Display panel and manufacturing method therefor

Abstract

A display panel is disclosed. The display panel comprises: a substrate; a plurality of substrate electrodes provided on the substrate; a plurality of first light-emitting diodes, which are electrically connected to the plurality of substrate electrodes and emit light of a first color; and a plurality of second light-emitting diodes, which are electrically connected to the plurality of substrate electrodes. The plurality of second light-emitting diodes can emit light of a second color and light of a third color, which are different from the light of the first color.

Description

Display panel and manufacturing method thereof

[0001] The present disclosure relates to a display panel and a method for manufacturing the same.

[0002] A display panel includes a TFT substrate having a plurality of thin film transistors (TFTs) and a plurality of light-emitting diodes mounted on the substrate. The plurality of light-emitting diodes operate in pixel or sub-pixel units to display various colors. The operation of each pixel or sub-pixel is controlled by a plurality of TFTs. Each light-emitting diode emits a variety of colors, such as red, green, and blue. The plurality of light-emitting diodes can be transferred from a wafer or a relay substrate to the TFT substrate by a pick-and-place transfer method, a stamping transfer method, or a laser transfer method.

[0003] A display panel according to one or more embodiments includes: a substrate; a plurality of substrate electrodes provided on the substrate; a plurality of first light-emitting diodes electrically connected to the plurality of substrate electrodes and emitting light of a first color; and a plurality of second light-emitting diodes electrically connected to the plurality of substrate electrodes. The plurality of second light-emitting diodes may emit light of a second color different from the light of the first color and light of a third color.

[0004] Each of the plurality of first light-emitting diodes may include a first vertically stacked light-emitting diode including a first light-emitting portion and a second light-emitting portion that are vertically stacked; a color conversion layer on a light-emitting surface of the first light-emitting portion; and a first contact electrode, a second contact electrode, a third contact electrode, and a fourth contact electrode connected to the plurality of substrate electrodes.

[0005] The color conversion layer may include a quantum dot that excites the light emitted from each of the first light emitting unit and the second light emitting unit to emit light of the first color.

[0006] The first light emitting portion and the second light emitting portion can be connected in series by a plurality of corresponding substrate electrodes.

[0007] The first light-emitting portion and the second light-emitting portion can be connected in series through the first contact electrode, the second contact electrode, the third contact electrode, and the fourth contact electrode.

[0008] The first contact electrode may be connected to the anode of the first light-emitting unit and the cathode of the second light-emitting unit. The second contact electrode may be connected to the cathode of the first light-emitting unit. The third contact electrode may be connected to the anode of the second light-emitting unit. The fourth contact electrode may be unconnected to the first light-emitting unit and the second light-emitting unit.

[0009] The plurality of second light-emitting diodes may include a second vertically stacked light-emitting diode in which a third light-emitting unit and a fourth light-emitting unit are vertically stacked; a transparent optical layer on the light-emitting surface of the third light-emitting unit; and a fifth contact electrode, a sixth contact electrode, a seventh contact electrode, and an eighth contact electrode connected to the plurality of substrate electrodes.

[0010] The third light emitting portion can emit light of the second color. The fourth light emitting portion can emit light of the third color.

[0011] The fifth contact electrode may be connected to the cathode of the third light-emitting unit. The sixth contact electrode may be connected to the anode of the third light-emitting unit. The seventh contact electrode may be connected to the cathode of the fourth light-emitting unit. The eighth contact electrode may be connected to the anode of the fourth light-emitting unit.

[0012] A light emitting diode according to one or more embodiments may include: a first light emitting portion emitting light in a blue wavelength band; a second light emitting portion on the first light emitting portion and emitting light in a green wavelength band; a color conversion layer on a light emitting surface of the first light emitting portion and including a circle dot that excites light emitted from each of the first light emitting portion and emits light in a red wavelength band; and a plurality of contact electrodes including a first contact electrode, a second contact electrode, a third contact electrode, and a fourth contact electrode.

[0013] A light emitting diode according to one or more embodiments may include: a first light emitting portion emitting light in a blue wavelength band; a second light emitting portion on the first light emitting portion and emitting light in a green wavelength band; a transparent optical layer on a light emitting surface of the first light emitting portion and through which light emitted from the first light emitting portion and light emitted from the second light emitting portion are transmitted; a first contact electrode connected to a cathode of the first light emitting portion; a second contact electrode connected to an anode of the first light emitting portion; a third contact electrode connected to a cathode of the second light emitting portion; and a fourth contact electrode connected to an anode of the second light emitting portion.

[0014] A method for manufacturing a display panel according to one or more embodiments may include: forming a plurality of first vertically stacked light-emitting diodes and a plurality of second vertically stacked light-emitting diodes, each including a first light-emitting unit emitting light of a first color and a second light-emitting unit emitting light of a second color different from the first color, on a wafer; transferring the plurality of first vertically stacked light-emitting diodes and the plurality of second vertically stacked light-emitting diodes from the wafer to a substrate; forming a color conversion layer on light-emitting surfaces of the plurality of first vertically stacked light-emitting diodes, each color conversion layer emitting light of a third color different from the first color and the second color, to form a plurality of first light-emitting diodes; and forming a transparent optical layer on light-emitting surfaces of the plurality of second vertically stacked light-emitting diodes, to form a plurality of second light-emitting diodes. The first light-emitting unit and the second light-emitting unit may be formed to be connected in series.

[0015] The above and other aspects, features and advantages of specific embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings.

[0016] FIG. 1 is a drawing illustrating a display panel according to one or more embodiments.

[0017] FIG. 2 is a drawing showing an example in which first light-emitting diodes and second light-emitting diodes forming one pixel according to one or more embodiments are arranged in a horizontal direction.

[0018] FIG. 3 is a drawing showing an example in which first light-emitting diodes and second light-emitting diodes forming one pixel according to one or more embodiments are arranged in a vertical direction.

[0019] FIG. 4 is a drawing showing the bottom surface of a vertically stacked light emitting diode according to one or more embodiments.

[0020] Figure 5 is a cross-sectional view taken along line A-A' shown in Figure 4.

[0021] FIG. 6 is a drawing showing a substrate according to one or more embodiments.

[0022] FIG. 7 is a drawing showing an example of a plurality of light-emitting diodes transferred to a substrate according to one or more embodiments.

[0023] FIG. 8 is a circuit diagram schematically showing the connection of a first substrate electrode group and a first light-emitting diode of a substrate according to one or more embodiments.

[0024] FIG. 9 is a circuit diagram schematically showing the connection of a second substrate electrode group and a second light-emitting diode of a substrate according to one or more embodiments.

[0025] FIG. 10 is a flowchart illustrating a method for manufacturing a vertically stacked light emitting diode according to one or more embodiments.

[0026] FIGS. 11 to 24 are drawings illustrating a method for manufacturing a vertically stacked light emitting diode according to one or more embodiments.

[0027] FIG. 25 is a flowchart illustrating a method for manufacturing a display panel according to one or more embodiments.

[0028] FIG. 26 is a drawing illustrating a display panel according to one or more embodiments.

[0029] FIG. 27 is a drawing showing the bottom surface of a vertically stacked light emitting diode according to one or more embodiments.

[0030] Fig. 28 is a cross-sectional view taken along the line B-B' shown in Fig. 27.

[0031] FIG. 29 is a drawing showing a substrate according to one or more embodiments.

[0032] FIG. 30 is a drawing showing an example of a plurality of light-emitting diodes transferred to a substrate according to one or more embodiments.

[0033] FIG. 31 is a diagram illustrating an example in which a plurality of vertically stacked light emitting diodes of different types according to one or more embodiments are grown on a single wafer.

[0034] FIGS. 32 to 37 are drawings illustrating a method for manufacturing a vertically stacked light emitting diode according to one or more embodiments.

[0035] FIG. 38 is a block diagram illustrating a display device according to one or more embodiments.

