Light-emitting element and display device including the same

Abstract

The light emitting element includes: an active layer; a plurality of first conductive type semiconductor layers located below the active layer; and a plurality of second conductive type semiconductor layers located above the active layer. The plurality of first conductive type semiconductor layers includes an adsorption prevention layer that is farthest away from the active layer. The adsorption prevention layer contains Al x1 Ga 1‑x1 For InP, x1 can be 0.6 or less, and the thickness of the adsorption prevention layer can be 2 μm or less.

Description

Technical Field

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

[0002] Display devices use self-luminous elements such as light-emitting diodes (LEDs) as light sources for pixels, displaying high-quality images. LEDs exhibit excellent durability even in harsh environments, and they offer long life and high brightness, making them a popular light source for next-generation display devices.

[0003] In recent years, research has been underway to manufacture ultra-small light-emitting diodes using highly reliable inorganic crystalline materials and to deploy them in panels of display devices (hereinafter referred to as "display panels") for use as next-generation pixel light sources.

[0004] To achieve high resolution, the size of pixels is gradually decreasing. Since a large number of light-emitting elements need to be aligned in such small-sized pixels, research on manufacturing ultra-small light-emitting diodes at the micron or nanometer level is being actively conducted.

[0005] Typically, a display panel includes millions of pixels. Therefore, it is difficult to align a plurality of light-emitting elements in each of the millions of pixels with a relatively small size. Therefore, various studies on schemes for aligning a plurality of light-emitting elements in a display panel are currently underway.

[0006] As light-emitting devices decrease in size, transferring them to substrates has become a crucial issue. Recently developed transfer technologies include pick-and-place processes, laser lift-off methods, and self-assembly methods. In particular, self-assembly methods, which utilize magnetic materials to transfer light-emitting devices to substrates, have recently attracted significant attention.

[0007] However, during the self-assembly process using magnetic materials, light-emitting elements can sometimes adhere to the bottom surface of the substrate instead of being assembled into designated locations on the substrate, significantly reducing the assembly rate. Light-emitting elements attached to the bottom surface of the substrate are not displaced by the magnetic material and therefore fail to be assembled into designated locations on the substrate. The assembly rate is the ratio of light-emitting elements assembled into designated locations on the substrate.

[0008] Therefore, there is an urgent need for research and development to improve the assembly rate by preventing the light emitting element from being attached to the bottom surface of the substrate during the self-assembly process. Summary of the Invention

[0009] Problems to be solved by the invention

[0010] The embodiments are directed to solving the aforementioned problems and other problems.

[0011] Another object of the embodiment is to provide a light emitting element that is not attached to the bottom surface of the substrate.

[0012] Another object of the embodiment is to provide a display device capable of improving assembly efficiency by self-assembly using light-emitting elements that are not attached to the bottom surface of a substrate.

[0013] Yet another object of the embodiment is to provide a display device capable of significantly improving the self-assembly speed by self-assembly using light-emitting elements that are not attached to the bottom surface of a substrate.

[0014] Another object of the embodiment is to provide a display device capable of improving light efficiency and ensuring high brightness by self-assembly using light-emitting elements that are not attached to the bottom surface of a substrate.

[0015] Technical solutions to the problem

[0016] According to one aspect of an embodiment for achieving the above or other purposes, a light emitting element includes: an active layer; a plurality of first conductive type semiconductor layers located below the active layer; and a plurality of second conductive type semiconductor layers located on the active layer. The plurality of first conductive type semiconductor layers include an adsorption prevention layer that is farthest away from the active layer. The adsorption prevention layer includes Al x1 Ga 1-x1 InP, the x1 can be less than 0.6, and the thickness of the adsorption prevention layer can be less than 2 μm. The above-described embodiment improves the assembly rate, improves the light efficiency, and ensures high brightness.

[0017] Effects of the Invention

[0018] The light-emitting element of the embodiment and the display device including the same have the following effects.

[0019] According to at least one embodiment, a light-emitting element comprising a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer includes an adsorption prevention layer on the first conductive semiconductor layer, thereby preventing the plurality of light-emitting elements from adsorbing to the bottom surface of the substrate during self-assembly. As a result, the plurality of light-emitting elements can be assembled into predetermined positions rather than adsorbing to the bottom surface of the substrate, significantly improving the assembly rate. As described above, as the assembly rate increases, the number of light-emitting elements provided in each sub-pixel increases, thereby improving light efficiency and achieving high brightness.

[0020] According to at least one embodiment, in a light-emitting element composed of a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer, a shielding layer capable of shielding the Al conductivity of the first conductive semiconductor layer is provided below the first conductive semiconductor layer, thereby preventing the light-emitting element from being adsorbed to the bottom surface of the substrate due to the negative (-) charge based on the Al conductivity of the first conductive semiconductor layer. As a result, a plurality of light-emitting elements can be assembled to predetermined positions rather than the bottom surface of the substrate, thereby significantly improving the assembly rate. As described above, as the assembly rate increases, the number of light-emitting elements provided in each sub-pixel increases, thereby not only improving light efficiency but also achieving high brightness.

[0021] According to at least one embodiment, a light-emitting element comprising a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer has a circular structure in which a first electrode disposed on the first conductive semiconductor layer surrounds a second electrode disposed on the second conductive semiconductor layer. This allows current to flow uniformly radially from the second electrode through the second conductive semiconductor layer, the active layer, and the first conductive semiconductor layer to the first electrode. Consequently, electrons located throughout the entire region of the first conductive semiconductor layer are injected into the active layer, contributing to light emission, thereby improving light emission efficiency.

[0022] The additional scope to which the embodiments are applicable will become clearer through the detailed description below. However, those skilled in the art will clearly understand various changes and modifications within the concept and scope of the embodiments, and therefore it should be understood that the detailed description and specific embodiments such as the preferred embodiments are only exemplary. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The living room of a house in which the display device 100 according to the embodiment is installed is shown.

[0024] Figure 2 This is a block diagram schematically showing a display device according to an embodiment.

[0025] Figure 3 It shows Figure 2 A circuit diagram of an example of a pixel.

[0026] Figure 4 It is shown in detail Figure 2 A plan view of the display panel.

[0027] Figure 5 It is shown in detail Figure 4 A plan view of pixels of the display area.

[0028] Figure 6 yes Figure 1 An enlarged view of the first panel area in the display device.

[0029] Figure 7 yes Figure 6 Magnified view of the A2 area.

[0030] Figure 8 This is a diagram showing an example in which the light-emitting element of the embodiment is assembled on a substrate by a self-assembly method.

[0031] Figure 9 shows the light emitting element through Figure 8 The morphology of the self-assembled structure inserted into the substrate is shown.

[0032] Figure 10 It is shown schematically Figure 2 A cross-sectional view of a display panel.

[0033] Figure 11 1 is a plan view showing the light emitting element according to the first embodiment.

[0034] Figure 12 is a cross-sectional view showing the light emitting element of the first embodiment.

[0035] Figure 13a shows a portion of the first conductivity type semiconductor layer of a comparative example, Figure 13b A portion of the first conductive type semiconductor layer in the light emitting element of the first embodiment is shown.

[0036] Figure 14a shows a light emitting element attached to the bottom surface of a substrate during self-assembly in a comparative example, Figure 14b The light emitting element is shown attached to the bottom surface of the substrate during self-assembly in the first embodiment.

[0037] Figure 15 The assembly and adsorption characteristics depending on the Al content of the adsorption prevention layer and the thickness of the adsorption prevention layer are shown.

[0038] Figure 16 is a cross-sectional view showing a light emitting element according to a second embodiment.

[0039] Figure 17 is a cross-sectional view showing a light emitting element according to a third embodiment. DETAILED DESCRIPTION

[0040] Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail. However, the technical concept of the present invention is not limited to the embodiments described, but can be implemented in various forms that are different from each other. As long as it is within the scope of the technical concept of the present invention, multiple components between the embodiments can be selectively combined and replaced. In addition, unless otherwise clearly defined and recorded, the terms (including technical and scientific terms) used in the embodiments of the present invention should be interpreted as the meanings commonly understood by those skilled in the art to which the present invention belongs. Like terms defined in dictionaries, commonly used terms can be interpreted in light of the contextual meaning of the relevant technology. In addition, the terms used in the embodiments of the present invention are used to illustrate the embodiments, not to limit the present invention. In this specification, unless otherwise clearly stated, a singular expression may include a plural expression. When it is recorded as "at least one (or more than one) of A, B, and (and) C", it may include one or more of all combinations that can be combined by A, B, and C. In addition, in the process of describing the components of the embodiments of the present invention, terms such as first, second, A, B, (a), (b) may be used. Such terms are only used to distinguish the component from another component, and the terms do not limit the nature, order, or sequence of the corresponding components. Furthermore, when a certain component is described as being “connected,” “combined,” or “joined” to another component, it includes not only the case where the component is directly “connected,” “combined,” or “joined” to the other component, but also the case where the component is “connected,” “combined,” or “joined” due to another component existing between the component and the other component. In addition, when it is described as being formed or arranged “on (above) or below (below)” of a component, “on (above)” or “below” includes not only the case where the two components are in direct contact with each other but also the case where one or more other components are formed or arranged between the two components. In addition, when expressed as “on (above) or below (below)”, it may include the meaning of the upper direction and the lower direction based on one component.

[0041] The display devices described in this specification may include mobile phones, smart phones, laptop computers, digital broadcast terminals, PDAs (personal digital assistants), PMPs (portable multimedia players), navigation systems, touchscreen tablet computers (Slate PCs), tablet computers (Tablet PCs), Ultrabooks, digital televisions (Digital TVs), desktop computers, etc. However, the configurations of the embodiments described in this specification may also be applied to devices of new product forms capable of displaying information that are developed in the future.

[0042] Hereinafter, a light-emitting element according to an embodiment and a display device including the light-emitting element will be described.

[0043] Figure 1 The living room of a house in which the display device 100 according to the embodiment is installed is shown.

[0044] The display device 100 of the embodiment can display the status of various electronic products such as a washing machine 101, a sweeping robot 102, and an air purifier 103, can communicate with each electronic product based on IOT, and can also control each electronic product based on user setting data.

[0045] The display device 100 of the embodiment may include a flexible display fabricated on a thin and flexible substrate. The flexible display can be bent or rolled like paper while maintaining the characteristics of conventional flat panel displays.

[0046] In a flexible display, visual information can be realized by independently controlling the light emission of unit pixels arranged in a matrix. A unit pixel is the smallest unit used to realize a color. The unit pixels of a flexible display can be realized by a semiconductor light emitting device. In an embodiment, the light emitting device can be a micro-LED, but is not limited thereto.

[0047] Figure 2 is a block diagram schematically showing a display device according to an embodiment. Figure 3 It shows Figure 2 A circuit diagram of an example of a pixel.

