymer into each of sub-pixels PXn and curing the conductive polymer. The conductive polymer can be dispersed in the ink along with the light-emitting element 30, and when the light-emitting element 30 is aligned between electrodes 21 and 22, the conductive polymer can be collected at both ends of each light-emitting element 30 and on electrodes 21 and 22. The conductive polymer can fix the light-emitting element 30 while in contact with the light-emitting element 30 and electrodes 21 and 22, and can later be cured to form contact electrodes 26 and 27. Because the conductive polymer is dispersed in the ink and then collected to form contact electrodes 26 and 27, contact electrodes 26 and 27 can have uneven thicknesses.

[0123] Figure 4 yes Figure 3 An enlarged cross-sectional view of portion A. Figure 4 A portion of the display device 10 in which the first electrode 21 and the first contact electrode 26 are provided on one of the first banks 40 is shown.

[0124] Reference Figure 4 The thickness of the contact electrodes 26 and 27 may be uneven, and a portion of the contact electrodes 26 and 27 may be thicker than another portion of the contact electrodes 26 and 27. The middle portion of the first bank 40 may be thicker than the rest of the first bank 40, and the contact electrodes 26 and 27 may be disposed so as to overlap at least a portion of the first bank 40 in the thickness direction. Figure 4 The first contact electrode 26 is shown to completely overlap one of the first banks 40 , but the disclosure is not limited thereto.

[0125] First contact electrode 26 may include a first portion, a second portion, and a third portion. The first portion is positioned to overlap the thick portion of first bank 40, the second portion covers the first end portion of light-emitting element 30, and the third portion occupies the remaining portion of first bank 40 and is positioned directly on first electrode 21 on first planarization layer 19. During the manufacture of display device 10, the conductive polymer of contact electrodes 26 and 27 may accumulate on electrodes 21 and 22 and first insulating layer 51 along the protruding outer surface of first bank 40. The conductive polymer may be dispersed in ink, and since the main chain portion of the conductive polymer is aligned in one direction by the electric field formed on electrodes 21 and 22, the conductive polymer may accumulate on electrodes 21 and 22 and light-emitting element 30. Here, due to the height difference formed by electrodes 21 and 22 and light-emitting element 30, the conductive polymer may primarily accumulate at a specific location.

[0126] The thickness d1 of the portion of contact electrodes 26 and 27 disposed to overlap the thick portion of first bank 40 may be greater than the thickness of the remaining portion of contact electrodes 26 and 27. On the thick portion of first bank 40, the portions of electrodes 21 and 22 on which contact electrodes 26 and 27 are disposed may have a maximum height from first planarization layer 19. The conductive polymer may be mainly accumulated in the region where electrodes 21 and 22 have the maximum height, and the thickness d1 of the first portion of contact electrodes 26 and 27 may be greater than the thickness of the remaining portion of contact electrodes 26 and 27.

[0127] Furthermore, contact electrodes 26 and 27 may contact both ends of each of the light-emitting elements 30, and the thickness d2 of the second portion of contact electrodes 26 and 27 may be greater than the thickness d3 of the third portion of contact electrodes 26 and 27. Both ends of each of the light-emitting elements 30 may be disposed on electrodes 21 and 22, and each end of each of the light-emitting elements 30 may be higher than the portion of electrodes 21 and 22 disposed directly on first planarization layer 19. A conductive polymer may be deposited to cover both ends of each of the light-emitting elements 30 and to secure the position of the light-emitting element 30 between electrodes 21 and 22 during manufacture of display device 10. The thickness d2 of the second portion of contact electrodes 26 and 27, which is lower than the first portion of contact electrodes 26 and 27, may be greater than the thickness d3 of the third portion of contact electrodes 26 and 27, which is the lowest portion of contact electrodes 26 and 27. Contact electrodes 26 and 27 may not have a uniform thickness and may have a shape different from the height difference formed by electrodes 21 and 22 and first bank 40.

[0128] In some embodiments, the thickness d2 of the second portions of the contact electrodes 26 and 27 can be greater than the diameter of the light-emitting element 30. The second portions of the contact electrodes 26 and 27 can be thick enough to cover the light-emitting element 30 in a cross-sectional view. Therefore, in some embodiments, the light-emitting element 30 can be arranged to have different heights in a cross-sectional view and overlap each other in the thickness direction between the electrodes 21 and 22. This will be described later.

[0129] In short, the display device 10 may include contact electrodes 26 and 27 containing a conductive polymer, and the contact electrodes 26 and 27 may not have a uniform thickness. During the manufacture of the display device 10, the conductive polymer included in the ink, dispersed in the ink along with the light-emitting element 30, may be formed to have different thicknesses depending on the height of the electrodes 21 and 22 where the conductive polymer will accumulate. Since the conductive polymer accumulates on the electrodes 21 and 22 during the arrangement of the light-emitting element 30 between the electrodes 21 and 22, the conductive polymer can fix the position of the light-emitting element 30, and the display device 10 may not require a separate member for fixing the light-emitting element 30. In addition, during the manufacture of the display device 10, the alignment of the light-emitting element 30 between the electrodes 21 and 22 and the formation of the contact electrodes 26 and 27 can be performed substantially simultaneously, thereby reducing the number of manufacturing processes.