[0036] Hereinafter, various embodiments will be described in more detail with reference to the accompanying drawings. One or more embodiments described herein may be variously modified. Specific embodiments may be depicted in the drawings and further described in the detailed description. However, the specific embodiments disclosed in the accompanying drawings are merely intended to facilitate understanding of various embodiments. Therefore, the technical concepts disclosed in the accompanying drawings are not intended to be limited by the specific embodiments disclosed in the accompanying drawings, but should be understood to include all equivalents or alternatives falling within the spirit and technical scope of the present disclosure.

[0037] In connection with the description of the drawings, similar or similar reference numbers may be used for similar or similar elements. In the present disclosure, terms including ordinal numbers such as "first," "second," etc. may be used to describe various components, but these components are not limited by the terms described above. The terms described above are used only for the purpose of distinguishing one component from another. In the present disclosure, it should be understood that terms such as "comprises" or "has" are intended to indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not preemptively exclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof. When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to the other component, but that other components may also be present in between. On the other hand, when a component is referred to as being "directly connected" or "directly connected" to another component, it should be understood that there are no other components present in between. In this disclosure, the term "same" may encompass not only complete matching but also differences that take into account the scope of processing errors. If a detailed description of a related known function or configuration is deemed likely to unnecessarily obscure the gist of this disclosure, the detailed description will be abbreviated or omitted.

[0038] Below, with reference to the attached drawings, an embodiment of the present disclosure is described in detail so that those skilled in the art can easily implement the present disclosure. However, the embodiment of the present disclosure may be implemented in various different forms and is not limited to the embodiment of the present disclosure described herein.

[0039] Hereinafter, with reference to the drawings, a display panel and a vertically stacked light-emitting diode included in the display panel according to one or more embodiments are described. The vertically stacked light-emitting diode may also be referred to as a "vertically stacked light-emitting structure."

[0040] FIG. 1 is a drawing illustrating a display panel according to one or more embodiments.

[0041] Referring to FIG. 1, the display panel (10) may include a substrate (50) and a plurality of first light-emitting diodes (100a) and a plurality of second light-emitting diodes (100b) arranged on the substrate (50).

[0042] The substrate (50) may have a TFT layer formed on the front surface, and a power supply circuit for supplying power to the TFT layer, a data driving driver, a gate driving driver, and a timing controller for controlling each driving driver may be placed on the back surface.

[0043] The TFT layer may include a plurality of TFTs for driving a plurality of first light-emitting diodes (100a) and a plurality of second light-emitting diodes (100b). The TFT layer may be integrally formed on the front surface of the substrate (50), but is not limited thereto, and may be manufactured in the form of a separate film and attached to the front surface of the substrate (50). A plurality of substrate electrodes (a first substrate electrode (51), a second substrate electrode (53), a third substrate electrode (55), a fourth substrate electrode (57)) (see FIGS. 1 to 4) disposed on the TFT layer may be electrically connected to the TFT layer.

[0044] The plurality of TFTs included in the TFT layer are not limited to a specific structure or type. For example, the TFT can be implemented as an LTPS TFT (low-temperature polycrystalline silicon TFT), an oxide TFT, a Si TFT (poly silicon, a-silicon), an organic TFT, a graphene TFT, etc. The TFT layer can be applied to a substrate (50) by forming only a P-type (or N-type) MOSFET (metal oxide semiconductor field effect transistor) on a Si wafer in a CMOS (complementary metal oxide semiconductor) process.

[0045] A conductive adhesive layer may be laminated on the TFT layer. The conductive adhesive layer may include a flux containing a large number of fine metal particles. For example, the conductive adhesive layer may be a non-conductive resin and an anisotropic conductive film in which fine conductive particles are arranged regularly or irregularly in the non-conductive resin. In this case, the non-conductive resin may have a black color to absorb external light. The external light may be natural light or light emitted from lights placed around the display panel. A plurality of element electrodes (a first contact electrode (191), a second contact electrode (193), a third contact electrode (195), a fourth contact electrode (197)) (see FIGS. 1 and 2) provided on each of a plurality of vertically stacked light-emitting diodes (100a, 100b) and a plurality of substrate electrodes (a first substrate electrode (51), a second substrate electrode (53), a third substrate electrode (55), a fourth substrate electrode (57)) of the substrate (50) can be electrically and physically interconnected by a conductive adhesive layer.

[0046] The first light-emitting diode (100a) may include a first vertically stacked light-emitting diode (110a) and a color conversion layer (113) stacked on the light-emitting surface of the first vertically stacked light-emitting diode (110a).

[0047] The first vertically stacked light emitting diode (110a) may include a first light emitting portion (120) that emits light of a first color and a second light emitting portion (160) that is stacked on the first light emitting portion (120) and emits light of a second color different from the first color. For example, the light of the first color may be blue light, and the light of the second color may be green light. The first vertically stacked light emitting diode (110a) may be driven to individually emit the light of the first color and the light of the second color.

[0048] The color conversion layer (113) may include a red quantum dot (QD) that can emit light in a red wavelength band when excited by light emitted from the first vertically stacked light emitting diode (110a). A quantum dot refers to a small spherical semiconductor particle with a size of a nanometer (nm, 1,000,000,000th of a meter), and may be composed of a core body with a size of approximately 2 nanometers (nm) to 10 nm and a shell made of zinc sulfide (ZnS). Here, cadmium selenite (CdSe), cadmium telluride (CdTe), or cadmium sulfide (CdS) may be used as the core body of the quantum dot. When an electric field is applied to the quantum dot, the quantum dot can emit light of a specific wavelength on its own, or can emit light of a specific wavelength when it absorbs high-energy light. At this time, the wavelength of the emitted light can depend on the size of the quantum dot. Smaller quantum dots emit light with shorter wavelengths, while larger ones can emit light with longer wavelengths. For example, a quantum dot with a diameter of approximately 6 nm can emit light of approximately red color.

[0049] In addition, the color conversion layer (113) may include a red nano-fluorescent material that can emit light in a red wavelength band when excited by light emitted from the first vertically stacked light-emitting diode (110a). For example, the red nano-fluorescent material may be SCASN (Si 1-x Ca x AlSiN3:Eu 2+ ) may be. In this case, the red nano-fluorescent material has an average particle size distribution value (d 50 ) is less than 0.5㎛ (preferably 0.1㎛ < d 50 < 0.5㎛).

[0050] The second light-emitting diode (100b) may include a transparent optical layer (115) laminated on the light-emitting surface (111b) of the second vertically stacked light-emitting diode (110b). The second vertically stacked light-emitting diode (110b) is substantially the same as the first vertically stacked light-emitting diode (110a). The transparent optical layer (115) may be made of a material that does not affect the transmittance, reflectance, and refractive index of light emitted from the second vertically stacked light-emitting diode (110b).

[0051] The first light emitting diode (100a) may include a first vertically stacked light emitting diode (110a) and a second vertically stacked light emitting diode (110b). The second light emitting diode (100b) may include a first vertically stacked light emitting diode (110a) and a second vertically stacked light emitting diode (110b) substantially the same as the first light emitting diode (100a). In this case, the first light emitting diode (100a) may emit red light through the color conversion layer (113), and the second light emitting diode (100b) may individually emit green light and blue light.

[0052] The color conversion layer (113) and the transparent optical layer (115) may be formed on the first vertically stacked light emitting diode (110a) and the second vertically stacked light emitting diode (110b), respectively, after the first vertically stacked light emitting diode (110a) and the second vertically stacked light emitting diode (110b) are transferred to the substrate (50). In this way, the first light emitting diode (100a) may include the first vertically stacked light emitting diode (110a) and the color conversion layer (113). The second light emitting diode (100b) may include the second vertically stacked light emitting diode (110b) and the transparent optical layer (115).

[0053] According to one or more embodiments, compared to the case where three light-emitting diodes (a red light-emitting diode, a green light-emitting diode, and a blue light-emitting diode) are used to form one pixel, one pixel can be formed with a first light-emitting diode (100a) including one type (here, “one type” means having the same structure) of a first vertically stacked light-emitting diode (110a) and a second vertically stacked light-emitting diode (110b) including one type of the first vertically stacked light-emitting diode (110a) and a second vertically stacked light-emitting diode (110b).