[0048] Reference Figure 2 and Figure 3The display device of the embodiment may include a display panel 10 , a driving circuit 20 , a scan driving unit 30 , and a power supply circuit 50 .

[0049] The display device 100 of the embodiment may drive the light emitting elements in an active matrix (AM) method or a passive matrix (PM) method.

[0050] The driving circuit 20 may include a data driving section 21 and a timing control section 22 .

[0051] The display panel 10 may be formed in a rectangular shape in a plane. The plane shape of the display panel 10 is not limited to a rectangle, and may be formed in various polygonal, circular, or elliptical shapes. At least one side of the display panel 10 may be formed to be curved with a predetermined curvature.

[0052] The display panel 10 can be divided into a display area DA and a non-display area NDA arranged around the display area DA. The display area DA is an area where a plurality of pixels PX are formed to display an image. The display panel 10 may include a plurality of data lines D1 to Dm (m is an integer greater than or equal to 2), a plurality of scan lines S1 to Sn (n is an integer greater than or equal to 2) intersecting the plurality of data lines D1 to Dm, a high-potential voltage line VDDL supplied with a high-potential voltage, a low-potential voltage line VSSL supplied with a low-potential voltage, and a plurality of pixels PX connected to the plurality of data lines D1 to Dm and the plurality of scan lines S1 to Sn.

[0053] Each of the plurality of pixels PX may include a first sub-pixel PX1, a second sub-pixel PX2, and a third sub-pixel PX3. The first sub-pixel PX1 may emit a first color light, the second sub-pixel PX2 may emit a second color light, and the third sub-pixel PX3 may emit a third color light. The first color light may be red light, the second color light may be green light, and the third color light may be blue light, but is not limited thereto. In addition, Figure 2 In the example, each of the plurality of pixels PX includes three sub-pixels, but the present invention is not limited thereto. That is, each of the plurality of pixels PX may include four or more sub-pixels.

[0054] Each of the first sub-pixel PX1, the second sub-pixel PX2, and the third sub-pixel PX3 may be connected to at least one of the plurality of data lines D1 to Dm, at least one of the plurality of scan lines S1 to Sn, and a high potential voltage line VDDL. Figure 3 As shown, the first subpixel PX1 may include a plurality of transistors for supplying current to the plurality of light emitting elements LD and the plurality of light emitting elements LD, and at least one capacitor.

[0055] Each of the plurality of light emitting elements LD may be an inorganic light emitting diode including a first electrode, an inorganic semiconductor, and a second electrode. Here, the first electrode may be an anode electrode, and the second electrode may be a cathode electrode.

[0056] like Figure 3 As shown, the plurality of transistors may include a driving transistor DT that supplies current to the plurality of light-emitting elements LD; and a scanning transistor ST that supplies a data voltage to the gate electrode of the driving transistor DT. The driving transistor DT may include a gate electrode connected to the source electrode of the scanning transistor ST; a source electrode connected to a high-potential voltage line VDDL to which a high-potential voltage is applied; and a drain electrode connected to the plurality of first electrodes of the plurality of light-emitting elements LD. The scanning transistor ST may include a gate electrode connected to a scanning line Sk (k is an integer satisfying 1≤k≤n); a source electrode connected to the gate electrode of the driving transistor DT; and a drain electrode connected to a data line Dj (j is an integer satisfying 1≤j≤m).

[0057] The capacitor Cst is formed between the gate electrode and the source electrode of the driving transistor DT. The storage capacitor Cst stores a difference voltage between the gate voltage and the source voltage of the driving transistor DT.

[0058] The driving transistor DT and the scanning transistor ST may be formed by thin film transistors. Figure 3 In the above description, the driving transistor DT and the scanning transistor ST are mainly formed by P-type MOSFETs (Metal Oxide Semiconductor Field Effect Transistors), but the present invention is not limited to this. The driving transistor DT and the scanning transistor ST can also be formed by N-type MOSFETs. In this case, the positions of the source electrode and the drain electrode of each of the driving transistor DT and the scanning transistor ST can be changed.

[0059] In addition, Figure 3 In the embodiment, each of the first subpixel PX1, the second subpixel PX2, and the third subpixel PX3 includes a 2T1C (2Transistor-1 capacitor) including a driving transistor DT, a scanning transistor ST, and a capacitor Cst, but the present invention is not limited thereto. Each of the first subpixel PX1, the second subpixel PX2, and the third subpixel PX3 may include a plurality of scanning transistors ST and a plurality of capacitors Cst.

[0060] The second sub-pixel PX2 and the third sub-pixel PX3 can be represented by substantially the same circuit diagram as the first sub-pixel PX1 , and thus detailed description thereof will be omitted.

[0061] The driving circuit 20 outputs a plurality of signals and a plurality of voltages for driving the display panel 10. To this end, the driving circuit 20 may include a data driving part 21 and a timing control part 22.

[0062] The data driving unit 21 receives digital video data DATA and a source control signal DCS from the timing control unit 22 . The data driving unit 21 converts the digital video data DATA into a plurality of analog data voltages according to the source control signal DCS and supplies the analog data voltages to the plurality of data lines D1 to Dm of the display panel 10 .

[0063] The timing control unit 22 receives digital video data DATA and a plurality of timing signals from a host system. The plurality of timing signals may include a vertical sync signal, a horizontal sync signal, a data enable signal, and a dot clock. The host system may be an application processor of a smartphone or tablet PC, a system-on-chip of a display or TV, or the like.

[0064] The timing control unit 22 generates a plurality of control signals for controlling the operation timings of the data driver 21 and the scan driver 30. The plurality of control signals may include a source control signal DCS for controlling the operation timing of the data driver 21 and a scan control signal SCS for controlling the operation timing of the scan driver 30.

[0065] The driving circuit 20 can be disposed in a non-display area (NDA) provided on one side of the display panel 10. The driving circuit 20 is formed of an integrated circuit (IC) and can be mounted on the display panel 10 using a COG (chip on glass) method, a COP (chip on plastic) method, or an ultrasonic bonding method, but the present invention is not limited thereto. For example, the driving circuit 20 can be mounted on a circuit board (not shown) instead of the display panel 10.

[0066] The data driving unit 21 may be mounted on the display panel 10 by a COG (chip on glass) method, a COP (chip on plastic) method, or an ultrasonic bonding method, and the timing control unit 22 may be mounted on a circuit board.

[0067] The scan driver 30 receives a scan control signal SCS from the timing control unit 22. Based on the scan control signal SCS, the scan driver 30 generates a plurality of scan signals and supplies them to a plurality of scan lines S1 to Sn of the display panel 10. The scan driver 30 includes a plurality of transistors and may be formed in the non-display area (NDA) of the display panel 10. Alternatively, the scan driver 30 may be formed as an integrated circuit, in which case it may be mounted on a gate flexible film attached to the other side of the display panel 10.

[0068] The circuit board can be attached to a plurality of pads provided on one side edge of the display panel 10 using an anisotropic conductive film. Therefore, a plurality of leads of the circuit board can be electrically connected to the plurality of pads. The circuit board can be a flexible printed circuit board, a printed circuit board, or a flexible film such as a chip on film. The circuit board can be bent toward the lower portion of the display panel 10. Therefore, one side of the circuit board can be attached to one side edge of the display panel 10, and the other side can be configured at the lower portion of the display panel 10, and can be connected to a system board on which a host system is installed.

[0069] The power supply circuit 50 can generate a plurality of voltages required for driving the display panel 10 from a main power supply applied from a system board, and supply the voltages to the display panel 10. For example, the power supply circuit 50 can generate a high potential voltage VDD and a low potential voltage VSS from the main power supply for driving the plurality of light-emitting elements LD of the display panel 10, and supply the voltages to a high potential voltage line VDDL and a low potential voltage line VSSL of the display panel 10. Furthermore, the power supply circuit 50 generates and supplies drive voltages from the main power supply for driving the drive circuit 20 and the scan driver 30.

[0070] Figure 4 It is shown in detail Figure 2 For ease of explanation, Figure 4 Only a plurality of data pads DP1~DPp (p is an integer greater than 2), a plurality of floating pads FD1, FD2, a plurality of power pads PP1, PP2, a plurality of floating lines FL1, FL2, a low potential voltage line VSSL, a plurality of data lines D1~Dm, a plurality of first pad electrodes 210 and a plurality of second pad electrodes 220 are shown.

[0071] Reference Figure 4In the display area DA of the display panel 10 , a plurality of data lines D1 -Dm, a plurality of first pad electrodes 210 , a plurality of second pad electrodes 220 and a plurality of pixels PX may be disposed.

[0072] The plurality of data lines D1 to Dm may extend long along the second direction (Y-axis direction) and one side of the plurality of data lines D1 to Dm may be connected to the driving circuit 20. Therefore, the plurality of data voltages of the driving circuit 20 may be applied to the plurality of data lines D1 to Dm.

[0073] The plurality of first pad electrodes 210 may be spaced apart at predetermined intervals along a first direction (X-axis direction). Therefore, the plurality of first pad electrodes 210 may not overlap with the plurality of data lines D1 to Dm. Among the plurality of first pad electrodes 210, the plurality of first pad electrodes 210 disposed at the right edge of the display area DA may be connected to the first floating line FL1 in the non-display area NDA. Among the plurality of first pad electrodes 210, the plurality of first pad electrodes 210 disposed at the left edge of the display area DA may be connected to the second floating line FL2 in the non-display area NDA.

[0074] Each of the plurality of second pad electrodes 220 may extend long along the first direction (X-axis direction). Therefore, the plurality of second pad electrodes 220 may overlap the plurality of data lines D1 to Dm. Furthermore, the plurality of second pad electrodes 220 may be connected to the low-potential voltage line VSSL in the non-display area NDA. Therefore, the low-potential voltage of the low-potential voltage line VSSL may be applied to the plurality of second pad electrodes 220.

[0075] Each of the plurality of pixels PX may include a first subpixel PX1, a second subpixel PX2, and a third subpixel PX3. The first subpixel PX1, the second subpixel PX2, and the third subpixel PX3 of each of the plurality of pixels PX may be arranged in a plurality of regions defined in a matrix by a plurality of first pad electrodes 210, a second electrode, and a plurality of data lines D1 to Dm. Figure 4 exemplified in FIG. 5 that a pixel PX includes three sub-pixels, but the present invention is not limited thereto. Each of the plurality of pixels PX may include more than four sub-pixels.

[0076] The first subpixel PX1, the second subpixel PX2, and the third subpixel PX3 of each of the plurality of pixels PX may be arranged along the first direction (X-axis direction), but are not limited thereto. That is, the first subpixel PX1, the second subpixel PX2, and the third subpixel PX3 of each of the plurality of pixels PX may be arranged along the second direction (Y-axis direction) or in a zigzag pattern, or in various other shapes.

