Display device and method of manufacturing the same

Abstract

A display device and a method for manufacturing the same are provided. The display device comprises a first alignment electrode and a second alignment electrode spaced apart from each other, light-emitting elements disposed between the first alignment electrode and the second alignment electrode, a first auxiliary electrode disposed on one side of the light-emitting element and separated from the first alignment electrode, and a second auxiliary electrode disposed on the other side of the light-emitting element and separated from the second alignment electrode, wherein an alignment signal is applied to the first alignment electrode and a first auxiliary signal having a phase different from the alignment signal is applied to the first auxiliary electrode.

Description

Technology Field

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

[0002] With the recent rise in interest in information displays, research and development on display devices is continuously being carried out. The problem to be solved

[0003] The problem that the present invention aims to solve is to provide a display device capable of improving the bias alignment efficiency of light-emitting elements and a method for manufacturing the same.

[0004] The problems of the present invention are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0005] A display device according to one embodiment for solving the above problem comprises a first alignment electrode and a second alignment electrode spaced apart from each other, light-emitting elements disposed between the first alignment electrode and the second alignment electrode, a first auxiliary electrode disposed on one side of the light-emitting element and separated from the first alignment electrode, and a second auxiliary electrode disposed on the other side of the light-emitting element and separated from the second alignment electrode, wherein an alignment signal is applied to the first alignment electrode and a first auxiliary signal having a phase different from the alignment signal is applied to the first auxiliary electrode.

[0006] The first auxiliary electrode is disposed between the first alignment electrode and the light-emitting elements, and the second auxiliary electrode can be disposed between the second alignment electrode and the light-emitting elements.

[0007] It may further include a third auxiliary electrode disposed between the first auxiliary electrode and the light-emitting elements and separated from the first auxiliary electrode, and a fourth auxiliary electrode disposed between the second auxiliary electrode and the light-emitting elements and separated from the second auxiliary electrode.

[0008] The first alignment electrode is disposed between the first auxiliary electrode and the light-emitting elements, and the second alignment electrode can be disposed between the second auxiliary electrode and the light-emitting elements.

[0009] It may further include a third auxiliary electrode disposed between the first alignment electrode and the light-emitting elements, and a fourth auxiliary electrode disposed between the second alignment electrode and the light-emitting elements.

[0010] The third auxiliary electrode can be electrically separated from the first alignment electrode and the first auxiliary electrode.

[0011] It may further include a third auxiliary electrode disposed between the first auxiliary electrode and the first alignment electrode, and a fourth auxiliary electrode disposed between the second auxiliary electrode and the second alignment electrode.

[0012] The third auxiliary electrode can receive the alignment signal and a second auxiliary signal having a different phase from the first auxiliary signal.

[0013] The first auxiliary electrode can be placed in the same layer as the first alignment electrode.

[0014] It may further include an insulating layer disposed between the first auxiliary electrode and the first alignment electrode.

[0015] It may further include a first connecting electrode that electrically connects one end of the first alignment electrode and the light-emitting elements, and a second connecting electrode that electrically connects the other end of the second alignment electrode and the light-emitting elements.

[0016] The light-emitting elements can be electrically separated from the first auxiliary electrode and the second auxiliary electrode.

[0017] A method for manufacturing a display device according to one embodiment for solving the above problem comprises the steps of forming a first alignment electrode and a second alignment electrode spaced apart from each other, forming a first auxiliary electrode and a second auxiliary electrode separated from the first alignment electrode and the second alignment electrode, and aligning light-emitting elements between the first alignment electrode and the second alignment electrode, wherein in the step of aligning the light-emitting elements, an alignment signal may be applied to the first alignment electrode and a first auxiliary signal having a phase different from the alignment signal may be applied to the first auxiliary electrode.

[0018] When the above alignment signal is set to a negative voltage, the above first auxiliary signal can be set to a positive voltage.

[0019] In the step of aligning the light-emitting elements, a ground voltage may be applied to the second alignment electrode and the second auxiliary electrode.

[0020] The first alignment electrode and the first auxiliary electrode can be formed simultaneously.

[0021] The method further includes the step of forming a third auxiliary electrode separated from the first auxiliary electrode and the second auxiliary electrode, and a fourth auxiliary electrode, and in the step of aligning the light-emitting elements, the alignment signal and a second auxiliary signal having a different phase from the first auxiliary signal may be applied to the third auxiliary electrode.

[0022] During the period when the alignment signal is set to a negative voltage, the first auxiliary signal is changed from a positive voltage to a negative voltage, and the second auxiliary signal can be changed from a negative voltage to a positive voltage.

[0023] In the step of aligning the light-emitting elements, a ground voltage may be applied to the fourth auxiliary electrode.

[0024] The first auxiliary electrode and the third auxiliary electrode can be formed simultaneously.

[0025] Specific details of other embodiments are included in the detailed description and drawings. Effects of the invention

[0026] According to an embodiment of the present invention, even if an electric field formed by alignment electrodes (or alignment signals) is formed in the opposite direction during the process of aligning light-emitting elements, an electric field can be formed using auxiliary electrodes (or auxiliary signals) to enable the light-emitting elements to rotate in the forward direction. Accordingly, the deflection alignment efficiency of the light-emitting elements can be improved.

[0027] The effects according to the embodiments are not limited to those exemplified above, and a wider variety of effects are included in this specification. Brief explanation of the drawing

[0028] FIGS. 1 and FIGS. 2 are a perspective view and a cross-sectional view showing a light-emitting element according to one embodiment. FIG. 3 is a plan view showing a display device according to one embodiment. FIG. 4 is a circuit diagram showing a pixel according to one embodiment. FIG. 5 is a plan view showing a pixel according to one embodiment. FIGS. 6 to 9 are cross-sectional views taken along the AA' line of FIG. 5. FIG. 10 shows an alignment signal and an auxiliary signal according to one embodiment. Figure 11 shows the electric field according to the alignment signal and auxiliary signal of Figure 10. FIG. 12 is a plan view showing a pixel according to another embodiment. Figure 13 is a cross-sectional view taken along the BB' line of Figure 12. FIG. 14 is a plan view showing a pixel according to another embodiment. Figure 15 is a cross-sectional view taken along the CC' line of Figure 14. FIG. 16 shows an alignment signal and an auxiliary signal according to one embodiment. Figure 17 shows the electric field according to the alignment signal and auxiliary signal of Figure 16. FIG. 18 is a plan view showing a pixel according to another embodiment. Figure 19 is a cross-sectional view taken along the DD' line of Figure 18. FIG. 20 is a plan view showing a pixel according to another embodiment. FIG. 21 is a cross-sectional view taken along the EE' line of FIG. 20. FIGS. 22 to 25 are cross-sectional views of the process steps of a method for manufacturing a display device according to one embodiment. FIGS. 26 to 29 are cross-sectional views of process steps of a method for manufacturing a display device according to another embodiment. Specific details for implementing the invention

[0029] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but can be implemented in various different forms. These embodiments are provided to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims.

[0030] The terms used herein are for describing the embodiments and are not intended to limit the invention. In this specification, the singular form includes the plural form unless specifically stated otherwise. As used herein, "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components, steps, actions, and / or elements to the mentioned components, steps, actions, and / or elements.

[0031] In addition, the terms "connection" or "connection" may comprehensively mean physical and / or electrical connections or connections. In addition, it may comprehensively mean direct or indirect connections or connections, and integral or non-integrated connections or connections.

[0032] When elements or layers are referred to as being on another element or layer, this includes cases where another layer or element is interposed directly on or in the middle of another element. Throughout the specification, the same reference numerals refer to the same components.

[0033] Although terms such as "first," "second," etc., are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used merely to distinguish one component from another. Therefore, it goes without saying that the first component mentioned below may also be the second component within the technical scope of the present invention.

[0034] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

[0035] FIGS. 1 and 2 are a perspective view and a cross-sectional view showing a light-emitting element according to one embodiment. FIGS. 1 and 2 show a pillar-type light-emitting element (LD), but the type and / or shape of the light-emitting element (LD) is not limited thereto.

[0036] Referring to FIGS. 1 and 2, the light-emitting element (LD) may include a first semiconductor layer (11), an active layer (12), a second semiconductor layer (13), and / or a contact electrode (14).

[0037] A light-emitting element (LD) may be formed in a column shape extending along one direction. The light-emitting element (LD) may have a first end (EP1) and a second end (EP2). One of the first and second semiconductor layers (11, 13) may be disposed at the first end (EP1) of the light-emitting element (LD). The other of the first and second semiconductor layers (11, 13) may be disposed at the second end (EP2) of the light-emitting element (LD). For example, the first semiconductor layer (11) may be disposed at the first end (EP1) of the light-emitting element (LD), and the second semiconductor layer (13) may be disposed at the second end (EP2) of the light-emitting element (LD).

[0038] According to the embodiments, the light-emitting element (LD) may be a light-emitting element manufactured into a pillar shape through an etching method or the like. In this specification, the term "pillar shape" encompasses rod-like shapes or bar-like shapes with an aspect ratio greater than 1, such as a cylindrical column or a polygonal column, and the shape of the cross-section is not limited.

[0039] The light-emitting element (LD) can have a size small enough to be on a nanometer scale to a micrometer scale. For example, the light-emitting element (LD) can each have a diameter (D) (or width) and / or length (L) in the range of nanometer scale to micrometer scale. However, the size of the light-emitting element (LD) is not limited to this, and the size of the light-emitting element (LD) can be varied depending on the design conditions of various devices that utilize the light-emitting device using the light-emitting element (LD) as a light source, such as display devices.

[0040] The first semiconductor layer (11) may be a semiconductor layer of the first conductivity type. For example, the first semiconductor layer (11) may include a p-type semiconductor layer. As an example, the first semiconductor layer (11) may include at least one semiconductor material among InAlGaN, GaN, AlGaN, InGaN, AlN, and InN, and may include a p-type semiconductor layer doped with a first conductivity type dopant such as Mg. However, the material constituting the first semiconductor layer (11) is not limited thereto, and various other materials may also constitute the first semiconductor layer (11).

[0041] The active layer (12) is disposed between the first semiconductor layer (11) and the second semiconductor layer (13) and can be formed as a single-quantum well or multi-quantum well structure. The position of the active layer (12) can be varied depending on the type of light-emitting device (LD). According to the embodiment, materials such as AlGaN and InAlGaN may be used to form the active layer (12), and various other materials may also constitute the active layer (12). A clad layer (not shown) doped with a conductive dopant may be formed on the upper and / or lower part of the active layer (12). As an example, the clad layer may be formed of AlGaN or InAlGaN.

[0042] The second semiconductor layer (13) is disposed on the active layer (12) and may include a semiconductor layer of a different type from the first semiconductor layer (11). The second semiconductor layer (13) may include an n-type semiconductor layer. For example, the second semiconductor layer (13) may include any one of the semiconductor materials of InAlGaN, GaN, AlGaN, InGaN, AlN, and InN, and may include an n-type semiconductor layer doped with a second conductivity type dopant such as Si, Ge, Sn, etc. However, the material constituting the second semiconductor layer (13) is not limited thereto, and the second semiconductor layer (13) may be composed of various other materials.

[0043] When a voltage greater than the threshold voltage is applied to both ends of the light-emitting element (LD), electron-hole pairs combine in the active layer (12), causing the light-emitting element (LD) to emit light. By controlling the light emission of the light-emitting element (LD) using this principle, the light-emitting element (LD) can be used as a light source for various light-emitting devices, including pixels of a display device.

[0044] The contact electrode (14) may be disposed on the first end (EP1) and / or the second end (EP2) of the light-emitting element (LD). FIG. 2 illustrates a case where the contact electrode (14) is formed on the first semiconductor layer (11), but is not necessarily limited thereto. For example, a separate contact electrode may be further disposed on the second semiconductor layer (13).

[0045] The contact electrode (14) may comprise a transparent metal or a transparent metal oxide. For example, the contact electrode (14) may comprise at least one of ITO (indium tin oxide), IZO (indium zinc oxide), ZnO (zinc oxide), and ZTO (zinc tin oxide), but is not necessarily limited thereto. In this way, when the contact electrode (14) is made of a transparent metal or a transparent metal oxide, light generated in the active layer (12) of the light-emitting element (LD) can pass through the contact electrode (14) and be emitted to the outside of the light-emitting element (LD).