[0054] Accordingly, when the first light-emitting diode (100a) and the second light-emitting diode (100b) are applied to the display panel (10), there is no need to separately provide a red light-emitting diode that emits red light, a blue light-emitting diode that emits blue light, and a green light-emitting diode that emits green light. According to one or more embodiments, the number of light-emitting diodes forming one pixel can be reduced from three to two, thereby improving (reducing) the area occupied by one pixel to approximately 2 / 3 compared to the case where three R / G / B light-emitting diodes are used. Accordingly, the pixel structure provided to the display panel (10) can be simplified, and the manufacturing process of the display panel (10) can be simplified.

[0055] Referring to FIG. 2, the first light-emitting diode (100a) and the second light-emitting diode (100b) forming one pixel may be arranged in a first direction. Here, the first direction may be a horizontal direction in FIG. 2. Adjacent pixels may have a first pitch (P1) in the horizontal direction and a second pitch (P2) in the vertical direction.

[0056] Referring to FIG. 3, the first light-emitting diode (100a) and the second light-emitting diode (100b) forming one pixel may be arranged in a second direction. Here, the second direction may be a vertical direction in FIG. 3. Adjacent pixels may have a third pitch (P3) in the horizontal direction and a fourth pitch (P4) in the vertical direction.

[0057] Fig. 4 is a drawing showing the bottom surface of a vertically stacked light emitting diode according to one or more embodiments. Fig. 5 is a cross-sectional view taken along line A-A' shown in Fig. 4. Since the first vertically stacked light emitting diode (110a) and the second vertically stacked light emitting diode (110b) have substantially the same structure, only the first vertically stacked light emitting diode (110a) will be described below.

[0058] Referring to FIGS. 4 and 5, the first vertically stacked light-emitting diode (110a) may be formed in a flip chip form in which a plurality of contact electrodes (a first contact electrode (191), a second contact electrode (193), a third contact electrode (195), and a fourth contact electrode (197)) are provided on the opposite side of the light-emitting surface (121a).

[0059] The first vertically stacked light emitting diode (110a) may include a first light emitting portion (120), a first transparent electrode layer (130), a second light emitting portion (160), a second transparent electrode layer (170), and four contact electrodes. The four contact electrodes may include a first contact electrode (191), a second contact electrode (193), a third contact electrode (195), and a fourth contact electrode (197).

[0060] The first light-emitting portion (120) may include a first semiconductor layer (121), a second semiconductor layer (125), and a first active layer (123) provided between the first semiconductor layer (121) and the second semiconductor layer (125).

[0061] The first semiconductor layer (121), the second semiconductor layer (125), and the first active layer (123) can be formed using a method such as metal organic chemical vapor deposition (MOCVD), chemical vapor deposition (CVD), or plasma-enhanced chemical vapor deposition (PECVD).

[0062] The first semiconductor layer (121) may include, for example, a p-type semiconductor layer. The p-type semiconductor layer may be selected from, for example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, etc., and may be doped with a p-type dopant such as Mg, Zn, Ca, Sr, or Ba.

[0063] The second semiconductor layer (125) may include, for example, an n-type semiconductor layer. The n-type semiconductor layer may be selected from, for example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, etc., and may be doped with an n-type dopant such as Si, Ge, or Sn.

[0064] The first light-emitting portion (120) is not limited to the configuration described above, and for example, the first semiconductor layer (121) may include an n-type semiconductor layer, and the second semiconductor layer (125) may include a p-type semiconductor layer.

[0065] The first active layer (123) is a region where electrons and holes recombine, and as the electrons and holes recombine, they transition to a lower energy level and can generate light having a corresponding wavelength. The active layer (123) may include a semiconductor material, for example, amorphous silicon or polycrystalline silicon. However, the present embodiment is not limited thereto, and may contain an organic semiconductor material, etc., and may be formed in a single quantum well (SQW) structure or a multi-quantum well (MQW) structure. The first active layer (123) may emit light in the blue wavelength band (455 to 475 nm).

[0066] A first transparent electrode layer (130) (e.g., ITO (indium tin oxide)) may be provided on a second semiconductor layer (125). The first transparent electrode layer (130) may be electrically connected to the second semiconductor layer (125). The first transparent electrode layer (130) may be covered by a first passivation layer (140).

[0067] The first passivation layer (140) may be deposited on the first transparent electrode layer (130) using techniques such as atomic layer deposition, e-beam evaporation, sputtering, chemical vapor deposition, and spin coating using an insulating material (e.g., SiO2, Al2O3, SiN, etc.). The first passivation layer (140) physically and electrically isolates the first light-emitting portion (120) and the second light-emitting portion (160) from each other. A mirror layer such as distributed Bragg reflectors (DBR) may be laminated on the first passivation layer (140) to improve the light extraction efficiency of the first light-emitting portion (120).

[0068] The second light-emitting portion (160) can be attached to the first light-emitting portion (120) in a laminated state by a bonding layer (150). The bonding layer (150) can be provided between the first passivation layer (140) and the third semiconductor layer (161) of the second light-emitting portion (160).

[0069] The second light-emitting portion (160) may include a third semiconductor layer (161), a fourth semiconductor layer (165), and a second active layer (163) provided between the third semiconductor layer (161) and the fourth semiconductor layer (165).

[0070] The third semiconductor layer (161), the fourth semiconductor layer (165), and the second active layer (163) can be formed using a method such as metal organic chemical vapor deposition (MOCVD), chemical vapor deposition (CVD), or plasma-enhanced chemical vapor deposition (PECVD).

[0071] The third semiconductor layer (161) may include, for example, a p-type semiconductor layer. The p-type semiconductor layer may be selected from, for example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, etc., and may be doped with a p-type dopant such as Mg, Zn, Ca, Sr, or Ba.

[0072] The fourth semiconductor layer (165) may include, for example, an n-type semiconductor layer. The n-type semiconductor layer may be selected from, for example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, etc., and may be doped with an n-type dopant such as Si, Ge, or Sn.

[0073] The second light-emitting portion (160) is not limited to the configuration described above, and for example, the third semiconductor layer (161) may include an n-type semiconductor layer, and the fourth semiconductor layer (165) may include a p-type semiconductor layer.

[0074] The second active layer (163) may include a semiconductor material, for example, amorphous silicon or polycrystalline silicon. In addition, the second active layer (163) may contain an organic semiconductor material, etc., and may be formed in a single quantum well (SQW) structure or a multi-quantum well (MQW) structure. The second active layer (163) may emit light in the green wavelength band (520 to 535 nm).

[0075] A second transparent electrode layer (170) may be provided on the fourth semiconductor layer (165). The second transparent electrode layer (170) may be electrically connected to the fourth semiconductor layer (165). The second transparent electrode layer (170) may be covered by a second passivation layer (180).

[0076] The first contact electrode (191), the second contact electrode (193), the third contact electrode (195), and the fourth contact electrode (197) may be provided on the opposite side of the light-emitting surface (121a) of the first vertically stacked light-emitting diode (110a). The first contact electrode (191), the second contact electrode (193), the third contact electrode (195), and the fourth contact electrode (197) may be arranged in a grid as shown in FIG. 4.

[0077] The first contact electrode (191) may be an anode (B+) electrically connected to the second semiconductor layer (125) of the first light-emitting portion (120) through the first transparent electrode layer (130). The second contact electrode (193) may be a cathode (B-) electrically connected to the first semiconductor layer (121) of the first light-emitting portion (120).

[0078] The third contact electrode (195) may be an anode (G+) electrically connected to the fourth semiconductor layer (165) of the second light-emitting portion (160) through the second transparent electrode layer (170). The fourth contact electrode (197) may be a cathode (G-) electrically connected to the third semiconductor layer (161) of the second light-emitting portion (160).