[0130] At the same time, as described above, a portion of the top surface of the first insulating layer 51 may be stepped, and a space may be formed between the top surface of the first insulating layer 51 and the light-emitting element 30. In some embodiments, the conductive polymer of the contact electrodes 26 and 27 may be provided between the bottom surface of the light-emitting element 30 and the first insulating layer 51. As mentioned above, during the formation of the contact electrodes 26 and 27, the light-emitting element 30 and the conductive polymer may be dispersed together in ink, and some of the conductive polymer may be provided to fill the space between the first insulating layer 51 and the light-emitting element 30. As a result, a portion of the bottom surface of the light-emitting element 30 may be in direct contact with the conductive polymer of the contact electrodes 26 and 27. However, the disclosure is not limited thereto.

[0131] Refer again Figure 3 , the second insulating layer 52 may be provided on the entire surface of the first substrate 11. The second insulating layer 52 may protect the elements provided on the first substrate 11 from the external environment. In some embodiments, the second insulating layer 52 may not only directly contact the contact electrodes 26 and 27, the first insulating layer 51, and the second bank 45, but may also directly contact the light emitting element 30 overlapping the gap between the contact electrodes 26 and 27.

[0132] The first insulating layer 51 and the second insulating layer 52 may include an inorganic insulating material or an organic insulating material. In one embodiment, the first insulating layer 51 and the second insulating layer 52 may include an inorganic insulating material or an organic insulating material. x 、SiN x 、SiO x N y, an inorganic insulating material such as aluminum oxide (Al2O3) or aluminum nitride (AlN). In another embodiment, the first insulating layer 51 and the second insulating layer 52 may include an organic insulating material such as acrylic resin, epoxy resin, phenolic resin, polyamide resin, PI resin, unsaturated polyester resin, polyphenylene resin, polyphenylene sulfide resin, benzocyclobutene, cardol resin, siloxane resin, silsesquioxane resin, polymethyl methacrylate, polycarbonate or polymethyl methacrylate-polycarbonate synthetic resin. However, the disclosure is not limited to these embodiments.

[0133] The light emitting element 30 may be an LED, particularly an inorganic LED having a size of several micrometers or nanometers and formed of an inorganic material. The inorganic LED may be aligned between two opposing electrodes that form polarity in response to an electric field generated in a specific direction therebetween.

[0134] Figure 5 is a schematic diagram of a light emitting element according to a disclosed embodiment.

[0135] Reference Figure 5 , the light emitting element 30 may extend in one direction. The light emitting element 30 may have a rod-like shape, a wire-like shape, or a tube-like shape. In one embodiment, the light emitting element 30 may have a cylindrical or rod-like shape. However, the shape of the light emitting element 30 is not particularly limited, and the light emitting element 30 may have various shapes such as a polygonal prism shape (e.g., a cube shape, a rectangular parallelepiped shape, or a hexagonal prism shape) or a shape extending in one direction and having a portion of its outer surface inclined.

[0136] The light-emitting element 30 may include a semiconductor layer doped with impurities of any conductivity type (e.g., p-type or n-type). The semiconductor layer may receive an electrical signal applied thereto from an external source, thereby emitting light of a specific wavelength band. The semiconductor layers included in the light-emitting element 30 may be sequentially arranged or stacked in one direction.

[0137] The light emitting element 30 may include a first semiconductor layer 31, a second semiconductor layer 32, an active layer 36, an electrode layer 37, and an insulating film 38. In order to properly visualize the elements of the light emitting element 30, Figure 5 The light emitting element 30 is shown in which a portion of the insulating film 38 is removed to expose the plurality of semiconductor layers 31 and 32 and the active layer 36. However, as will be described later, the insulating film 38 may be provided to surround the outer surfaces of the semiconductor layers 31 and 32 and the active layer 36.

[0138] Specifically, the first semiconductor layer 31 may be an n-type semiconductor. For example, in the case where the light emitting element 30 emits light of a blue wavelength, the first semiconductor layer 31 may include a semiconductor material (ie, Al x Ga yIn 1-x-y N (where 0≤x≤1, 0≤y≤1, and 0≤x+y≤1). For example, the first semiconductor layer 31 may include at least one of AlGaInN, GaN, AlGaN, InGaN, AlN, and InN doped with an n-type dopant. The first semiconductor layer 31 may be doped with an n-type dopant, which may be, for example, Si, Ge, Se, or Sn. For example, the first semiconductor layer 31 may be n-GaN doped with n-type Si. The first semiconductor layer 31 may have a length of 1.5 μm to 5 μm, but the disclosure is not limited thereto.

[0139] The second semiconductor layer 32 may be provided on the active layer 36 to be described later. The second semiconductor layer 32 may be a p-type semiconductor. In the case where the light emitting element 30 emits light of a blue wavelength or a green wavelength, the second semiconductor layer 32 may include a semiconductor material (i.e., Al x Ga y In 1-x-y N (where 0≤x≤1, 0≤y≤1, and 0≤x+y≤1). For example, the second semiconductor layer 32 may include at least one of AlGaInN, GaN, AlGaN, InGaN, AlN, and InN doped with a p-type dopant. The second semiconductor layer 32 may be doped with a p-type dopant, which may be, for example, Mg, Zn, Ca, or Ba. In one embodiment, the second semiconductor layer 32 may be p-GaN doped with p-type Mg. The second semiconductor layer 32 may have a length of 0.05 μm to 0.10 μm, but the disclosure is not limited thereto.

[0140] The first semiconductor layer 31 and the second semiconductor layer 32 are shown as being formed as a single layer, but the disclosure is not limited thereto. Alternatively, in some embodiments, each of the first semiconductor layer 31 and the second semiconductor layer 32 may include more than one layer (such as a cap layer or a tensile strain barrier reduction (TSBR) layer, for example) depending on the material of the active layer 36.

