Display device and method for fabricating the same

Abstract

A display device according to one embodiment comprises a substrate, a pixel electrode disposed on the substrate, a light-emitting element disposed on the pixel electrode and extending in the thickness direction of the substrate, a common electrode disposed on the light-emitting element, a wavelength conversion layer disposed on the common electrode and comprising wavelength conversion particles that convert a first light emitted from the light-emitting element into a second light, and a selective reflective film disposed on the upper surface and sides of the wavelength conversion layer, which reflects the first light and transmits the second light.

Description

Technology Field

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

[0002] As the information society develops, the demand for display devices for displaying images is increasing in various forms. The display device may be a flat panel display device such as a Liquid Crystal Display, a Field Emission Display, or a Light Emitting Display. The light emitting display device may include an organic light emitting display device comprising an organic light emitting diode element as a light emitting element, an inorganic light emitting display device comprising an inorganic semiconductor element as a light emitting element, or a micro light emitting diode element (or micro light emitting diode element) as a light emitting element.

[0003] Recently, head-mounted displays (HMDs) including light-emitting display devices are being developed. A Head Mounted Display (HMD) is a glasses-type monitor device for Virtual Reality (VR) or Augmented Reality that is worn in the form of glasses or a helmet, with the focus formed close to the user's eyes.

[0004] A high-resolution, ultra-small light-emitting diode display panel containing micro light-emitting diode elements is applied to the head-mounted display. To prevent light emitted from a micro light-emitting diode element from mixing with light emitted from another adjacent micro light-emitting diode element, a barrier may be placed between the micro light-emitting diode elements. However, since the integration density of the micro light-emitting diode elements is high, the width of the barrier must be thin, making it difficult to manufacture the barrier. The problem to be solved

[0005] The problem that the present invention aims to solve is to provide a display device capable of preventing the mixing of light from adjacent light-emitting elements without a separate partition, and a method for manufacturing the same.

[0006] The problems of the present invention are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0007] A display device according to one embodiment for solving the above problem comprises a substrate, a pixel electrode disposed on the substrate, a light-emitting element disposed on the pixel electrode and extending in the thickness direction of the substrate, a common electrode disposed on the light-emitting element, a wavelength conversion layer disposed on the common electrode and including wavelength conversion particles that convert a first light emitted from the light-emitting element into a second light, and a selective reflective film disposed on the upper surface and sides of the wavelength conversion layer, which reflects the first light and transmits the second light.

[0008] A display device according to another embodiment for solving the above problem comprises a substrate, a pixel electrode disposed on the substrate, a light-emitting element disposed on the pixel electrode and extending in the thickness direction of the substrate, a wavelength conversion layer disposed on the light-emitting element and including wavelength conversion particles that convert a first light emitted from the light-emitting element into a second light, a common electrode disposed on the wavelength conversion layer, and a selective reflective film disposed on the common electrode that reflects the first light and transmits the second light.

[0009] A display device according to another embodiment for solving the above problem comprises a light-emitting element disposed in each of a first light-emitting region emitting a first light, a second light-emitting region emitting a second light, and a third light-emitting region emitting a third light, and a selective reflective film disposed on the sides of the light-emitting element in the first light-emitting region and disposed on the top surfaces and sides of the light-emitting element in the second light-emitting region. The selective reflective film reflects the first light and transmits the second light.

[0010] A method for manufacturing a display device according to another embodiment for solving the above problem comprises the steps of: forming a first connecting electrode layer on a first substrate and forming a second connecting electrode layer on a light-emitting material layer of a second substrate; bonding the first connecting electrode layer and the second connecting electrode layer to form a connecting electrode layer and removing the second substrate; forming a mask pattern on the light-emitting material layer and etching the light-emitting material layer and the connecting electrode layer according to the mask pattern to form light-emitting elements; forming an insulating film on the sides of each of the light-emitting elements and forming a common electrode on the upper surface of each of the light-emitting elements and on the insulating film; forming a light-transmitting layer on the common electrode in a first light-emitting region; forming a wavelength conversion layer on the common electrode in a second light-emitting region and a third light-emitting region that converts a first light emitted from the light-emitting element into a second light; and forming a selective reflective film on the wavelength conversion layer of each of the second light-emitting region and the third light-emitting region that reflects the first light and transmits the second light.

[0011] Specific details of other embodiments are included in the detailed description and drawings. Effects of the invention

[0012] According to the display device and the method of manufacturing the same according to the embodiments, a light-transmitting layer is disposed on the upper surface and sides of a light-emitting element in each of the first light-emitting regions, and a wavelength conversion layer is disposed on the upper surface and sides of a light-emitting element in each of the second and third light-emitting regions. Additionally, a reflective film is disposed on the sides of the light-transmitting layer in each of the first light-emitting regions and on the sides of the wavelength conversion layer in each of the second and third light-emitting regions. Therefore, among the light emitted from the light-emitting element, light traveling in the up, down, left, and right lateral directions rather than in the upward direction can be reflected by the reflective film. Accordingly, even without placing a separate partition between the light-emitting elements of adjacent light-emitting regions, it is possible to prevent the mixing of light emitted from the light-emitting elements of adjacent light-emitting regions.

[0013] According to the display device and the method of manufacturing the same according to the embodiments, the wavelength conversion layer comprises a material identical to the second semiconductor layer of the light-emitting element and includes a third semiconductor layer having a plurality of pores that accommodate a first wavelength conversion particle. Additionally, a reflective film is disposed on the sides of the wavelength conversion layer in each of the first light-emitting regions and on the sides of the wavelength conversion layer in each of the second and third light-emitting regions. Therefore, among the light emitted from the light-emitting element, light traveling in the up, down, left, and right lateral directions rather than in the upward direction can be reflected by the reflective film. Accordingly, even without placing a separate partition between the light-emitting elements of adjacent light-emitting regions, it is possible to prevent the mixing of light emitted from the light-emitting elements of adjacent light-emitting regions.

[0014] According to the display device and the method of manufacturing the same according to the embodiments, the selective reflective film reflects the first light emitted from the light-emitting element in each of the second light-emitting regions and the third light-emitting regions that is not converted by the first wavelength conversion particle of the wavelength conversion layer, and transmits the fourth light converted by the first wavelength conversion particle. Since the first light reflected by the selective reflective film is re-incident on the wavelength conversion layer, it can be converted into the fourth light by the first wavelength conversion particle of the wavelength conversion layer. Therefore, due to the selective reflective film, the efficiency of converting the first light emitted from the light-emitting element into the fourth light by the first wavelength conversion particle of the wavelength conversion layer can be increased.

[0015] The effects according to the embodiments are not limited to those exemplified above, and a wider variety of effects are included in this specification. Brief explanation of the drawing

[0016] FIG. 1 is a layout diagram showing a display device according to one embodiment. Figure 2 is a layout diagram showing area A of Figure 1 in detail. FIG. 3 is a layout diagram showing pixels of a display panel according to one embodiment. FIG. 4 is a cross-sectional view showing an example of a display panel cut along A-A' of FIG. 2. FIG. 5 is a cross-sectional view showing an example of a display panel cut along B-B' of FIG. 3. FIG. 6 is an enlarged cross-sectional view showing the light-emitting element, wavelength conversion layer, selective reflective film, and second color filter of the second light-emitting region of FIG. 5. Figure 7 is an enlarged cross-sectional view showing in detail an example of the light-emitting element of Figure 5. Figure 8 is an enlarged cross-sectional view showing in detail an example of the selective reflective film of Figure 6. Figure 9 is a graph showing the reflection wavelength band of the selective reflective film of Figure 8. FIG. 10a is a cross-sectional view showing another example of a display panel cut along B-B' of FIG. 3. FIG. 10b is a cross-sectional view showing another example of a display panel cut along B-B' of FIG. 3. FIG. 10c is a cross-sectional view showing another example of a display panel cut along B-B' of FIG. 3. FIG. 11 is a flowchart showing a method for manufacturing a display device according to one embodiment. FIGS. 12 to 20 are cross-sectional views illustrating a method for manufacturing a display device according to one embodiment. FIG. 21 is a cross-sectional view showing another example of a display panel cut along B-B' of FIG. 3. FIG. 22 is an enlarged cross-sectional view showing the light-emitting element, wavelength conversion layer, selective reflective film, and second color filter of the second light-emitting region of FIG. 21. FIG. 23 is an enlarged cross-sectional view showing in detail an example of the light-emitting element and wavelength conversion layer of FIG. 22. FIG. 24a is a cross-sectional view showing another example of a display panel cut along B-B' of FIG. 3. FIG. 24b is a cross-sectional view showing another example of a display panel cut along B-B' of FIG. 3. FIG. 24c is a cross-sectional view showing another example of a display panel cut along B-B' of FIG. 3. FIG. 25 is a flowchart showing a method for manufacturing a display device according to one embodiment. FIGS. 26 to 32 are cross-sectional views illustrating a method for manufacturing a display device according to another embodiment. FIG. 33 is an exemplary drawing showing a virtual reality device including a display device according to one embodiment. FIG. 34 is an example drawing showing a smart device including a display device according to one embodiment. FIG. 35 is an exemplary drawing showing an automobile instrument panel and center fascia including a display device according to one embodiment. FIG. 36 is an exemplary drawing showing a transparent display device including a display device according to one embodiment. FIG. 37 is a circuit diagram of a pixel circuit and a light-emitting element according to one embodiment. FIG. 38 is a circuit diagram of a pixel circuit and a light-emitting element according to another embodiment. FIG. 39 is a circuit diagram of a pixel circuit and a light-emitting element according to another embodiment. Specific details for implementing the invention