[0079] FIG. 6 is a diagram showing a substrate according to one or more embodiments. FIG. 7 is a diagram showing an example in which a plurality of light-emitting diodes are transferred to a substrate according to one or more embodiments. FIG. 8 is a circuit diagram showing the connection between a first substrate electrode group and a first light-emitting diode of a substrate according to one or more embodiments. FIG. 9 is a circuit diagram showing the connection between a second substrate electrode group and a second light-emitting diode of a substrate according to one or more embodiments.

[0080] Referring to FIGS. 6 and 7, a substrate (50) according to one or more embodiments may have a plurality of substrate electrodes arranged on the front surface. The plurality of substrate electrodes may include a first substrate electrode group (50a) corresponding to a first light-emitting diode (100a) emitting red light and a second substrate electrode group (50b) corresponding to a second light-emitting diode (100b) emitting green light and blue light.

[0081] The first substrate electrode group (50a) may include first to fourth substrate electrodes (first substrate electrode (51), second substrate electrode (53), third substrate electrode (55), fourth substrate electrode (57)) arranged in a grid arrangement to correspond to the first to fourth contact electrodes (first contact electrode (191), second contact electrode (193), third contact electrode (195), fourth contact electrode (197)) of the first light-emitting diode (100a). For example, the first substrate electrode (51) may be electrically connected to the first contact electrode (191) of the first light-emitting diode (100a), the second substrate electrode (53) may be electrically connected to the second contact electrode (193) of the first light-emitting diode (100a), the third substrate electrode (55) may be electrically connected to the third contact electrode (195) of the first light-emitting diode (100a), and the fourth substrate electrode (57) may be electrically connected to the fourth contact electrode (197) of the first light-emitting diode (100a).

[0082] Referring to Fig. 8, the first substrate electrode group (50a) can be electrically connected to the second substrate electrode (53) and the third substrate electrode (55) by a wiring pattern (54). Accordingly, the first to fourth substrate electrodes (the first substrate electrode (51), the second substrate electrode (53), the third substrate electrode (55), and the fourth substrate electrode (57)) of the first substrate electrode group (50a) can be connected in series. Accordingly, the first light-emitting diode (100a) electrically connected to the first substrate electrode group (50a) can simultaneously drive the first light-emitting unit (120) and the second light-emitting unit (160) when current is applied to the first substrate electrode group (50a). Since the light simultaneously emitted from the first light-emitting unit (120) and the second light-emitting unit (160) is excited by the color conversion layer (113), the first light-emitting diode (100a) can emit red light.

[0083] The second substrate electrode group (50b) may include fifth to eighth substrate electrodes (fifth substrate electrode (51'), sixth substrate electrode (53'), seventh substrate electrode (55'), eighth substrate electrode (57')) arranged in a grid arrangement to correspond to the first to fourth contact electrodes (first contact electrode (191), second contact electrode (193), third contact electrode (195), and fourth contact electrode (197)) of the second light-emitting diode (100b), respectively. For example, the fifth substrate electrode (51') may be electrically connected to the first contact electrode (191) of the second light-emitting diode (100b), the sixth substrate electrode (53') may be electrically connected to the second contact electrode (193) of the second light-emitting diode (100b), the seventh substrate electrode (55') may be electrically connected to the third contact electrode (195) of the second light-emitting diode (100b), and the eighth substrate electrode (57') may be electrically connected to the fourth contact electrode (197) of the second light-emitting diode (100b).

[0084] Referring to Fig. 9, unlike the first substrate electrode group (50a), the second substrate electrode group (50b) is not electrically connected to the sixth substrate electrode (53') and the seventh substrate electrode (55'). Accordingly, the first light-emitting unit (120) connected to the fifth substrate electrode (51') and the sixth substrate electrode (53') of the second substrate electrode group (50b) can be driven individually from the second light-emitting unit (160) connected to the seventh substrate electrode (55') and the eighth substrate electrode (57'). Accordingly, when current is applied to the second substrate electrode group (50b), the second light-emitting diode (100b) electrically connected to the second substrate electrode group (50b) can be driven individually from the first light-emitting unit (120) and the second light-emitting unit (160). Accordingly, the second light-emitting diode (100b) can individually emit blue light emitted from the first light-emitting unit (120) and green light emitted from the second light-emitting unit (160).

[0085] FIG. 10 is a flowchart illustrating a method for manufacturing a vertically stacked light-emitting diode according to one or more embodiments. FIGS. 11 to 24 are drawings illustrating a method for manufacturing a vertically stacked light-emitting diode according to one or more embodiments.

[0086] The first vertically stacked light-emitting diode (110a) and the second vertically stacked light-emitting diode (110b) can be formed on a single wafer. The first vertically stacked light-emitting diode (110a) and the second vertically stacked light-emitting diode (110b) can have substantially the same structure. Hereinafter, only the manufacturing method of the first vertically stacked light-emitting diode (110a) will be described.

[0087] Referring to FIG. 11, a first light-emitting portion (120) is formed on a wafer (e.g., a sapphire substrate) (90) (component 1001 of FIG. 10). The first light-emitting portion (120) may include a first semiconductor layer (121) formed on a buffer layer (91) of the wafer (90), a second semiconductor layer (125), and a first active layer (123) formed between the first semiconductor layer (121) and the second semiconductor layer (125) through ion implantation. The first semiconductor layer (121) may be a p-type semiconductor layer doped with a p-type dopant. The second semiconductor layer (125) may be an n-type semiconductor layer doped with an n-type dopant. The first active layer (123) includes a single quantum well (SQW) structure or a multiple quantum well (MQW) structure and may emit light in a blue wavelength band.

[0088] Referring to Fig. 12, one side of the first light-emitting portion (120) is etched to form a first contact portion (C) so that one end of the second contact electrode (193) comes into contact with the first semiconductor layer (121).

[0089] Referring to Fig. 13, a first transparent electrode layer (130) is formed on the second semiconductor layer (125) of the first light-emitting portion (120) (component 1002 of Fig. 10). The first transparent electrode layer (130) can be in contact with one end of the first contact electrode (191).

[0090] Referring to Fig. 14, a first passivation layer (140) is formed to block the electrical connection between the first transparent electrode layer (130) and the second light-emitting portion (160) and to protect the first light-emitting portion (120). The first passivation layer (140) covers the first transparent electrode layer (130) and may cover a portion of the first light-emitting portion (120) that is not covered by the first transparent electrode layer (130). In this case, the first contact portion (C) of the first semiconductor layer (121) may be covered by the first passivation layer (140).

[0091] Referring to FIG. 15, a portion of the first passivation layer (140) is etched to expose a second contact portion that can be in contact with one end of the first contact electrode (191), and another portion of the first passivation layer (140) is etched to expose a first contact portion (C) that can be in contact with one end of the second contact electrode (193). The second contact portion (D) is a portion of the first transparent electrode layer (130).

[0092] Referring to FIG. 16, a bonding layer (150) is formed on the first light-emitting portion (120) to connect the second light-emitting portion (160) to be laminated on the upper side of the first light-emitting portion (120) to the first light-emitting portion (120) (component 1003 of FIG. 10). In this case, the first passivation layer (140) may be covered by the bonding layer (150) together with the first light-emitting portion (120).

[0093] Referring to Fig. 17, a second light-emitting portion (160) is formed on a bonding layer (150) (component 1004 of Fig. 10). The second light-emitting portion (160) may include a third semiconductor layer (161), a fourth semiconductor layer (165), and a second active layer (163) formed between the third semiconductor layer (161) and the fourth semiconductor layer (165) through ion implantation. The third semiconductor layer (161) may be a p-type semiconductor layer doped with a p-type dopant. The fourth semiconductor layer (165) may be an n-type semiconductor layer doped with an n-type dopant. The second active layer (163) includes a single quantum well (SQW) structure or a multiple quantum well (MQW) structure and may emit light in a green wavelength band.

[0094] Referring to Fig. 18, a portion of the second light-emitting layer is etched to expose the first edge portion (E1) and the second edge portion (E2) of the bonding layer (150). The first edge portion (E1) may be at a position corresponding to the first contact portion (C) of the first semiconductor layer (121), and the second edge portion (E2) may be at a position corresponding to the second contact portion (D) of the first transparent electrode layer (130).