[0046] The light-emitting element (LD) may further include an insulating film (INF) formed on its surface. The insulating film (INF) may be placed directly on the surface of the first semiconductor layer (11), the active layer (12), the second semiconductor layer (13), and / or the contact electrode (14). The insulating film (INF) may expose the first and second ends (EP1, EP2) of the light-emitting element (LD) having different polarities. According to an embodiment, the insulating film (INF) may expose the side of the contact electrode (14) and / or the second semiconductor layer (13) adjacent to the first and second ends (EP1, EP2) of the light-emitting element (LD).

[0047] The insulating film (INF) may comprise at least one of aluminum oxide (AlOx), aluminum nitride (AlNx), silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy), zirconium oxide (ZrOx), hafnium oxide (HfOx), and titanium oxide (TiOx). For example, the insulating film (INF) is composed of a double layer, and each layer constituting the double layer may comprise different materials. In this case, each layer constituting the double layer of the insulating film (INF) may be formed by different processes. In one embodiment, the insulating film (INF) may be composed of a double layer consisting of aluminum oxide (AlOx) and silicon oxide (SiOx), but is not necessarily limited thereto. Depending on the embodiment, the insulating film (INF) may be omitted.

[0048] When an insulating film (INF) is provided on the surface of a light-emitting element (LD), the active layer (12) may be prevented from being short-circuited with at least one electrode (e.g., at least one connecting electrode among the connecting electrodes connected to both ends of the light-emitting element (LD)). Accordingly, electrical stability of the light-emitting element (LD) can be ensured. In addition, surface defects of the light-emitting element (LD) can be minimized to improve lifespan and efficiency.

[0049] A light-emitting device including the aforementioned light-emitting element (LD) can be used in various types of devices requiring a light source, including display devices. For example, light-emitting elements (LDs) can be placed within each pixel of a display panel and used as the light source for each pixel. However, the application fields of the light-emitting element (LD) are not limited to the examples described above. For example, the light-emitting element (LD) can also be used in other types of devices requiring a light source, such as lighting devices.

[0050] FIG. 3 is a plan view showing a display device according to one embodiment.

[0051] In FIG. 3, as an example of an electronic device that can use the light-emitting element (LD) described in the embodiments of FIG. 1 and 2 as a light source, a display device, in particular a display panel (PNL) provided in the display device is to be illustrated.

[0052] Each pixel unit (PXU) of the display panel (PNL) and each pixel constituting it may include at least one light-emitting element (LD). For convenience of explanation, the structure of the display panel (PNL) is briefly illustrated in FIG. 3 with the display area (DA) as the center. However, depending on the embodiment, at least one driving circuit unit (e.g., at least one of a scanning driving unit and a data driving unit), wirings, and / or pads that are not illustrated may be further disposed in the display panel (PNL).

[0053] Referring to FIG. 3, a display panel (PNL) may include a substrate (SUB) and a pixel unit (PXU) disposed on the substrate (SUB). The pixel unit (PXU) may include first pixels (PXL1), second pixels (PXL2) and / or third pixels (PXL3). Hereinafter, when arbitrarily referring to at least one pixel among the first pixels (PXL1), second pixels (PXL2) and third pixels (PXL3), or when referring to two or more types of pixels collectively, it will be referred to as "pixel (PXL)" or "pixels (PXL)".

[0054] The substrate (SUB) constitutes the base member of the display panel (PNL) and may be a rigid or flexible substrate or film. For example, the substrate (SUB) may be a rigid substrate made of glass or reinforced glass, or a flexible substrate made of plastic or metal (or a thin film), and the material and / or physical properties of the substrate (SUB) are not particularly limited.

[0055] A display panel (PNL) and a substrate (SUB) for forming the same may include a display area (DA) for displaying an image and a non-display area (NDA) excluding the display area (DA). Pixels (PXL) may be arranged in the display area (DA). Various wirings, pads, and / or embedded circuits connected to the pixels (PXL) of the display area (DA) may be arranged in the non-display area (NDA). The pixels (PXL) may be arranged regularly according to a stripe or pentile arrangement structure, etc. However, the arrangement structure of the pixels (PXL) is not limited thereto, and the pixels (PXL) may be arranged in the display area (DA) in various structures and / or ways.

[0056] According to an embodiment, two or more types of pixels (PXL) emitting different colors of light may be arranged in a display area (DA). For example, first pixels (PXL1) emitting a first color of light, second pixels (PXL2) emitting a second color of light, and third pixels (PXL3) emitting a third color of light may be arranged in the display area (DA). At least one first to third pixel (PXL1, PXL2, PXL3) arranged adjacent to each other may constitute a single pixel unit (PXU) capable of emitting various colors of light. For example, the first to third pixels (PXL1, PXL2, PXL3) may each be a sub-pixel emitting a predetermined color of light. According to an embodiment, the first pixel (PXL1) may be a red pixel emitting red light, the second pixel (PXL2) may be a green pixel emitting green light, and the third pixel (PXL3) may be a blue pixel emitting blue light, but is not limited thereto.

[0057] In one embodiment, the first pixel (PXL1), the second pixel (PXL2), and the third pixel (PXL3) each have light-emitting elements that emit light of the same color, and by including different colored color conversion layers and / or color filters disposed on each light-emitting element, they may emit light of the first color, the second color, and the third color, respectively. In another embodiment, the first pixel (PXL1), the second pixel (PXL2), and the third pixel (PXL3) each may emit light of the first color, the second color, and the third color, respectively, by having a light-emitting element of the first color, a light-emitting element of the second color, and a light-emitting element of the third color, respectively, as light sources. However, the color, type, and / or number, etc., of the pixels (PXL) constituting each pixel unit (PXU) are not particularly limited. That is, the color of the light emitted by each pixel (PXL) can be varied.

[0058] A pixel (PXL) may include at least one light source driven by a predetermined control signal (e.g., a scan signal and a data signal) and / or a predetermined power source (e.g., a first power source and a second power source). In one embodiment, the light source may include at least one light-emitting element (LD) according to any one of the embodiments of FIGS. 1 and FIGS. 2, for example, a microscopic pillar-shaped light-emitting element (LD) having a size small to the nanometer scale or micrometer scale. However, it is not necessarily limited thereto, and various other types of light-emitting elements (LDs) may be used as the light source of the pixel (PXL).

[0059] In one embodiment, each pixel (PXL) may be composed of an active pixel. However, the type, structure, and / or driving method of the pixels (PXL) that can be applied to the display device is not particularly limited. For example, each pixel (PXL) may be composed of a pixel of a passive or active light-emitting display device with various structures and / or driving methods.

[0060] FIG. 4 is a circuit diagram showing a pixel according to one embodiment.

[0061] According to an embodiment, the pixel (PXL) illustrated in FIG. 4 may be any one of the first pixel (PXL1), the second pixel (PXL2), and the third pixel (PXL3) provided in the display panel (PNL) of FIG. 3. The first pixel (PXL1), the second pixel (PXL2), and the third pixel (PXL3) may have substantially the same or similar structure to each other.

[0062] Referring to FIG. 4, the pixel (PXL) may include a light-emitting unit (LSU) for generating light of brightness corresponding to a data signal, and a pixel circuit (PXC) for driving the light-emitting unit (LSU).

[0063] The light-emitting unit (LSU) may include at least one light-emitting element (LD) connected between a first power source (VDD) and a second power source (VSS). For example, the light-emitting unit (LSU) may include a first electrode (ELT1) connected to the first power source (VDD) via a pixel circuit (PXC) and a first power line (PL1), a second electrode (ELT2) connected to the second power source (VSS) via a second power line (PL2), and a plurality of light-emitting elements (LDs) electrically connected between the first and second electrodes (ELT1, ELT2). In one embodiment, the first electrode (ELT1) may be an anode electrode and the second electrode (ELT2) may be a cathode electrode.

[0064] Each light-emitting element (LD) may include a first end connected to a first power source (VDD) via a first electrode (ELT1) and / or a pixel circuit (PXC), and a second end connected to a second power source (VSS) via a second electrode (ELT2). That is, the light-emitting elements (LD) may be forward-connected between the first and second electrodes (ELT1, ELT2). Each light-emitting element (LD) forward-connected between the first power source (VDD) and the second power source (VSS) constitutes an effective light source, and these effective light sources may be combined to form a light-emitting unit (LSU) of a pixel (PXL).

[0065] The first power supply (VDD) and the second power supply (VSS) may have different potentials so that the light-emitting elements (LDs) can emit light. For example, the first power supply (VDD) may be set to a high potential power supply, and the second power supply (VSS) may be set to a low potential power supply. In this case, the potential difference between the first power supply (VDD) and the second power supply (VSS) may be set to be greater than or equal to the threshold voltage of the light-emitting elements (LDs) at least during the light-emitting period of the pixel (PXL).

[0066] One end of each light-emitting element (LD) constituting each light-emitting unit (LSU) is commonly connected to a pixel circuit (PXC) through one electrode of the light-emitting unit (LSU) (for example, the first electrode (ELT1) of each pixel (PXL)), and can be connected to a first power source (VDD) through the pixel circuit (PXC) and a first power line (PL1). The other end of the light-emitting element (LD) can be commonly connected to a second power source (VSS) through another electrode of the light-emitting unit (LSU) (for example, the second electrode (ELT2) of each pixel (PXL)) and a second power line (PL2).

[0067] Light-emitting elements (LDs) can emit light with a brightness corresponding to the driving current supplied through the corresponding pixel circuit (PXC). For example, during each frame period, the pixel circuit (PXC) can supply a driving current to the light-emitting unit (LSU) corresponding to the grayscale value to be expressed in that frame. The driving current supplied to the light-emitting unit (LSU) can be divided and flow to the light-emitting elements (LDs) connected in the forward direction. Accordingly, as each light-emitting element (LD) emits light with a brightness corresponding to the current flowing therethrough, the light-emitting unit (LSU) can emit light with a brightness corresponding to the driving current.

[0068] The pixel circuit (PXC) can be connected between the first power supply (VDD) and the first electrode (ELT1). The pixel circuit (PXC) can be connected to the scan line (Si) and data line (Dj) of the corresponding pixel (PXL). For example, if the pixel (PXL) is placed in the i-th (i is a natural number) horizontal line (row) and the j-th (j is a natural number) vertical line (column) of the display area (DA), the pixel circuit (PXC) can be connected to the i-th scan line (Si) and the j-th data line (Dj) of the display area (DA).

[0069] According to an embodiment, the pixel circuit (PXC) may include a plurality of transistors (T1, T2, T3) and at least one storage capacitor (Cst).

[0070] The first transistor (T1) can be connected between the first power supply (VDD) and the light-emitting unit (LSU). For example, the first electrode (e.g., drain electrode) of the first transistor (T1) can be connected to the first power supply (VDD), and the second electrode (e.g., source electrode) of the first transistor (T1) can be connected to the first electrode (ELT1). The gate electrode of the first transistor (T1) can be connected to the first node (N1). This first transistor (T1) can control the driving current supplied to the light-emitting unit (LSU) in response to the voltage of the first node (N1). That is, the first transistor (T1) can be a driving transistor that controls the driving current of the pixel (PXL).

[0071] The second transistor (T2) can be connected between the data line (Dj) and the first node (N1). For example, the first electrode of the second transistor (T2) can be connected to the data line (Dj), and the second electrode of the second transistor (T2) can be connected to the first node (N1). The gate electrode of the second transistor (T2) can be connected to the scan line (Si). The second transistor (T2) can be turned on when a scan signal (SSi) of gate-on voltage (e.g., low-level voltage) is supplied from the scan line (Si), thereby electrically connecting the data line (Dj) and the first node (N1).