[0077] The first subpixel PX1 can emit a first color light, the second subpixel PX2 can emit a second color light, and the third subpixel PX3 can emit a third color light. The first color light can be red light, the second color light can be green light, and the third color light can be blue light, but is not limited thereto.

[0078] The non-display area NDA of the display panel 10 may include a pad portion PA including a plurality of data pads DP1 to DPp, a plurality of floating pads FD1 and FD2, and a plurality of power pads PP1 and PP2, a driving circuit 20, a first floating line FL1, a second floating line FL2, and a low potential voltage line VSSL.

[0079] The pad portion PA including the plurality of data pads DP1-DPp, the plurality of floating pads FD1, FD2, and the plurality of power pads PP1, PP2 may be disposed at a side edge, such as a lower edge, of the display panel 10. The plurality of data pads DP1-DPp, the plurality of floating pads FD1, FD2, and the plurality of power pads PP1, PP2 may be arranged side by side along a first direction (X-axis direction) on the pad portion PA.

[0080] The circuit board can be attached to the plurality of data pads DP1-DPp, the plurality of floating pads FD1, FD2, and the plurality of power pads PP1, PP2 using an anisotropic conductive film. Therefore, the circuit board and the plurality of data pads DP1-DPp, the plurality of floating pads FD1, FD2, and the plurality of power pads PP1, PP2 can be electrically connected.

[0081] The driving circuit 20 may be connected to a plurality of data pads DP1-DPp via a plurality of link lines LL. The driving circuit 20 may receive digital video data DATA and a plurality of timing signals via the plurality of data pads DP1-DPp. The driving circuit 20 may convert the digital video data DATA into a plurality of analog data voltages and supply the analog data voltages to the plurality of data lines D1-Dm of the display panel 10.

[0082] The low-potential voltage line VSSL can be connected to the first power pad PP1 and the second power pad PP2 of the pad portion PA. The low-potential voltage line VSSL can extend long along the second direction (Y-axis direction) in the non-display area NDA on the left and right sides of the display area DA. The low-potential voltage line VSSL can be connected to the second pad electrode 220. Therefore, the low-potential voltage of the power supply circuit 50 can be applied to the second pad electrode 220 through the circuit board, the first power pad PP1, the second power pad PP2, and the low-potential voltage line VSSL.

[0083] The first floating line FL1 may be connected to the first floating pad FD1 of the pad portion PA and may extend long in the second direction (Y-axis direction) in the non-display area NDA on the left and right sides of the display area DA.

[0084] The first floating pad FD1 and the first floating line FL1 may be a dummy pad and a dummy line to which no voltage is applied.

[0085] The second floating line FL2 may be connected to the second floating pad FD2 of the pad portion PA. The first floating line FL1 may extend long in the second direction (Y-axis direction) in the non-display area NDA on the left and right sides of the display area DA.

[0086] The second floating pad FD2 and the second floating line FL2 may be a dummy pad and a dummy line to which no voltage is applied.

[0087] On the other hand, a plurality of light emitting elements ( Figure 5 The pixel 300 has a very small size and is therefore difficult to be mounted on the first sub-pixel PX1, the second sub-pixel PX2, and the third sub-pixel PX3 of each of the plurality of pixels PX.

[0088] In order to solve this problem, an alignment method using dielectrophoresis has been proposed.

[0089] That is, during the manufacturing process, an electric field may be formed in the first sub-pixel PX1, the second sub-pixel PX2, and the third sub-pixel PX3 of each of the plurality of pixels PX to align the plurality of light-emitting elements 300. Specifically, during the manufacturing process, a dielectrophoretic force may be applied to the plurality of light-emitting elements 300 using dielectrophoresis to align the plurality of light-emitting elements 300.

[0090] However, it is difficult to apply a ground voltage to the plurality of first pad electrodes 210 by driving the plurality of thin film transistors during the manufacturing process.

[0091] Therefore, in the completed display device, the plurality of first pad electrodes 210 can be arranged at predetermined intervals along the first direction (X-axis direction), but during the manufacturing process, the plurality of first pad electrodes 210 can be arranged to extend long without being disconnected in the first direction (X-axis direction).

[0092] Therefore, during the manufacturing process, the plurality of first pad electrodes 210 can be connected to the first floating line FL1 and the second floating line FL2. Therefore, the plurality of first pad electrodes 210 can receive a ground voltage through the first floating line FL1 and the second floating line FL2. Therefore, during the manufacturing process, after the plurality of light-emitting elements 300 are aligned using dielectrophoresis, the plurality of first pad electrodes 210 are disconnected, allowing the plurality of first pad electrodes 210 to be spaced apart at predetermined intervals along the first direction (X-axis direction).

[0093] On the other hand, the first and second floating lines FL1 and FL2 are used to apply a ground voltage during the manufacturing process, and no voltage may be applied to the finished display device. Alternatively, a ground voltage may be applied to the first and second floating lines FL1 and FL2 to prevent static electricity in the finished display device.

[0094] Figure 5 It is shown in detail Figure 4 A plan view of pixels of the display area.

[0095] Reference Figure 5 The pixel PX may include a first subpixel PX1, a second subpixel PX2, and a third subpixel PX3. The first subpixel PX1, the second subpixel PX2, and the third subpixel PX3 of each of the plurality of pixels PX may be arranged in a matrix at a plurality of regions defined by the intersection of a plurality of scan lines Sk and a plurality of data lines Dj, Dj+1, Dj+2, and Dj+3.

[0096] A plurality of scan lines Sk can be configured to extend long along a first direction (X-axis direction), and a plurality of data lines Dj, Dj+1, Dj+2, and Dj+3 can be configured to extend long along a second direction (Y-axis direction) intersecting the first direction (X-axis direction).

[0097] Each of the first subpixel PX1, the second subpixel PX2, and the third subpixel PX3 may include a first pad electrode 210, a second pad electrode 220, and a plurality of light emitting elements 300. The first pad electrode 210 and the second pad electrode 220 may be electrically connected to the plurality of light emitting elements 300 and may receive voltages, respectively, to cause the light emitting elements 300 to emit light.

[0098] The first pad electrode 210 of one of the first subpixel PX1, the second subpixel PX2, and the third subpixel PX3 may be spaced apart from the first pad electrode 210 of the adjacent subpixel. For example, the first pad electrode 210 of the first subpixel PX1 may be spaced apart from the first pad electrode 210 of the adjacent second subpixel PX2. Furthermore, the first pad electrode 210 of the second subpixel PX2 may be spaced apart from the first pad electrode 210 of the adjacent third subpixel PX3. Furthermore, the first pad electrode 210 of the third subpixel PX3 may be spaced apart from the first pad electrode 210 of the adjacent first subpixel PX1.

[0099] In contrast, the second pad electrode 220 of one of the first, second, and third subpixels PX1, PX2, and PX3 can be connected to the second pad electrode 220 of the adjacent subpixel. For example, the second pad electrode 220 of the first subpixel PX1 can be connected to the second electrode 210 of the adjacent second subpixel PX2. Additionally, the second pad electrode 220 of the second subpixel PX2 can be connected to the second pad electrode 220 of the adjacent third subpixel PX3. Furthermore, the second pad electrode 220 of the third subpixel PX3 can be connected to the second pad electrode 220 of the adjacent first subpixel PX1.

[0100] Furthermore, during the manufacturing process, the first and second pad electrodes 210 and 220 can be used to form an electric field in each of the first, second, and third subpixels PX1, PX2, and PX3 to align the light-emitting elements 300. Specifically, during the manufacturing process, dielectrophoresis is used to apply a dielectrophoretic force to the plurality of light-emitting elements 300 to align the plurality of light-emitting elements 300. A voltage applied to the first and second pad electrodes 210 and 220 creates an electric field, which in turn forms a capacitor, thereby applying the dielectrophoretic force to the light-emitting elements 300.

[0101] The first pad electrode 210 may be an anode electrode connected to the second conductive semiconductor layer of the plurality of light-emitting elements 300, and the second pad electrode 220 may be a cathode electrode connected to the first conductive semiconductor layer of the plurality of light-emitting elements 300. The first conductive semiconductor layer of the plurality of light-emitting elements 300 may be an n-type semiconductor layer, and the second conductive semiconductor layer may be a p-type semiconductor layer. However, the present invention is not limited thereto, and the first pad electrode 210 may be a cathode electrode, and the second pad electrode 220 may be an anode electrode.

[0102] The first pad electrode 210 may include a first electrode stem 210S extending long in a first direction (X-axis direction) and at least one first electrode branch 210B branching from the first electrode stem 210S in a second direction (Y-axis direction). The second pad electrode 220 may include a second electrode stem 220S extending long in the first direction (X-axis direction) and at least one second electrode branch 220B branching from the second electrode stem 220S in a second direction (Y-axis direction).

[0103] The first electrode stem 210S may be electrically connected to the thin film transistor 120 through the first electrode contact hole CNTD.

[0104] Therefore, the first electrode stem 210S can receive a prescribed driving voltage from the thin film transistor 120. The thin film transistor 120 connected to the first electrode stem 210S can be Figure 3 The driving transistor DT is shown.

[0105] The second electrode stem 220S may be electrically connected to the low potential auxiliary wiring 161 through the second electrode contact hole CNTS.

[0106] Therefore, the second electrode stem 220S can receive the low potential voltage of the low potential auxiliary wiring 161 . Figure 5 In the example, the second electrode stem 220S in each of the first sub-pixel PX1, the second sub-pixel PX2, and the third sub-pixel PX3 of the pixel PX is connected to the low potential auxiliary wiring 161 through the second electrode contact hole CNTS, but the present invention is not limited thereto. For example, the second electrode stem 220S can be connected to the low potential auxiliary wiring 161 through the second electrode contact hole CNTS from one of the first sub-pixel PX1, the second sub-pixel PX2, and the third sub-pixel PX3 of the pixel PX. Alternatively, as Figure 4 As shown, the second electrode stem 220S is connected to the low potential voltage line VSSL of the non-display area NDA, and therefore may not be connected to the low potential auxiliary wiring 161 through the second electrode contact hole CNTS. That is, the second electrode contact hole CNTS may also be omitted.

[0107] The first electrode stem 210S of a subpixel can be arranged side by side in the first direction (X-axis direction) with the first electrode stem 210S of a subpixel adjacent to it in the first direction (X-axis direction). For example, the first electrode stem 210S of the first subpixel PX1 can be arranged side by side in the first direction (X-axis direction) with the first electrode stem 210S of the second subpixel PX2, the first electrode stem 210S of the second subpixel PX2 can be arranged side by side in the first direction (X-axis direction) with the first electrode stem 210S of the third subpixel PX3, and the first electrode stem 210S of the third subpixel PX3 can be arranged side by side in the first direction (X-axis direction) with the first electrode stem 210S of the first subpixel PX1. This is because the first electrode stems 210S are connected as one during the manufacturing process and then disconnected by a laser process after the plurality of light-emitting elements 300 are aligned.