[0141] The active layer 36 is disposed between the first semiconductor layer 31 and the second semiconductor layer 32. The active layer 36 may include a single quantum well structure material or a multi-quantum well structure material. When the active layer 36 includes a material having a multi-quantum well structure, the active layer 36 may have a structure in which multiple quantum layers and multiple well layers are alternately stacked. The active layer 36 can emit light by combining electron-hole pairs in response to an electrical signal applied thereto via the first semiconductor layer 31 and the second semiconductor layer 32. For example, when the active layer 36 emits blue wavelength light, the quantum layers may include materials such as AlGaN or AlGaInN. In particular, when the active layer 36 has a multi-quantum well structure in which multiple quantum layers and multiple well layers are alternately stacked, the quantum layers may include materials such as AlGaN or AlGaInN, and the well layers may include materials such as GaN or AlInN. In one embodiment, when the active layer 36 includes AlGaInN as its quantum layers and AlInN as its well layers, the active layer 36 can emit blue light having a central wavelength range of 450 nm to 495 nm.

[0142] However, the disclosure is not limited thereto. Optionally, depending on the wavelength of the light to be emitted, the active layer 36 may 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 a Group III or Group V semiconductor material. The type of light emitted by the active layer 36 is not particularly limited. If desired, the active layer 36 may emit light in the red or green wavelength range instead of blue light. The active layer 36 may have a length of 0.05 μm to 0.10 μm, but the disclosure is not limited thereto.

[0143] Light may be emitted not only from the circumferential surface of the light emitting element 30 in the length direction but also from both sides of the light emitting element 30. The directionality of light emitted from the active layer 36 is not particularly limited.

[0144] The electrode layer 37 may be an ohmic contact electrode, but the disclosure is not limited thereto. Alternatively, the electrode layer 37 may be a Schottky contact electrode. The light emitting element 30 may include at least one electrode layer 37. The light emitting element 30 is shown as including one electrode layer 37, but the disclosure is not limited thereto. Alternatively, the light emitting element 30 may include more than one electrode layer 37, or may not include an electrode layer 37. However, the following description of the light emitting element 30 may also be directly applicable to a light emitting element having more than one electrode layer 37 or having a light emitting element having more than one electrode layer 37. Figure 5 The light emitting element 30 has a different structure from the light emitting element 30 .

[0145] When the light-emitting element 30 is electrically connected to an electrode (or contact electrode) in the display device 10, 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 one of Al, Ti, In, Au, Ag, ITO, IZO, and ITZO. In addition, the electrode layer 37 may include a semiconductor material doped with an n-type dopant or a p-type dopant. The electrode layer 37 may include the same material or different materials. The electrode layer 37 may have a length of 0.05 μm to 0.10 μm, but the disclosure is not limited thereto.

[0146] The insulating film 38 is provided to surround the outer surfaces of the semiconductor layer and the electrode layer. In one embodiment, the insulating film 38 may be provided to surround at least the outer surface of the active layer 36 and may extend in the direction along which the light-emitting element 30 extends. The insulating film 38 may protect other components of the light-emitting element 30. For example, the insulating film 38 may be formed to surround the side surfaces of the other components of the light-emitting element 30, but to expose both ends of the light-emitting element 30 in the longitudinal direction.

[0147] The insulating film 38 is shown as extending in the length direction of the light-emitting element 30 to cover the side surfaces of the multiple layers of the light-emitting element 30 (ranging from the first semiconductor layer 31 to the electrode layer 37), but the disclosure is not limited thereto. The insulating film 38 may cover only some of the semiconductor layers and the outer surface of the active layer 36, or may cover only a portion of the outer surface of the electrode layer 37 to expose a portion of the outer surface of the electrode layer 37. In addition, the insulating film 38 may have a rounded top surface near at least one end of the light-emitting element 30.

[0148] The insulating film 38 may have a thickness of 10 nm to 1.0 μm, but the disclosure is not limited thereto. Preferably, the insulating film 38 may have a thickness of about 40 nm.

[0149] The insulating film 38 may include a film having insulating properties (such as SiO x 、SiN x 、SiO x N y Insulating film 38 can prevent any short circuit that may occur when active layer 36 is placed in direct contact with an electrode that directly transmits an electrical signal to light-emitting element 30. In addition, since insulating film 38 covers active layer 36 to protect the outer surface of light-emitting element 30, any degradation of the emission efficiency of light-emitting element 30 can be prevented.

[0150] Furthermore, in some embodiments, the outer surface of the insulating film 38 may be surface treated. During the manufacture of the display device 10, the light-emitting elements 30 may be sprayed onto the electrodes while being dispersed in a predetermined ink. Here, the surface of the insulating film 38 may be treated with a hydrophobic or hydrophilic treatment to keep the light-emitting elements 30 dispersed in the ink without agglomerating with other light-emitting elements 30.

[0151] 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, preferably 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. The plurality of light-emitting elements 30 included in the display device 10 may have different diameters depending on the composition of their respective active layers 36. Preferably, the diameter of the light-emitting element 30 may be about 500 nm.

[0152] Hereinafter, a method of manufacturing the display device 10 will be described.

[0153] As described above, during the manufacture of the display device 10, the light-emitting elements 30 can be sprayed onto the electrodes 21 and 22 while being dispersed in ink along with the conductive polymer. Furthermore, liquid crystal molecules can be dispersed in the ink to properly align the light-emitting elements 30. During the manufacture of the display device 10, the liquid crystal molecules can also be aligned in one direction by an electric field used to align the light-emitting elements 30. The alignment of the liquid crystal molecules can influence the light-emitting elements 30 to be positioned between the electrodes 21 and 22 with a high degree of alignment, while being positioned on the electrodes 21 and 22 by the electric field.