[0072] For each frame period, the data signal (DSj) of the corresponding frame is supplied to the data line (Dj), and the data signal (DSj) can be transmitted to the first node (N1) through the second transistor (T2) which is turned on during the period when the scan signal (SSi) of the gate-on voltage is supplied. That is, the second transistor (T2) may be a switching transistor for transmitting each data signal (DSj) into the pixel (PXL).

[0073] The third transistor (T3) can be connected between the first transistor (T1) and the sensing line (SLj). For example, one electrode of the third transistor (T3) can be connected to the second electrode (e.g., source electrode) of the first transistor (T1) which is connected to the first electrode (ELT1), and the other electrode of the third transistor (T3) can be connected to the sensing line (SLj). Meanwhile, if the sensing line (SLj) is omitted, the other electrode of the third transistor (T3) may be connected to the data line (Dj).

[0074] The gate electrode of the third transistor (T3) can be connected to the sensing control line (SCLi). If the sensing control line (SCLi) is omitted, the gate electrode of the third transistor (T3) can be connected to the scanning line (Si). The third transistor (T3) can be turned on by a sensing control signal (SCSi) of a gate-on voltage (e.g., a high-level voltage) supplied to the sensing control line (SCLi) during a predetermined sensing period, thereby electrically connecting the sensing line (SLj) and the first transistor (T1).

[0075] According to the embodiment, the sensing period may be a period for extracting the characteristics of each pixel (PXL) placed in the display area (DA) (e.g., threshold voltage of the first transistor (T1)). During the sensing period, the first transistor (T1) may be turned on by supplying a predetermined reference voltage to the first node (N1) through the data line (Dj) and the second transistor (T2) to turn on the first transistor (T1), or by connecting each pixel (PXL) to a current source, etc. Additionally, the first transistor (T1) may be connected to the sensing line (SLj) by turning on the third transistor (T3) by supplying a sensing control signal (SCSi) of the gate-on voltage to the third transistor (T3). Subsequently, a sensing signal (SENj) is acquired through the sensing line (SLj), and the characteristics of each pixel (PXL), including the threshold voltage of the first transistor (T1), can be detected using the sensing signal (SENj). Information regarding the characteristics of each pixel (PXL) can be used to convert image data so that characteristic deviations between pixels (PXL) placed in the display area (DA) can be compensated.

[0076] One electrode of the storage capacitor (Cst) may be connected to the second electrode of the first transistor (T1), and the other electrode may be connected to the first node (N1). The storage capacitor (Cst) may charge a voltage corresponding to the data signal (DSj) supplied to the first node (N1) during each frame period.

[0077] Meanwhile, FIG. 4 discloses an embodiment in which the first, second, and third transistors (T1, T2, T3) are all n-type transistors, but is not necessarily limited thereto. The invention is not limited thereto. For example, at least one of the first, second, and third transistors (T1, T2, T3) may be changed to a p-type transistor.

[0078] Additionally, FIG. 4 illustrates an embodiment in which the effective light sources, i.e., the light-emitting elements (LDs), constituting each light-emitting unit (LSU) are all connected in parallel, but is not necessarily limited thereto. For example, the light-emitting unit (LSU) of each pixel (PXL) may be configured to include at least two series structures. In this case, the light-emitting elements constituting each series stage may be connected in series with each other by at least one intermediate electrode.

[0079] FIG. 5 is a plan view showing a pixel according to one embodiment. FIGS. 6 to 9 are cross-sectional views cut along the line AA' of FIG. 5.

[0080] For example, FIG. 5 may be any one of the first to third pixels (PXL1, PXL2, PXL3) constituting the pixel unit (PXU) of FIG. 3, and the first to third pixels (PXL1, PXL2, PXL3) may have substantially the same or similar structure to each other.

[0081] Each pixel (PXL) may include a first alignment electrode (ME1) and a second alignment electrode (ME2), light-emitting elements (LD), and a first auxiliary electrode (AE1) and a second auxiliary electrode (AE2).

[0082] The first and second alignment electrodes (ME1, ME2) each extend in the second direction (Y-axis direction) and may be spaced apart from each other along the first direction (X-axis direction). However, this is not necessarily limited thereto, and the shape and / or mutual arrangement relationship of the first and second alignment electrodes (ME1, ME2) may be varied.

[0083] The first and second alignment electrodes (ME1, ME2) can receive an alignment signal (or alignment voltage) during the alignment step of the light-emitting elements (LD). Accordingly, an electric field is formed between the first and second alignment electrodes (ME1, ME2), so that the light-emitting elements (LD) supplied to each pixel (PXL) can be aligned between the first and second alignment electrodes (ME1, ME2).

[0084] The first alignment electrode (ME1) is electrically connected to the second power supply (VSS) (or second power line (PL2)) described with reference to FIG. 4 through the first contact hole (CNT1), and the second alignment electrode (ME2) can be electrically connected to the first transistor (T1) described with reference to FIG. 4, etc. For example, the first alignment electrode (ME1) may correspond to the second electrode (ELT2) of FIG. 4, and the second alignment electrode (ME2) may correspond to the first electrode (ELT1) of FIG. 4.

[0085] Light-emitting elements (LDs) can be placed between first and second alignment electrodes (ME1, ME2). Light-emitting elements (LDs) can be aligned with directionality between the first and second alignment electrodes (ME1, ME2). For example, when the light-emitting elements (LDs) are biased in the forward direction, the first end (EP1) of the light-emitting elements (LDs) may face the second alignment electrode (ME2), and the second end (EP2) of the light-emitting elements (LDs) may face the first alignment electrode (ME1).

[0086] According to an embodiment, light-emitting elements (LDs) are prepared in a dispersed form within a predetermined solution and can be supplied to each pixel (PXL) through an inkjet printing method or a slit coating method. As an example, light-emitting elements (LDs) can be mixed with a volatile solvent and supplied to each pixel (PXL). At this time, when a predetermined voltage is applied between the first and second alignment electrodes (ME1, ME2), an electric field is formed between the first and second alignment electrodes (ME1, ME2), and light-emitting elements (LDs) can be aligned between the first and second alignment electrodes (ME1, ME2). After the light-emitting elements (LDs) are aligned, the solvent can be evaporated or removed by other means, thereby allowing the light-emitting elements (LDs) to be stably arranged between the first and second alignment electrodes (ME1, ME2).

[0087] The first and second auxiliary electrodes (AE1, AE2) each extend in the second direction (Y-axis direction) and may be spaced apart from each other along the first direction (X-axis direction). The first and second auxiliary electrodes (AE1, AE2) may be separated and spaced apart from the first and second alignment electrodes (ME1, ME2).

[0088] In one embodiment, the first and second auxiliary electrodes (AE1, AE2) may be positioned between the first alignment electrode (ME1) and the second alignment electrode (ME2). The first auxiliary electrode (AE1) may be positioned between the first alignment electrode (ME1) and the light-emitting elements (LD), and the second auxiliary electrode (AE2) may be positioned between the second alignment electrode (ME2) and the light-emitting elements (LD). That is, the first auxiliary electrode (AE1) may be positioned on one side of the light-emitting elements (LD), and the second auxiliary electrode (AE2) may be positioned on the other side of the light-emitting elements (LD). For example, the first auxiliary electrode (AE1) may be adjacent to the second end (EP2) of the light-emitting elements (LD), and the second auxiliary electrode (AE2) may be adjacent to the first end (EP1) of the light-emitting elements (LD). However, this is not necessarily limited thereto, and the shape and / or mutual arrangement relationship of the first and second auxiliary electrodes (AE1, AE2) may be varied.

[0089] The width of the first direction (X-axis direction) of the first and second auxiliary electrodes (AE1, AE2) may differ from the width of the first direction (X-axis direction) of the first and second alignment electrodes (ME1, ME2). For example, the width of the first direction (X-axis direction) of the first and second auxiliary electrodes (AE1, AE2) may be smaller than the width of the first direction (X-axis direction) of the first and second alignment electrodes (ME1, ME2), but is not necessarily limited thereto. For example, the width of the first direction (X-axis direction) of the first and second auxiliary electrodes (AE1, AE2) may be varied in consideration of the space in which the electrodes and light-emitting elements (LDs) are placed within the pixel (PXL).

[0090] The first and second auxiliary electrodes (AE1, AE2) may receive an auxiliary signal (or auxiliary voltage) during the alignment step of the light-emitting elements (LD). For example, the first and second auxiliary electrodes (AE1, AE2) may be electrically isolated from the first and second alignment electrodes (ME1, ME2) to receive an auxiliary signal different from the alignment signal. In this way, when an auxiliary signal is supplied to the first and second auxiliary electrodes (AE1, AE2), the direction of the electric field can be maintained constant using the auxiliary signal even if the direction of the electric field caused by the alignment signal changes, thereby improving the deflection alignment efficiency of the light-emitting elements (LD). Reference is made to FIGS. 10 and FIGS. 11 for a detailed explanation of this.

[0091] FIG. 10 shows an alignment signal and an auxiliary signal according to one embodiment. FIG. 11 shows an electric field according to the alignment signal and the auxiliary signal of FIG. 10.

[0092] Referring to FIGS. 10 and 11, a first alignment signal (M1) may be supplied to a first alignment electrode (ME1), and a second alignment signal (M2) may be supplied to a second alignment electrode (ME2). For example, the first alignment signal (M1) may be an AC signal, and the second alignment signal (M2) may be a DC signal. FIG. 10 illustrates a case where the first alignment signal (M1) is an AC signal with an asymmetric waveform and the second alignment signal (M2) is a DC signal with a ground potential, but is not necessarily limited thereto.

[0093] When a predetermined alignment signal (M1, M2) is supplied to the first and second alignment electrodes (ME1, ME2), an electric field (Em) is formed between the first and second alignment electrodes (ME1, ME2), and light-emitting elements (LDs) can be aligned between the first and second alignment electrodes (ME1, ME2). At this time, the direction of the electric field (Em) caused by the alignment signal (M1, M2) can be periodically switched. For example, in FIG. 11, the sign of the electric field (E) indicates the direction of the electric field, and the electric field (Em) caused by the alignment signal (M1, M2) can be changed to the opposite direction based on the first time point (t1). In this way, when the direction of the electric field (Em) changes, the rotation direction of the light-emitting elements (LDs) can be changed depending on the direction in which the electric field (Em) is formed. For example, during the first period (0 to t1), the light-emitting elements (LDs) rotate in the forward direction and are aligned in the forward direction, and during the second period (t1 to t2), an electric field (Em) is formed in the opposite direction, causing the light-emitting elements (LDs) to rotate in the reverse direction, which may reduce the alignment of the light-emitting elements (LDs). Accordingly, a display device according to one embodiment can minimize the rotation of the light-emitting elements (LDs) in the reverse direction during the second period (t1 to t2) by supplying auxiliary signals (A1, A2) to the first and second auxiliary electrodes (AE1, AE2).

[0094] A first auxiliary signal (A1) may be supplied to the first auxiliary electrode (AE1), and a second auxiliary signal (A2) may be supplied to the second auxiliary electrode (AE2). When a predetermined auxiliary signal (A1, A2) is supplied to the first and second auxiliary electrodes (AE1, AE2), an electric field (Ea) is formed between the first and second auxiliary electrodes (AE1, AE2), and the light-emitting elements (LD) may rotate and be aligned.

[0095] As described above, in order to minimize the reverse rotation of the light-emitting elements (LDs) by forming an electric field (Em) by the alignment signals (M1, M2) in the opposite direction during the second period (t1~t2), the first auxiliary signal (A1) may be composed of a signal with a different phase from the first alignment signal (M1). For example, the first auxiliary signal (A1) may be a signal having the same amplitude as the first alignment signal (M1) but with a phase difference. For example, the first auxiliary signal (A1) may be a signal generated by phase-modulating the first alignment signal (M1) by 180° using a phase shifter (for example, by sequentially phase-delaying). For example, when the first alignment signal (M1) is set to a negative voltage during the second period (t1~t2), the first auxiliary signal (A1) may be set to a positive voltage. Accordingly, even if the electric field (Em) by the alignment signals (M1, M2) is formed in the opposite direction during the second period (t1~t2), an electric field (Ea) can be formed using auxiliary signals (A1, A2) so that the light-emitting elements (LD) can rotate in the forward direction.