[0108] The second electrode branches 220B may be disposed between the plurality of first electrode branches 210B. The plurality of first electrode branches 210B may be symmetrically disposed with respect to the first electrode branches 220B. Figure 5 2 illustrates that each of the first subpixel PX1, the second subpixel PX2, and the third subpixel PX3 of the pixel PX includes two first electrode branches 220B, but the present invention is not limited thereto. For example, each of the first subpixel PX1, the second subpixel PX2, and the third subpixel PX3 of the pixel PX may include three or more first electrode branches 220B.

[0109] in addition, Figure 5 , each of the first subpixel PX1, the second subpixel PX2, and the third subpixel PX3 of the pixel PX includes one second electrode branch 220B, but the present invention is not limited thereto. For example, when each of the first subpixel PX1, the second subpixel PX2, and the third subpixel PX3 of the pixel PX includes a plurality of second electrode branches 220B, the first electrode branch 210B may be arranged between the plurality of second electrode branches 220B. That is, in each of the first subpixel PX1, the second subpixel PX2, and the third subpixel PX3 of the pixel PX, the first electrode branch 210B, the second electrode branch 220B, the first electrode branch 210B, and the second electrode branch 220B may be arranged in the order of the first electrode branch 210B, the second electrode branch 220B, the first electrode branch 210B, and the second electrode branch 220B along the first direction (X-axis direction).

[0110] The plurality of light-emitting elements 300 can be arranged between the first electrode branch 210B and the second electrode branch 220B. At least one of the plurality of light-emitting elements 300 can have one end overlapping the first electrode branch 210B and the other end overlapping the second electrode branch 220B. The second conductive type semiconductor layer can be configured as a p-type semiconductor layer at one end of the plurality of light-emitting elements 300, and the first conductive type semiconductor layer can be configured as an n-type semiconductor layer at the other end, but the present invention is not limited to this. For example, the first conductive type semiconductor layer can be configured as an n-type semiconductor layer at one end of the plurality of light-emitting elements 300, and the second conductive type semiconductor layer can be configured as a p-type semiconductor layer at the other end.

[0111] The plurality of light-emitting elements 300 may be arranged substantially side by side along a first direction (X-axis direction). The plurality of light-emitting elements 300 may be arranged spaced apart along a second direction (Y-axis direction). In this case, the spacing between the plurality of light-emitting elements 300 may be different. For example, some of the plurality of light-emitting elements 300 may be arranged adjacent to each other to form one group, while the remaining light-emitting elements 300 may be arranged adjacent to each other to form another group.

[0112] A connecting electrode 260 may be disposed on each of the first electrode branch 210B and the second electrode branch 220B. The connecting electrodes 260 may extend long along the second direction (Y-axis direction) and may be spaced apart from each other along the first direction (X-axis direction). The connecting electrode 260 may be connected to one end of at least one of the plurality of light-emitting elements 300. The connecting electrode 260 may be connected to the first pad electrode 210 or the second pad electrode 220.

[0113] The connection electrode 260 may include a first connection electrode 261, disposed on the first electrode branch 210B and connected to one end of at least one light-emitting element 300 among the plurality of light-emitting elements 300; and a second connection electrode 262, disposed on the second electrode branch 220B and connected to one end of at least one light-emitting element 300 among the plurality of light-emitting elements 300. Therefore, the first connection electrode 261 serves to electrically connect the plurality of light-emitting elements 300 to the first pad electrode 210, and the second connection electrode 262 serves to electrically connect the plurality of light-emitting elements 300 to the second pad electrode 220.

[0114] The width of the first connection electrode 261 in the first direction (X-axis direction) may be wider than the width of the first electrode branch 210B in the first direction (X-axis direction). In addition, the width of the second connection electrode 262 in the first direction (X-axis direction) may be wider than the width of the second electrode branch 220B in the first direction (X-axis direction).

[0115] For example, each end portion of the light-emitting element 300 is disposed on the first electrode branch 210B of the first pad electrode 210 and the second electrode branch 220B of the second pad electrode 220. However, due to an insulating layer (not shown) formed on the first pad electrode 210 and the second pad electrode 220, the light-emitting element 300 may not be electrically connected to the first pad electrode 210 and the second pad electrode 220. Therefore, a portion of the side surface and / or top surface of the light-emitting element 300 may be electrically connected to the first connection electrode 261 and the second connection electrode 262, respectively.

[0116] Figure 6 yes Figure 1 An enlarged view of the first panel area in the display device.

[0117] according to Figure 6 In the display device 100 of the embodiment, a plurality of panel areas such as the first panel area A1 can be manufactured by tiling mechanically and electrically connecting.

[0118] The first panel area A1 may include each unit pixel ( Figure 2 The light emitting element 150 may be a plurality of light emitting elements 150 configured as PX. Figure 5 The light emitting element 300 is provided.

[0119] For example, the light-emitting element 150 may include a red light-emitting element 150R, a green light-emitting element 150G, and a blue light-emitting element 150B. For example, the unit pixel PX may include a first subpixel PX1, a second subpixel PX2, and a third subpixel PX3. For example, a plurality of red light-emitting elements 150R may be configured in the first subpixel PX1, a plurality of green light-emitting elements 150G may be configured in the second subpixel PX2, and a plurality of blue light-emitting elements 150B may be configured in the third subpixel PX3. The unit pixel PX may further include a fourth subpixel that is not configured with a light-emitting element, but is not limited thereto.

[0120] Figure 7 yes Figure 6 Magnified view of the A2 area.

[0121] Reference Figure 7 The display device 100 of the embodiment may include a substrate 200 , wiring electrodes 201 and 202 , an insulating layer 206 , and a plurality of light emitting elements 150 .

[0122] The wire electrode may include a first wire electrode 201 and a second wire electrode 202 that are spaced apart from each other.

[0123] In order to realize each unit pixel (sub-pixel), the light emitting element 150 may include a red light emitting element 150R, a green light emitting element 150G and a blue light emitting element 150B, but is not limited thereto. It may also have a red phosphor and a green phosphor, etc., to realize red and green respectively.

[0124] Substrate 200 can be formed of glass or polyimide. Alternatively, substrate 200 can include a flexible material such as PEN (Polyethylene Naphthalate) or PET (Polyethylene Terephthalate). Furthermore, substrate 200 can be transparent, but is not limited thereto.

[0125] The insulating layer 130 may include a material with insulating properties and flexibility, such as polyimide, PEN, PET, etc., and may also be integrally formed with the substrate 200 to form a single substrate.

[0126] The insulating layer 130 may be a conductive adhesive layer having both adhesive and conductive properties. The conductive adhesive layer is flexible, thereby enabling the flexible function of the display device. For example, the insulating layer 130 may be a conductive adhesive layer such as an anisotropic conductive film (ACF), an anisotropic conductive medium, or a solution containing conductive particles. The conductive adhesive layer may be a layer that is conductive in the vertical direction of its thickness and electrically insulating in the horizontal direction of its thickness.

[0127] The insulating layer 130 may include an assembly hole 203 for inserting the light emitting element 150. Therefore, the light emitting element 150 may be easily inserted into the assembly hole 203 of the insulating layer 130 during self-assembly.

[0128] Figure 8 This is a diagram showing an example in which the light-emitting element of the embodiment is assembled on a substrate by a self-assembly method.

[0129] Below, refer to Figure 8 , an example in which the light emitting element 150R of the embodiment is assembled onto the substrate 200 by using a self-assembly method of an electromagnetic field is described.

[0130] exist Figure 8 In the embodiment, the substrate 200 may be a panel substrate of a display device or a temporary donor substrate for transfer.

[0131] In the following description, the substrate 200 is described as a panel substrate of a display device, but the embodiment is not limited thereto.

[0132] The substrate 200 may be formed of glass or polyimide. Alternatively, the substrate 200 may be made of a flexible material such as PEN (Polyethylene Naphthalate) or PET (Polyethylene Terephthalate). Alternatively, the substrate 200 may be made of a transparent material, but is not limited thereto.

[0133] Reference Figure 8 The light emitting element 150R can be placed in a chamber 1300 filled with a fluid 1200. The fluid 1200 can be water, such as ultrapure water, but is not limited thereto. The chamber can be referred to as a water tank, a container, a vessel, or the like.

[0134] Next, the substrate 200 may be placed on the chamber 1300. According to an embodiment, the substrate 200 may also be loaded into the chamber 1300.

[0135] A pair of first electrodes 211 and second electrodes 212 corresponding to the light emitting elements 150R to be assembled may be formed on the substrate 200 .

[0136] The first electrode 211 and the second electrode 212 may be formed of a transparent electrode ITO, or may include a metal material with excellent conductivity. For example, the first electrode 211 and the second electrode 212 may be formed of at least one of titanium (Ti), chromium (Cr), nickel (Ni), aluminum (Al), platinum (Pt), gold (Au), tungsten (W), molybdenum (Mo), or an alloy thereof.

[0137] The first electrode 211 and the second electrode 212 release an electric field when a voltage is applied, thereby functioning as a pair of assembly electrodes for fixing the light emitting element 150R assembled into the assembly hole 203 on the substrate 200 .

[0138] The interval between the first electrode 211 and the second electrode 212 is formed to be smaller than the width of the light emitting element 150R and the width of the assembly hole 203 , so that the assembly position of the light emitting element 150R using an electric field can be fixed more accurately.

[0139] An insulating layer 220 is formed on the first electrode 211 and the second electrode 212 to protect the first electrode 211 and the second electrode 212 from the fluid 1200 and prevent leakage of current flowing through the first electrode 211 and the second electrode 212. The insulating layer 220 can be formed of an inorganic insulator such as silicon dioxide or aluminum oxide, or an organic insulator in a single layer or multiple layers.

[0140] In addition, the insulating layer 220 may include a material with insulating properties and flexibility, such as polyimide, PEN, PET, etc., and may also be integrally formed with the substrate 200 to form a single substrate.

[0141] The insulating layer 220 may be an insulating layer having adhesiveness or a conductive adhesive layer having conductivity. The insulating layer 220 is flexible, thereby enabling the flexible function of the display device to be realized.

[0142] A partition wall 200S may be formed on the insulating layer 220 . A portion of the partition wall 200S may be located above the first electrode 211 and the second electrode 212 .

[0143] For example, when forming the substrate 200, a portion of a partition wall formed on the insulating layer 220 may be removed to form an assembly hole 203 for assembling each of the plurality of light-emitting elements 150R to the substrate 200. A second pad electrode 222 for applying power to the light-emitting element 150R may be formed between the partition wall 200S and the insulating layer 220.