[0154] Figure 6 is a flowchart illustrating a method of manufacturing a display device according to a disclosed embodiment. Figures 7 to 12 is a cross-sectional view illustrating a method of manufacturing a display device according to a disclosed embodiment.

[0155] Reference Figure 6 The method of manufacturing the display device 10 may include: preparing a target substrate SUB and a plurality of electrodes 21 and 22 on the target substrate SUB (S100); ejecting ink S including light-emitting elements 30, a conductive polymer PM, and liquid crystal molecules LC onto the electrodes 21 and 22 (S200); aligning the liquid crystal molecules LC and aligning the light-emitting elements 30 between the electrodes 21 and 22 by applying an alignment signal to the electrodes 21 and 22 (S300); and forming contact electrodes 26 and 27 by applying light and curing the conductive polymer PM. Not only the light-emitting elements 30 and the conductive polymer PM for forming the contact electrodes 26 and 27, but also the liquid crystal molecules LC may be dispersed in the ink S ejected onto the target substrate SUB.

[0156] The alignment signal applied to the electrodes 21 and 22 can generate an electric field E on the target substrate SUB, and the light-emitting element 30 and the liquid crystal molecules LC can be aligned in one direction by the electric field E. The light-emitting element 30 receiving power from the electric field E can be affected by the alignment of the liquid crystal molecules LC. The light-emitting element 30 can be aligned along the direction along which the liquid crystal molecules LC are aligned, thereby improving the degree of alignment of the light-emitting element 30 between the electrodes 21 and 22.

[0157] Hereinafter, the manufacture of the display device 10 will be described. Figure 7 , prepare a target substrate SUB, and form electrodes 21 and 22 on the target substrate SUB. The electrodes 21 and 22 may include a first electrode 21 and a second electrode 22 that are spaced apart from each other and face each other. In addition, as mentioned above, a plurality of first banks 40 may be provided between the first electrode 21 and the second electrode 22 and the target substrate SUB. Although not specifically shown, the target substrate SUB may include a first substrate 11 and a plurality of circuit elements formed of a plurality of conductive layers and a plurality of insulating layers. For convenience, the first substrate 11 and the circuit elements are simply shown and described as the target substrate SUB.

[0158] Afterwards, refer to Figure 8 , forming a first insulating layer 51 and a second bank 45 that partially covers the first electrode 21 and the second electrode 22. The first insulating layer 51 may be provided on a portion of the surface of the target substrate SUB to expose portions of the top surface of the electrodes 21 and 22. A second bank 45 may be provided on the first insulating layer 51 to surround the region where the electrodes 21 and 22 are provided.

[0159] Afterwards, refer to Figure 9 , ink S having light-emitting elements 30, liquid crystal molecules LC and conductive polymer PM dispersed therein is sprayed onto a target substrate SUB. In one embodiment, the light-emitting elements 30 can be prepared in a state of being dispersed in the ink together with the liquid crystal molecules LC and the conductive polymer PM, and then the light-emitting elements 30 can be sprayed onto the target substrate SUB by an inkjet printing device (not shown) through a printing process, but the disclosure is not limited to this. Alternatively, the ink S can be sprayed onto the target substrate SUB through a slit process. The ink S may include a solvent and the light-emitting elements 30, liquid crystal molecules LC and conductive polymer PM dispersed in the solvent, and may be provided in the form of a solution or a colloid. For example, the solvent may be acetone, water, ethanol, toluene, propylene glycol (PG) or propylene glycol methyl acetate (PGMA), but the disclosure is not limited to this.

[0160] The light-emitting element 30 is as described above. The light-emitting element 30 can be positioned between the electrodes 21 and 22 by applying an alignment signal to the electrodes 21 and 22. For example, in response to the alignment signal applied to the first and second electrodes 21 and 22, an electric field can be generated in the ink ejected onto the electrodes 21 and 22. Once the electric field is generated across the first and second electrodes 21 and 22, the light-emitting element 30 dispersed in the ink can experience an electrophoretic force. The light-emitting element 30, receiving the electrophoretic force, can then be positioned between the first and second electrodes 21 and 22, changing its orientation and position.

[0161] The conductive polymer PM can be cured later, so that the conductive polymer PM can form contact electrodes 26 and 27. Similar to light-emitting element 30, the conductive polymer PM can include polymer chains and have a molecular structure extending in a single direction. Even in the case of the conductive polymer PM, the direction in which the polymer chains extend can be oriented in a specific direction by the electric field formed in the ink S.

[0162] The liquid crystal molecules LC can also be aligned in a single direction by an electric field generated in the ink S. In one embodiment, the liquid crystal molecules LC can have positive dielectric anisotropy and can be aligned by the direction of the electric field generated in the ink S. The light-emitting element 30 can be oriented in a single direction by the electric field generated on the electrodes 21 and 22, and can be influenced by the aligned liquid crystal molecules LC in the ink S. The light-emitting element 30 can be aligned with the liquid crystal molecules LC by the electric field, and can therefore be positioned between the electrodes 21 and 22 with a higher degree of alignment.