[0096] In one embodiment, the first auxiliary signal (A1) may be an AC signal, and the second auxiliary signal (A2) may be a DC signal. The first auxiliary signal (A1) may be an AC signal with an asymmetric waveform, and the second auxiliary signal (A2) may be a DC signal having a ground potential. For example, as shown in FIG. 10, the time at which the first auxiliary signal (A1) changes from 0 to a maximum value and the time at which the first auxiliary signal (A1) changes from 0 to a minimum value during the second period (t1 to t2) may be different. In this way, when auxiliary signals (A1, A2) with an asymmetric waveform are applied, the strength and direction of the electric field (Ea) caused by the auxiliary signals (A1, A2) may be formed asymmetrically. Accordingly, as illustrated in FIG. 11, even if the electric field (Em) formed by the alignment signals (M1, M2) is formed in the opposite direction during the second period (t1~t2), the direction and strength of the electric field (Ea) can be controlled by applying auxiliary signals (A1, A2) of an asymmetric waveform to form an electric field (Ea) that allows the light-emitting elements (LD) to rotate in the forward direction. That is, since the rotation of the light-emitting elements (LD) in the reverse direction during the second period (t1~t2) can be minimized, the deflection alignment efficiency of the light-emitting elements (LD) can be improved.

[0097] Referring again to FIG. 5, a pixel (PXL) according to one embodiment may further include connecting electrodes (CE1, CE2) that electrically connect alignment electrodes (ME1, ME2) and light-emitting elements (LD). A first connecting electrode (CE1) is disposed on a second end (EP2) of a first alignment electrode (ME1) and light-emitting elements (LD) and can come into contact with the second end (EP2) of the first alignment electrode (ME1) and light-emitting elements (LD). That is, the first connecting electrode (CE1) can electrically connect the first alignment electrode (ME1) and light-emitting elements (LD). A second connecting electrode (CE2) is disposed on a first end (EP1) of a second alignment electrode (ME2) and light-emitting elements (LD) and can come into contact with the first end (EP1) of the second alignment electrode (ME2) and light-emitting elements (LD). That is, the second connecting electrode (CE2) can electrically connect the second alignment electrode (ME2) and the light-emitting elements (LD). The first and second connecting electrodes (CE1, CE2) may extend along the second direction (Y-axis direction), but are not necessarily limited thereto.

[0098] According to an embodiment, the pixel (PXL) may further include bank patterns (BNP) that overlap at least partially with the first and second alignment electrodes (ME1, ME2). The bank patterns (BNP) are spaced apart from each other within each pixel (PXL) and may protrude one region of each of the first and second alignment electrodes (ME1, ME2) toward the front direction of the display panel (PNL), i.e., a third direction (Z-axis direction).

[0099] Hereinafter, with reference to FIGS. 6 to 9, the cross-sectional structure of each pixel (PXL) will be described in detail, centering on the light-emitting element (LD). FIGS. 6 to 9 illustrate a transistor (T) (for example, the first transistor (T1) of FIG. 4) among the various circuit elements constituting the pixel circuit (PXC). Hereinafter, if there is no need to specify the first transistor (T1) separately, the first transistor (T1) will also be collectively referred to as "transistor (T)." Meanwhile, the structure and / or layer-by-layer position of the transistors (T) are not limited to the embodiments illustrated in FIGS. 6 to 9 and may be varied according to the embodiment. Furthermore, the transistors (T) constituting each pixel circuit (PXC) may have substantially the same or similar structures, but are not limited thereto. For example, in other embodiments, at least one of the transistors (T) constituting the pixel circuit (PXC) may have a cross-sectional structure different from the remaining transistors (T) and / or be placed on a different layer.

[0100] Referring to FIG. 6, a pixel (PXL) and a display device equipped with the same may include a substrate (SUB), a circuit layer (PCL) disposed on the substrate (SUB), and a display layer (DPL) disposed on the circuit layer (PCL). The circuit layer (PCL) may include insulating layers disposed between the transistors (T) and circuit elements constituting the pixel circuit (PXC) of each pixel (PXL).

[0101] Specifically, the substrate (SUB) constitutes the base member and may be a rigid or flexible substrate or film. For example, the substrate (SUB) may be a rigid substrate made of glass or reinforced glass, a flexible substrate made of plastic or metal (or a thin film), or at least one insulating layer. The material and / or physical properties of the substrate (SUB) are not particularly limited. In one embodiment, the substrate (SUB) may be substantially transparent. Here, "substantially transparent" may mean that it can transmit light above a certain transmittance. In another embodiment, the substrate (SUB) may be translucent or opaque. Additionally, the substrate (SUB) may include a reflective material depending on the embodiment.

[0102] Each transistor (T) may include a semiconductor pattern (SCP), a gate electrode (GAT), and first and second transistor electrodes (TE1, TE2). Meanwhile, FIG. 6 illustrates an embodiment in which the transistor (T) has first and second transistor electrodes (TE1, TE2) formed separately from the semiconductor pattern (SCP), but is not necessarily limited thereto. For example, in other embodiments, the first and / or second transistor electrodes (TE1, TE2) provided in at least one transistor (T) may be configured to be integrated with each semiconductor pattern (SCP).

[0103] A buffer layer (BFL) may be disposed on a substrate (SUB). The buffer layer (BFL) can prevent impurities from diffusing into each circuit element. The buffer layer (BFL) may be composed of a single layer, but may also be composed of at least two or more layers. When the buffer layer (BFL) is formed as multiple layers, each layer may be formed of the same material or different materials.

[0104] A semiconductor pattern (SCP) may be disposed on the buffer layer (BFL). For example, the semiconductor pattern (SCP) may include a first region in contact with a first transistor electrode (TE1), a second region in contact with a second transistor electrode (TE2), and a channel region located between the first and second regions. According to an embodiment, one of the first and second regions may be a source region and the other may be a drain region.

[0105] According to an embodiment, the semiconductor pattern (SCP) may be composed of polysilicon, amorphous silicon, oxide semiconductor, etc. Additionally, the channel region of the semiconductor pattern (SCP) may be an intrinsic semiconductor as a semiconductor pattern not doped with impurities, and the first and second regions of the semiconductor pattern (SCP) may each be a semiconductor doped with a predetermined impurity.

[0106] A gate insulating layer (GI) may be disposed on a semiconductor pattern (SCP). For example, the gate insulating layer (GI) may be disposed between the semiconductor pattern (SCP) and the gate electrode (GAT). The gate insulating layer (GI) may be composed of a single layer or multiple layers and may include various types of inorganic materials, including silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy), aluminum nitride (AlNx), aluminum oxide (AlOx), zirconium oxide (ZrOx), hafnium oxide (HfOx), or titanium oxide (TiOx).

[0107] A gate electrode (GAT) may be disposed on the gate insulating layer (GI). The gate electrode (GAT) may be disposed to overlap with the semiconductor pattern (SCP) on the gate insulating layer (GI) in a third direction (Z-axis direction).

[0108] A first interlayer insulating layer (ILD1) may be disposed on the gate electrode (GAT). For example, the first interlayer insulating layer (ILD1) may be disposed between the gate electrode (GAT) and the first and second transistor electrodes (TE1, TE2). The first interlayer insulating layer (ILD1) may be composed of a single layer or multiple layers and may include various types of inorganic materials including silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy), aluminum nitride (AlNx), aluminum oxide (AlOx), zirconium oxide (ZrOx), hafnium oxide (HfOx), or titanium oxide (TiOx).

[0109] First and second transistor electrodes (TE1, TE2) may be disposed on the first interlayer insulating layer (ILD1). The first and second transistor electrodes (TE1, TE2) may be disposed to overlap with the semiconductor pattern (SCP) in a third direction (Z-axis direction). The first and second transistor electrodes (TE1, TE2) may be electrically connected to the semiconductor pattern (SCP). For example, the first transistor electrode (TE1) may be electrically connected to a first region of the semiconductor pattern (SCP) through a contact hole penetrating the first interlayer insulating layer (ILD1) and the gate insulating layer (GI). The second transistor electrode (TE2) may be electrically connected to a second region of the semiconductor pattern (SCP) through a contact hole penetrating the first interlayer insulating layer (ILD1) and the gate insulating layer (GI). According to the embodiment, one of the first and second transistor electrodes (TE1, TE2) may be a source electrode and the other may be a drain electrode.

[0110] A second interlayer insulating layer (ILD2) may be disposed on the first and second transistor electrodes (TE1, TE2). The second interlayer insulating layer (ILD2) may be composed of a single layer or multiple layers and may include various types of inorganic materials including silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy), aluminum nitride (AlNx), aluminum oxide (AlOx), zirconium oxide (ZrOx), hafnium oxide (HfOx), or titanium oxide (TiOx).

[0111] A power line (PL) and / or a bridge pattern (BRP) may be disposed on the second interlayer insulating layer (ILD2). The power line (PL) may be made of the same conductive layer as the bridge pattern (BRP). That is, the power line (PL) and the bridge pattern (BRP) may be formed simultaneously in the same process, but are not necessarily limited thereto. The power line (PL) may constitute the second power line (PL2) described with reference to FIG. 4. The bridge pattern (BRP) may be electrically connected to the second transistor electrode (TE2) through a contact hole penetrating the second interlayer insulating layer (ILD2).

[0112] A protective layer (PSV) may be disposed on top of circuit elements including transistors (T). The protective layer (PSV) may be made of an organic material to flatten the lower step. For example, the protective layer (PSV) may include organic materials such as acrylates resin, epoxy resin, phenolic resin, polyamides resin, polyimides resin, polyesters resin, polyphenylenesulfides resin, or benzocyclobutene (BCB). However, it is not necessarily limited thereto, and the protective layer (PSV) may include various types of inorganic materials including silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy), aluminum nitride (AlNx), aluminum oxide (AlOx), zirconium oxide (ZrOx), hafnium oxide (HfOx), or titanium oxide (TiOx).

[0113] A display layer (DPL) may be disposed on the protective layer (PSV) of the circuit layer (PCL). The display layer (DPL) may include a bank pattern (BNP), first and second alignment electrodes (ME1, ME2), light-emitting elements (LD), first and second auxiliary electrodes (AE1, AE2), and first and second connecting electrodes (CE1, CE2).

[0114] A bank pattern (BNP) may be disposed on the protective layer (PSV). The bank pattern (BNP) may have various shapes depending on the embodiment. In one embodiment, the bank pattern (BNP) may have a shape protruding in a third direction (Z-axis direction) on the substrate (SUB). Additionally, the bank pattern (BNP) may be formed to have an inclined surface tilted at a predetermined angle with respect to the substrate (SUB). However, it is not necessarily limited thereto, and the bank pattern (BNP) may have side walls such as curved surfaces or stepped shapes. As an example, the bank pattern (BNP) may have a cross-section such as a semicircle or a semi-ellipse shape.

[0115] The electrodes and insulating layers disposed on top of the bank pattern (BNP) may have a shape corresponding to the bank pattern (BNP). For example, the first and second alignment electrodes (ME1, ME2) disposed on the bank pattern (BNP) may include an inclined surface or a curved surface having a shape corresponding to the shape of the bank pattern (BNP). Accordingly, the bank pattern (BNP), together with the first and second alignment electrodes (ME1, ME2) provided on top, may function as a reflective member that guides light emitted from the light-emitting elements (LD) toward the front direction of the pixel (PXL), i.e., the third direction (Z-axis direction), thereby improving the light emission efficiency of the display panel (PNL).

[0116] The bank pattern (BNP) may include at least one organic material and / or inorganic material. For example, the bank pattern (BNP) may include organic materials such as acrylates resin, epoxy resin, phenolic resin, polyamides resin, polyimides resin, polyesters resin, polyphenylenesulfides resin, or benzocyclobutene (BCB). However, it is not necessarily limited thereto, and the bank pattern (BNP) may include various types of inorganic materials including silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy), aluminum nitride (AlNx), aluminum oxide (AlOx), zirconium oxide (ZrOx), hafnium oxide (HfOx), or titanium oxide (TiOx).