[0095] Referring to FIG. 19, a portion of the bonding layer (150) is etched to expose the first contact portion (C) of the first semiconductor layer (121) and the second contact portion (D) of the first transparent electrode layer (130), respectively.

[0096] Referring to FIG. 20, a portion of the second light-emitting portion (160) is etched to expose the third contact portion (E) so that the fourth contact electrode (197) can contact the third semiconductor layer (161) of the second light-emitting portion (160).

[0097] Referring to Fig. 21, a second transparent electrode layer (170) is formed on the fourth semiconductor layer (165) of the second light-emitting portion (160) (component 1005 of Fig. 10). The second transparent electrode layer (170) can be in contact with one end of the third contact electrode (195). A portion of the second transparent electrode layer (170) can be etched so that the third contact portion (E) of the third semiconductor layer (161) is exposed.

[0098] Referring to Fig. 22, a second passivation layer (180) is formed to cover the second light-emitting portion (160). The second passivation layer (180) can cover both an exposed portion of the first light-emitting portion (120) and an exposed portion of the bonding layer (150).

[0099] Referring to FIG. 23, each portion of the second passivation layer (180) is etched to expose the first contact portion (C) of the first semiconductor layer (121), the second contact portion (D) of the first transparent electrode layer (130), the third contact portion (E) of the third semiconductor layer (161), and the fourth contact portion (F) of the second transparent electrode layer (170).

[0100] Referring to FIG. 24, a first contact electrode (191), a second contact electrode (193), a third contact electrode (195), and a fourth contact electrode (197) are formed on a second passivation layer (180) (component 1106 of FIG. 11). The first contact electrode (191), the second contact electrode (193), the third contact electrode (195), and the fourth contact electrode (197) may be arranged in a roughly grid shape.

[0101] The first contact electrode (191) may be in contact with the second contact portion (D) of the first transparent electrode layer (130). The second contact electrode (193) may be in contact with the first contact portion (C) of the first semiconductor layer (121). The third contact electrode (195) may be in contact with the fourth contact portion (F) of the second transparent electrode layer (170). The fourth contact electrode (197) may be in contact with the third contact portion (E) of the third semiconductor layer (161).

[0102] FIG. 25 is a flowchart illustrating a method for manufacturing a display panel according to one or more embodiments.

[0103] A method for manufacturing a display panel (10) according to one or more embodiments includes growing a vertically stacked light emitting diode structure on a wafer and then individually forming a plurality of first vertically stacked light emitting diodes (110a) and second vertically stacked light emitting diodes (110b) through an isolation process (component 2501 of FIG. 25). Here, the first vertically stacked light emitting diodes (110a) and the second vertically stacked light emitting diodes (110b) may have substantially the same structure.

[0104] A plurality of first vertically stacked light emitting diodes (110a) and a plurality of second vertically stacked light emitting diodes (110b) formed on a wafer may be directly transferred to a substrate (50, see FIG. 1) (here, the substrate (50) may be referred to as a “target substrate”) through a transfer process or may be transferred to a separate transfer substrate (component 2502 of FIG. 25). When transferred to a separate transfer substrate, the plurality of first vertically stacked light emitting diodes (110a) and the plurality of second vertically stacked light emitting diodes (110b) may be transferred from the wafer to a first transfer substrate, transferred from the first transfer substrate to a second transfer substrate, and then finally transferred from the second transfer substrate to the substrate (50). For example, the transfer process may employ a laser transfer method, a stamp transfer method, a rollable transfer method, or a pick-and-place transfer method.

[0105] A color conversion layer (113, see Fig. 1) is formed on the light-emitting surface (121a) of a plurality of first vertically stacked light-emitting diodes (110a) transferred to the substrate (50) (component 2503 of Fig. 25).

[0106] A transparent optical layer (115, see FIG. 1) is formed on the light-emitting surface (121b, see FIG. 1) of a plurality of second vertically stacked light-emitting diodes (110b) transferred to a substrate (50) (component 2504 of FIG. 25). In the present disclosure, the process of forming the color conversion layer (113) is described as preceding the process of forming the transparent optical layer (115), but is not limited thereto. For example, it is also possible to perform the process of forming the color conversion layer (113) after the process of forming the transparent optical layer (115).

[0107] According to one or more embodiments, one type of first vertically stacked light emitting diode (110a) and one type of second vertically stacked light emitting diode (110b) can be transferred to a substrate (50) from one wafer. In contrast, when transferring three types of individual light emitting diodes, three wafers corresponding to red, green, and blue light emitting diodes are required, and the light emitting diodes of each wafer must be sequentially transferred to the substrate. Therefore, the present disclosure can improve (reduce) the time required for the transfer process to approximately 1 / 3 compared to the process of transferring three types of individual light emitting diodes described above.

[0108] FIG. 26 is a drawing illustrating a display panel according to one or more embodiments. FIG. 27 is a drawing illustrating a bottom surface of a vertically stacked light emitting diode according to one or more embodiments. FIG. 28 is a cross-sectional view taken along line B-B' illustrated in FIG. 27.

[0109] Referring to FIG. 26, according to one or more embodiments, each of the plurality of pixels provided on the display panel (10a) may include a second light emitting diode (100b) and a third light emitting diode (100c).

[0110] The second light-emitting diode (100b) may include a second vertically stacked light-emitting diode (110b) and a transparent optical layer (115). The second light-emitting diode (100b) illustrated in FIG. 26 has substantially the same structure as the second light-emitting diode (100b) illustrated in FIG. 1, and therefore, a description thereof is omitted.

[0111] The third light-emitting diode (100c) may include a third vertically stacked light-emitting diode (110c) and a color conversion layer (113). The third vertically stacked light-emitting diode (110c) has a structure similar to that of the first vertically stacked light-emitting diode (110a, see FIGS. 2 and 3) described above, and differs only in some configurations.

[0112] The third vertically stacked light emitting diode (110c) may include a first light emitting portion (120) that emits light of a first color and a second light emitting portion (160) that is stacked on the first light emitting portion (120) and emits light of a second color different from the first color. For example, the light of the first color may be blue light, and the light of the second color may be green light. The third vertically stacked light emitting diode (110c) may be driven to individually emit the light of the first color and the light of the second color.

[0113] The color conversion layer (113) may include a red quantum dot (QD) that can emit light in a red wavelength band by being excited by light emitted from the third vertically stacked light emitting diode (110c).

[0114] The third vertically stacked light-emitting diode (110c) differs from the structure of the first vertically stacked light-emitting diode (110a, see FIGS. 2 and 3) described above in that the ninth contact electrode (191”), the tenth contact electrode (193”), the eleventh contact electrode (195”), and the twelfth contact electrode (197”) are connected in series. In this case, the 9th to 12th substrate electrodes (51”, 52”, 55”, 57”) of the substrate (50’) to which the 9th to 12th contact electrodes (9th contact electrode (191”), 10th contact electrode (193”), 11th contact electrode (195”), 12th contact electrode (197”)) of the 3rd vertically stacked light-emitting diode (110c) are electrically connected may have the same pattern as the 5th to 8th substrate electrodes (5th substrate electrode (51’), 6th substrate electrode (53’), 7th substrate electrode (55’), 8th substrate electrode (57’)).

[0115] Hereinafter, the third vertical stacked light-emitting diode (110c) will be described with reference to the drawings, and each component that is substantially the same as the first vertical stacked light-emitting diode (110a, see FIGS. 4 and 5) will be given the same reference numerals and briefly described.

[0116] Referring to FIGS. 27 and 28, the third vertically stacked light-emitting diode (110c) may include a first light-emitting portion (120), a first transparent electrode layer (130), a second light-emitting portion (160), a second transparent electrode layer (170), and four contact electrodes. The four contact electrodes may include a ninth contact electrode (191”), a tenth contact electrode (193”), an eleventh contact electrode (195”), and a twelfth contact electrode (197”).