[0017] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims.

[0018] When elements or layers are referred to as being "on" another element or layer, this includes cases where another layer or element is interposed directly on or in the middle of another element. Throughout the specification, the same reference numerals refer to the same components. Shapes, sizes, ratios, angles, numbers, etc., disclosed in the drawings for describing embodiments are exemplary and therefore the invention is not limited to the depicted details.

[0019] Although terms such as "first," "second," etc., are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used merely to distinguish one component from another. Therefore, it goes without saying that the first component mentioned below may also be the second component within the technical scope of the present invention.

[0020] The features of each of the various embodiments of the present invention may be combined or combined with one another, either partially or wholly, and may technically enable various interlocking and operation. Each embodiment may be implemented independently of one another or may be implemented together in an associated relationship.

[0021] Specific embodiments will be described below with reference to the attached drawings.

[0022] FIG. 1 is a layout diagram showing a display device according to one embodiment. FIG. 2 is a layout diagram showing area A of FIG. 1 in detail. FIG. 3 is a layout diagram showing pixels of a display panel according to one embodiment.

[0023] In FIGS. 1 to 3, the display device according to one embodiment is described primarily as a micro-light-emitting diode display device (micro or nano light-emitting diode display device) comprising a micro-light-emitting diode (micro or nano light-emitting diode) as a light-emitting element (LE), but the embodiments of the present specification are not limited thereto.

[0024] Additionally, in FIGS. 1 to 3, the display device according to one embodiment is described mainly as an LEDoS (Light Emitting Diode on Silicon) in which light-emitting diodes are arranged as light-emitting elements on a semiconductor circuit board (110) formed by a semiconductor process using a silicon wafer, but it should be noted that the embodiments of this specification are not limited thereto.

[0025] Additionally, in FIGS. 1 to 3, the first direction (DR1) refers to the horizontal direction of the display panel (100), the second direction (DR2) refers to the vertical direction of the display panel (100), and the third direction (DR3) refers to the thickness direction of the display panel (100) or the thickness direction of the semiconductor circuit board (110). In this case, "left," "right," "up," and "down" indicate the direction when viewing the display panel (100) from a flat plane. For example, "right" indicates one side of the first direction (DR1), "left" indicates the other side of the first direction (DR1), "up" indicates one side of the second direction (DR2), and "down" indicates the other side of the second direction (DR2). Additionally, "up" indicates one side of the third direction (DR3), and "down" indicates the other side of the third direction (DR3).

[0026] Referring to FIGS. 1 to 3, a display device (10) according to one embodiment has a display panel (100) including a display area (DA) and a non-display area (NDA).

[0027] The display panel (100) may have a rectangular planar shape having a long side in the first direction (DR1) and a short side in the second direction (DR2). However, the planar shape of the display panel (100) is not limited to this and may have a polygonal, circular, elliptical, or irregular planar shape other than a rectangle.

[0028] The display area (DA) is an area where an image is displayed, and the non-display area (NDA) may be an area where an image is not displayed. The planar shape of the display area (DA) may follow the planar shape of the display panel (100). In FIG. 1, the planar shape of the display area (DA) is exemplified as being rectangular. The display area (DA) may be placed in the central area of ​​the display panel (100). The non-display area (NDA) may be placed around the display area (DA). The non-display area (NDA) may be placed to surround the display area (DA).

[0029] The display area (DA) of the display panel (100) may include a plurality of pixels (PX). A pixel (PX) may be defined as a minimum light-emitting unit capable of displaying white light.

[0030] Each of the plurality of pixels (PX) may include a plurality of light-emitting regions (EA1, EA2, EA3) that emit light. In the embodiments of this specification, each of the plurality of pixels (PX) is exemplified as including three light-emitting regions (EA1, EA2, EA3), but is not limited thereto. For example, each of the plurality of pixels (PX) may include four light-emitting regions. Each of the plurality of light-emitting regions (EA1, EA2, EA3) may include a light-emitting element (LE) that emits a first light.

[0031] Each of the first light-emitting regions (EA1) indicates a region that emits the first light. Each of the first light-emitting regions (EA1) may output the first light output from the light-emitting element (LE) as is. The first light may be light in the blue wavelength band. The blue wavelength band may be approximately 370 nm to 460 nm, but the embodiments of the present specification are not limited thereto.

[0032] Each of the second light-emitting regions (EA2) indicates a region that emits second light. Each of the second light-emitting regions (EA2) can convert a portion of the first light output from the light-emitting element (LE) into second light and output it. The second light may be light in the green wavelength band. The green wavelength band may be approximately 480 nm to 560 nm, but the embodiments of this specification are not limited thereto.

[0033] Each of the third light-emitting regions (EA3) indicates a region that emits third light. Each of the third light-emitting regions (EA2) can convert a portion of the first light output from the light-emitting element (LE) into third light and output it. The third light may be light in the red wavelength band. The red wavelength band may be approximately 600 nm to 750 nm, but the embodiments of this specification are not limited thereto.

[0034] The first light-emitting regions (EA1), the second light-emitting regions (EA2), and the third light-emitting regions (EA3) may be arranged alternately in the first direction (DR1). For example, the first light-emitting regions (EA1), the second light-emitting regions (EA2), and the third light-emitting regions (EA3) may be arranged in the order of the first light-emitting region (EA1), the second light-emitting region (EA2), and the third light-emitting region (EA3) in the first direction (DR1).

[0035] The first light-emitting regions (EA1) can be arranged in a second direction (DR2). The second light-emitting regions (EA2) can be arranged in a second direction (DR2). The third light-emitting regions (EA3) can be arranged in a second direction (DR2).

[0036] Each of the first light-emitting regions (EA1) may include a light-emitting element (LE), a light-transmitting layer (TPL), and a first color filter (CF1). The light-emitting element (LE), the light-transmitting layer (TPL), and the first color filter (CF1) may overlap in a third direction (DR3). The light-transmitting layer (TPL) transmits the first light output from the light-emitting element (LE) as is, and the first color filter (CF1) transmits the first light. Therefore, each of the first light-emitting regions (EA1) can emit the first light.

[0037] Each of the second light-emitting regions (EA2) may include a light-emitting element (LE), a wavelength conversion layer (QDL), and a second color filter (CF2). The light-emitting element (LE), the wavelength conversion layer (QDL), and the second color filter (CF2) may overlap in a third direction (DR3). The wavelength conversion layer (QDL) may emit a first light output from the light-emitting element (LE) by converting a portion of the first light into a fourth light. For example, the fourth light may be light in the yellow wavelength band. The fourth light may be light that includes both the green wavelength band and the red wavelength band. That is, the fourth light may be light that is a mixture of the second light and the third light. The second color filter (CF2) may transmit the second light. Therefore, each of the second light-emitting regions (EA2) may emit the second light.