[0144] The substrate 200 is formed with assembly holes 203 for attaching the plurality of light emitting elements 150R, and the surface where the assembly holes 203 are formed can come into contact with the fluid 1200. The assembly holes 203 can guide the accurate assembly position of the light emitting elements 150R.

[0145] On the other hand, the assembly hole 203 may have a shape and size corresponding to the shape of the light emitting element 150R assembled to the corresponding position, thereby preventing other light emitting elements or a plurality of light emitting elements from being assembled to the assembly hole 203 .

[0146] Refer again Figure 8 After configuring the substrate 200, the assembly device 1100 including the magnetic body can be moved along the substrate 200. As the magnetic body, for example, a magnet or an electromagnet can be used. In order to maximize the area affecting the magnetic field within the fluid 1200, the assembly device 1100 can be moved in a state of contact with the substrate 200. According to an embodiment, the assembly device 1100 may include a plurality of magnetic bodies, or may also include a magnetic body of a size corresponding to the substrate 200. In this case, the moving distance of the assembly device 1100 may also be limited to within a specified range.

[0147] The light emitting element 150R in the chamber 1300 can move toward the assembling apparatus 1100 using the magnetic field generated by the assembling apparatus 1100 .

[0148] During the process of moving toward the assembly device 1100 , the light emitting element 150R may enter the assembly hole 203 and contact the substrate 200 .

[0149] At this time, the electric field applied by the first electrode 211 and the second electrode 212 formed on the substrate 200 can prevent the light emitting element 150R in contact with the substrate 200 from being separated due to the movement of the assembly device 1100 .

[0150] That is, by utilizing the electromagnetic field self-assembly method, the time required to assemble each of the plurality of light emitting elements 150R onto the substrate 200 can be significantly shortened, thereby enabling a large-area, high-pixel display to be realized more quickly and economically.

[0151] A predetermined solder layer 225 is formed between the light emitting element 150R mounted on the mounting hole 203 of the substrate 200 and the second pad electrode 222 , thereby improving the bonding strength of the light emitting element 150R.

[0152] Thereafter, the first pad electrode 221 is connected to the light emitting element 150R, and power can be applied.

[0153] Next, a molding layer 230 may be formed on the partition wall 200S and the assembly hole 203 of the substrate 200. The molding layer 230 may be a transparent region or a layer containing a reflective material or a scattering material.

[0154] Figure 9 shows the light emitting element through Figure 8 The morphology of the self-assembled structure inserted into the substrate is shown.

[0155] like Figure 8 and Figure 9 As shown, the light emitting element 150 can be pulled out by the magnetic body of the assembly device 1100 and inserted into the assembly hole 203 of the substrate 200 .

[0156] On the substrate 200 , the first wiring electrode 201 and the second wiring electrode 202 may be arranged to be spaced apart from each other.

[0157] The insulating layer 205 may be disposed on the first and second wiring electrodes 201 and 202, and the insulating layer 206 may be disposed on the insulating layer 205. For convenience of description, the insulating layer 205 and the insulating layer 206 may be referred to as a first insulating layer and a second insulating layer, respectively.

[0158] The first insulating layer 205 and the second insulating layer 206 may be formed of the same material or different materials, but are not limited thereto. For example, the first insulating layer 205 may be formed of an inorganic material, and the second insulating layer 206 may be formed of an organic material, or vice versa.

[0159] The second insulating layer 206 may have an assembly hole 203 for inserting the light emitting element 150 . The top surface of the first insulating layer 205 may be exposed through the assembly hole 203 of the second insulating layer 206 .

[0160] When the light emitting element 150 is inserted into the assembly hole 203 , the bottom surface of the light emitting element may contact the top surface of the first insulating layer 205 exposed by the assembly hole 203 .

[0161] For example, a voltage is applied to the first wiring electrode 201 and the second wiring electrode 202, thereby forming an electric field between the first wiring electrode 201 and the second wiring electrode 202. The dielectrophoretic force generated by this electric field can affect the light-emitting element 150. In other words, due to the dielectrophoretic force formed between the first wiring electrode 201 and the second wiring electrode 202, the light-emitting element 150 inserted into the assembly hole 203 can be fixed to the top surface of the first insulating layer 205 while remaining inserted into the assembly hole 203.

[0162] Although not shown, in a subsequent process, an insulating layer is formed in the space of the assembly hole 203 not occupied by the light emitting element 150, and then the first pad electrode ( Figure 5 210) and the second pad electrode 220. In addition, a first connection electrode 261 for connecting the first electrode of the light emitting element 150 to the first pad electrode 210 and a second connection electrode 262 for connecting the second electrode of the light emitting element 150 to the second pad electrode 220 may be formed. Figure 5 210) and the second pad electrode 220 apply a voltage so that the light emitting element 150 can emit light.

[0163] On the other hand, in the display device of the embodiment, a light-emitting element is used as a light source. The light-emitting element of the embodiment is a self-luminous element that emits light in response to the application of electricity, and can be a semiconductor light-emitting element. The light-emitting element of the embodiment is formed of an inorganic semiconductor material, which is resistant to degradation and has a semi-permanent lifespan. Therefore, it can provide stable light, thereby contributing to the display device achieving high-quality and high-definition images.

[0164] Figure 10 It is shown schematically Figure 2 A cross-sectional view of a display panel.

[0165] Reference Figure 10 The display panel 10 of the embodiment may include a first substrate 40, a light emitting portion 41, a color generating portion 42, and a second substrate 46. The display panel 10 of the embodiment may include more components than the above components, which are not limited. The first substrate 40 may be Figure 7 The substrate 200 is shown.

[0166] Although not shown, at least one insulating layer may be disposed between the first substrate 40 and the light emitting portion 41 , between the light emitting portion 41 and the color generating portion 42 , and / or between the color generating portion 42 and the second substrate 46 , but the present invention is not limited thereto.

[0167] The first substrate 40 can support the light emitting portion 41, the color generating portion 42 and the second substrate 46. The second substrate 46 can form various components as described above, such as Figure 2 As shown, a plurality of data lines D1 to Dm (m is an integer greater than 2), a plurality of scanning lines S1 to Sn, a high potential voltage line VDDL and a low potential voltage line VSSL, Figure 3 The plurality of transistors and at least one capacitor shown and Figure 4 A first pad electrode 210 and a second pad electrode 220 are shown.

[0168] The first substrate 40 may be formed of glass, but is not limited thereto.

[0169] The light emitting section 41 may provide light to the color generating section 42. The light emitting section 41 may include a plurality of light sources that emit light by themselves when electricity is applied. For example, the light source may include a light emitting element ( Figure 5 300, Figure 6 and Figure 12 150 Figure 16 150A and Figure 17 150B).

[0170] As an example, the plurality of light emitting elements 150 are separately arranged for each sub-pixel of a pixel, and can emit light independently by controlling each sub-pixel.

[0171] As another example, the plurality of light-emitting elements 150 may be arranged regardless of pixel division, so that light can be emitted from all sub-pixels simultaneously.

[0172] The light emitting element 150 of the embodiment may emit blue light, but is not limited thereto. For example, the light emitting element 150 of the embodiment may also emit white light or purple light.

[0173] Alternatively, the light-emitting element 150 may emit red, green, and blue light for each sub-pixel. For example, a red light-emitting element emitting red light may be arranged in the first sub-pixel (red sub-pixel), a green light-emitting element emitting green light may be arranged in the second sub-pixel (green sub-pixel), and a blue light-emitting element emitting blue light may be arranged in the third sub-pixel (blue sub-pixel).

[0174] For example, each of the red light emitting element, the green light emitting element, and the blue light emitting element may include a Group II-IV compound or a Group III-V compound, but is not limited thereto. For example, the III-V compound can be selected from a binary compound selected from the group consisting of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb and a mixture thereof; a ternary compound selected from the group consisting of GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlInP, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP and a mixture thereof; and a quaternary compound selected from the group consisting of AlGaInP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb and a mixture thereof.

[0175] The color generating section 42 can generate light of a color different from the light provided from the light emitting section 41 .

[0176] For example, the color generating section 42 may include a first color generating section 43, a second color generating section 44, and a third color generating section 45. The first color generating section 43 may correspond to the first sub-pixel PX1 of the pixel, the second color generating section 44 may correspond to the second sub-pixel PX2 of the pixel, and the third color generating section 45 may correspond to the third sub-pixel PX3 of the pixel.

[0177] The first color generating section 43 can generate a first color light based on the light provided by the light emitting section 41, the second color generating section 44 can generate a second color light based on the light provided by the light emitting section 41, and the third color generating section 45 can generate a third color light based on the light provided by the light emitting section 41. For example, the first color generating section 43 can output the blue light from the light emitting section 41 as red light, the second color generating section 44 can output the blue light from the light emitting section 41 as green light, and the third color generating section 45 can output the blue light from the light emitting section 41 as is.

[0178] As an example, the first color generating unit 43 may include a first color filter, the second color generating unit 44 may include a second color filter, and the third color generating unit 45 may include a third color filter.

[0179] The first color filter, the second color filter, and the third color filter may be formed of a transparent material that can transmit light.

[0180] For example, at least one of the first color filter, the second color filter, and the third color filter may include quantum dots.

[0181] The quantum dots of the embodiment may be selected from Group II-IV compounds, Group III-V compounds, Group IV-VI compounds, Group IV elements, Group IV compounds, and combinations thereof.

[0182] The II-VI compound can be a binary compound selected from the group consisting of CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS and mixtures thereof; CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHg Se, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS and mixtures thereof; and the group consisting of four-element compounds selected from the group consisting of HgZnTeS, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe and mixtures thereof.

[0183] The III-V compound can be a binary compound selected from the group consisting of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb and a mixture thereof; a ternary compound selected from the group consisting of GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlInP, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP and a mixture thereof; and a quaternary compound selected from the group consisting of AlGaInP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb and a mixture thereof.

[0184] The IV-VI group compound can be selected from the group consisting of a binary compound selected from the group consisting of SnS, SnSe, SnTe, PbS, PbSe, PbTe and a mixture thereof; a ternary compound selected from the group consisting of SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe and a mixture thereof; and a quaternary compound selected from the group consisting of SnPbSSe, SnPbSeTe, SnPbSTe and a mixture thereof.

[0185] The Group IV element may be selected from the group consisting of Si, Ge, and mixtures thereof. The Group IV compound may be a binary compound selected from the group consisting of SiC, SiGe, and mixtures thereof.

[0186] Such quantum dots can have a full width of half maximum (FWHM) of luminescence wavelength of approximately 45 nm or less, and light emitted by the quantum dots can be emitted in all directions, thereby increasing the viewing angle of the light-emitting display device.