[0117] The first light-emitting portion (120) may include a first semiconductor layer (121), a second semiconductor layer (125), and a first active layer (123) provided between the first semiconductor layer (121) and the second semiconductor layer (125). The first light-emitting portion (120) is not limited to the configuration described above, and for example, the first semiconductor layer (121) may include an n-type semiconductor layer, and the second semiconductor layer (125) may include a p-type semiconductor layer.

[0118] The first active layer (123) can be formed as a single quantum well (SQW) structure or a multi quantum well (MQW) structure. The first active layer (123) can emit light in the blue wavelength band (455 to 475 nm).

[0119] A first transparent electrode layer (130) may be provided on a second semiconductor layer (125). The first transparent electrode layer (130) may be electrically connected to the semiconductor layer (125). The first transparent electrode layer (130) may be covered by a first passivation layer (140).

[0120] The second light-emitting portion (160) can be attached to the first light-emitting portion (120) in a laminated state by a bonding layer (150). The bonding layer (150) can be provided between the first passivation layer (140) and the third semiconductor layer (161) of the second light-emitting portion (160).

[0121] The second light-emitting portion (160) may include a third semiconductor layer (161), a fourth semiconductor layer (165), and a second active layer (163) provided between the third semiconductor layer (161) and the fourth semiconductor layer (165). The second light-emitting portion (160) is not limited to the configuration described above, and for example, the third semiconductor layer (161) may include an n-type semiconductor layer, and the fourth semiconductor layer (165) may include a p-type semiconductor layer.

[0122] The second active layer (163) can be formed as a single quantum well (SQW) structure or a multi quantum well (MQW) structure. The second active layer (163) can emit light in the green wavelength band (520 to 535 nm).

[0123] A second transparent electrode layer (170) may be provided on the fourth semiconductor layer (165). The second transparent electrode layer (170) may be electrically connected to the fourth semiconductor layer (165). The second transparent electrode layer (170) may be covered by a second passivation layer (180).

[0124] The ninth contact electrode (191”), the tenth contact electrode (193”), the eleventh contact electrode (195”), and the twelfth contact electrode (197”) may be provided on the opposite side of the light-emitting surface (121c) of the third vertically stacked light-emitting diode (110c). The ninth contact electrode (191”), the tenth contact electrode (193”), the eleventh contact electrode (195”), and the twelfth contact electrode (197”) may be arranged in a grid as shown in FIG. 28.

[0125] The ninth contact electrode (191”) may be a terminal (B+ / G-) having one portion electrically connected to the third semiconductor layer (161) of the second light-emitting portion (160) and the other portion electrically connected to the second semiconductor layer (125) of the first light-emitting portion (120) through the first transparent electrode layer (130). The tenth contact electrode (193”) may be a cathode (B-) electrically connected to the first semiconductor layer (121) of the first light-emitting portion (120). The 11th contact electrode (195”) may be an anode (G+) electrically connected to the 4th semiconductor layer (165) of the second light-emitting portion (160) through the 2nd transparent electrode layer (170). The 12th contact electrode (197”) may be a structure disposed on the 2nd passivation layer (180) and not electrically connected to the 1st light-emitting portion (120) and the 2nd light-emitting portion (160).

[0126] In this way, the third vertically stacked light-emitting diode (110c) connects the anode (B+) of the first light-emitting unit (120) and the cathode (G-) of the second light-emitting unit (160) through the ninth contact electrode (191”), so that the first light-emitting unit (120) and the second light-emitting unit (160) are connected in series. Therefore, when current is applied to the eleventh contact electrode (195”), the first light-emitting unit (120) and the second light-emitting unit (160) can be driven simultaneously.

[0127] FIG. 29 is a drawing showing a substrate according to one or more embodiments. FIG. 30 is a drawing showing an example in which a plurality of light-emitting diodes are transferred to a substrate according to one or more embodiments.

[0128] Referring to FIG. 29, a substrate (50') according to one or more embodiments may have a plurality of substrate electrodes arranged on the front surface. The plurality of substrate electrodes may include a second substrate electrode group (50b) corresponding to a second light-emitting diode (100b) emitting green light and blue light, and a third substrate electrode group (50c) corresponding to a third light-emitting diode (100c) emitting red light.

[0129] The second substrate electrode group (50b) may be arranged in a grid shape with the fifth to eighth contact electrodes (the fifth contact electrode (191'), the sixth contact electrode (193'), the seventh contact electrode (195'), and the eighth contact electrode (197')) of the second vertically stacked light-emitting diode (110b) corresponding to the fifth to eighth contact electrodes (the fifth contact electrode (191'), the sixth contact electrode (193'), the seventh contact electrode (195'), and the eighth contact electrode (197'). The first light-emitting unit (120) connected to the fifth substrate electrode (51') and the sixth substrate electrode (53') of the second substrate electrode group (50b) may be individually driven with the second light-emitting unit (160) connected to the seventh substrate electrode (55') and the eighth substrate electrode (57').

[0130] The third substrate electrode group (50c) may be configured substantially identically to the second substrate electrode group (50b). The third substrate electrode group (50c) may have the ninth to twelfth contact electrodes (the ninth contact electrode (191”), the tenth contact electrode (193”), the eleventh contact electrode (195”), and the twelfth contact electrode (197”) of the third vertical light-emitting diode (110c) arranged in a grid pattern, such that the ninth substrate electrode (51”), the tenth substrate electrode (53”), the eleventh substrate electrode (55”), and the twelfth substrate electrode (57”) correspond to the ninth to twelfth contact electrodes (the ninth contact electrode (191”), the tenth contact electrode (193”), the eleventh contact electrode (195”), and the twelfth contact electrode (197”).

[0131] Referring to FIG. 30, the third light-emitting diode (100c) electrically connected to the third substrate electrode group (50c, see FIG. 29) can drive the first light-emitting unit (120) and the second light-emitting unit (160) simultaneously when current is applied to the third substrate electrode group (50c). Since the light simultaneously emitted from the first light-emitting unit (120) and the second light-emitting unit (160) is excited by the color conversion layer (113), the third light-emitting diode (100c) can emit red light.

[0132] The second light-emitting diode (100b) electrically connected to the second substrate electrode group (50b, see FIG. 29) can individually drive the first light-emitting unit (120) and the second light-emitting unit (160) when current is applied to the second substrate electrode group (50b).

[0133] FIG. 31 is a diagram illustrating an example in which a plurality of vertically stacked light emitting diodes of different types according to one or more embodiments are grown on a single wafer.

[0134] Referring to FIG. 31, the second vertically stacked light-emitting diode (110b) and the third vertically stacked light-emitting diode (110c) can be formed on a single wafer (90a). The plurality of second vertically stacked light-emitting diodes (110b) and the plurality of third vertically stacked light-emitting diodes (110c) can be arranged in a grid shape. In this case, the plurality of second vertically stacked light-emitting diodes (110b) and the plurality of third vertically stacked light-emitting diodes (110c) can be arranged alternately in one row each.

[0135] The arrangement of the plurality of second vertically stacked light emitting diodes (110b) and the plurality of third vertically stacked light emitting diodes (110c) on the wafer (90a) may have a fifth pitch (P5) in the horizontal direction and a sixth pitch (P6) in the vertical direction. If the horizontal pitch and the vertical pitch of the plurality of second vertically stacked light emitting diodes (110b) and the plurality of third vertically stacked light emitting diodes (110c) to be transferred to the substrate (50) are substantially the same as the fifth pitch (P5) and the sixth pitch (P6) on the wafer (90a), the plurality of second vertically stacked light emitting diodes (110b) and the plurality of third vertically stacked light emitting diodes (110c) may be directly transferred from the wafer (90a) to the substrate (50) without going through a separate transfer substrate. In this case, the time required for the transfer process may be improved (shortened).

[0136] Although the present disclosure describes that the second vertically stacked light-emitting diode (110b) and the third vertically stacked light-emitting diode (110c) are formed on a single wafer (90a), this is not limited to this. For example, the second vertically stacked light-emitting diode (110b) and the third vertically stacked light-emitting diode (110c) may be formed on different wafers, respectively.