[0163] Reference Figure 10 , an electric field E is generated in the ink S by applying an alignment signal to the electrodes 21 and 22, so as to align the light-emitting elements 30 and the liquid crystal molecules LC and arrange the light-emitting elements 30 between the electrodes 21 and 22. Each of the light-emitting elements 30 may include a semiconductor layer doped with an n-type dopant or a p-type dopant, and thus may have a dipole moment. The light-emitting elements 30 may receive an electrophoretic force from the electric field E generated in the ink S, and thus may be aligned between the electrodes 21 and 22. Then, when the orientation direction and position of the light-emitting elements 30 are changed by the electrophoretic force, the light-emitting elements 30 may be arranged so that the first end and the second end of each of the light-emitting elements 30 may be placed on the first electrode 21 and the second electrode 22, respectively. The light-emitting elements 30 may be arranged between the electrodes 21 and 22 along the direction in which the electrodes 21 and 22 extend.

[0164] Liquid crystal molecules LC can be dispersed in ink S and then oriented by an electric field E so that they align along the direction of the electric field E. As described above, since the liquid crystal molecules LC have positive dielectric anisotropy, the liquid crystal molecules LC can be oriented so that the direction in which they extend is parallel to the direction in which the electric field E is generated. The liquid crystal molecules LC and the light-emitting elements 30 can both extend in a single direction and have specific orientations. Since the light-emitting elements 30 are disposed between the electrodes 21 and 22 in a state dispersed in the ink S, the alignment of the light-emitting elements 30 can be affected by the orientation of the liquid crystal molecules LC. The liquid crystal molecules LC can be oriented in the direction of the electric field E (i.e., the direction in which the first and second electrodes 21 and 22 extend), and the light-emitting elements 30 can be aligned by the oriented liquid crystal molecules LC so that the direction in which the light-emitting elements 30 extend aligns with the direction in which the liquid crystal molecules LC extend. The light-emitting elements 30 can be disposed so that both ends of the light-emitting elements 30 are positioned on the first and second electrodes 21 and 22, with the direction in which the light-emitting elements 30 extend oriented in a direction spaced apart from each other. Compared to when the liquid crystal molecules LC are not provided, the light emitting element 30 may be uniformly aligned between the electrodes 21 and 22 and may have a high degree of alignment between the electrodes 21 and 22 .

[0165] The conductive polymer PM included in the ink S can be aligned along with the liquid crystal molecules LC by an electric field E. The main chain portion of the polymer chain of the conductive polymer PM can be aligned along the direction in which the liquid crystal molecules LC are aligned. The conductive polymer PM can be concentrated on the electrodes 21 and 22 that generate the electric field E, and even on both ends of each light-emitting element 30 on the electrodes 21 and 22. The conductive polymer PM can be dispersed in the ink S and can be concentrated on the electrodes 21 and 22 along with the light-emitting elements 30, and can fix the position of the light-emitting elements 30 aligned between the electrodes 21 and 22.

[0166] When contact electrodes 26 and 27 are formed after aligning light-emitting elements 30 between electrodes 21 and 22, the initial aligned positions of light-emitting elements 30 may change. In this case, the orientation direction or position of some of light-emitting elements 30 may change between electrodes 21 and 22, so that the corresponding light-emitting elements 30 are not electrically connected to electrodes 21 and 22 via contact electrodes 26 and 27. However, since contact electrodes 26 and 27 of display device 10 include a conductive polymer PM, light-emitting elements 30 can be aligned between electrodes 21 and 22, and the conductive polymer PM can be used to fix light-emitting elements 30. Therefore, a separate member or separate process for fixing the aligned positions of light-emitting elements 30 may not be required, and alignment of light-emitting elements 30 and formation of contact electrodes 26 and 27 can be performed by substantially the same process.

[0167] Afterwards, refer to Figure 11 , contact electrodes 26 and 27 are formed by applying UV light to the target substrate SUB to cure the aggregated conductive polymer PM. The UV light may be light generally irradiated for curing the conductive polymer PM. In one embodiment, the UV light may be ultraviolet (UV) light, but the disclosure is not limited thereto.

[0168] The conductive polymer PM accumulated on both ends of each of electrodes 21 and 22 and light-emitting element 30 can be cured by UV light, thereby forming contact electrodes 26 and 27. Depending on the height of electrodes 21 and 22 generating the electric field E, the conductive polymer PM can accumulate at different densities. For example, the conductive polymer PM can accumulate at the highest density on the portion of electrodes 21 and 22 that has the greatest height due to the presence of first bank 40, while accumulating at a relatively low density on the portion of electrodes 21 and 22 directly disposed on the target substrate SUB. Consequently, contact electrodes 26 and 27 can have varying thicknesses from one location to another.

[0169] The conductive polymer PM can form contact electrodes 26 and 27 and can also secure the light-emitting element 30. In some embodiments, UV light irradiation for curing the conductive polymer PM and generation of an electric field E for aligning the light-emitting element 30 can be performed simultaneously. In one embodiment, the light-emitting element 30 can be secured by generating an electric field E in the ink S to align the liquid crystal molecules LC and the light-emitting element 30 and applying UV light to cure the conductive polymer PM. In this step, the contact electrodes 26 and 27 can be formed while simultaneously securing the aligned position of the light-emitting element 30.

[0170] Afterwards, refer to Figure 12 , and the solvent and the liquid crystal molecules LC of the ink S are removed. In addition, although not specifically shown, a second insulating layer 52 covering the contact electrodes 26 and 27 and the light emitting element 30 may be formed, thereby obtaining the display device 10 .

[0171] As in display device 10, liquid crystal molecules LC and light-emitting elements 30 are oriented, and light-emitting elements 30 can be uniformly aligned. Furthermore, by using a conductive polymer PM that forms contact electrodes 26 and 27 and secures light-emitting elements 30, any variation in the alignment position of light-emitting elements 30 can be prevented. Consequently, the number of manufacturing processes for display device 10 can be reduced, and the degree of alignment of light-emitting elements 30 can be improved.