[0117] First and second alignment electrodes (ME1, ME2) may be disposed on the protective layer (PSV) and the bank pattern (BNP). The first and second alignment electrodes (ME1, ME2) may be disposed spaced apart from each other. The first and second alignment electrodes (ME1, ME2) may receive an alignment signal during the alignment step of the light-emitting elements (LD) as described above. Accordingly, an electric field is formed between the first and second alignment electrodes (ME1, ME2), so that the light-emitting elements (LD) supplied to each pixel (PXL) can be aligned between the first and second alignment electrodes (ME1, ME2).

[0118] The first alignment electrode (ME1) can be electrically connected to the power line (PL) through the first contact hole (CNT1) penetrating the protective layer (PSV). The second alignment electrode (ME2) can be electrically connected to the bridge pattern (BRP) through the second contact hole (CNT2) penetrating the protective layer (PSV), and can be electrically connected to the second transistor electrode (TE2) through this.

[0119] The first and second alignment electrodes (ME1, ME2) may each include at least one conductive material. For example, the first and second alignment electrodes (ME1, ME2) may each comprise at least one metal or an alloy containing the same among various metal materials including silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), titanium (Ti), molybdenum (Mo), copper (Cu), etc., a conductive oxide such as ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), ITZO (Indium Tin Zinc Oxide), ZnO (Zinc Oxide), AZO (Aluminum Zinc Oxide), GZO (Gallium Zinc Oxide), ZTO (Zinc Tin Oxide), GTO (Gallium Tin Oxide), or FTO (Fluorine Tin Oxide), and at least one conductive material among a conductive polymer such as PEDOT, It is not necessarily limited to this.

[0120] First and second auxiliary electrodes (AE1, AE2) may be disposed on the protective layer (PSV). In one embodiment, the first and second auxiliary electrodes (AE1, AE2) may be disposed on the same layer as the first and second alignment electrodes (ME1, ME2). That is, the first and second auxiliary electrodes (AE1, AE2) may be made of the same conductive layer as the first and second alignment electrodes (ME1, ME2). The first and second auxiliary electrodes (AE1, AE2) and the first and second alignment electrodes (ME1, ME2) may be formed simultaneously in the same process, but are not necessarily limited thereto.

[0121] A first insulating layer (INS1) may be disposed on the first and second alignment electrodes (ME1, ME2) and the first and second auxiliary electrodes (AE1, AE2). The first insulating layer (INS1) may be composed of a single layer or multiple layers and may include various types of inorganic materials including silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy), aluminum nitride (AlNx), aluminum oxide (AlOx), zirconium oxide (ZrOx), hafnium oxide (HfOx), or titanium oxide (TiOx).

[0122] Meanwhile, the cross-sectional arrangement of the first and second alignment electrodes (ME1, ME2) and the first and second auxiliary electrodes (AE1, AE2) is not limited to this and can be varied according to the embodiment.

[0123] For example, the first and second alignment electrodes (ME1, ME2) and the first and second auxiliary electrodes (AE1, AE2) may be disposed on different layers. As shown in FIG. 7, the first and second alignment electrodes (ME1, ME2) may be disposed on a protective layer (PSV), and the first and second auxiliary electrodes (AE1, AE2) may be disposed on the first and second alignment electrodes (ME1, ME2). Alternatively, as shown in FIG. 8, the first and second auxiliary electrodes (AE1, AE2) may be disposed on a protective layer (PSV), and the first and second alignment electrodes (ME1, ME2) may be disposed on the first and second auxiliary electrodes (AE1, AE2). In this way, when the first and second alignment electrodes (ME1, ME2) and the first and second auxiliary electrodes (AE1, AE2) are made of different conductive layers, a second insulating layer (INS2) may be further disposed between the first and second alignment electrodes (ME1, ME2) and the first and second auxiliary electrodes (AE1, AE2). The second insulating layer (INS2) may be composed of a single layer or multiple layers and may include various types of inorganic materials including silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy), aluminum nitride (AlNx), aluminum oxide (AlOx), zirconium oxide (ZrOx), hafnium oxide (HfOx), or titanium oxide (TiOx).

[0124] Light-emitting elements (LDs) may be disposed on the first insulating layer (INS1). The light-emitting elements (LDs) may be disposed between the first and second alignment electrodes (ME1, ME2) on the first insulating layer (INS1). Additionally, the light-emitting elements (LDs) may be disposed between the first and second auxiliary electrodes (AE1, AE2) on the first insulating layer (INS1).

[0125] The light-emitting elements (LDs) are prepared in a dispersed form within a predetermined solution and can be supplied to each pixel (PXL) through an inkjet printing method or the like. For example, the light-emitting elements (LDs) can be dispersed in a volatile solvent and supplied to the light-emitting area of ​​each pixel (PXL). In the process of aligning the light-emitting elements (LDs), when an alignment signal is supplied through the first and second alignment electrodes (ME1, ME2), an electric field is formed between the first and second alignment electrodes (ME1, ME2), and the light-emitting elements (LDs) can be aligned between the first and second alignment electrodes (ME1, ME2). At this time, even if the electric field formed by the alignment signal is formed in the opposite direction, an auxiliary signal can be supplied through the first and second auxiliary electrodes (AE1, AE2) to form an electric field that allows the light-emitting elements (LDs) to rotate in the forward direction. That is, as previously explained, the deflection alignment efficiency of the light-emitting elements (LD) can be improved by using the first and second auxiliary electrodes (AE1, AE2).

[0126] After the light-emitting elements (LDs) are aligned, the solvent can be evaporated or removed by other means to stably arrange the light-emitting elements (LDs) between the first and second alignment electrodes (ME1, ME2).

[0127] A third insulating layer (INS3) may be disposed on the light-emitting elements (LD). The third insulating layer (INS3) may be partially disposed on the light-emitting elements (LD). If the third insulating layer (INS3) is formed on the light-emitting elements (LD) after the alignment of the light-emitting elements (LD) is completed, it is possible to prevent the light-emitting elements (LD) from deviating from their aligned positions. The third insulating layer (INS3) may be disposed on the light-emitting elements (LD) while exposing the first and second ends (EP1, EP2) of the light-emitting elements (LD).

[0128] The third insulating layer (INS3) may be composed of a single layer or multiple layers and may include various types of inorganic materials including silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy), aluminum nitride (AlNx), aluminum oxide (AlOx), zirconium oxide (ZrOx), hafnium oxide (HfOx), or titanium oxide (TiOx).

[0129] First and second connecting electrodes (CE1, CE2) may be disposed on the first and second ends (EP1, EP2) of the light-emitting elements (LD) exposed by the third insulating layer (INS3). The first connecting electrode (CE1) may be disposed on the second end (EP2) of the light-emitting element (LD). The first connecting electrode (CE1) may be in contact with the second end (EP2) of the light-emitting element (LD) exposed by the third insulating layer (INS3). Additionally, the first connecting electrode (CE1) may be disposed on the first alignment electrode (ME1). The first connecting electrode (CE1) may be in contact with the first alignment electrode (ME1) exposed by the first insulating layer (INS1). That is, the first connecting electrode (CE1) may electrically connect the light-emitting element (LD) and the first alignment electrode (ME1). Additionally, the first connecting electrode (CE1) may be electrically separated from the first auxiliary electrode (AE1). Accordingly, the first auxiliary electrode (AE1) may be electrically separated from the first alignment electrode (ME1) and / or light-emitting elements (LD), but is not necessarily limited thereto.

[0130] A second connecting electrode (CE2) may be placed on a first end (EP1) of a light-emitting element (LD). The second connecting electrode (CE2) may be in contact with the first end (EP1) of the light-emitting element (LD) exposed by a third insulating layer (INS3). Additionally, the second connecting electrode (CE2) may be placed on a second alignment electrode (ME2). The second connecting electrode (CE2) may be in contact with the second alignment electrode (ME2) exposed by a first insulating layer (INS1). That is, the second connecting electrode (CE2) may electrically connect the light-emitting element (LD) and the second alignment electrode (ME2). Additionally, the second connecting electrode (CE2) may be electrically separated from the second auxiliary electrode (AE2). Accordingly, the second auxiliary electrode (AE2) may be electrically separated from the second alignment electrode (ME2) and / or the light-emitting elements (LD), but is not necessarily limited thereto.

[0131] In one embodiment, the first and second connecting electrodes (CE1, CE2) may be disposed on the same layer. That is, the first and second connecting electrodes (CE1, CE2) may be made of the same conductive layer. The first and second connecting electrodes (CE1, CE2) may be formed simultaneously in the same process, but are not necessarily limited thereto.

[0132] In another embodiment, the first and second connecting electrodes (CE1, CE2) may be disposed on different layers. For example, as shown in FIG. 9, the first connecting electrode (CE1) may be disposed on a third insulating layer (INS3), and the second connecting electrode (CE2) may be disposed on the first connecting electrode (CE1). In this way, when the first and second connecting electrodes (CE1, CE2) are composed of different conductive layers, a fourth insulating layer (INS4) may be further disposed between the first connecting electrode (CE1) and the second connecting electrode (CE2). The fourth insulating layer (INS4) may cover the first connecting electrode (CE1) while exposing the first end (EP1) of the light-emitting element (LD). The second connecting electrode (CE2) may be disposed on the first end (EP1) of the light-emitting element (LD) exposed by the fourth insulating layer (INS4). In this way, when a fourth insulating layer (INS4) is disposed between connecting electrodes (CE1, CE2) composed of different conductive layers, the connecting electrodes (CE1, CE2) can be stably separated by the third insulating layer (INS3), thereby ensuring electrical stability between the first and second ends (EP1, EP2) of the light-emitting elements (LD). Accordingly, short circuit defects between the first and second ends (EP1, EP2) of the light-emitting elements (LD) can be effectively prevented.

[0133] The first and second connecting electrodes (CE1, CE2) may each be composed of various transparent conductive materials. For example, the first and second connecting electrodes (CE1, CE2) may include at least one of various transparent conductive materials including ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), ITZO (Indium Tin Zinc Oxide), ZnO (Zinc Oxide), AZO (Aluminum Zinc Oxide), GZO (Gallium Zinc Oxide), ZTO (Zinc Tin Oxide), GTO (Gallium Tin Oxide), or FTO (Fluorine Tin Oxide), and may be implemented to be substantially transparent or translucent to satisfy a predetermined light transmittance. Accordingly, light emitted from the first and second ends (EP1, EP2) of the light-emitting elements (LD) can pass through the first and second connecting electrodes (CE1, CE2) and be emitted outside the display panel (PNL).

[0134] The fourth insulating layer (INS4) may be composed of a single layer or multiple layers and may include various types of inorganic materials including silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy), aluminum nitride (AlNx), aluminum oxide (AlOx), zirconium oxide (ZrOx), hafnium oxide (HfOx), or titanium oxide (TiOx).

[0135] A fifth insulating layer (INS5) may be disposed on the first and second connecting electrodes (CE1, CE2). The fifth insulating layer (INS5) may cover the first and second connecting electrodes (CE1, CE2), light-emitting elements (LD), first and second alignment electrodes (ME1, ME2), and first and second auxiliary electrodes (AE1, AE2) disposed below. The fifth insulating layer (INS5) may be composed of a single layer or multiple layers and may include various types of inorganic materials including silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy), aluminum nitride (AlNx), aluminum oxide (AlOx), zirconium oxide (ZrOx), hafnium oxide (HfOx), or titanium oxide (TiOx).

[0136] According to the display device of the above-described embodiment, even if the electric field (Em) formed by the alignment signal (M1, M2) supplied to the alignment electrodes (ME1, ME2) is formed in the opposite direction, an auxiliary signal (A1, A2) can be supplied through the auxiliary electrodes (AE1, AE2) to form an electric field (Ea) so that the light-emitting elements (LD) can rotate in the forward direction. That is, since the rotation of the light-emitting elements (LD) in the reverse direction during the period when the electric field (Em) formed by the alignment signal (M1, M2) is formed in the opposite direction can be minimized, the deflection alignment efficiency of the light-emitting elements (LD) can be improved.