[0137] Hereinafter, a method for forming a second vertically stacked light-emitting diode (110b) and a third vertically stacked light-emitting diode (110c) together on a single wafer (90a) is described with reference to the drawings.

[0138] FIGS. 32 to 37 are drawings illustrating a method for manufacturing a vertically stacked light emitting diode according to one or more embodiments.

[0139] The second vertically stacked light-emitting diode (110b) can be formed on the wafer (90a) through a process substantially identical to the manufacturing method of the first vertically stacked light-emitting diode (110a) described above.

[0140] Some of the processes for manufacturing the third vertically stacked light-emitting diode (110c) may be substantially the same as some of the processes for manufacturing the first vertically stacked light-emitting diode (110a). For example, among the processes for manufacturing the third vertically stacked light-emitting diode (110c), from the process of forming the first light-emitting portion (120) on the buffer layer (91a) of the wafer (90a) to the process of forming the second light-emitting portion (160) on the bonding layer (150) are the same as some of the processes for manufacturing the first vertically stacked light-emitting diode (110a) (see FIGS. 11 to 18). Hereinafter, the process for manufacturing the third vertically stacked light-emitting diode (110c) will be described with reference to the drawings.

[0141] Referring to FIG. 32, a portion of the bonding layer (150) and a portion of the first passivation layer (140) are etched to expose the fifth contact portion (J) of the first transparent electrode layer (130), respectively. A portion of the ninth contact electrode (191”) can be brought into contact with the fifth contact portion (J).

[0142] Referring to FIG. 33, a portion of the second light-emitting portion (160) is etched to expose the sixth contact portion (K) so that another portion of the ninth contact electrode (191”) can contact the third semiconductor layer (161) of the second light-emitting portion (160).

[0143] Referring to Fig. 34, a second transparent electrode layer (170) is formed on the fourth semiconductor layer (165) of the second light-emitting portion (160).

[0144] Referring to FIG. 35, a second passivation layer (180) is formed to cover the second light-emitting portion (160). In this case, the second passivation layer (180) can cover both the fifth contact portion (J) of the first transparent electrode layer (130) and the sixth contact portion (K) of the third semiconductor layer (161).

[0145] Referring to FIG. 36, the second passivation layer (180) is etched to expose the fifth contact portion (J) of the first transparent electrode layer (130), the sixth contact portion (K) of the third semiconductor layer (161), the seventh contact portion (L) of the second transparent electrode layer (170), and the eighth contact portion (M) of the first semiconductor layer (121), respectively. One end of the eleventh contact electrode (195") may be in contact with the seventh contact portion (L) of the second transparent electrode layer (170). One end of the tenth contact electrode (193") may be in contact with the eighth contact portion (M) of the first semiconductor layer (121).

[0146] Referring to FIG. 37, a ninth contact electrode (191”), a tenth contact electrode (193”), an eleventh contact electrode (195”), and a twelfth contact electrode (197”) are formed on the second passivation layer (180). The ninth contact electrode (191”), the tenth contact electrode (193”), the eleventh contact electrode (195”), and the twelfth contact electrode (197”) may be arranged in a roughly grid shape.

[0147] The ninth contact electrode (191”) can be in contact with the fifth contact portion (J) of the first transparent electrode layer (130) and the sixth contact portion (K) of the third semiconductor layer (161) simultaneously. The tenth contact electrode (193”) can be in contact with the eighth contact portion (M) of the first semiconductor layer (121). The eleventh contact electrode (195”) can be in contact with the seventh contact portion (L) of the second transparent electrode layer (170).

[0148] The 12th contact electrode (197”) may be isolated from and not in electrical contact with the first light-emitting portion (120) and the second light-emitting portion (160). The 12th contact electrode (197”) may be connected to the 12th substrate electrode (59”) of the substrate (50’), but may not be involved in driving the first light-emitting portion (120) and the second light-emitting portion (160), and may correspond to a physical connection structure by which the third vertically stacked light-emitting diode (110c) may be connected to the substrate (50’).

[0149] A method of manufacturing a display panel (10a) according to one or more embodiments may include a step of forming a plurality of second vertically stacked light emitting diodes (110b) and a plurality of third vertically stacked light emitting diodes (110c) on a single wafer (90a) as described above.

[0150] A plurality of second vertically stacked light emitting diodes (110b) and a plurality of third vertically stacked light emitting diodes (110c) formed on a single wafer (90a) may be directly transferred from the wafer (90a) to the substrate (50') through a transfer process or may be transferred to a separate transfer substrate. When transferred to a separate transfer substrate, the plurality of second vertically stacked light emitting diodes (110b) and the plurality of third vertically stacked light emitting diodes (110c) may be transferred from the wafer to a first transfer substrate, transferred from the first transfer substrate to a second transfer substrate, and then finally transferred from the second transfer substrate to the substrate (50'). For example, the transfer process may employ a laser transfer method, a stamp transfer method, a rollable transfer method, or a pick-and-place transfer method.

[0151] A color conversion layer (113) is formed on the light-emitting surface (121c, see FIG. 26) of a plurality of third vertically stacked light-emitting diodes (110c) transferred to the substrate (50').

[0152] A transparent optical layer (115) is formed on the light-emitting surface (121b, see FIG. 26) of a plurality of second vertically stacked light-emitting diodes (110b) transferred to the substrate (50).

[0153] In the present disclosure, the process of forming the color conversion layer (113) is described as preceding the process of forming the transparent optical layer (115), but is not limited thereto. For example, it is also possible to perform the process of forming the color conversion layer (113) after the process of forming the transparent optical layer (115).

[0154] In this way, when a display panel (10a) is formed by applying a plurality of second light-emitting diodes (100b) and a plurality of third light-emitting diodes (100c) having a structure different from that of the second light-emitting diodes (100b), the substrate (50') may have a plurality of second substrate electrode groups (50b) and a plurality of third substrate electrode groups (50c) having the same pattern.

[0155] FIG. 38 is a block diagram illustrating a display device according to one or more embodiments.

[0156] Referring to FIG. 38, a display device (1) may include a display module (3) and a processor (5). The display module (3) may include a display panel (10) and a display driver integrated circuit (IC) (7) for controlling the display panel (10).

[0157] The processor (5) may be implemented as a digital signal processor (DSP), a microprocessor, a graphics processing unit (GPU), an artificial intelligence (AI) processor, a neural processing unit (NPU), or a time controller (TCON) that processes a digital image signal. However, the present invention is not limited thereto, and may include one or more of a central processing unit (CPU), a micro controller unit (MCU), a micro processing unit (MPU), a controller, an application processor (AP), a communication processor (CP), or an ARM processor, or may be defined by the relevant terminology. In addition, the processor (5) may be implemented as a system on chip (SoC) or large scale integration (LSI) having a built-in processing algorithm, or may be implemented in the form of an application specific integrated circuit (ASIC), or a field programmable gate array (FPGA).

[0158] The processor (5) can control hardware or software components connected to the processor (5) by running an operating system or application program, and can perform various data processing and calculations. In addition, the processor (5) can load commands or data received from at least one of the other components into volatile memory and process them, and store various data in non-volatile memory.

[0159] The display driver IC (7) may include an interface module (7a), a memory (7b) (e.g., a buffer memory), an image processing module (7c), or a mapping module (7d). The display driver IC (7) may receive, for example, image information including image data or an image control signal corresponding to a command for controlling the image data, from another component of the display device (1) through the interface module (7a). For example, according to one embodiment, the image information may be received from a processor (5) (e.g., a main processor (e.g., an application processor) or an auxiliary processor (e.g., a graphics processing unit) that operates independently of the function of the main processor).