[0187] On the other hand, quantum dots have morphologies such as spherical, pyramidal, multi-arm or cubic nanoparticles, nanotubes, nanowires, nanofibers, nanoplate-like particles, etc., but are not limited thereto.

[0188] For example, if light-emitting element 150 emits blue light, the first color filter may include red quantum dots, and the second color filter may include green quantum dots. The third color filter may not include quantum dots, but is not limited thereto. For example, if the blue light from light-emitting element 150 is absorbed by the first color filter, the wavelength of the absorbed blue light may be switched by the red quantum dots, resulting in red light output. For example, if the blue light from light-emitting element 150 is absorbed by the second color filter, the wavelength of the absorbed blue light may be switched by the green quantum dots, resulting in green light output. For example, if the blue light from the light-emitting element is absorbed by the third color filter, the absorbed blue light may be emitted as is.

[0189] On the other hand, when light emitting element 150 emits white light, not only the first and second color filters but also the third color filter may include quantum dots. That is, due to the quantum dots included in the third color filter, the wavelength of the white light from light emitting element 150 can be switched to blue light.

[0190] For example, at least one of the first, second, and third color filters may include a phosphor. For example, a portion of the first, second, and third color filters may include quantum dots, and another portion of the color filters may include a phosphor. For example, each of the first, second, and third color filters may include a phosphor and quantum dots. For example, at least one of the first, second, and third color filters may include scattering particles. Blue light incident on each of the first, second, and third color filters is scattered by the scattering particles, and the scattered blue light may be color-switched by the corresponding quantum dots, thereby improving light output efficiency.

[0191] As another example, the first color generating unit 43 may include a first color conversion layer and a first color filter. The second color generating unit 44 may include a second color conversion layer and a second color filter. The third color generating unit 45 may include a third color conversion layer and a third color filter. Each of the first, second, and third color conversion layers may be disposed adjacent to the light emitting unit 41. The first, second, and third color filters may be disposed adjacent to the second substrate 46.

[0192] For example, the first color filter may be disposed between the first color conversion layer and the second substrate 46. For example, the second color filter may be disposed between the second color conversion layer and the second substrate 46. For example, the third color filter may be disposed between the third color conversion layer and the second substrate 46.

[0193] For example, the first color filter may be in contact with the top surface of the first color conversion layer and have the same size as the first color conversion layer, but is not limited thereto. For example, the second color filter may be in contact with the top surface of the second color conversion layer and have the same size as the second color conversion layer, but is not limited thereto. For example, the third color filter may be in contact with the top surface of the third color conversion layer and have the same size as the third color conversion layer, but is not limited thereto.

[0194] For example, the first color conversion layer may include red quantum dots, the second color conversion layer may include green quantum dots, and the third color conversion layer may not include quantum dots. For example, the first color filter may include a red-based material that selectively transmits red light converted in the first color conversion layer, the second color filter may include a green-based material that selectively transmits green light converted in the second color conversion layer, and the third color filter may include a blue-based material that selectively transmits blue light directly transmitted through the third color conversion layer.

[0195] On the other hand, if light-emitting element 150 emits white light, not only the first and second color conversion layers but also the third color conversion layer may include quantum dots. That is, the quantum dots included in the third color filter can shift the wavelength of white light emitted by light-emitting element 150 to blue light.

[0196] Refer again Figure 10 The second substrate 46 is disposed on the color generating portion 42 to protect the color generating portion 42. The second substrate 46 may be formed of glass, but is not limited thereto.

[0197] The second substrate 46 may be referred to as a cover window, cover glass, or the like.

[0198] The second substrate 46 may be formed of glass, but is not limited thereto.

[0199] On the other hand, the embodiment provides a light emitting element that is not attached to the bottom surface of a substrate.

[0200] The embodiment provides a display device capable of improving an assembly rate by performing self-assembly using a light emitting element that is not attached to a bottom surface of a substrate.

[0201] The embodiment provides a display device capable of significantly improving a self-assembly speed by performing self-assembly using a light emitting element that is not attached to a bottom surface of a substrate.

[0202] The embodiment provides a display device capable of improving light efficiency and ensuring high brightness by performing self-assembly using a light emitting element that is not attached to a bottom surface of a substrate.

[0203] Various embodiments for achieving such a solution to the problem will be described below.

[0204] [First embodiment]

[0205] Figure 11 is a top view showing the light emitting element of the first embodiment, Figure 12 is a cross-sectional view showing the light emitting element of the first embodiment.

[0206] Reference Figure 11 and Figure 12 The light emitting element 150 of the first embodiment may include a plurality of first conductive type semiconductor layers 171, an active layer 172, a plurality of second conductive type semiconductor layers 173, a first electrode 180 and a second electrode 190. The light emitting element 150 of the first embodiment may be Figure 5 The light emitting element 300 or Figure 6 The light emitting element 150 is provided.

[0207] The light-emitting element 150 of the first embodiment may have a circular shape, but is not limited thereto. For example, the plurality of second-conductivity-type semiconductor layers 173 may have a circular shape when viewed from above. For example, the active layer 172 may have a circular shape when viewed from above. For example, the plurality of first-conductivity-type semiconductor layers 171 may have a circular shape when viewed from above.

[0208] The light emitting element 150 of the first embodiment may be a horizontal light emitting element, but is not limited thereto. The light emitting element 150 of the first embodiment may be a red light emitting element ( Figure 6 For example, the light emitting element 150 of the first embodiment may include a compound semiconductor. Examples of compound semiconductors include group II-IV compounds and group III-V compounds. For example, the III-V compound can be a binary compound selected from the group consisting of GaP, GaAs, GaSb, AlP, AlAs, AlSb, InP, InAs, InSb and a mixture thereof; a ternary compound selected from the group consisting of GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlInP, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP and a mixture thereof; and a quaternary compound selected from the group consisting of AlGaInP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb and a mixture thereof.

[0209] For example, a plurality of first conductive type semiconductor layers 171, an active layer 172, and a plurality of second conductive type semiconductor layers 173 may be grown on a substrate (not shown). Figure 12 As shown, the substrate is removed, and the substrate may not be visible in the final product of the light emitting element, but is not limited thereto. The substrate may be a sapphire substrate or a semiconductor substrate, but is not limited thereto.

[0210] The plurality of first conductive type semiconductor layers 171 may be provided by a compound semiconductor. For example, the plurality of first conductive type semiconductor layers 171 may be provided by a Group II-VI compound semiconductor or a Group III-V compound semiconductor. For example, the plurality of first conductive type semiconductor layers 171 may be doped with an n-type dopant such as Si, Ge, Sn, Se, or Te.

[0211] The active layer 172 can generate light of a wavelength band corresponding to the recombination of first carriers (e.g., electrons) provided from the plurality of first conductive type semiconductor layers 171 and second carriers (e.g., holes) provided from the plurality of second conductive type semiconductor layers 173. The active layer 172 can be provided in one or more of a single well structure, a multi-well structure, a quantum dot structure, or a quantum wire structure. The active layer 172 can be provided by a compound semiconductor. For example, the active layer 172 can be provided by a Group II-VI or Group III-V compound semiconductor. When the active layer 172 is provided in a multi-well structure, the active layer 172 can be provided by stacking a plurality of barrier layers and a plurality of well layers.

[0212] The plurality of second conductive type semiconductor layers 173 may be provided by a compound semiconductor. For example, the plurality of second conductive type semiconductor layers 173 may be provided by a Group II-VI compound semiconductor or a Group III-V compound semiconductor. For example, the plurality of second conductive type semiconductor layers 173 may be doped with a p-type dopant such as Mg, Zn, Ca, Sr, or Ba.

[0213] If the plurality of first conductive type semiconductor layers 171, the active layer 172, and the plurality of second conductive type semiconductor layers 173 are grown, a portion of the plurality of second conductive type semiconductor layers 173, the active layer 172, and the plurality of first conductive type semiconductor layers 171 may be removed by performing mesa etching. Figure 11 and Figure 12 As shown, the plurality of second conductive type semiconductor layers 173 and the active layer 172 corresponding to the peripheral region other than the central region of the light emitting element 150 of the first embodiment may be removed, and a portion of the upper side of the plurality of first conductive type semiconductor layers 171 may be removed. The peripheral region may surround the central region.

[0214] As an example, mesa etching can be performed using a photosensitive pattern. That is, a protective pattern is formed in the center region of the light emitting element 150 of the first embodiment, and mesa etching can be performed using the protective pattern as a mask to obtain a mesa structure.

[0215] As another example, mesa etching can be performed using the second electrode 190. Specifically, the second electrode 190 can be formed in the central region of the light-emitting element 150 of the first embodiment, and a mesa structure can be obtained by performing mesa etching using the second electrode 190 as a mask. After the plurality of first-conductivity-type semiconductor layers 171, the active layer 172, and the plurality of second-conductivity-type semiconductor layers 173 are grown, the second electrode 190 can be formed in the central region of the light-emitting element 150 of the first embodiment. In this case, the dimensions of the plurality of second-conductivity-type semiconductor layers 173, the active layer 172, and the plurality of first-conductivity-type semiconductor layers 171 subjected to mesa etching can be the same as those of the second electrode 190.

[0216] The first electrode 180 may be formed on the top surfaces of the plurality of first conductive type semiconductor layers 171 exposed by mesa etching, and the second electrode 190 may be formed on the top surfaces of the plurality of second conductive type semiconductor layers 173. In this case, the first electrode 180 may surround the second electrode 190.

[0217] Each of the first electrode 180 and the second electrode 190 may include a plurality of layers, but is not limited thereto.

[0218] The second electrode 190 may include a transparent conductive material. For example, the second electrode 190 may include a conductive material such as ITO, ZnO, GZO, or IGZO. When the second electrode 190 is formed on the plurality of second conductive semiconductor layers 173 using such a conductive material, a current diffusion effect occurs, whereby current diffuses along the surface of the second electrode 190. This causes current to flow from the entire area of ​​the second electrode 190 to the plurality of second conductive semiconductor layers 173, allowing uniform light to be emitted from the entire area of ​​the active layer 172.

[0219] like Figure 11 As shown, the first electrode 180 is located in the central area of ​​the light-emitting element 150 of the first embodiment, and the first electrode 180 can surround the second electrode 190. The light-emitting element 150 of the first embodiment may include a central area and a peripheral area surrounding the central area. For example, the central area is an area that is not etched by mesa etching, and the peripheral area can be an area removed by mesa etching. In this case, the first electrode 180 can be configured on the plurality of first conductive type semiconductor layers 171 located in the peripheral area, and the second electrode 190 can be configured on the plurality of second conductive type semiconductor layers 173 located in the central area. As shown above, the light-emitting element 150 of the embodiment removes the peripheral area except the central area by mesa etching, so the second electrode 190 can surround the first electrode 180.