[0038] Each of the third light-emitting regions (EA3) may include a light-emitting element (LE), a wavelength conversion layer (QDL), and a third color filter (CF3). The light-emitting element (LE), the wavelength conversion layer (QDL), and the third color filter (CF3) may overlap in a third direction (DR3). The wavelength conversion layer (QDL) may emit a first light output from the light-emitting element (LE) by converting a portion of the first light into a fourth light. The third color filter (CF3) may transmit the third light. Therefore, each of the second light-emitting regions (EA3) may emit the third light.

[0039] The area of ​​the light-transmitting layer (TPL) and the area of ​​the wavelength conversion layer (QDL) may each be larger than the area of ​​the light-emitting element (LE). The area of ​​each of the first color filter (CF1), the second color filter (CF2), and the third color filter (CF3) may each be larger than the area of ​​the light-emitting element (LE). Additionally, the area of ​​each of the first color filter (CF1), the second color filter (CF2), and the third color filter (CF3) may each be larger than the area of ​​the light-transmitting layer (TPL) and the area of ​​the wavelength conversion layer (QDL).

[0040] In the first light-emitting region (EA1), the light-emitting element (LE) is completely covered by a light-transmitting layer (TPL), and the light-transmitting layer (TPL) can be completely covered by a first color filter (CF1). Additionally, in the second light-emitting region (EA2), the light-emitting element (LE) is completely covered by a wavelength conversion layer (QDL), and the wavelength conversion layer (QDL) can be completely covered by a second color filter (CF2). Furthermore, in the third light-emitting region (EA3), the light-emitting element (LE) is completely covered by a wavelength conversion layer (QDL), and the wavelength conversion layer (QDL) can be completely covered by a third color filter (CF3).

[0041] An example has been provided in which the planar shape of the light-transmitting layer (TPL), the planar shape of the wavelength conversion layer (QDL), the planar shape of the first color filter (CF1), the planar shape of the second color filter (CF2), and the planar shape of the third color filter (CF3) follow the planar shape of the light-emitting element (LE). For example, if the light-emitting element (LE) has a rectangular planar shape, the light-transmitting layer (TPL), the wavelength conversion layer (QDL), the first color filter (CF1), the second color filter (CF2), and the third color filter (CF3) may each have a rectangular planar shape. Alternatively, the light-emitting element (LE) may have a polygonal, circular, elliptical, or irregular shape other than a rectangle, and in this case, the light-transmitting layer (TPL), the wavelength conversion layer (QDL), the first color filter (CF1), the second color filter (CF2), and the third color filter (CF3) may also have a polygonal, circular, elliptical, or irregular shape other than a rectangle.

[0042] Alternatively, the planar shape of the light-transmitting layer (TPL), the planar shape of the wavelength conversion layer (QDL), the planar shape of the first color filter (CF1), the planar shape of the second color filter (CF2), and the planar shape of the third color filter (CF3) may not follow the planar shape of the light-emitting element (LE). In this case, the planar shape of the light-transmitting layer (TPL), the planar shape of the wavelength conversion layer (QDL), the planar shape of the first color filter (CF1), the planar shape of the second color filter (CF2), and the planar shape of the third color filter (CF3) may each be different from the planar shape of the light-emitting element (LE). Additionally, the planar shape of the light-transmitting layer (TPL) and the planar shape of the wavelength conversion layer (QDL) may each be different from the planar shape of the first color filter (CF1), the planar shape of the second color filter (CF2), and the planar shape of the third color filter (CF3).

[0043] The non-display area (NDA) may include a first common connection area (CCA1), a second common connection area (CCA2), a first pad section (PDA1), and a second pad section (PDA2).

[0044] A first common connection area (CCA1) may be positioned between a first pad portion (PDA1) and a display area (DA). A second common connection area (CCA2) may be positioned between a second pad portion (PDA2) and a display area (DA). Each of the first common connection area (CCA1) and the second common connection area (CCA2) may include a plurality of common connection electrodes (CCE) connected to a common electrode (CE in FIG. 4 and 5). As a result, a common voltage may be supplied to the common electrode (CE in FIG. 4 and 5) through the plurality of common connection electrodes (CCE). The plurality of common connection electrodes (CCE) of the first common connection area (CCA1) may be electrically connected to any one of the first pads (PD1) of the first pad portion (PDA1). A plurality of common connection electrodes (CCE) of the second common connection area (CCA2) can be electrically connected to any one of the second pads (PD2) of the second pad section (PDA2).

[0045] The first pad section (PDA1) may be positioned on the upper side of the display panel (100). The first pad section (PDA1) may include first pads (PD1) connected to an external circuit board (CB in FIG. 4).

[0046] The second pad section (PDA2) may be positioned on the lower side of the display panel (100). The second pad section (PDA2) may include second pads for connecting to an external circuit board (CB in FIG. 4). The second pad section (PDA2) may be omitted.

[0047] FIG. 4 is a cross-sectional view showing an example of a display panel cut along A-A' of FIG. 2. FIG. 5 is a cross-sectional view showing an example of a display panel cut along B-B' of FIG. 3. FIG. 6 is an enlarged cross-sectional view showing a light-emitting element, a wavelength conversion layer, a selective reflective film, and a second color filter in the second light-emitting region of FIG. 5. FIG. 7 is an enlarged cross-sectional view showing an example of a light-emitting element of FIG. 5 in detail.

[0048] Referring to FIGS. 4 to 7, the display panel (100) may include a semiconductor circuit board (110) and a light-emitting element layer (120).

[0049] A semiconductor circuit board (110) may include a first substrate (SUB1), a plurality of pixel circuit sections (PXC), pixel electrodes (111), a first pad (PD1), a first common connection electrode (CCE1) of a common connection electrode (CCE), and a first insulating film (INS1).

[0050] The first substrate (SUB1) may be a silicon wafer substrate. The first substrate (SUB1) may be made of single-crystal silicon.

[0051] Each of the plurality of pixel circuits (PXCs) may be disposed on a first substrate (SUB1). Each of the plurality of pixel circuits (PXCs) may include a CMOS (Complementary Metal-Oxide Semiconductor) circuit formed using a semiconductor process. Each of the plurality of pixel circuits (PXCs) may include at least one transistor formed using a semiconductor process. Additionally, each of the plurality of pixel circuits (PXCs) may further include at least one capacitor formed using a semiconductor process.

[0052] A plurality of pixel circuits (PXCs) may be placed in a display area (DA). Each of the plurality of pixel circuits (PXCs) may be connected to a corresponding pixel electrode (111). That is, the plurality of pixel circuits (PXCs) and the plurality of pixel electrodes (111) may be connected in a one-to-one correspondence. Each of the plurality of pixel circuits (PXCs) may apply a pixel voltage or an anode voltage to the pixel electrode (111).

[0053] Each of the pixel electrodes (111) may be disposed on a corresponding pixel circuit (PXC). Each of the pixel electrodes (111) may be an exposed electrode exposed from the pixel circuit (PXC). That is, each of the pixel electrodes (111) may protrude from the upper surface of the pixel circuit (PXC). Each of the pixel electrodes (111) may be formed integrally with the pixel circuit (PXC). Each of the pixel electrodes (111) may receive a pixel voltage or an anode voltage from the pixel circuit (PXC). The pixel electrodes (111) may include aluminum (Al).

[0054] Each of the first pad (PD1) and the first common connection electrode (CCE1) may be an exposed electrode exposed from the first substrate (SUB1). The first pad (PD1) and the first common connection electrode (CCE1) may contain the same material as the pixel electrodes (111). For example, the first pad (PD1) and the first common connection electrode (CCE1) may contain aluminum (Al).

[0055] The second pads of the second pad section (PDA2) may be substantially identical to the second pad (PD2) described in conjunction with Fig. 4, so a description thereof is omitted.

[0056] The first insulating film (INS1) may be disposed on a first substrate (SUB1) on which pixel electrodes (111), first pads (PD1), and first common connection electrodes (CCE1) are not disposed. The upper surface of the first insulating film (INS1), the upper surface of each of the pixel electrodes (111), the upper surface of each of the first pads (PD1), and the upper surface of each of the first common connection electrodes (CCE1) may be flatly connected. Alternatively, the first insulating film (INS1) may be disposed to cover the pixel electrodes (111), the first pads (PD1), and the first common connection electrodes (CCE1). In this case, at least a portion of each of the pixel electrodes (111), the first pads (PD1), and the first common connection electrodes (CCE1) may be exposed without being covered by the first insulating film (INS1) through a contact hole penetrating the first insulating film (INS1). The first insulating film (INS1) is a silicon oxide film (SiO2), an aluminum oxide film (Al2O3), or a hafnium oxide film (HfO2). x It can be formed into an inorganic membrane such as ).