[0172] Various other embodiments of the display device 10 will be described below.

[0173] Figure 13 FIG. 4 is a plan view of a sub-pixel of a display device according to another disclosed embodiment.

[0174] Reference Figure 13 , the display device 10_1 may include a relatively large number of electrodes 21 and 22, first banks 40, and contact electrodes 26 and 27. Each subpixel PXn of the display device 10_1 may include a plurality of first electrodes 21 and at least one second electrode 22 disposed between the first electrodes 21. In each subpixel PXn, the first and second electrodes 21 and 22 may be disposed so as to be spaced apart from and face each other in the first direction DR1, and may be alternately arranged along the first direction DR1. Due to the increase in the number of electrodes 21 and 22 disposed in each subpixel PXn, a relatively large number of first banks 40 may be disposed on the first planarization layer 19, and a relatively large number of contact electrodes 26 and 27 may be disposed on the electrodes 21 and 22. Figure 13 In the example of the embodiment of the present invention, when two first electrodes 21 and one second electrode 22 are provided in each sub-pixel PXn of the display device 10_1, three first banks 40, two first contact electrodes 26, and one second contact electrode 27 are provided. However, the present invention is not limited thereto. The number of first banks 40, electrodes 21 and 22, and contact electrodes 26 and 27 may be further increased.

[0175] As the number of light emitting elements 30 disposed between the first electrode 21 and the second electrode 22 of the display device 10_1 increases, the amount of light emitted by each unit pixel PX or each sub-pixel PXn may increase.

[0176] Each of the first electrodes 21 may be in contact with the first conductive pattern CDP via a first contact hole CT1 and thus may be electrically connected to the driving transistor DT. A light-emitting element 30 disposed between one of the first electrodes 21 and the second electrode 22 may be connected in parallel with a light-emitting element 30 disposed between another first electrode 21 and the second electrode 22, but the disclosure is not limited thereto. In some embodiments, the display device 10_1 may further include an electrode that is not directly connected to the circuit element disposed below the first planarization layer 19, and the light-emitting element 30 disposed between the electrodes may be connected in series.

[0177] Figure 14 FIG. 4 is a plan view of a sub-pixel of a display device according to another disclosed embodiment.

[0178] Reference Figure 14The display device 10_2 may further include a first electrode 21 and a second electrode 22, and may further include a third electrode 23 disposed between the first electrode 21 and the second electrode 22. In addition, the contact electrodes 26, 27, and 28 may further include a third contact electrode 28 disposed on the third electrode 23. The first bank 40 may also be disposed between the third electrode 23 and the first planarization layer 19, and the plurality of light-emitting elements 30 may be disposed between the first electrode 21 and the third electrode 23 and between the third electrode 23 and the second electrode 22. The display device 10_2 and Figure 2 The difference from its corresponding portion is that each sub-pixel PXn further includes a third electrode 23 and a third contact electrode 28. The third electrode 23 will be described below.

[0179] The third electrode 23 is disposed between the first electrode 21 and the second electrode 22. A plurality of first banks 40 (e.g., three first banks 40) may be disposed on the first planarization layer 19, and the first electrode 21, the third electrode 23, and the second electrode 22 may be sequentially arranged on the first bank 40. The third electrode 23 may extend in the second direction DR2. Unlike the first electrode 21 and the second electrode 22, the third electrode 23 may extend in the second direction DR2, but may be disposed so as not to overlap with the portion of the second bank 45 extending in the first direction DR1 but to be spaced apart from the portion of the second bank 45 extending in the first direction DR1. In other words, the length of the third electrode 23 in the second direction DR2 may be smaller than the length of the first electrode 21 and the second electrode 22, and the third electrode 23 may be disposed so as not to extend beyond the boundary between adjacent sub-pixels PXn.

[0180] The light emitting element 30 may be provided between the first electrode 21 and the third electrode 23 and between the third electrode 23 and the second electrode 22. The third contact electrode 28 may have the same shape as the first contact electrode 26 and the second contact electrode 27 and may be provided on the third electrode 23. That is, the third contact electrode 28 may include a conductive polymer.

[0181] The light emitting element 30 disposed between the first electrode 21 and the third electrode 23 may be in contact with the first contact electrode 26 and the third contact electrode 28, and thus may be electrically connected to the first electrode 21 and the third electrode 23. The light emitting element 30 disposed between the third electrode 23 and the second electrode 22 may be in contact with the third contact electrode 28 and the second contact electrode 27, and thus may be electrically connected to the third electrode 23 and the second electrode 22.

[0182] Unlike the first and second electrodes 21 and 22, the third electrode 23 can be directly connected to the circuit element layer without a contact hole. Electrical signals applied to the first and second electrodes 21 and 22 can be transmitted to the third electrode 23 via the first and second contact electrodes 26 and 27 and the light-emitting element 30. In other words, the light-emitting element 30 disposed between the first and third electrodes 21 and 23 can be connected in series with the light-emitting element 30 disposed between the third and second electrodes 23 and 22. Since the display device 10_2 also includes the third electrode 23, a series connection can be established between the light-emitting elements 30, and the emission efficiency of each subpixel PXn can be further improved.

[0183] Figure 15 FIG. 4 is a plan view of a sub-pixel of a display device according to another disclosed embodiment. Figure 16 It is along Figure 15 A cross-sectional view taken along line VI-VI'.