[0220] Figure 11Although the first electrode 180 is shown as being disposed on a portion of the top surface of the plurality of first conductive type semiconductor layers 171 , it may be disposed on the entire top surface of the plurality of first conductive type semiconductor layers 171 . Figure 12 Although the second electrode 190 is shown as being disposed on a portion of the top surface of the plurality of second conductive type semiconductor layers 173 , it may be disposed on the entire top surface of the plurality of second conductive type semiconductor layers 173 .

[0221] For example, the first electrode 180 can have a closed loop shape surrounding the second electrode 190. For example, when viewed from above, the second electrode 190 can have a circular shape. Because the first electrode 180 has a closed loop shape, current can flow uniformly in a radial direction from the second electrode 190 through the plurality of second-conductivity-type semiconductor layers 173, the active layer 172, and the plurality of first-conductivity-type semiconductor layers 171 to the first electrode 180. As a result, electrons located throughout the plurality of first-conductivity-type semiconductor layers 171 are injected into the active layer 172 and contribute to light emission, thereby improving light emission efficiency.

[0222] like Figure 12 As shown, the light emitting element 150 of the first embodiment can have a circular shape, but is not limited thereto. For example, when viewed from above, the plurality of second conductive type semiconductor layers 173 can have a circular shape. For example, when viewed from above, the active layer 172 can have a circular shape. For example, when viewed from above, the plurality of first conductive type semiconductor layers 171 can have a circular shape.

[0223] Hereinafter, the plurality of first conductive type semiconductor layers 171 of the embodiment will be described in detail.

[0224] The plurality of first conductive type semiconductor layers 171 may include an adsorption prevention layer 171_1, a cladding layer 171_2, and a contact layer 171_3. For example, one of the adsorption prevention layer 171_1, the cladding layer 171_2, and the contact layer 171_3 may be named a 1-1 conductive type semiconductor layer, another may be named a 1-2 conductive type semiconductor layer, and yet another may be named a 1-3 conductive type semiconductor layer.

[0225] The adsorption prevention layer 171_1 , the capping layer 171_2 , and the contact layer 171_3 may include, but are not limited to, a II-IV compound or a III-V compound.

[0226] This embodiment includes an adsorption prevention layer 171_1, which prevents the light-emitting element 150 of the first embodiment from adsorbing to the bottom surface of the substrate during self-assembly. Typically, the first conductive semiconductor layer 171 contains Al, and the Al content affects its charge characteristics. During self-assembly, the light-emitting element may be adsorbed to the bottom surface of the substrate due to the first conductive semiconductor layer 171 being affected by its charge characteristics.

[0227] Therefore, in the embodiment, the first conductive type semiconductor layer includes an adsorption prevention layer 171_1 with an adjusted Al content, thereby preventing the light emitting element from not adhering to the bottom surface of the substrate.

[0228] Of the adsorption prevention layer 171_1, the cover layer 171_2, and the contact layer 171_3, the adsorption prevention layer 171_1 may be the furthest away from the active layer 172. That is, the adsorption prevention layer 171_1 may be disposed farther from the active layer 172 than the cover layer 171_2 and the contact layer 171_3. For example, the contact layer 171_3 may be disposed below the active layer 172, the cover layer 171_2 may be disposed below the contact layer 171_3, and the adsorption prevention layer 171_1 may be disposed below the cover layer 171_2.

[0229] During the self-assembly process, the adsorption preventing layer 171_1 can prevent the light emitting element 150 of the first embodiment from being adsorbed to the substrate. For example, the adsorption preventing layer 171_1 can include Al x1 Ga 1-x1 InP, but not limited to.

[0230] For example, in order to function as the adsorption prevention layer 171_1, x1 may be less than 0.6. Preferably, x1 may be greater than or equal to 0.2 and less than or equal to 0.6. Figure 15 As shown, when x1 is less than 0.2, the assembly rate decreases, and when x1 exceeds 0.6, the possibility of the light emitting element 150 of the first embodiment being adsorbed to the bottom surface of the substrate may become high. For example, when x1 is 0.4, the adsorption prevention layer 171_1 may include Al 0.4 Ga 0.6 InP.

[0231] For example, the concentration ratio of Al to Ga in the adsorption prevention layer 171_1 may be greater than or equal to 0.5 and less than or equal to 5. Here, the concentration may be expressed in weight %, and the concentration of Al may be greater than or equal to 0.5 and less than or equal to 5 compared to the concentration of Ga. For example, when the concentration of Ga is 5 weight %, the concentration of Al may be greater than or equal to 2.5 weight % and less than or equal to 25 weight %.

[0232] For example, in order to function as the adsorption prevention layer 171_1, the thickness of the adsorption prevention layer 171_1 may be less than 2 μm. Preferably, the thickness of the adsorption prevention layer 171_1 may be greater than or equal to 0.5 μm and less than or equal to 1.5 μm. If the thickness of the adsorption prevention layer 171_1 is less than 0.5 μm, it is difficult to function as the adsorption prevention layer 171_1 due to its very thin thickness. Figure 15 As shown, when the thickness of the adsorption prevention layer 171_1 exceeds 1.5 μm, the light emitting element 150 of the first embodiment may be more likely to be adsorbed to the bottom surface of the substrate.

[0233] For example, the cladding layer 171_2 may supply a plurality of electrons to the active layer 172. For example, the cladding layer 171_2 may include at least one semiconductor layer.

[0234] For example, the capping layer 171_2 may include Al x2 Ga 1-x2 InP, but not limited thereto. For example, x2 may be smaller than x1. For example, in the case where x1 is 0.6, x2 may be 0.2. In this case, the adsorption prevention layer 171_1 may include Al 0.6 Ga 0.4 InP, the capping layer 171_2 may include Al 0.2 Ga 0.8 InP.

[0235] The cover layer 171_2 may be disposed between the active layer 172 and the adsorption prevention layer 171_1. For example, the bottom surface of the cover layer 171_2 may be in contact with the top surface of the adsorption prevention layer 171_1, but the present invention is not limited thereto.

[0236] The contact layer 171_3 may allow a plurality of electrons of the cladding layer 171_2 to be easily supplied to the active layer 172. For example, the contact layer 171_3 may include AlInP, but is not limited thereto.

[0237] Figure 13a shows a portion of a plurality of first conductivity type semiconductor layers of a comparative example, Figure 13b Part of a plurality of first conductivity type semiconductor layers in the light emitting element of the first embodiment is shown.

[0238] like Figure 13a As shown, in the comparative example, the first conductive type semiconductor layer 110 may be formed of a single semiconductor layer including AlInP. The first conductive type semiconductor layer 110 of the comparative example may include Al but not Ga. In this case, as shown in FIG. Figure 14aAs shown, during self-assembly, a very large number of light-emitting elements 510 in the comparative example are attracted to the bottom surface of substrate 500. As a result, not many light-emitting elements 510 are assembled at specific locations on substrate 500, potentially reducing the assembly rate. Consequently, the desired number of light-emitting elements 510 is not assembled at specific locations, resulting in reduced brightness and lowered light efficiency, making commercialization of the display difficult.

[0239] like Figure 13b As shown, in an embodiment, the first conductive type semiconductor layer 171 may include at least a gettering prevention layer 171_1 and a capping layer 171_2 .

[0240] For example, the ratio of the thickness of the adsorption prevention layer 171_1 to the thickness of the coating layer 171_2 may be at least 1. That is, the thickness t1 of the adsorption prevention layer 171_1 may be equal to or smaller than the thickness t2 of the coating layer 171_2 .

[0241] like Figure 14b As shown, during the self-assembly, the plurality of light emitting elements 150 of the first embodiment are hardly adsorbed to the bottom surface of the substrate 200. Therefore, each of the plurality of light emitting elements 150 of the first embodiment can be assembled to a specific position.

[0242] In this embodiment, an adsorption prevention layer 171_1 is disposed below the cover layer 171_2. Therefore, during self-assembly, the adsorption prevention layer 171_1 prevents the plurality of light-emitting elements 150 of the first embodiment from adsorbing to the bottom surface of the substrate. This allows for the assembly of more light-emitting elements 150 of the first embodiment at a specific location than would be possible if they were adsorbed to the bottom surface of the substrate. This significantly improves assembly efficiency, increases light efficiency, and achieves a high-brightness display device.

[0243] Figure 15 The assembly and adsorption characteristics depending on the Al content of the adsorption prevention layer and the thickness of the adsorption prevention layer are shown.

[0244] like Figure 15 As shown in FIG. 1 , it can be seen that in the X region, the assembly rate is excellent and the adsorption rate to the bottom surface of the substrate is also reduced. For example, in the X region, the Al contained in the adsorption prevention layer 171_1 x1 Ga 1-x1In InP, x1 is greater than or equal to 0.2 and less than or equal to 0.6. For example, in the X region, the thickness of the adsorption prevention layer 171_1 can be greater than or equal to 0.5 μm and less than or equal to 1.5 μm. For example, in the Y region, x1 exceeds 0.6, and the thickness of the adsorption prevention layer 171_1 can be greater than or equal to 0.5 μm and less than or equal to 2 μm. For example, in the Y region, x1 can be greater than or equal to 0.2 and less than or equal to 0.6, and the thickness of the adsorption prevention layer 171_1 can be greater than or equal to 1.5 μm and less than or equal to 2 μm. For example, in the Z region, x1 can be less than 0.2. For example, in the Z region, the thickness of the adsorption prevention layer 171_1 can be greater than or equal to 0.5 μm and less than or equal to 2 μm.

[0245] Figure 16 is a cross-sectional view showing a light emitting element according to a second embodiment.

[0246] The second embodiment is the same as the first embodiment except for the shielding layer 175. In the second embodiment, components having the same functions, structures, and shapes as those of the first embodiment are given the same reference numerals and detailed descriptions thereof are omitted.

[0247] The following omitted description can be easily understood from the description of the first embodiment.

[0248] Reference Figure 16 The light emitting element 150A of the second embodiment may include a plurality of first conductive type semiconductor layers 171, an active layer 172, a plurality of second conductive type semiconductor layers 173, a first electrode 180, and a second electrode 190. The light emitting element 150A of the second embodiment may be Figure 5 The light emitting element 300 or Figure 6 The light emitting element 150 is provided.

[0249] The plurality of first-conductivity-type semiconductor layers 171 may include an adsorption prevention layer 171_1, a cladding layer 171_2, and a contact layer 171_3. For example, one of the adsorption prevention layer 171_1, the cladding layer 171_2, and the contact layer 171_3 may be designated as a 1-1 conductivity-type semiconductor layer, another as a 1-2 conductivity-type semiconductor layer, and yet another as a 1-3 conductivity-type semiconductor layer. Each of the adsorption prevention layer 171_1, the cladding layer 171_2, and the contact layer 171_3 has been described in the second embodiment, and therefore a detailed description thereof will be omitted.