[0057] The light-emitting element layer (120) may be a layer that emits light by including a plurality of light-emitting regions (EA1, EA2, EA3). The light-emitting element layer (120) may include connecting electrodes (112), a pad connecting electrode (PDE), a second common connecting electrode (CCE2) of a common connecting electrode (CCE), light-emitting elements (LE), a second insulating film (INS2), a common electrode (CE), a wavelength conversion layer (QDL), a selective reflective film (RTF), a reflective film (RF), and a plurality of color filters (CF1, CF2, CF3).

[0058] Each of the connecting electrodes (112) can be placed on the corresponding pixel electrode (111). That is, the connecting electrodes (112) can be connected to the pixel electrodes (111) in a one-to-one correspondence. The connecting electrodes (112) can serve as a bonding metal for bonding the pixel electrodes (111) and light-emitting elements (LE) in the manufacturing process. For example, the connecting electrodes (112) may include at least one of gold (Au), copper (Cu), aluminum (Al), and tin (Sn). Alternatively, the connecting electrodes (112) may include a first layer comprising any one of gold (Au), copper (Cu), aluminum (Al), and tin (Sn), and a second layer comprising the other of gold (Au), copper (Cu), aluminum (Al), and tin (Sn). In this case, the second layer may be placed on the first layer.

[0059] A pad connecting electrode (PDE) may be disposed on a first pad (PD1), and a second common connecting electrode (CCE2) may be disposed on the first common connecting electrode (CCE1). The pad connecting electrode (PDE) may be in contact with the upper surface of the first pad (PD1), and the second common connecting electrode (CCE2) may be in contact with the upper surface of the first common connecting electrode (CCE1). The pad connecting electrode (PDE) and the second common connecting electrode (CCE2) may include the same material as the connecting electrodes (112). For example, each of the pad connecting electrode (PDE) and the second common connecting electrode (CCE2) may include at least one of gold (Au), copper (Cu), aluminum (Al), and tin (Sn). If each of the connecting electrodes (112) includes a first layer and a second layer, each of the pad connecting electrode (PDE) and the second common connecting electrode (CCE2) may include a first layer and a second layer.

[0060] The pad connection electrode (PDE) can be connected to the pad (CPD) of the circuit board (CB) through a conductive connection member such as a wire (WR). That is, the first pad (PD1), the pad connection electrode (PDE), the wire (WR), and the pad (CPD) of the circuit board (CB) can be electrically connected to each other.

[0061] A semiconductor circuit board (110) and a circuit board (CB) can be placed on a base substrate (BSUB). The semiconductor circuit board (110) and the circuit board (CB) can be attached to the upper surface of the base substrate (BSUB) using an adhesive material such as a pressure-sensitive adhesive.

[0062] The circuit board (CB) may be a flexible printed circuit board (FPCB), a printed circuit board (PCB), a flexible printed circuit (FPC), or a flexible film such as a chip on film (COF).

[0063] Each of the light-emitting elements (LE) can be placed on the connecting electrode (112). The light-emitting element (LE) may be a vertical light-emitting diode element extending in a third direction (DR3). That is, the length of the light-emitting element (LE) in the third direction (DR3) may be longer than the length in the horizontal direction. The length in the horizontal direction refers to the length in the first direction (DR1) or the length in the second direction (DR2). For example, the length of the light-emitting element (LE) in the third direction (DR3) may be approximately 1 to 5 μm.

[0064] The light-emitting element (LE) may be a micro light-emitting diode or a nano light-emitting diode. As shown in FIG. 7, the light-emitting element (LE) includes a first semiconductor layer (SEM1), an electron blocking layer (EBL), an active layer (MQW), a superlattice layer (SLT), and a second semiconductor layer (SEM2) in the third direction (DR3). The first semiconductor layer (SEM1), the electron blocking layer (EBL), the active layer (MQW), the superlattice layer (SLT), and the second semiconductor layer (SEM2) may be stacked sequentially in the third direction (DR3).

[0065] The first semiconductor layer (SEM1) may be disposed on the connecting electrode (112). The first semiconductor layer (SEM1) may be doped with a first conductivity type dopant such as Mg, Zn, Ca, Se, Ba, etc. For example, the first semiconductor layer (31) may be p-GaN doped with p-type Mg. The thickness (Tsem1) of the first semiconductor layer (31) may be approximately 30 to 200 nm.

[0066] An electron blocking layer (EBL) may be placed on the first semiconductor layer (SEM1). The electron blocking layer (EBL) may be a layer for suppressing or preventing too many electrons from flowing into the active layer (MQW). For example, the electron blocking layer (EBL) may be p-AlGaN doped with p-type Mg. The thickness (Tebl) of the electron blocking layer (EBL) may be approximately 10 to 50 nm. The electron blocking layer (EBL) may be omitted.

[0067] The active layer (MQW) can be placed on the electron blocking layer (EBL). The active layer (MQW) can emit light by the coupling of electron-hole pairs according to an electrical signal applied through the first semiconductor layer (SEM1) and the second semiconductor layer (SEM2). The active layer (MQW) can emit first light, i.e., light in the blue wavelength band, having a central wavelength band in the range of 450 nm to 495 nm.

[0068] The active layer (MQW) may include a material having a single or multiple quantum well structure. When the active layer (MQW) includes a material having a multiple quantum well structure, it may have a structure in which multiple well layers and barrier layers are alternately stacked. In this case, the well layers may be formed of InGaN, and the barrier layers may be formed of GaN or AlGaN, but are not limited thereto. The thickness of the well layers may be approximately 1 to 4 nm, and the thickness of the barrier layers may be 3 to 10 nm.

[0069] Alternatively, the active layer (MQW) may have a structure in which semiconductor materials with large band gap energy and semiconductor materials with small band gap energy are alternately stacked, or it may include different Group 3 to Group 5 semiconductor materials depending on the wavelength range of the emitted light. The light emitted by the active layer (MQW) is not limited to the first light (light in the blue wavelength band) and may, in some cases, emit a second light (light in the green wavelength band) or a third light (light in the red wavelength band).

[0070] A superlattice layer (SLT) may be disposed on the active layer (MQW). The superlattice layer (SLT) may be a layer for relieving stress between the second semiconductor layer (SEM2) and the active layer (MQW). For example, the superlattice layer (SLT) may be formed of InGaN or GaN. The thickness (Tslt) of the superlattice layer (SLT) may be approximately 50 to 200 nm. The superlattice layer (SLT) may be omitted.

[0071] The second semiconductor layer (SEM2) may be disposed on a superlattice layer (SLT). The second semiconductor layer (SEM2) may be doped with a second conductivity type dopant such as Si, Ge, Sn, etc. For example, the second semiconductor layer (SEM2) may be n-GaN doped with n-type Si. The thickness (Tsem2) of the second semiconductor layer (SEM2) may be approximately 500 nm to 1 µm.

[0072] The second insulating film (INS2) may be disposed on the sides of each of the light-emitting elements (LE). The second insulating film (INS2) may not be disposed on the upper surface of each of the light-emitting elements (LE). Additionally, the second insulating film (INS2) may be disposed on the sides of each of the pixel electrodes (111) and the connecting electrodes (112). The second insulating film (INS2) may be a silicon oxide film (SiO2), an aluminum oxide film (Al2O3), or a hafnium oxide film (HfO2). x It can be formed with an inorganic membrane such as ), but is not limited thereto.

[0073] A common electrode (CE) may be disposed on the upper surface of each of the light-emitting elements (LE), the upper surface of the first insulating film (INS1), and the upper surface of the second insulating film (INS2). The common electrode (CE) may be disposed to completely cover each of the light-emitting elements (LE).

[0074] The common electrode (CE) may include a transparent conductive material. For example, the common electrode (CE) may include a transparent conductive oxide (TCO), such as Indium Tin Oxide (ITO) or Indium Zinc Oxide (IZO).

[0075] A light-transmitting layer (TPL) may be placed on a common electrode (CE) in each of the first light-emitting regions (EA1). The light-transmitting layer (TPL) may overlap with a light-emitting element (LE) in a third direction (DR3) in each of the first light-emitting regions (EA1). The light-transmitting layer (TPL) may be placed to completely cover the light-emitting element (LE) in each of the first light-emitting regions (EA1).