[0137] Other embodiments are described below. In the following embodiments, configurations identical to those already described are referred to by the same reference numerals, and redundant descriptions are omitted or simplified.

[0138] FIG. 12 is a plan view showing a pixel according to another embodiment. FIG. 13 is a cross-sectional view taken along the BB' line of FIG. 12. For convenience of explanation, the circuit layer (PCL) has been omitted from the cross-sectional view below.

[0139] Referring to FIGS. 12 and 13, the display device according to the present embodiment is distinguished from the embodiment of FIGS. 1 to 11 in that the alignment electrodes (ME1, ME2) are placed between the auxiliary electrodes (AE1, AE2).

[0140] Specifically, the first and second alignment electrodes (ME1, ME2) may be positioned between the first auxiliary electrode (AE1) and the second auxiliary electrode (AE2). For example, the first and second alignment electrodes (ME1, ME2) may be positioned on one side and the other side of the light-emitting elements (LD), respectively, between the first auxiliary electrode (AE1) and the second auxiliary electrode (AE2). For example, the first alignment electrode (ME1) may be positioned between the first auxiliary electrode (AE1) and the light-emitting elements (LD), and the second alignment electrode (ME2) may be positioned between the second auxiliary electrode (AE2) and the light-emitting elements (LD). The first and second alignment electrodes (ME1, ME2) and the first and second auxiliary electrodes (AE1, AE2) may be separated and spaced apart from each other.

[0141] The first and second auxiliary electrodes (AE1, AE2) may overlap at least partially with the bank patterns (BNP). For example, the first and second auxiliary electrodes (AE1, AE2) may be placed on the bank patterns (BNP). In one embodiment, the first and second auxiliary electrodes (AE1, AE2) may be placed on the same layer as the first and second alignment electrodes (ME1, ME2). However, this is not necessarily limited thereto, and as described with reference to FIGS. 7 and 8, the first and second auxiliary electrodes (AE1, AE2) and the first and second alignment electrodes (ME1, ME2) may be composed of different conductive layers.

[0142] Detailed descriptions of the other alignment electrodes (ME1, ME2) and auxiliary electrodes (AE1, AE2) have been described above with reference to FIGS. 1 to 11, so redundant content is omitted.

[0143] FIG. 14 is a plan view showing a pixel according to another embodiment. FIG. 15 is a cross-sectional view cut along the CC' line of FIG. 14.

[0144] Referring to FIGS. 14 and 15, the display device according to the present embodiment is distinguished from the embodiment of FIGS. 1 to 11 in that it further includes a third auxiliary electrode (AE3) and a fourth auxiliary electrode (AE4).

[0145] Specifically, the third and fourth auxiliary electrodes (AE3, AE4) each extend in a second direction (Y-axis direction) and may be spaced apart from each other along a first direction (X-axis direction). The third and fourth auxiliary electrodes (AE3, AE4) may be separated and spaced apart from the first and second auxiliary electrodes (AE1, AE2) and / or the first and second alignment electrodes (ME1, ME2). That is, the third and fourth auxiliary electrodes (AE3, AE4) may be electrically separated from the first and second auxiliary electrodes (AE1, AE2) and / or the first and second alignment electrodes (ME1, ME2).

[0146] In one embodiment, the third and fourth auxiliary electrodes (AE3, AE4) may be placed between the first alignment electrode (ME1) and the second alignment electrode (ME2). Additionally, the third and fourth auxiliary electrodes (AE3, AE4) may be placed between the first auxiliary electrode (AE1) and the second auxiliary electrode (AE2). The third auxiliary electrode (AE3) may be placed between the first auxiliary electrode (AE1) and the light-emitting elements (LD), and the fourth auxiliary electrode (AE4) may be placed between the second auxiliary electrode (AE2) and the light-emitting elements (LD). That is, the third auxiliary electrode (AE3) may be placed on one side of the light-emitting elements (LD), and the fourth auxiliary electrode (AE4) may be placed on the other side of the light-emitting elements (LD). For example, the third auxiliary electrode (AE3) may be adjacent to the second end (EP2) of the light-emitting elements (LD), and the fourth auxiliary electrode (AE4) may be adjacent to the first end (EP1) of the light-emitting elements (LD). However, this is not necessarily limited thereto, and the shape and / or mutual arrangement relationship of the third and fourth auxiliary electrodes (AE3, AE4) may be varied.

[0147] The width of the third and fourth auxiliary electrodes (AE3, AE4) in the first direction (X-axis direction) may differ from the width of the first and second alignment electrodes (ME1, ME2) in the first direction (X-axis direction). For example, the width of the third and fourth auxiliary electrodes (AE3, AE4) in the first direction (X-axis direction) may be smaller than the width of the first and second alignment electrodes (ME1, ME2) in the first direction (X-axis direction), but is not necessarily limited thereto. Additionally, the width of the third and fourth auxiliary electrodes (AE3, AE4) in the first direction (X-axis direction) may be substantially the same as the width of the first and second auxiliary electrodes (AE1, AE2) in the first direction (X-axis direction), but is not necessarily limited thereto. For example, the width of the third and fourth auxiliary electrodes (AE3, AE4) in the first direction (X-axis direction) can be varied by taking into account the space in which the electrodes and light-emitting elements (LD) are placed within the pixel (PXL).

[0148] The third and fourth auxiliary electrodes (AE3, AE4) may be disposed on the protective layer (PSV). The third and fourth auxiliary electrodes (AE3, AE4) may be disposed between the protective layer (PSV) and the first insulating layer (INS1). For example, the third and fourth auxiliary electrodes (AE3, AE4) may be disposed on the same layer as the first and second auxiliary electrodes (AE1, AE2). That is, the third and fourth auxiliary electrodes (AE3, AE4) may be made of the same conductive layer as the first and second auxiliary electrodes (AE1, AE2). The third and fourth auxiliary electrodes (AE3, AE4) and the first and second auxiliary electrodes (AE1, AE2) may be formed simultaneously in the same process, but are not necessarily limited thereto. For example, the third and fourth auxiliary electrodes (AE3, AE4) are composed of a different conductive layer from the first and second auxiliary electrodes (AE1, AE2), and an insulating layer may be disposed between the third and fourth auxiliary electrodes (AE3, AE4) and the first and second auxiliary electrodes (AE1, AE2).

[0149] Additionally, the third and fourth auxiliary electrodes (AE3, AE4) may be placed on the same layer as the first and second alignment electrodes (ME1, ME2). That is, the third and fourth auxiliary electrodes (AE3, AE4) may be made of the same conductive layer as the first and second alignment electrodes (ME1, ME2). The third and fourth auxiliary electrodes (AE3, AE4) and the first and second alignment electrodes (ME1, ME2) may be formed simultaneously in the same process, but are not necessarily limited thereto. For example, the third and fourth auxiliary electrodes (AE3, AE4) may be composed of a different conductive layer from the first and second alignment electrodes (ME1, ME2), and an insulating layer may be placed between the third and fourth auxiliary electrodes (AE3, AE4) and the first and second alignment electrodes (ME1, ME2). That is, the cross-sectional arrangement of the third and fourth auxiliary electrodes (AE3, AE4) may be varied.

[0150] The third and fourth auxiliary electrodes (AE3, AE4) can receive an auxiliary signal (or auxiliary voltage) together with the first and second auxiliary electrodes (AE1, AE2) during the alignment step of the light-emitting elements (LD). For example, the third and fourth auxiliary electrodes (AE3, AE4) may be electrically isolated from the first and second auxiliary electrodes (AE1, AE2) to receive different auxiliary signals. Reference is made to FIGS. 16 and 17 for a detailed explanation thereof.

[0151] FIG. 16 shows an alignment signal and an auxiliary signal according to one embodiment. FIG. 17 shows an electric field according to the alignment signal and the auxiliary signal of FIG. 16.

[0152] Referring to FIGS. 16 and 17, a first alignment signal (M1) may be supplied to a first alignment electrode (ME1), and a second alignment signal (M2) may be supplied to a second alignment electrode (ME2). For example, the first alignment signal (M1) may be an AC signal, and the second alignment signal (M2) may be a DC signal. FIG. 16 illustrates a case where the first alignment signal (M1) is an AC signal with an asymmetric waveform and the second alignment signal (M2) is a DC signal with a ground potential, but is not necessarily limited thereto.

[0153] When a predetermined alignment signal (M1, M2) is supplied to the first and second alignment electrodes (ME1, ME2), an electric field (Em) is formed between the first and second alignment electrodes (ME1, ME2), and light-emitting elements (LDs) can be aligned between the first and second alignment electrodes (ME1, ME2). At this time, the direction of the electric field (Em) caused by the alignment signal (M1, M2) may be periodically switched, and the rotation direction of the light-emitting elements (LDs) may vary depending on the direction of the electric field (Em). For example, during the first period (0 to t1), the light-emitting elements (LDs) rotate in the forward direction and are aligned in the forward direction, and during the second period (t1 to t2), the direction of the electric field (Em) is formed in the opposite direction, causing the light-emitting elements (LDs) to rotate in the reverse direction, which may reduce the degree of alignment of the light-emitting elements (LDs). Accordingly, a display device according to one embodiment can minimize the reverse rotation of light-emitting elements (LDs) during a second period (t1 to t2) by supplying auxiliary signals (A1, A2, A3, A4) to the first to fourth auxiliary electrodes (AE1, AE2, AE3, AE4).

[0154] A first auxiliary signal (A1) may be supplied to the first auxiliary electrode (AE1), and a second auxiliary signal (A2) may be supplied to the second auxiliary electrode (AE2). Additionally, a third auxiliary signal (A3) may be supplied to the third auxiliary electrode (AE3), and a fourth auxiliary signal (A4) may be supplied to the fourth auxiliary electrode (AE4).

[0155] For example, the first auxiliary signal (A1) and / or the third auxiliary signal (A3) may be an AC signal, and the second auxiliary signal (A2) and / or the fourth auxiliary signal (A4) may be a DC signal. FIG. 16 illustrates a case where the first auxiliary signal (A1) and / or the third auxiliary signal (A3) is an AC signal with an asymmetric waveform and the second auxiliary signal (A2) and / or the fourth auxiliary signal (A4) is a DC signal having a ground potential, but is not necessarily limited thereto.

[0156] When a predetermined auxiliary signal (A1, A2) is supplied to the first and second auxiliary electrodes (AE1, AE2), an electric field (Ea1) is formed between the first and second auxiliary electrodes (AE1, AE2), and the light-emitting elements (LD) can be rotated and aligned. Additionally, when a predetermined auxiliary signal (A3, A4) is supplied to the third and fourth auxiliary electrodes (AE3, AE4), an electric field (Ea2) is formed between the third and fourth auxiliary electrodes (AE3, AE4), and the light-emitting elements (LD) can be rotated and aligned. As described above, in order to minimize the rotation of the light-emitting elements (LD) in the reverse direction by the electric field (Em) caused by the alignment signal (M1, M2) being formed in the opposite direction during the second period (t1~t2), the first auxiliary signal (A1) and the third auxiliary signal (A3) may be composed of signals with a different phase from the first alignment signal (M1). For example, the first auxiliary signal (A1) and / or the third auxiliary signal (A3) may be signals having the same amplitude as the first alignment signal (M1) but with a phase difference. For example, the first auxiliary signal (A1) may be a signal generated by phase-modulating the first alignment signal (M1) by 120° (for example, by sequentially delaying the phase) using a phase shifter. Additionally, the third auxiliary signal (A3) may be a signal generated by phase-modulating the first alignment signal (M1) by 240° (for example, by sequentially delaying the phase) using a phase shifter. For example, when the first alignment signal (M1) is set to a negative voltage during the second period (t1 to t2), the first auxiliary signal (A1) and / or the third auxiliary signal (A3) may be set to a positive voltage. For example, when the first alignment signal (M1) is set to a negative voltage during the second period (t1 to t2), the first auxiliary signal (A1) can be changed from a positive voltage to a negative voltage, and the third auxiliary signal (A3) can be changed from a negative voltage to a positive voltage.For example, even if the first auxiliary signal (A1) is set to a negative voltage during the second period (t1 to t2), the third auxiliary signal (A3) can be set to a positive voltage. Additionally, even if the third auxiliary signal (A3) is set to a negative voltage during the second period (t1 to t2), the first auxiliary signal (A1) can be set to a positive voltage. Accordingly, even if the electric field (Em) caused by the alignment signals (M1, M2) is formed in the opposite direction during the second period (t1 to t2), the electric fields (Ea1, Ea2) can be formed using the auxiliary signals (A1, A2, A3, A4) to allow the light-emitting elements (LD) to rotate in the forward direction. Therefore, since the rotation of the light-emitting elements (LD) in the reverse direction during the second period (t1 to t2) can be minimized, the deflection alignment efficiency of the light-emitting elements (LD) can be improved.