[0160] The display driver IC (7) can communicate with the sensor module through the interface module (7a). In addition, the display driver IC (7) can store at least a part of the received image information in the memory (7b), for example, on a frame basis. The image processing module (7c) can, for example, perform preprocessing or postprocessing (e.g., resolution, brightness, or size adjustment) on at least a part of the image data based on at least the characteristics of the image data or the characteristics of the display panel (10). The mapping module (7d) can generate a voltage value or a current value corresponding to the image data preprocessed or postprocessed through the image processing module (7c). According to one embodiment, the generation of the voltage value or the current value can be performed based at least in part on, for example, the properties of the pixels of the display panel (10) (e.g., the arrangement of the pixels (RGB stripe or pentile structure), or the size of each subpixel). At least some pixels of the display panel (10) may be driven based at least in part on, for example, the voltage value or current value, so that visual information (e.g., text, image, or icon) corresponding to the image data may be displayed through the display panel (10).

[0161] The display driver IC (7) can transmit a driving signal (e.g., a driver driving signal, a gate driving signal, etc.) to the display based on image information received from the processor (5).

[0162] The display driver IC (7) can display an image based on an image signal received from the processor (5). For example, the display driver IC (7) can display an image by generating a driving signal for a plurality of sub-pixels based on the image signal received from the processor (5) and controlling the light emission of the plurality of sub-pixels based on the driving signal.

[0163] According to one or more embodiments, the display module (3) may further include a touch circuit. The touch circuit may include a touch sensor and a touch sensor IC for controlling the same. The touch sensor IC may control the touch sensor to detect, for example, a touch input or a hovering input for a designated location of the display panel (10). For example, the touch sensor IC may detect a touch input or a hovering input by measuring a change in a signal (e.g., voltage, light quantity, resistance, or charge quantity) for a designated location of the display panel (10). The touch sensor IC may provide information (e.g., location, area, pressure, or time) about the detected touch input or hovering input to the processor (5). According to one embodiment, at least a portion of the touch circuit (e.g., the touch sensor IC) may be included as a part of the display driver IC (7), the display panel (10), or another component (e.g., a coprocessor) disposed externally to the display module (3).

[0164] According to one or more embodiments, the pixel driving method of the display module (3) may be an AM (active matrix) driving method or a PM (passive matrix) driving method.

[0165] According to one or more embodiments, the display device (1) may include a display module (3). The display module (3) may display various images. Here, the images may include still images and / or moving images. The display module (3) may display various images, such as broadcast content, multimedia content, etc. In addition, the display module (3) may also display a user interface and icons.

[0166] According to one or more embodiments, the display module (3) can be installed and applied in a wearable device, a portable device, a handheld device, and various electronic products or battlefields requiring a display.

[0167] According to one or more embodiments, the display device (1) may include a plurality of display modules (3). The plurality of display modules (3) may be physically connected to implement a large display (e.g., a large format display). The large display may be a monitor for a personal computer, a high-resolution television, a signage (or digital signage), or an electronic display by connecting a plurality of display modules in a grid arrangement.

[0168] While the present disclosure has been illustrated and described above with reference to various examples, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents.

Claims

1. In the display panel, substrate; A plurality of substrate electrodes provided on the substrate; a plurality of first light-emitting diodes electrically connected to the plurality of substrate electrodes and emitting light of a first color; and comprising a plurality of second light-emitting diodes electrically connected to the plurality of substrate electrodes; A display panel, wherein the plurality of second light-emitting diodes emit light of a second color different from the first color of light and light of a third color.

2. In paragraph 1, Each of the above plurality of first light-emitting diodes, A first vertically stacked light emitting diode comprising a first light emitting portion and a second light emitting portion that are vertically stacked; A color conversion layer on the light-emitting surface of the first light-emitting portion; and A display panel comprising: a first contact electrode, a second contact electrode, a third contact electrode, and a fourth contact electrode connected to the plurality of substrate electrodes.

3. In paragraph 2, A display panel, wherein the color conversion layer includes a quantum dot that excites light emitted from each of the first light-emitting unit and the second light-emitting unit to emit light of the first color.

4. In paragraph 2, A display panel, wherein the first light-emitting portion and the second light-emitting portion are connected in series by a plurality of substrate electrodes.

5. In paragraph 2, A display panel, wherein the first light-emitting portion and the second light-emitting portion are connected in series through the first contact electrode, the second contact electrode, the third contact electrode, and the fourth contact electrode.

6. In paragraph 5, The first contact electrode is connected to the anode of the first light-emitting portion and the cathode of the second light-emitting portion, The second contact electrode is connected to the cathode of the first light-emitting portion, The third contact electrode is connected to the anode of the second light-emitting portion, A display panel, wherein the fourth contact electrode is not connected to the first light-emitting portion and the second light-emitting portion.

7. In paragraph 1, The above plurality of second light emitting diodes, A second vertically stacked light-emitting diode in which the third light-emitting portion and the fourth light-emitting portion are vertically stacked; A transparent optical layer on the light-emitting surface of the third light-emitting unit; and A display panel, comprising a fifth contact electrode, a sixth contact electrode, a seventh contact electrode, and an eighth contact electrode connected to the plurality of substrate electrodes.

8. In paragraph 7, The third light emitting portion emits light of the second color, A display panel, wherein the fourth light emitting portion emits light of the third color.

9. In paragraph 8, The fifth contact electrode is connected to the cathode of the third light-emitting portion, The sixth contact electrode is connected to the anode of the third light-emitting portion, The seventh contact electrode is connected to the cathode of the fourth light-emitting portion, A display panel, wherein the eighth contact electrode is connected to the anode of the fourth light-emitting portion.

10. A first light emitting unit that emits light in the blue wavelength band; A second light emitting portion located on the first light emitting portion and emitting light of a green wavelength band; A color conversion layer including a circle dot that is located on the light-emitting surface of the first light-emitting unit and emits light in the red wavelength band by exciting light emitted from the first light-emitting unit and the second light-emitting unit, respectively; and A light emitting diode comprising a plurality of contact electrodes, including a first contact electrode, a second contact electrode, a third contact electrode, and a fourth contact electrode.

11. In paragraph 10, The first contact electrode is connected to the cathode of the first light-emitting portion, The second contact electrode is connected to the anode of the first light-emitting portion, The third contact electrode is connected to the cathode of the second light-emitting portion, A light-emitting diode, wherein the fourth contact electrode is connected to the anode of the second light-emitting portion.

12. In paragraph 10, The first contact electrode is connected to the anode of the first light-emitting portion and the cathode of the second light-emitting portion, The second contact electrode is connected to the cathode of the first light-emitting portion, The third contact electrode is connected to the anode of the second light-emitting portion, A light emitting diode, wherein the fourth contact electrode is not connected to the first light emitting portion and the second light emitting portion.

13. A first light emitting unit emitting light in the blue wavelength band; A second light emitting portion having the first light emitting portion above and emitting light of a green wavelength band; A transparent optical layer on the light-emitting surface of the first light-emitting unit and through which light emitted from the first light-emitting unit and light emitted from the second light-emitting unit are transmitted; A first contact electrode connected to the cathode of the first light emitting portion; A second contact electrode connected to the anode of the first light emitting portion; a third contact electrode connected to the cathode of the second light emitting portion; and A light emitting diode, comprising a fourth contact electrode connected to the anode of the second light emitting portion.

14. In a method for manufacturing a display panel, A step of forming a plurality of first vertically stacked light-emitting diodes and a plurality of second vertically stacked light-emitting diodes, each of which includes a first light-emitting portion emitting light of a first color and a second light-emitting portion emitting light of a second color different from the light of the first color on a wafer; A step of transferring the plurality of first vertically stacked light-emitting diodes and the plurality of second vertically stacked light-emitting diodes from the wafer to a substrate; A step of forming a color conversion layer that emits light of a third color different from the light of the first color and the light of the second color on the light-emitting surface of the plurality of first vertically stacked light-emitting diodes to form a plurality of first light-emitting diodes; and A method for manufacturing a display panel, comprising the step of forming a plurality of second light-emitting diodes by forming a transparent optical layer on the light-emitting surfaces of the plurality of second vertically stacked light-emitting diodes.

15. In paragraph 14, A method for manufacturing a display panel, wherein the first light-emitting portion and the second light-emitting portion are formed to be connected in series.

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