[0076] The light-transmitting layer (TPL) may include a light-transmitting organic material. For example, the light-transmitting layer (TPL) may include an epoxy resin, an acrylic resin, a cardo resin, or an imide resin.

[0077] The wavelength conversion layer (QDL) may be placed on the common electrode (CE) in each of the second light-emitting regions (EA2) and the third light-emitting regions (EA3). The wavelength conversion layer (QDL) may overlap with the light-emitting element (LE) in the third direction (DR3) in each of the second light-emitting regions (EA2) and the third light-emitting regions (EA3). The wavelength conversion layer (QDL) may be placed to completely cover the light-emitting element (LE) in each of the second light-emitting regions (EA2) and the third light-emitting regions (EA3).

[0078] The wavelength conversion layer (QDL) may include a first base resin (BRS1) and a first wavelength conversion particle (WCP1). The first base resin (BRS1) may include a transparent organic material. For example, the first base resin (BRS1) may include an epoxy resin, an acrylic resin, a cardo resin, or an imide resin.

[0079] The first wavelength conversion particle (WCP1) can convert the first light emitted from the light-emitting element (LE) into the fourth light. For example, the first wavelength conversion particle (WCP1) can convert light in the blue wavelength band into light in the yellow wavelength band. The first wavelength conversion particle (WCP1) may be a quantum dot (QD), a quantum rod, a fluorescent material, or a phosphorescent material. The quantum dot may include a group IV nanocrystal, a group II-VI compound nanocrystal, a group III-V compound nanocrystal, a group IV-VI nanocrystal, or a combination thereof.

[0080] The quantum dot may comprise a core and a shell overcoating the core. The core may be, for example, at least one of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InP, InAs, InSb, SiC, Ca, Se, In, P, Fe, Pt, Ni, Co, Al, Ag, Au, Cu, FePt, Fe2O3, Fe3O4, Si, and Ge. The shell may include, for example, at least one of ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, HgS, HgSe, HgTe, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, GaSe, InN, InP, InAs, InSb, TlN, TlP, TlAs, TlSb, PbS, PbSe, and PbTe, but is not limited thereto.

[0081] The wavelength conversion layer (QDL) may further include scatterers for scattering light from a light-emitting element (LE) in random directions. In this case, the scatterers may include metal oxide particles or organic particles. For example, the metal oxide may be titanium oxide (TiO2), zirconium oxide (ZrO2), silicon dioxide (SiO2), aluminum oxide (Al2O3), indium oxide (In2O3), zinc oxide (ZnO), or tin oxide (SnO2). Additionally, the organic particles may include acrylic resin or urethane resin. The diameter of the scatterers may be several to tens of nanometers.

[0082] The selective reflective film (RTF) may be disposed on the sides of the light-transmitting layer (TPL) in each of the first light-emitting regions (EA1), while it may be disposed on the top and sides of the wavelength conversion layer (QDL) in each of the second light-emitting regions (EA2) and the third light-emitting regions (EA3). The selective reflective film (RTF) may be disposed to completely cover the wavelength conversion layer (QDL) in each of the second light-emitting regions (EA2) and the third light-emitting regions (EA3). The selective reflective film (RTF) may be disposed on the common electrode (CE) disposed on the first insulating film (INS1).

[0083] As shown in FIG. 6, the selective reflective film (RTF) reflects the first light (LT1) emitted from the light-emitting element (LE) in each of the second light-emitting regions (EA2) and the third light-emitting region (EA3) that is not converted by the first wavelength conversion particle (WCP1) of the wavelength conversion layer (QDL), and transmits the fourth light (LT4) converted by the first wavelength conversion particle (WCP1). Since the first light (LT1) reflected by the selective reflective film (RTF) is re-incident on the wavelength conversion layer (QDL), it can be converted into the fourth light (LT4) by the first wavelength conversion particle (WCP1) of the wavelength conversion layer (QDL). Additionally, since the fourth light (LT4) is a mixture of the second light (LT2) and the third light (LT3), the second light (LT2) can be transmitted through the second color filter (CF2). Therefore, due to the selective reflective film (RTF), the efficiency of converting the first light (LT1) emitted from the light-emitting element (LE) into the fourth light (LT4) by the first wavelength conversion particle (WCP1) of the wavelength conversion layer (QDL) can be increased.

[0084] The selective reflective film (RTF) may be a distributed Bragg reflector, and a detailed description of the selective reflective film (RTF) will be provided later in conjunction with Figures 8 and 9.

[0085] The reflective film (RF) may be disposed on the selective reflective film (RTF) placed on the sides of the light-transmitting layer (TPL) and the sides of the wavelength conversion layer (QDL). Additionally, the reflective film (RF) may be disposed on the common electrode (CE) placed on the first insulating film (INS1). The reflective film (RF) serves to reflect light emitted from the light-emitting element (LE) that travels in the up, down, left, and right lateral directions, rather than in the upward direction. The reflective film (RF) may include a highly reflective metallic material such as aluminum (Al). The thickness of the reflective film (RF) may be approximately 0.1 μm.

[0086] A plurality of color filters (CF1, CF2, CF3) may include first color filters (CF1), second color filters (CF2), and third color filters (CF3).

[0087] Each of the first color filters (CF1) can be placed on the light-transmitting layer (TPL) in the first light-emitting region (EA1). Each of the first color filters (CF1) can transmit the first light and absorb or block the second and third light. For example, each of the first color filters (CF1) can transmit light in the blue wavelength band and absorb or block light in the green and red wavelength bands. Therefore, each of the first color filters (CF1) can transmit the first light emitted from the light-emitting element (LE). That is, the first light emitted from the light-emitting element (LE) in the first light-emitting region (EA1) is not converted by a separate wavelength conversion layer and can pass through the first color filter (CF1) through the light-transmitting layer (TPL). Accordingly, each of the first light-emitting regions (EA1) can emit the first light.

[0088] Each of the second color filters (CF2) can be placed on the wavelength conversion layer (QDL) in the second light emission region (EA2). Each of the second color filters (CF2) can transmit the second light and absorb or block the first light and the third light. For example, each of the second color filters (CF2) can transmit light in the green wavelength band and absorb or block light in the blue and red wavelength bands. Therefore, each of the second color filters (CF2) can absorb or block the first light that is not converted by the wavelength conversion layer (QDL) among the first light emitted from the light-emitting element (LE). Additionally, each of the second color filters (CF2) can transmit the second light corresponding to the green wavelength band among the fourth light converted by the wavelength conversion layer (QDL) and absorb or block the third light corresponding to the blue wavelength band. Accordingly, each of the second light emission regions (EA1) can emit the second light.

[0089] Each of the third color filters (CF3) can be placed on the wavelength conversion layer (QDL) in the third light emission region (EA3). Each of the third color filters (CF3) can transmit the third light and absorb or block the first light and the second light. For example, each of the third color filters (CF3) can transmit light in the red wavelength band and absorb or block light in the blue and green wavelength bands. Therefore, each of the third color filters (CF3) can absorb or block the first light that is not converted by the wavelength conversion layer (QDL) among the first light emitted from the light-emitting element (LE). Additionally, each of the third color filters (CF3) can transmit the third light corresponding to the red wavelength band among the fourth light converted by the wavelength conversion layer (QDL) and absorb or block the second light corresponding to the green wavelength band. Accordingly, each of the third light emission regions (EA3) can emit the third light.

[0090] A black matrix may be placed between multiple color filters (CF1, CF2, CF3). For example, the black matrix may be placed between the first color filter (CF1) and the second color filter (CF2), between the second color filter (CF2) and the third color filter (CF3), and between the first color filter (CF1) and the third color filter (CF3). The black matrix may include an inorganic black pigment, such as carbon black, or an organic black pigment.

[0091] Meanwhile, to simplify the manufacturing process, a wavelength conversion layer (QDL) may be placed instead of a light transmission layer (TPL) in each of the first light-emitting regions (EA1) in FIG. 5.