[0250] The light-emitting element 150A of the second embodiment may include a shielding layer 175. For example, the shielding layer 175 may be disposed below the active layer 172. For example, the shielding layer 175 may be disposed below the first conductive semiconductor layer 171. For example, the shielding layer 175 may be disposed below the adsorption prevention layer 171_1. For example, the top surface of the shielding layer 175 may be in contact with the bottom surface of the adsorption prevention layer 171_1, but the present invention is not limited thereto.

[0251] Shielding layer 175 can shield the electronegativity of Al in first conductive semiconductor layer 171, namely, contact layer 171_3, capping layer 171_2, and / or adsorption prevention layer 171_1. Electronegativity refers to the ability of atoms to attract electron pairs that have been removed when they are combined. For example, a greater electronegativity indicates a greater negative charge.

[0252] The capping layer 171_2 and / or the adsorption prevention layer 171_1 may have a negative (-) charge due to the electronegativity of Al contained in the first conductive semiconductor layer 171. As described above, when the first conductive semiconductor layer 171 has a negative (-) charge, the light-emitting element 150A of the second embodiment may be adsorbed to the bottom surface of the substrate during self-assembly.

[0253] In the second embodiment, shielding layer 175 is disposed adjacent to first conductive semiconductor layer 171. Thus, even when self-assembly is performed, light-emitting element 150A of the second embodiment is prevented from adsorbing to the bottom surface of the substrate. Consequently, compared to adsorption to the bottom surface of the substrate, a greater number of light-emitting elements 150A of the second embodiment can be assembled at a specific location, resulting in a significantly improved assembly rate, improved light efficiency, and a high-brightness display device.

[0254] In particular, in the embodiment, the thickness of the shielding layer 175 can be at least 300 nm. As described above, due to the thick shielding layer 175, the Al conductivity of the first conductive type semiconductor layer 171 is shielded, so that the light emitting element 150A of the second embodiment can be prevented from being adsorbed to the bottom surface of the substrate during self-assembly.

[0255] For example, the shielding layer 175 may be a third conductive type semiconductor layer. The third conductive type semiconductor layer may include, but is not limited to, a compound semiconductor. For example, the third conductive type semiconductor layer may not include Al. For example, the third conductive type semiconductor layer may include GaInP.

[0256] For example, the shielding layer 175 may contain an n-type dopant such as Si, Ge, Sn, Se, or Te. Alternatively, the shielding layer 175 may not contain a dopant, or may contain a p-type dopant.

[0257] On the other hand, the shielding layer 175 may be an etch stop layer. For example, as described above, after the first conductive type semiconductor layer 171, the active layer 172, and the second conductive type semiconductor layer 173 are grown on a substrate (not shown), the substrate may be removed.

[0258] For example, the substrate can be removed by a chemical lift-off process. That is, when the light emitting element 150A of the second embodiment is immersed in a chemical etching solution for etching, the shielding layer 175 can prevent the first conductive semiconductor layer 171 from being etched by the chemical etching solution.

[0259] On the other hand, although not shown, a metal layer may be provided below the shielding layer 175. The metal layer provided below the shielding layer 175 can improve the assembly efficiency. The metal layer may be any metal. Preferably, the metal layer may include a magnetizable nickel layer. In this case, during self-assembly, the nickel layer included in the light-emitting element 150A of the second embodiment is magnetized by the magnetic body, and the light-emitting element 150A of the second embodiment can move in the direction of movement of the magnetic body, thereby allowing the moving light-emitting element to be assembled to a specific position.

[0260] Figure 17 is a cross-sectional view showing a light emitting element according to a third embodiment.

[0261] The third embodiment is the same as the second embodiment except for the shape. That is, the second embodiment ( Figure 16 ) has a circular shape, while the light emitting element 150B of the third embodiment may not have a circular shape.

[0262] Reference Figure 17 The light emitting element 150B of the third embodiment may include a plurality of first conductive type semiconductor layers 171, an active layer 172, a plurality of second conductive type semiconductor layers 173, a shielding layer 175, a first electrode 180, and a second electrode 190. The shielding layer 175 may be omitted. The light emitting element 150B of the third embodiment may be Figure 5 The light emitting element 300 or Figure 6 The light emitting element 150 is provided.

[0263] The plurality of first-conductivity-type semiconductor layers 171 may include an adsorption prevention layer 171_1, a cladding layer 171_2, and a contact layer 171_3. For example, one of the adsorption prevention layer 171_1, the cladding layer 171_2, and the contact layer 171_3 may be designated as a 1-1 conductivity-type semiconductor layer, another as a 1-2 conductivity-type semiconductor layer, and yet another as a 1-3 conductivity-type semiconductor layer. Each of the adsorption prevention layer 171_1, the cladding layer 171_2, and the contact layer 171_3 has been described in the second embodiment, and therefore a detailed description thereof will be omitted.

[0264] The light-emitting element 150B of the third embodiment may have a quadrilateral shape when viewed from above, but is not limited thereto. In this case, the top surface of the first conductive semiconductor layer 171 is exposed by mesa-etching a portion of the corners of the quadrilateral light-emitting element 150B. The first electrode 180 may be formed on the exposed top surface of the first conductive semiconductor layer 171, and the second electrode 190 may be formed on the top surface of the second conductive semiconductor layer 173.

[0265] The shape of the light emitting element 150B in the third embodiment is merely an example, and various other shapes are also possible.

[0266] On the other hand, the light emitting elements 150 , 150A, and 150B are described as being lateral light emitting elements.

[0267] However, the light emitting elements 150 , 150A, and 150B of the embodiment may also be applied to other light emitting elements, such as a flip-chip light emitting element or a vertical light emitting element.

[0268] In the case of a vertical light-emitting element, the first electrode 180 may be disposed on the bottom surface of the first conductive semiconductor layer 171. For example, the vertical light-emitting element may have a size of 5 μm to 50 μm when viewed from above. For example, the vertical light-emitting element may have a size of 5 μm to 30 μm when viewed from above.

[0269] The above detailed description should not be interpreted as limiting in all aspects, but should be considered as illustrative. The scope of the embodiments should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the embodiments are included in the scope of the embodiments.

[0270] Industrial Applicability

[0271] The embodiments can be applied to light-emitting elements that can improve light efficiency and ensure high brightness by preventing adsorption to the substrate. Examples of such light-emitting elements include, but are not limited to, cylindrical light-emitting elements, disk-shaped light-emitting elements, micro-light-emitting elements, nano-light-emitting elements, and rod-shaped light-emitting elements.

[0272] The embodiments may be applicable to the display field for displaying images or information.

Claims

1. A light-emitting element, wherein: include: active layer; A plurality of first conductive type semiconductor layers are located below the active layer; A plurality of second conductive type semiconductor layers are located on the active layer; a shielding layer, located below the first conductive type semiconductor layer; as well as A metal layer, located below the shielding layer, The metal layer includes a magnetizable nickel layer, The plurality of first conductive type semiconductor layers include an adsorption prevention layer that is farthest away from the active layer. The adsorption prevention layer contains Al x1 Ga 1-x1 InP, the x1 is 0.6 or less, the thickness of the adsorption prevention layer is 2 μm or less, The adsorption prevention layer prevents the light emitting element from adhering to the bottom surface of the substrate, The shielding layer shields the electronegativity of Al in the first conductive semiconductor layer.

2. The light-emitting element according to claim 1, wherein The x1 is greater than or equal to 0.2 and less than or equal to 0.

6.

3. The light-emitting element according to claim 1, wherein The anti-adsorption layer has a thickness of 0.5 μm or more and 1.5 μm or less.

4. The light-emitting element according to claim 1, wherein The concentration ratio of Al to Ga in the adsorption prevention layer is 0.5 or more and 5 or less. The light-emitting element according to claim 1 , wherein The thickness of the shielding layer is greater than 300 nm. The light-emitting element according to claim 1 , wherein The shielding layer is a third conductive type semiconductor layer, The shielding layer is arranged below the adsorption prevention layer and contacts the bottom surface of the adsorption prevention layer.

7. The light-emitting element according to claim 6, wherein The third conductive type semiconductor layer includes GaInP.

8. The light-emitting element according to claim 6, wherein The third conductive type semiconductor layer does not contain Al.

9. The light-emitting element according to claim 1, wherein The shielding layer is an etch stop layer.

10. The light-emitting element according to claim 1, wherein The plurality of first conductive type semiconductor layers include a capping layer located between the active layer and the adsorption prevention layer, wherein the capping layer includes Al x2 Ga 1-x2 InP, x2 is smaller than x1. The light-emitting element according to claim 10 , wherein The ratio of the thickness of the adsorption prevention layer to the thickness of the coating layer is 1 or less.

12. The light-emitting element according to claim 1, wherein Also includes: a first electrode, located on the first conductive type semiconductor layer; as well as a second electrode, located on the second conductive type semiconductor layer; The second electrode is located in a central area of ​​the light-emitting element, and the first electrode surrounds the second electrode.

13. The light-emitting element according to claim 10, wherein The plurality of first conductive type semiconductor layers include a contact layer located between the active layer and the cladding layer.

14. The light-emitting element according to claim 13, wherein The contact layer includes AlInP.

15. A display device, wherein: include: substrate; A first wiring electrode and a second wiring electrode are located on the substrate; a partition wall layer having a plurality of assembly holes and located on the first wiring electrode and the second wiring electrode; as well as A light emitting element is disposed in each of the plurality of assembly holes. The light emitting element comprises: active layer; A plurality of first conductive type semiconductor layers are located below the active layer; A plurality of second conductive type semiconductor layers are located on the active layer; a shielding layer, located below the first conductive type semiconductor layer; and A metal layer, located below the shielding layer, The metal layer includes a magnetizable nickel layer, The plurality of first conductive type semiconductor layers include an adsorption prevention layer that is farthest away from the active layer. The adsorption prevention layer contains Al x1 Ga 1-x1 InP, the x1 is 0.6 or less, the thickness of the adsorption prevention layer is 2 μm or less, and the adsorption prevention layer prevents the light emitting element from adhering to the bottom surface of the substrate, The shielding layer shields the electronegativity of Al in the first conductive semiconductor layer.

16. The display device according to claim 15, wherein The x1 is greater than or equal to 0.2 and less than or equal to 0.

6.

17. The display device according to claim 15, wherein: The anti-adsorption layer has a thickness of 0.5 μm or more and 1.5 μm or less.

18. The display device according to claim 15, wherein The concentration ratio of Al to Ga in the adsorption prevention layer is 0.5 or more and 5 or less.

19. The display device according to claim 15, wherein: The thickness of the shielding layer is greater than 300 nm. The shielding layer is arranged below the adsorption prevention layer and contacts the bottom surface of the adsorption prevention layer.

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