[0157] FIG. 18 is a plan view showing a pixel according to another embodiment. FIG. 19 is a cross-sectional view cut along the DD' line of FIG. 18.

[0158] Referring to FIGS. 18 and 19, the display device according to the present embodiment is distinguished from the embodiment of FIGS. 14 to 17 in that the alignment electrodes (ME1, ME2) are placed between the auxiliary electrodes (AE1, AE2, AE3, AE4).

[0159] Specifically, the first and second alignment electrodes (ME1, ME2) may be positioned between the first and second auxiliary electrodes (AE1, AE2). The first alignment electrode (ME1) may be positioned between the first auxiliary electrode (AE1) and the third auxiliary electrode (AE3), and the second alignment electrode (ME2) may be positioned between the second auxiliary electrode (AE2) and the fourth auxiliary electrode (AE4).

[0160] Additionally, third and fourth auxiliary electrodes (AE3, AE4) may be placed between the first and second alignment electrodes (ME1, ME2). The third auxiliary electrode (AE3) may be placed between the first alignment electrode (ME1) and the light-emitting elements (LD), and the fourth auxiliary electrode (AE4) may be placed between the second alignment electrode (ME2) and the light-emitting elements (LD).

[0161] Detailed descriptions of the other alignment electrodes (ME1, ME2) and auxiliary electrodes (AE1, AE2, AE3, AE4) have been described above with reference to FIGS. 1 to 17, so redundant content is omitted.

[0162] FIG. 20 is a plan view showing a pixel according to another embodiment. FIG. 21 is a cross-sectional view cut along the EE' line of FIG. 20.

[0163] Referring to FIGS. 20 and 21, the display device according to the present embodiment is distinguished from the embodiments of FIGS. 14 to 19 in that the alignment electrodes (ME1, ME2) are placed between the auxiliary electrodes (AE1, AE2, AE3, AE4) and the light-emitting elements (LD).

[0164] Specifically, third and fourth auxiliary electrodes (AE3, AE4) may be disposed between the first and second auxiliary electrodes (AE1, AE2), and first and second alignment electrodes (ME1, ME2) may be disposed between the third and fourth auxiliary electrodes (AE3, AE4). That is, the third auxiliary electrode (AE3) may be disposed between the first auxiliary electrode (AE1) and the first alignment electrode (ME1), and the fourth auxiliary electrode (AE4) may be disposed between the second auxiliary electrode (AE2) and the second alignment electrode (ME2). Additionally, the first alignment electrode (ME1) may be disposed between the third auxiliary electrode (AE3) and the light-emitting elements (LD), and the second alignment electrode (ME2) may be disposed between the fourth auxiliary electrode (AE4) and the light-emitting elements (LD).

[0165] Detailed descriptions of the other alignment electrodes (ME1, ME2) and auxiliary electrodes (AE1, AE2, AE3, AE4) have been described above with reference to FIGS. 1 to 17, so redundant content is omitted.

[0166] Next, a method for manufacturing a display device according to the above-described embodiment will be described.

[0167] FIGS. 22 to 25 are cross-sectional views of process steps of a method for manufacturing a display device according to one embodiment. FIGS. 22 to 25 are cross-sectional views for explaining the method for manufacturing a display device of FIG. 5, wherein components substantially identical to those in FIG. 5 are indicated by the same reference numerals and detailed reference numerals are omitted.

[0168] Referring to FIG. 22, first, first and second aligned electrodes (ME1, ME2) and first and second auxiliary electrodes (AE1, AE2) spaced apart from each other are formed on a bank pattern (BNP).

[0169] The bank pattern (BNP) may be formed from at least one organic material and / or inorganic material. For example, the bank pattern (BNP) may be formed from organic materials such as acrylates resin, epoxy resin, phenolic resin, polyamides resin, polyimides resin, polyesters resin, polyphenylenesulfides resin, or benzocyclobutene (BCB). However, it is not necessarily limited thereto, and the bank pattern (BNP) may also be formed from various types of inorganic materials including silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy), aluminum nitride (AlNx), aluminum oxide (AlOx), zirconium oxide (ZrOx), hafnium oxide (HfOx), or titanium oxide (TiOx).

[0170] The first and second aligned electrodes (ME1, ME2) may be formed to overlap at least partially with the bank pattern (BNP). The first and second aligned electrodes (ME1, ME2) may be formed separated from each other in a first direction (X-axis direction).

[0171] The first and second auxiliary electrodes (AE1, AE2) may be formed between the first and second alignment electrodes (ME1, ME2). The first and second auxiliary electrodes (AE1, AE2) may be formed separately from the first alignment electrode (ME1) and / or the second alignment electrode (ME2).

[0172] The first and second auxiliary electrodes (AE1, AE2) can be formed simultaneously with the first and second alignment electrodes (ME1, ME2). In this case, the number of masks can be reduced, thereby simplifying the manufacturing process of the display device. However, this is not necessarily limited thereto, and the order of formation of the first and second alignment electrodes (ME1, ME2) and the first and second auxiliary electrodes (AE1, AE2) can be varied. For example, the first and second alignment electrodes (ME1, ME2) can be formed first, an insulating layer can be formed on the first and second alignment electrodes (ME1, ME2), and then the first and second auxiliary electrodes (AE1, AE2) can be formed on the insulating layer. Alternatively, first and second auxiliary electrodes (AE1, AE2) may be formed first, and then an insulating layer may be formed on the first and second auxiliary electrodes (AE1, AE2), and then first and second aligned electrodes (ME1, ME2) may be formed on the insulating layer.

[0173] Referring to FIG. 23, light-emitting elements (LDs) are subsequently provided within each pixel (PXL). The light-emitting elements (LDs) may be supplied between first and second alignment electrodes (ME1, ME2) that are spaced apart from each other. Additionally, the light-emitting elements (LDs) may be supplied between first and second auxiliary electrodes (AE1, AE2) that are spaced apart from each other. For example, the light-emitting elements (LDs) may be supplied to the light-emitting area of ​​each pixel (PXL) via an inkjet method, a slit coating method, or various other methods, but are not necessarily limited thereto.

[0174] Referring to FIGS. 24 and 25, light-emitting elements (LDs) are then aligned between first and second alignment electrodes (ME1, ME2). During the process of aligning the light-emitting elements (LDs), a first alignment signal (M1 in FIG. 10) may be applied to the first alignment electrode (ME1), and a second alignment signal (M2 in FIG. 10) may be applied to the second alignment electrode (ME2). Accordingly, an electric field (Em) is formed between the first and second alignment electrodes (ME1, ME2), so that the light-emitting elements (LDs) supplied to each pixel (PXL) can be aligned between the first and second alignment electrodes (ME1, ME2).

[0175] Additionally, during the process of aligning the light-emitting elements (LDs), a first auxiliary signal (A1 in FIG. 10) may be applied to the first auxiliary electrode (AE1), and a second auxiliary signal (A2 in FIG. 10) may be applied to the second auxiliary electrode (AE2). Accordingly, an electric field (Ea) is formed between the first and second auxiliary electrodes (AE1, AE2), thereby allowing the light-emitting elements (LDs) to be easily aligned by bias.

[0176] For example, referring to FIG. 24, an electric field (Em) may be formed between the first and second alignment electrodes (ME1, ME2) by the alignment signal (M1, M2) during the first period (0 to t1 in FIG. 11). The light-emitting elements (LDs) may be aligned directionally between the first and second alignment electrodes (ME1, ME2) by the electric field (Em) by the alignment signal (M1, M2). For example, the light-emitting elements (LDs) may be aligned in the forward direction such that the first end (EP1) faces the second alignment electrode (ME2) and the second end (EP2) faces the first alignment electrode (ME1).

[0177] Referring to FIG. 25, as described above, even if the degree of alignment of the light-emitting elements (LDs) is reduced because the electric field (Em) caused by the alignment signals (M1, M2) is formed in the opposite direction during the second period (t1 to t2 in FIG. 11), auxiliary signals (A1, A2) can be applied to the first and second auxiliary electrodes (AE1, AE2) to form an electric field (Ea) so that the light-emitting elements (LDs) can rotate in the forward direction. That is, since the rotation of the light-emitting elements (LDs) in the reverse direction during the second period (t1 to t2) can be minimized, the deflection alignment efficiency of the light-emitting elements (LDs) can be improved. To this end, the first auxiliary signal (A1) may be composed of a signal with a different phase from the first alignment signal (M1). For example, as described with reference to FIG. 10, the first auxiliary signal (A1) may be a signal having the same amplitude as the first alignment signal (M1) but with a phase difference. For example, when the first alignment signal (M1) is set to a negative voltage during the second period (t1 to t2), the first auxiliary signal (A1) may be set to a positive voltage. However, this is not necessarily limited thereto, and the waveforms of the alignment signals (M1, M2) and auxiliary signals (A1, A2) may be varied according to the embodiment by considering the direction of the electric field. In addition, the alignment signals (M1, M2) and auxiliary signals (A1, A2) have been described above with reference to FIG. 10, so redundant details are omitted.

[0178] Next, first and second connecting electrodes (CE1, CE2) can be formed on the biased light-emitting elements (LDs) to complete the display device shown in FIG. 5.

[0179] The first and second connecting electrodes (CE1, CE2) can each be formed of various transparent conductive materials. For example, the first and second connecting electrodes (CE1, CE2) include at least one of various transparent conductive materials including ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), ITZO (Indium Tin Zinc Oxide), ZnO (Zinc Oxide), AZO (Aluminum Zinc Oxide), GZO (Gallium Zinc Oxide), ZTO (Zinc Tin Oxide), GTO (Gallium Tin Oxide), or FTO (Fluorine Tin Oxide), and can be formed to be substantially transparent or translucent to satisfy a predetermined light transmittance. Accordingly, light emitted from the first and second ends (EP1, EP2) of the light-emitting elements (LD) can pass through the first and second connecting electrodes (CE1, CE2) and be emitted outside the display panel (PNL).

[0180] A first connecting electrode (CE1) is positioned on the second end (EP2) of the light-emitting elements (LD) to electrically connect the light-emitting elements (LD) and the first alignment electrode (ME1). In this case, the first connecting electrode (CE1) may be electrically separated from the first auxiliary electrode (AE1), but is not necessarily limited thereto.

[0181] A second connecting electrode (CE2) is positioned on the first end (EP1) of the light-emitting elements (LD) to electrically connect the light-emitting elements (LD) and the second alignment electrode (ME2). In this case, the second connecting electrode (CE2) may be electrically separated from the second auxiliary electrode (AE2), but is not necessarily limited thereto.

[0182] Other embodiments are described below. In the following embodiments, configurations identical to those already described are referred to by the same reference numerals, and redundant descriptions are omitted or simplified.

[0183] FIGS. 26 to 29 are cross-sectional views of process steps of a method for manufacturing a display device according to another embodiment. FIGS. 26 to 29 are cross-sectional views for explaining the method for manufacturing a display device of FIG. 14, wherein components substantially identical to those in FIG. 14 are indicated by the same reference numerals and detailed reference numerals are omitted.

[0184] Referring to FIG. 26, first, first and second aligned electrodes (ME1, ME2), first and second auxiliary electrodes (AE1, AE2), and third and fourth auxiliary electrodes (AE3, AE4) spaced apart from each other are formed on a bank pattern (BNP).