[0092] As shown in FIGS. 4 to 7, a light-transmitting layer (TPL) is disposed on the upper surface and sides of the light-emitting element (LE) in each of the first light-emitting regions (EA1), and a wavelength-converting layer (QDL) is disposed on the upper surface and sides of the light-emitting element (LE) in each of the second light-emitting regions (EA2) and the third light-emitting regions (EA3). Additionally, a reflective film (RF) is disposed on the sides of the light-transmitting layer (TPL) in each of the first light-emitting regions (EA1) and on the sides of the wavelength-converting layer (QDL) in each of the second light-emitting regions (EA2) and the third light-emitting regions (EA3). Therefore, among the light emitted from the light-emitting element (LE), light traveling in the upper, lower, left, and right side directions rather than in the upward direction can be reflected by the reflective film (RF). Therefore, even without placing a separate partition between the light-emitting elements (LE) of adjacent light-emitting regions (EA1, EA2, EA3), it is possible to prevent the light emitted from the light-emitting elements (LE) of adjacent light-emitting regions (EA1, EA2, EA3) from mixing.

[0093] Additionally, as shown in FIGS. 4 to 7, the selective reflective film (RTF) reflects the first light (LT1) emitted from the light-emitting element (LE) in each of the second light-emitting regions (EA2) and the third light-emitting region (EA3) that is not converted by the first wavelength conversion particle (WCP1) of the wavelength conversion layer (QDL), and transmits the fourth light converted by the first wavelength conversion particle (WCP1). Since the first light reflected by the selective reflective film (RTF) is re-incident on the wavelength conversion layer (QDL), it can be converted into the fourth light by the first wavelength conversion particle (WCP1) of the wavelength conversion layer (QDL). Therefore, due to the selective reflective film (RTF), the efficiency of converting the first light emitted from the light-emitting element (LE) into the fourth light by the first wavelength conversion particle (WCP1) of the wavelength conversion layer (QDL) can be increased.

[0094] FIG. 8 is an enlarged cross-sectional view showing in detail an example of the selective reflective film of FIG. 6. FIG. 9 is a graph showing the reflection wavelength band of the selective reflective film of FIG. 8. FIG. 8 shows an enlarged cross-sectional view of region C of FIG. 6.

[0095] Referring to FIGS. 8 and 9, the selective reflective film (RTF) may include a plurality of layers to serve as a dispersed Bragg reflector. The plurality of layers may include first to eighth layers (L1, L2, L3, L4, L5, L6, L7, L8).

[0096] Among the first to eighth layers (L1, L2, L3, L4, L5, L6, L7, L8), the refractive index of each of the odd-numbered layers (odd-numbered layers), namely the first layer (L1), the third layer (L3), the fifth layer (L5), and the seventh layer (L7), may be higher than the refractive index of each of the even-numbered layers (even-numbered layers), namely the second layer (L2), the fourth layer (L4), the sixth layer (L6), and the eighth layer (L8). In summary, the first layer (L1), the third layer (L3), the fifth layer (L5), and the seventh layer (L7) may be high-refractive-index layers, and the second layer (L2), the fourth layer (L4), the sixth layer (L6), and the eighth layer (L8) may be low-refractive-index layers. The selective reflective film (RTF) may have a structure in which high-refractive-index layers and low-refractive-index layers are alternately arranged. For example, the low refractive layer may be a silicon oxide film (SiO2) having a refractive index of approximately 1.46488, and the high refractive layer may be a titanium oxide film (TiO2) having a refractive index of approximately 2.40695.

[0097] The wavelength band in which light incident on the selective reflective film (RTF) is reflected can be set by adjusting the thickness of the first to eighth layers (L1, L2, L3, L4, L5, L6, L7, L8). For example, when the thickness of the first layer (L1) (Tl1), the thickness of the second layer (L2) (Tl2), the thickness of the third layer (L3) (Tl3), the thickness of the fourth layer (L4) (Tl4), the thickness of the fifth layer (L5) (Tl5), the thickness of the sixth layer (L6) (Tl6), the thickness of the seventh layer (L7) (Tl7), and the thickness of the eighth layer (L8) (Tl8) are set as shown in Table 1, more than 90% of light in the wavelength band of approximately 400 to 500 nm can be reflected as shown in FIG. 9.

[0098] Thickness (Tl1) of the first layer (L1) 49.49㎚ Thickness (Tl2) of the second layer (L2) 63.38㎚ Thickness (Tl3) of the third layer (L3) 62.74㎚ Thickness (Tl4) of the 4th layer (L4) 63.38㎚ Thickness (Tl5) of the 5th layer (L5) 60.44㎚ Thickness (Tl6) of the 6th layer (L6) 63.33㎚ Thickness (Tl7) of the 7th layer (L7) 50.86㎚ Thickness (Tl8) of the 8th layer (L8) 49.56㎚

[0100] Therefore, most of the first light (LT1) emitted from the light-emitting element (LE) that is not converted by the first wavelength conversion particle (WCP1) of the wavelength conversion layer (QDL) can be reflected by the selective reflective film (RTF). Additionally, most of the fourth light (LT1) emitted from the light-emitting element (LE) that is converted by the first wavelength conversion particle (WCP1) of the wavelength conversion layer (QDL) can pass through the selective reflective film (RTF) without being reflected by the selective reflective film (RTF). Accordingly, due to the selective reflective film (RTF), the efficiency of converting the first light emitted from the light-emitting element (LE) into the fourth light by the first wavelength conversion particle (WCP1) of the wavelength conversion layer (QDL) can be increased.

[0101] FIG. 10a is a cross-sectional view showing another example of a display panel cut along B-B' of FIG. 3. The embodiment of FIG. 10a differs from the embodiment of FIG. 5 in that a first wavelength conversion layer (QDL1) is disposed in each of the second light-emitting regions (EA2), and a second wavelength conversion layer (QDL2) is disposed in each of the third light-emitting regions (EA3). Descriptions that overlap with the embodiment of FIG. 5 are omitted in FIG. 10a.

[0102] Referring to FIG. 10a, the first wavelength conversion layer (QDL1) may be placed on the common electrode (CE) in each of the second light-emitting regions (EA2). The first wavelength conversion layer (QDL1) may overlap with the light-emitting element (LE) in the third direction (DR3) in each of the second light-emitting regions (EA2). The first wavelength conversion layer (QDL1) may be placed to completely cover the light-emitting element (LE) in each of the second light-emitting regions (EA2).

[0103] The first wavelength conversion layer (QDL1) may include a second base resin (BRS2) and a second wavelength conversion particle (WCP2). The second base resin (BRS2) may be substantially the same as the first base resin (BRS1). The second base resin (BRS2) may include an epoxy resin, an acrylic resin, a cardo resin, or an imide resin. The second wavelength conversion particle (WCP2) can convert a first light emitted from a light-emitting element (LE) into a second light. For example, the second wavelength conversion particle (WCP2) can convert light in the blue wavelength band into light in the green wavelength band.

[0104] The second wavelength conversion layer (QDL2) may be placed on the common electrode (CE) in each of the third light-emitting regions (EA3). The second wavelength conversion layer (QDL2) may overlap with the light-emitting element (LE) in the third direction (DR3) in each of the third light-emitting regions (EA3). The second wavelength conversion layer (QDL2) may be placed to completely cover the light-emitting element (LE) in each of the third light-emitting regions (EA3).

[0105] The second wavelength conversion layer (QDL2) may include a third base resin (BRS3) and a third wavelength conversion particle (WCP3). The second wavelength conversion layer (QDL2) may include a third base resin (BRS3) and a third wavelength conversion particle (WCP3). The third base resin (BRS3) may be substantially the same as the first base resin (BRS1). The third base resin (BRS3) may include an epoxy resin, an acrylic resin, a cardo resin, or an imide resin, etc. The third wavelength conversion particle (WCP3) can convert a first light emitted from a light-emitting element (LE) into a third light. For example, the third wavelength conversion particle (WCP3) can convert light in the blue wavelength band into light in the red wavelength band.

[0106] Among the first light emitted from the light-emitting element (LE) in the second light-emitting region (EA2), the second light converted by the second wavelength conversion particle (WCP2) of the first wavelength conversion layer (QDL1) can pass through the second color filter (CF2). Among the first light emitted from the light-emitting element (LE) in the second light-emitting region (EA2), the first light that is not converted by the first wavelength conversion layer (QDL1) can be absorbed or blocked by the second color filter (CF2). Therefore, the second light-emitting region (EA2) can emit the second light.