[0184] Reference Figure 15 and Figure 16 In the display device 10_3, the widths of the contact electrodes 26_3 and 27_3 may be smaller than the widths of the electrodes 21 and 22. The contact electrodes 26_3 and 27_3 may be provided to cover only the portions of the top surfaces of the electrodes 21 and 22 that are exposed due to the absence of the first insulating layer 51 thereon. For example, the first contact electrode 26_3 may be provided to contact the first end portion of the light-emitting element 30 and a portion of the top surface of the first electrode 21, and to cover only the side of the first electrode 21 that faces the second electrode 22. The second contact electrode 27_3 may be provided to contact the second end portion of the light-emitting element 30 and a portion of the top surface of the second electrode 22, and to cover only the side of the second electrode 22 that faces the first electrode 21.

[0185] During the accumulation of conductive polymer PM on electrodes 21 and 22 and light-emitting element 30, the width of contact electrodes 26_3 and 27_3 can be controlled. As described above, when an electric field E is generated in ink S to align the liquid crystal molecules LC and light-emitting element 30, the main chain portion of the polymer chain of the conductive polymer PM can also be aligned in one direction, allowing the conductive polymer PM to accumulate. Here, if the electric field E is strong in the space between light-emitting element 30 and electrodes 21 and 22, the conductive polymer PM can accumulate strongly. As a result, the conductive polymer PM can accumulate on light-emitting element 30 and on the sides of electrodes 21 and 22 to form contact electrodes 26_3 and 27_3, which can have a relatively small width. Figure 15 Examples and Figure 2 and Figure 3The embodiment of FIG. 2 differs in the widths of the contact electrodes 26_3 and 27_3 , and description of any redundant features will be omitted.

[0186] Figure 17 FIG. 4 is a plan view of a sub-pixel of a display device according to another disclosed embodiment. Figure 18 It is along Figure 17 A sectional view taken along line VIII-VIII'.

[0187] Reference Figure 17 and Figure 18 In the display device 10_4, the contact electrodes 26_4 and 27_4 may be provided only on the portions of the electrodes 21 and 22 where the light emitting element 30 is provided. The contact electrodes 26_4 and 27_4 may not extend in one direction and may be provided spaced apart from each other to correspond to the portions of the electrodes 21 and 22 where the light emitting element 30 is provided. Therefore, the contact electrodes 26_4 and 27_4 may form an island pattern in each sub-pixel PXn. Figure 17 and Figure 18 The embodiment of FIG. 1 is different from the previous embodiment in the layout and shape of the contact electrodes 26_4 and 27_4.

[0188] As described above, when an electric field E is generated in the ink S, the liquid crystal molecules LC and the light-emitting elements 30 can be aligned, and the conductive polymer PM can be concentrated on the electrodes 21 and 22 and the light-emitting elements 30. Here, the conductive polymer PM can be concentrated under the influence of the light-emitting elements 30, which are aligned under the influence of the orientation direction of the liquid crystal molecules LC. When the light-emitting elements 30 are positioned on the electrodes 21 and 22 by the electric field E, the conductive polymer PM can be concentrated on both ends of each of the light-emitting elements 30. Therefore, the conductive polymer PM can be mainly concentrated on the portions of both ends of each of the light-emitting elements 30 and the sides of the first bank 40 of the electrodes 21 and 22. The contact electrodes 26_4 and 27_4 can be positioned to correspond to the portions of the electrodes 21 and 22 where the both ends of each of the light-emitting elements 30 are placed. However, at least some of the conductive polymer PM can be concentrated on the portions of the top surfaces of the electrodes 21 and 22 that are exposed due to the absence of the first insulating layer 51 thereon, and the contact electrodes 26_4 and 27_4 can be in contact with the electrodes 21 and 22.

[0189] Furthermore, in some embodiments, the contact electrodes 26_4 and 27_4 may be thickest between both ends of each of the light-emitting elements 30 and the portions of the electrodes 21 and 22 on the sides of the first bank 40. In the case where the conductive polymer PM is placed on the portions of the electrodes 21 and 22 on which the both ends of each of the light-emitting elements 30 are disposed, a relatively large amount of the conductive polymer PM may be accumulated near both ends of each of the light-emitting elements 30. Therefore, the contact electrodes 26_4 and 27_4 formed by curing the conductive polymer PM may be thickest between both ends of each of the light-emitting elements 30 and the portions of the electrodes 21 and 22 on the sides of the first bank 40, but the disclosure is not limited thereto.

[0190] Figure 19 FIG. 4 is a plan view of a sub-pixel of a display device according to another disclosed embodiment.

[0191] Reference Figure 19 , the light emitting element 30_5 of the display device 10_5 may be arranged in a direction not perpendicular to the direction in which the electrodes 21 and 22 extend but oblique to the direction in which the electrodes 21 and 22 extend. Therefore, the first contact electrode 26_5 and the second contact electrode 27_5 may be spaced apart from each other in a direction between the first direction DR1 and the second direction DR2. Figure 19 Examples and Figure 17 The embodiment is different in that the orientation direction of the light emitting element 30_5 is different from the direction in which the contact electrodes 26_5 and 27_5 are spaced apart from each other.

[0192] The light-emitting elements 30_5 can be aligned along with the liquid crystal molecules LC and can be affected by the alignment direction of the liquid crystal molecules LC. In some embodiments, the liquid crystal molecules LC can be aligned in a direction that is not perpendicular to the direction in which the electrodes 21 and 22 extend, and the light-emitting elements 30_5 can be arranged in an oblique direction relative to the direction in which the electrodes 21 and 22 extend. Multiple light-emitting elements 30_5 can be aligned between the first electrode 21 and the second electrode 22, but the alignment direction of the light-emitting elements 30_5 may not be perpendicular to the alignment direction of the light-emitting elements 30_5. However, when the liquid crystal molecules LC are aligned in a uniform direction, the light-emitting elements 30_5 can be aligned in the uniform direction.