[0185] The third and fourth auxiliary electrodes (AE3, AE4) may be formed between the first alignment electrode (ME1) and the second alignment electrode (ME2). The third and fourth auxiliary electrodes (AE3, AE4) may be formed separately from the first alignment electrode (ME1) and / or the second alignment electrode (ME2). Additionally, the third and fourth auxiliary electrodes (AE3, AE4) may be formed between the first auxiliary electrode (AE1) and the second auxiliary electrode (AE2). The third and fourth auxiliary electrodes (AE3, AE4) may be formed separately from the first auxiliary electrode (AE1) and / or the second auxiliary electrode (AE2).

[0186] The third and fourth auxiliary electrodes (AE3, AE4) may be formed simultaneously with the first and second auxiliary electrodes (AE1, AE2) and / or the first and second alignment electrodes (ME1, ME2). In this case, the number of masks can be reduced, thereby simplifying the manufacturing process of the display device. However, this is not necessarily limited thereto, and the order of formation of the first and second alignment electrodes (ME1, ME2), the first and second auxiliary electrodes (AE1, AE2), and the third and fourth auxiliary electrodes (AE3, AE4) may be varied.

[0187] The manufacturing method of the bank pattern (BNP), the first and second aligned electrodes (ME1, ME2), and the first and second auxiliary electrodes (AE1, AE2) has been described with reference to FIG. 22, so the redundant content is omitted.

[0188] Referring to FIG. 27, light-emitting elements (LDs) are subsequently provided within each pixel (PXL). For example, the light-emitting elements (LDs) may be supplied to the light-emitting area of ​​each pixel (PXL) through an inkjet method, a slit coating method, or various other methods, but are not necessarily limited thereto.

[0189] Referring to FIGS. 28 and 29, light-emitting elements (LDs) are then aligned between first and second alignment electrodes (ME1, ME2). During the process of aligning the light-emitting elements (LDs), a first alignment signal (M1 in FIG. 16) may be applied to the first alignment electrode (ME1), and a second alignment signal (M2 in FIG. 16) may be applied to the second alignment electrode (ME2). Accordingly, an electric field (Em) is formed between the first and second alignment electrodes (ME1, ME2), so that the light-emitting elements (LDs) supplied to each pixel (PXL) can be aligned between the first and second alignment electrodes (ME1, ME2).

[0190] Additionally, during the process of aligning the light-emitting elements (LDs), a first auxiliary signal (A1 in FIG. 16) may be applied to the first auxiliary electrode (AE1), a second auxiliary signal (A2 in FIG. 16) may be applied to the second auxiliary electrode (AE2), a third auxiliary signal (A3 in FIG. 16) may be applied to the third auxiliary electrode (AE3), and a fourth auxiliary signal (A4 in FIG. 16) may be applied to the fourth auxiliary electrode (AE4). Accordingly, an electric field (Ea1 in FIG. 17) is formed between the first and second auxiliary electrodes (AE1, AE2), and an electric field (Ea2 in FIG. 17) is formed between the third and fourth auxiliary electrodes (AE3, AE4), thereby allowing the light-emitting elements (LDs) to be easily aligned by bias.

[0191] For example, referring to FIG. 28, an electric field (Em) may be formed between the first and second alignment electrodes (ME1, ME2) by the alignment signal (M1, M2) during the first period (0 to t1 in FIG. 16). The light-emitting elements (LD) may be aligned directionally between the first and second alignment electrodes (ME1, ME2) by the electric field (Em) by the alignment signal (M1, M2). For example, the light-emitting elements (LD) may be aligned in the forward direction such that the first end (EP1) faces the second alignment electrode (ME2) and the second end (EP2) faces the first alignment electrode (ME1).

[0192] Referring to FIG. 29, as described above, even if the degree of alignment of the light-emitting elements (LDs) is reduced because the electric field (Em) caused by the alignment signals (M1, M2) is formed in the opposite direction during the second period (t1 to t2 in FIG. 11), auxiliary signals (A1, A2, A3, A4) can be applied to the first to fourth auxiliary electrodes (AE1, AE2, AE3, AE4) to form an electric field (Ea1, Ea2) so that the light-emitting elements (LDs) can rotate in the forward direction. That is, since the rotation of the light-emitting elements (LDs) in the reverse direction during the second period (t1 to t2) can be minimized, the deflection alignment efficiency of the light-emitting elements (LDs) can be improved. To this end, the first auxiliary signal (A1) and / or the third auxiliary signal (A3) may be composed of signals with a different phase from the first alignment signal (M1). For example, as described with reference to FIG. 16, the first auxiliary signal (A1) and / or the third auxiliary signal (A3) may be signals having the same amplitude as the first alignment signal (M1) but with a phase difference. For example, the first auxiliary signal (A1) may be a signal generated by phase-modulating the first alignment signal (M1) by 120° (for example, by sequentially delaying the phase) using a phase shifter. Additionally, the third auxiliary signal (A3) may be a signal generated by phase-modulating the first alignment signal (M1) by 240° (for example, by sequentially delaying the phase) using a phase shifter. For example, when the first alignment signal (M1) is set to a negative voltage during a second period (t1 to t2), the first auxiliary signal (A1) and / or the third auxiliary signal (A3) may be set to a positive voltage. For example, when the first alignment signal (M1) is set to a negative voltage during the second period (t1 to t2), the first auxiliary signal (A1) can be changed from a positive voltage to a negative voltage, and the third auxiliary signal (A3) can be changed from a negative voltage to a positive voltage.For example, even if the first auxiliary signal (A1) is set to a negative voltage during the second period (t1 to t2), the third auxiliary signal (A3) may be set to a positive voltage. Additionally, even if the third auxiliary signal (A3) is set to a negative voltage during the second period (t1 to t2), the first auxiliary signal (A1) may be set to a positive voltage. However, this is not necessarily limited thereto, and the waveforms of the alignment signals (M1, M2) and auxiliary signals (A1, A2, A3, A4) may be varied according to the embodiment by considering the direction of the electric field. Furthermore, since the alignment signals (M1, M2) and auxiliary signals (A1, A2, A3, A4) have been described above with reference to FIG. 16, redundant details are omitted.

[0193] Next, first and second connecting electrodes (CE1, CE2) can be formed on the biased light-emitting elements (LDs) to complete the display device shown in FIG. 14.

[0194] A first connecting electrode (CE1) is positioned on a second end (EP2) of the light-emitting elements (LD) to electrically connect the light-emitting elements (LD) and the first alignment electrode (ME1). In this case, the first connecting electrode (CE1) may be electrically separated from the first auxiliary electrode (AE1) and / or the third auxiliary electrode (AE3), but is not necessarily limited thereto.

[0195] A second connecting electrode (CE2) is positioned on the first end (EP1) of the light-emitting elements (LD) to electrically connect the light-emitting elements (LD) and the second alignment electrode (ME2). In this case, the second connecting electrode (CE2) may be electrically separated from the second auxiliary electrode (AE2) and / or the fourth auxiliary electrode (AE4), but is not necessarily limited thereto.

[0196] Those skilled in the art related to the embodiments will understand that the above-described embodiments may be implemented in modified forms without departing from the essential characteristics of the description. Therefore, the disclosed methods should be considered in an illustrative rather than a restrictive sense. The scope of the invention is defined by the claims, not by the foregoing description, and all variations within the equivalent scope should be interpreted as being included in the invention. Explanation of the symbols

[0197] PXL: Pixels LD: Light-emitting element ME1: First alignment electrode ME2: Second alignment electrode AE1: First auxiliary electrode AE2: Second auxiliary electrode M1: First alignment signal M2: Second alignment signal A1: First auxiliary signal A2: Second auxiliary signal

Claims

Claim 1 A display device comprising: a first alignment electrode and a second alignment electrode spaced apart from each other; light-emitting elements disposed between the first alignment electrode and the second alignment electrode; a first auxiliary electrode disposed on one side of the light-emitting element and separated from the first alignment electrode; and a second auxiliary electrode disposed on the other side of the light-emitting element and separated from the second alignment electrode, wherein an alignment signal is applied to the first alignment electrode and a first auxiliary signal having a phase different from the alignment signal is applied to the first auxiliary electrode. Claim 2 A display device according to claim 1, wherein the first auxiliary electrode is disposed between the first alignment electrode and the light-emitting elements, and the second auxiliary electrode is disposed between the second alignment electrode and the light-emitting elements. Claim 3 A display device according to claim 2, further comprising: a third auxiliary electrode disposed between the first auxiliary electrode and the light-emitting elements and separated from the first auxiliary electrode; and a fourth auxiliary electrode disposed between the second auxiliary electrode and the light-emitting elements and separated from the second auxiliary electrode. Claim 4 A display device according to claim 1, wherein the first alignment electrode is disposed between the first auxiliary electrode and the light-emitting elements, and the second alignment electrode is disposed between the second auxiliary electrode and the light-emitting elements. Claim 5 A display device according to claim 4, further comprising: a third auxiliary electrode disposed between the first alignment electrode and the light-emitting elements; and a fourth auxiliary electrode disposed between the second alignment electrode and the light-emitting elements. Claim 6 In claim 5, the third auxiliary electrode is a display device electrically separated from the first alignment electrode and the first auxiliary electrode. Claim 7 A display device according to claim 4, further comprising: a third auxiliary electrode disposed between the first auxiliary electrode and the first alignment electrode; and a fourth auxiliary electrode disposed between the second auxiliary electrode and the second alignment electrode. Claim 8 In claim 7, the third auxiliary electrode is a display device that receives the alignment signal and a second auxiliary signal having a different phase from the first auxiliary signal. Claim 9 In claim 1, the first auxiliary electrode is a display device disposed on the same layer as the first alignment electrode. Claim 10 A display device according to claim 1, further comprising an insulating layer disposed between the first auxiliary electrode and the first alignment electrode. Claim 11 A display device according to claim 1, further comprising: a first connecting electrode electrically connecting one end of the first alignment electrode and the light-emitting elements; and a second connecting electrode electrically connecting the other end of the second alignment electrode and the light-emitting elements. Claim 12 In claim 1, the light-emitting elements are a display device electrically separated from the first auxiliary electrode and the second auxiliary electrode. Claim 13 A method for manufacturing a display device comprising: a step of forming a first alignment electrode and a second alignment electrode spaced apart from each other; a step of forming a first auxiliary electrode and a second auxiliary electrode separated from the first alignment electrode and the second alignment electrode; and a step of aligning light-emitting elements between the first alignment electrode and the second alignment electrode, wherein in the step of aligning the light-emitting elements, an alignment signal is applied to the first alignment electrode and a first auxiliary signal having a phase different from the alignment signal is applied to the first auxiliary electrode. Claim 14 A method for manufacturing a display device according to claim 13, wherein when the alignment signal is set to a negative polarity voltage, the first auxiliary signal is set to a positive polarity voltage. Claim 15 A method for manufacturing a display device according to claim 13, wherein, in the step of aligning the light-emitting elements, a ground voltage is applied to the second alignment electrode and the second auxiliary electrode. Claim 16 A method for manufacturing a display device according to claim 13, wherein the first alignment electrode and the first auxiliary electrode are formed simultaneously. Claim 17 A method for manufacturing a display device according to claim 13, further comprising the step of forming a third auxiliary electrode separated from the first auxiliary electrode and the second auxiliary electrode, and a fourth auxiliary electrode, wherein, in the step of aligning the light-emitting elements, the alignment signal and a second auxiliary signal having a different phase from the first auxiliary signal are applied to the third auxiliary electrode. Claim 18 A method for manufacturing a display device according to claim 17, wherein during the period in which the alignment signal is set to a negative polarity voltage, the first auxiliary signal is changed from a positive polarity voltage to a negative polarity voltage and the second auxiliary signal is changed from a negative polarity voltage to a positive polarity voltage. Claim 19 A method for manufacturing a display device according to claim 17, wherein, in the step of aligning the light-emitting elements, a ground voltage is applied to the fourth auxiliary electrode. Claim 20 A method for manufacturing a display device according to claim 17, wherein the first auxiliary electrode and the third auxiliary electrode are formed simultaneously.

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