[0107] Among the first light emitted from the light-emitting element (LE) in the third light-emitting region (EA2), the third light converted by the second wavelength conversion layer (QDL2) can pass through the third color filter (CF3). Among the first light emitted from the light-emitting element (LE) in the third light-emitting region (EA3), the first light that is not converted by the second wavelength conversion layer (QDL2) can be absorbed or blocked by the third color filter (CF3). Therefore, the third light-emitting region (EA3) can emit the third light.

[0108] FIG. 10b is a cross-sectional view showing another example of a display panel cut along B-B' of FIG. 3.

[0109] The embodiment of FIG. 10b differs from the embodiment of FIG. 5 in that the selective reflective film (RTF) is not placed between adjacent light-emitting regions. In FIG. 10b, descriptions that overlap with the embodiment of FIG. 5 are omitted.

[0110] Referring to FIG. 10b, the selective reflective film (RTF) may not be placed on the common electrode (CE) between the first light-emitting region (EA1) and the second light-emitting region (EA2), between the second light-emitting region (EA2) and the third light-emitting region (EA3), and between the first light-emitting region (EA1) and the third light-emitting region (EA3). As a result, light emitted from the light-emitting element (LE) of the first light-emitting region (EA1) may not travel to the second light-emitting region (EA2) through the selective reflective film (RTF), or light emitted from the light-emitting element (LE) of the second light-emitting region (EA2) may not travel to the first light-emitting region (EA1) through the selective reflective film (RTF). In addition, it is possible to prevent light emitted from the light-emitting element (LE) of the second light-emitting region (EA2) from proceeding to the third light-emitting region (EA3) through the selective reflective film (RTF), or light emitted from the light-emitting element (LE) of the third light-emitting region (EA3) from proceeding to the second light-emitting region (EA2) through the selective reflective film (RTF). In addition, it is possible to prevent light emitted from the light-emitting element (LE) of the first light-emitting region (EA1) from proceeding to the third light-emitting region (EA3) through the selective reflective film (RTF), or light emitted from the light-emitting element (LE) of the third light-emitting region (EA3) from proceeding to the first light-emitting region (EA1) through the selective reflective film (RTF). That is, it is possible to prevent the selective reflective film (RTF) from acting as an optical waveguide between adjacent light-emitting regions.

[0111] FIG. 10c is a cross-sectional view showing another example of a display panel cut along B-B' of FIG. 3.

[0112] The embodiment of FIG. 10c differs from the embodiment of FIG. 5 in that the reflective film (RF) is omitted, and a first lens pattern (LEN1) covering the light-transmitting layer (TPL) and the first color filter (CF1) in the first light-emitting region (EA1), a second lens pattern (LEN2) covering the wavelength conversion layer (QDL) and the second color filter (CF2) in the second light-emitting region (EA2), and a third lens pattern (LEN3) covering the wavelength conversion layer (QDL) and the third color filter (CF3) in the third light-emitting region (EA3) are added. In FIG. 10c, descriptions that overlap with the embodiment of FIG. 5 are omitted.

[0113] Referring to FIG. 10c, each of the first lens pattern (LEN1), the second lens pattern (LEN2), and the third lens pattern (LEN3) may have a cross-sectional shape that is convex in the upward direction. The refractive index of each of the first lens pattern (LEN1), the second lens pattern (LEN2), and the third lens pattern (LEN3) may be substantially the same as the refractive index of the eighth layer (L8) of the selective reflective film (RTF) shown in FIG. 8. Alternatively, the difference between the refractive index of each of the first lens pattern (LEN1), the second lens pattern (LEN2), and the third lens pattern (LEN3) and the refractive index of the eighth layer (L8) of the selective reflective film (RTF) shown in FIG. 8 may be 0.1 or less. Each of the first lens pattern (LEN1), the second lens pattern (LEN2), and the third lens pattern (LEN3) may include an organic material. For example, the light-transmitting layer (TPL) may include epoxy resin, acrylic resin, cardo resin, or imide resin.

[0114] Among the light emitted from the light-emitting element (LE) in the first light-emitting region (EA1), the light traveling toward the side of the light-transmitting layer (TPL) can be refracted at the interface between the first lens pattern (LEN1) and air and travel upward. Additionally, among the light emitted from the light-emitting element (LE) in the second light-emitting region (EA2), the light traveling toward the side of the wavelength conversion layer (QDL) can be refracted at the interface between the second lens pattern (LEN2) and air and travel upward. Furthermore, among the light emitted from the light-emitting element (LE) in the third light-emitting region (EA3), the light traveling toward the side of the wavelength conversion layer (QDL) can be refracted at the interface between the third lens pattern (LEN3) and air and travel upward. Therefore, even if the reflective film (RF) is removed, the mixing of light between adjacent light-emitting regions can be prevented by the first lens pattern (LEN1), the second lens pattern (LEN2), and the third lens pattern (LEN3).

[0115] FIG. 11 is a flowchart illustrating a method for manufacturing a display device according to one embodiment. FIGS. 12 to 20 are cross-sectional views for explaining a method for manufacturing a display device according to one embodiment. FIGS. 12 to 20 show cross-sectional views of a display panel cut along B-B' of FIG. 3. Hereinafter, a method for manufacturing a display panel according to one embodiment will be described in detail in conjunction with FIGS. 11 to 20.

[0116] First, as shown in FIG. 12, a first connecting electrode layer (112L1) is formed on the pixel electrodes (111) of the first substrate (SUB1) and on the first insulating film (INS1), and a second connecting electrode layer (112L2) is formed on the light-emitting material layer (LEML) of the second substrate (SUB2). (S110 of FIG. 11)

[0117] A first insulating film (INS1) is formed on a first substrate (SUB1) on which pixel electrodes (111), first pads (PD1), and first common connection electrodes (CCE1) are not disposed. The upper surface of the first insulating film (INS1), the upper surface of each pixel electrode (111), the upper surface of each first pad (PD1), and the upper surface of each first common connection electrode (CCE1) can be flatly connected. That is, the height difference between the upper surface of the first substrate (SUB1) and the upper surface of the pixel electrode (111) can be eliminated by the first insulating film (INS1). The first insulating film (INS1) is a silicon oxide film (SiO2), an aluminum oxide film (Al2O3), or a hafnium oxide film (HfO2). x It can be formed into an inorganic membrane such as ).

[0118] Then, a first connecting electrode layer (112L1) is deposited on the pixel electrodes (111) and the first insulating film (INS1). The first connecting electrode layer (112L1) may include gold (Au), copper (Cu), aluminum (Al), or tin (Sn).

[0119] Additionally, a buffer film (BF) may be formed on one side of the second substrate (SUB2). The second substrate (SUB2) may be a silicon substrate or a sapphire substrate. The buffer film (BF) may be a silicon oxide film (SiO2), an aluminum oxide film (Al2O3), or a hafnium oxide film (HfO2). x It can be formed into an inorganic membrane such as ).

[0120] A light-emitting material layer (LEML) may be disposed on a buffer film (BF). The light-emitting material layer (LEML) may include a first semiconductor material layer (LEMD) and a second semiconductor material layer (LEMU). The second semiconductor material layer (LEMU) may be disposed on the buffer film (BF), and the first semiconductor material layer (LEMD) may be disposed on the second semiconductor material layer (LEMU). The thickness of the second semiconductor material layer (LEMU) may be greater than the thickness of the first semiconductor material layer (LEMD).

[0121] The first semiconductor material layer (LEMD) may include a first semiconductor layer (SEM1), an electron blocking layer (EBL), an active layer (MQW), a superlattice layer (SLT), and a second semiconductor layer (SEM2) as shown in FIG. 7. The second semiconductor material layer (LEMU) may be a semiconductor layer that is not doped with a dopant, i.e., an undoped semiconductor layer. For example, the second semiconductor material layer (LEMU) may be undoped-GaN that is not doped with a dopant.

[0122] The second connecting electrode layer (112L2) may be deposited on the first semiconductor material layer (LEMD). The second connecting electrode layer (112L2) may include gold (Au), copper (Cu), aluminum (Al), or tin (Sn).