[0193] Furthermore, some of the light-emitting elements 30_5 may be arranged so that only one end thereof can be placed on electrodes 21 and 22. However, if the conductive polymer PM is arranged in an aggregated state on both ends of each of the light-emitting elements 30_5, they can be electrically connected to electrodes 21 and 22 even if the light-emitting elements 30_5 are oriented in an oblique direction relative to the direction in which electrodes 21 and 22 extend. Contact electrodes 26_5 and 27_5 may be arranged to correspond to both ends of each of the light-emitting elements 30_5. Since contact electrodes 26_5 and 27_5 have a predetermined width, contact electrodes 26_5 and 27_5 can contact portions of the top surfaces of electrodes 21 and 22. Even if one end of each light-emitting element 30_5 is not placed on electrodes 21 and 22, contact electrodes 26_5 and 27_5 can still contact the corresponding end of each light-emitting element 30_5 and portions of electrodes 21 and 22. Descriptions of other redundant features of the previous embodiment will be omitted.

[0194] Meanwhile, contact electrodes 26 and 27 may have a uniform thickness in the region covering light emitting element 30. In some embodiments, the portion of contact electrodes 26 and 27 covering light emitting element 30 may be larger than the diameter of light emitting element 30, and some of light emitting elements 30 may be disposed at different heights in a cross-sectional view.

[0195] Figure 20 FIG. 4 is a plan view of a sub-pixel of a display device according to another disclosed embodiment.

[0196] Reference Figure 20 The light-emitting element 30 of the display device 10_6 may include light-emitting elements 30A and 30B disposed at different heights. The light-emitting element 30 may be disposed so that both ends thereof may be placed on the electrodes 21 and 22, and may include a first light-emitting element 30A disposed directly on the first insulating layer 51 and a second light-emitting element 30B disposed on the first light-emitting element 30A.

[0197] The first light emitting element 30A may be directly provided on the first insulating layer 51. The first light emitting element 30A may be the same as the light emitting element 30 included in the display device 10.

[0198] In the cross-sectional view, the second light-emitting element 30B can be arranged on the first light-emitting element 30A and can be positioned at a different height from the first light-emitting element 30A. The plurality of light-emitting elements 30 dispersed in the ink S can be oriented by the electric field E and can therefore be arranged on the electrodes 21 and 22. Here, the conductive polymer PM can be gathered on both ends of each of the light-emitting elements 30, and one or more light-emitting elements 30 can be fixed by an aggregate formed by the conductive polymer PM. In this case, some of the light-emitting elements 30 can be arranged to overlap each other in the thickness direction. When the conductive polymer PM is cured to form the contact electrodes 26 and 27, one or more light-emitting elements 30 can be arranged to overlap each other in the thickness direction and can have different heights.

[0199] Since the plurality of light emitting elements 30 are arranged to overlap each other in the thickness direction and at different heights, a relatively large number of light emitting elements 30 can be arranged in each sub-pixel PXn. Therefore, the amount of light emitted per unit area of ​​each sub-pixel PXn of the display device 10_6 can be increased.

[0200] At the end of the detailed description, it will be appreciated by those skilled in the art that many changes and modifications may be made to the preferred embodiment without departing substantially from the principles of the invention. Therefore, the preferred embodiments of the disclosed invention are used in a generic and descriptive sense only and not for the purpose of limitation.

Claims

1. A method for manufacturing a display device, the method comprising: preparing a target substrate and a first electrode and a second electrode disposed on the target substrate; ejecting ink comprising a plurality of light emitting elements, liquid crystal molecules, and a conductive polymer onto the target substrate; as well as A plurality of contact electrodes disposed on the first electrode and the second electrode are formed by generating an electric field on the target substrate to align the liquid crystal molecules and the plurality of light emitting elements and to cure the conductive polymer.

2. The method according to claim 1, wherein The plurality of light emitting elements and the liquid crystal molecules extend in one direction, and The step of forming the plurality of contact electrodes includes aligning the plurality of light emitting elements and the liquid crystal molecules so that a direction in which the plurality of light emitting elements and the liquid crystal molecules extend is parallel to a top surface of the target substrate.

3. The method according to claim 2, wherein: The liquid crystal molecules have positive dielectric anisotropy.

4. The method according to claim 2, wherein: The conductive polymer is oriented by the electric field so that its main chain portion is oriented in the one direction and aggregated on the first electrode and the second electrode, and The plurality of light emitting elements are fixed by the conductive polymer in such a manner that both end portions thereof are oriented in the one direction.

5. The method according to claim 4, wherein The conductive polymer includes PEDOT:PSS.

6. The method according to claim 4, wherein: The step of curing the conductive polymer is performed by applying light with the plurality of light emitting elements and the liquid crystal molecules aligned in the one direction.

7. The method according to claim 4, wherein: The plurality of light emitting elements include a first light emitting element and a second light emitting element, wherein both ends of the first light emitting element are disposed on the first electrode and the second electrode, and the second light emitting element is disposed on the first light emitting element and both ends of the second light emitting element are disposed on the first electrode and the second electrode.

8. The method according to claim 7, wherein: The plurality of contact electrodes include a first contact electrode contacting the first end portions of the plurality of light emitting elements and the first electrode, and a second contact electrode contacting the second end portions of the plurality of light emitting elements and the second electrode and spaced apart from the first contact electrode.

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