[0123] Secondly, as shown in FIG. 13, the first connecting electrode layer (112L1) and the second connecting electrode layer (112L2) are bonded, and the second substrate (SUB2) is removed. (S210 of FIG. 11)

[0124] The first connecting electrode layer (112L1) of the first substrate (SUB1) and the second connecting electrode layer (112L2) of the second substrate (SUB2) are brought into contact. Then, the first connecting electrode layer (112L1) and the second connecting electrode layer (112L2) are melt-bonded at a predetermined temperature to form a single connecting electrode layer (112L). That is, the connecting electrode layer (112L) is positioned between the pixel electrodes (111) of the first substrate (SUB1) and the light-emitting material layer (LEML) of the second substrate (SUB2), and serves as a bonding metal layer that bonds the pixel electrodes (111) of the first substrate (SUB1) and the light-emitting material layer (LEML) of the second substrate (SUB2).

[0125] Then, the second substrate (SUB2) and the buffer film (BF) can be removed through a polishing process such as Chemical Mechanical Polishing (CMP) and / or an etching process. Additionally, the second semiconductor material layer (LEMU) of the light-emitting material layer (LEML) can be removed through a polishing process such as CMP.

[0126] Third, a mask pattern (MP) is formed on the light-emitting material layer (LEML) as shown in FIG. 14. (S310 in FIG. 11)

[0127] A mask pattern (MP) is formed on the upper surface of the light-emitting material layer (LEML). The upper surface of the light-emitting material layer (LEML) may be the upper surface of the first light-emitting material layer (LEMD) exposed after the second substrate (SUB2), the buffer film (BF), and the second light-emitting material layer (LEMU) have been removed. The mask pattern (MP) may be placed in the area where the light-emitting element (LE) is to be formed. As a result, the mask pattern (MP) may overlap with the pixel electrode (111) in the third direction (DR3). The mask pattern (MP) may include a conductive material such as nickel (Ni). The thickness of the mask pattern (MP) may be approximately 0.01 to 1 μm.

[0128] Fourth, as shown in FIG. 15, the light-emitting material layer (LEML) and the connecting electrode layer (112L) are etched according to the mask pattern (MP) to form light-emitting elements (LE), and the mask pattern (MP) is removed. (S410 in FIG. 11)

[0129] The mask pattern (MP) may not be etched by the first etching material for etching the light-emitting material layer (LEML) and the second etching material for etching the connecting electrode layer (112L) and the planarization insulating film (PINS). As a result, the light-emitting material layer (LEML) and the connecting electrode layer (112L) in the area where the mask pattern (MP) is placed may not be etched. Therefore, the connecting electrode (112) and the light-emitting element (LE) can be formed on the upper surface of each of the pixel electrodes (111). Then, the mask pattern (MP) is removed.

[0130] Fifth, as shown in FIG. 16, a second insulating film (INS2) is formed on the sides of each of the light-emitting elements (LE), and a common electrode (CE) is formed on the upper surface of each of the light-emitting elements (LE) and on the second insulating film (INS2). (S510 of FIG. 11)

[0131] A second insulating layer is deposited on the upper and side surfaces of each of the light-emitting elements (LE). The second insulating layer may be disposed on the upper and side surfaces of each of the light-emitting elements (LE), the side surfaces of each of the connecting electrodes (112), and the first insulating layer (INS1). The second insulating layer may be a silicon oxide film (SiO2), an aluminum oxide film (Al2O3), or a hafnium oxide film (HfO2). x It can be formed into an inorganic membrane such as ).

[0132] Then, a large voltage difference is formed in the third direction (DR3) without a separate mask, and the second insulating layer is etched by the first etching material. In this case, the first etching material moves in the third direction (DR3), that is, moves from top to bottom, and can etch the second insulating layer. As a result, the second insulating layer placed on the horizontal plane defined by the first direction (DR1) and the second direction (DR2) is removed, whereas the second insulating layer placed on the vertical plane defined by the third direction (DR3) may not be removed. Therefore, the second insulating layer placed on the upper surface of each of the light-emitting elements (LE) and the upper surface of the first insulating layer (INS1) may be removed. In contrast, the second insulating layer placed on the sides of each of the light-emitting elements (LE) and the sides of each of the connecting electrodes (112) may not be removed. Thus, the second insulating layer (INS2) may be formed on the sides of each of the light-emitting elements (LE) and the sides of each of the connecting electrodes (112).

[0133] Then, a common electrode (CE) is deposited on the upper surface of each of the light-emitting elements (LE) and on the second insulating film (INS2). Additionally, the common electrode (CE) may be placed on the sides of the first common connecting electrode (CCE1) and on the upper surface and sides of the second common connecting electrode (CCE2) in the non-display area (NDA) as shown in FIG. 4. The common electrode (CE) may comprise a transparent conductive oxide (TCO), such as Indium Tin Oxide (ITO) or Indium Zinc Oxide (IZO).

[0134] Sixth, as shown in FIG. 17, a light-transmitting layer (TPL) is formed on the common electrode (CE) in each of the first light-emitting regions (EA1). (S610 in FIG. 11)

[0135] The light-transmitting layer (TPL) can be formed entirely on the light-emitting elements (LE) in the first light-emitting regions (EA1), the second light-emitting regions (EA2), and the third light-emitting regions (EA3), and then patterned using a photolithography process. As the thickness of the light-emitting elements (LE) increases, the flow of the light-transmitting layer (TPL) becomes difficult, making it difficult to form the light-transmitting layer (TPL) entirely on the light-emitting elements (LE) in the first light-emitting regions (EA1), the second light-emitting regions (EA2), and the third light-emitting regions (EA3); therefore, to prevent this, the thickness of each light-emitting element (LE) may be approximately 1 μm or less. In this case, the thickness of the second semiconductor layer (SEM2) of each light-emitting element (LE) may be approximately 500 nm to 1 μm, but is not limited thereto. The light-transmitting layer (TPL) may include an epoxy resin, an acrylic resin, a cardo resin, or an imide resin.

[0136] The light-transmitting layer (TPL) can overlap with the light-emitting element (LE) in the third direction (DR3) in each of the first light-emitting regions (EA1). The light-transmitting layer (TPL) can be positioned to completely cover the light-emitting element (LE) in each of the first light-emitting regions (EA1).

[0137] Seventh, as shown in FIG. 18, a wavelength conversion layer (QDL) is formed on the common electrode (CE) in each of the second light-emitting regions (EA2) and the third light-emitting regions (EA3). (S710 in FIG. 11)

[0138] The wavelength conversion layer (QDL) can be patterned using a photolithography process after being formed entirely on the light-emitting elements (LE) in the second light-emitting regions (EA2) and the third light-emitting regions (EA3). As the thickness of the light-emitting elements (LE) increases, the flow of the wavelength conversion layer (QDL) becomes difficult, making it difficult to form the wavelength conversion layer (QDL) entirely on the light-emitting elements (LE) in the first light-emitting regions (EA1), the second light-emitting regions (EA2), and the third light-emitting regions (EA3). To prevent this, the thickness of each light-emitting element (LE) may be approximately 1 μm or less. In this case, the thickness of the second semiconductor layer (SEM2) of each light-emitting element (LE) may be approximately 500 nm, but is not limited thereto.

[0139] The wavelength conversion layer (QDL) may include a first base resin (BRS1) and a first wavelength conversion particle (WCP1). For example, the first base resin (BRS1) may include an epoxy resin, an acrylic resin, a cardo resin, or an imide resin.

[0140] The wavelength conversion layer (QDL) can overlap with the light-emitting element (LE) in the third direction (DR3) in each of the second light-emitting regions (EA2) and the third light-emitting region (EA3). The wavelength conversion layer (QDL) can be positioned to completely cover the light-emitting element (LE) in each of the second light-emitting regions (EA2) and the third light-emitting region (EA3).

[0141] The process error in the width of the pattern formed by the photolithography process can be reduced as the thickness of the pattern formed by the photolithography process decreases. When the light-emitting element (LE) is a micro light-emitting diode or a nano light-emitting diode, the spacing between the light-emitting elements (LE) is very narrow, to the extent of a few μm, so in order to reduce the process error in the width of the pattern formed by the photolithography process, the thickness of the light-transmitting layer (TPL) and the wavelength conversion layer (QDL) can be approximately 1 μm to 2 μm.

[0142] Eighth, as shown in FIG. 19, a selective reflective film (RTF) is formed on the wavelength conversion layer (QDL) in each of the second light-emitting regions (EA2) and the third light-emitting regions (EA3). (S810 in FIG. 11)

[0143] Selective reflective film (RTF) can be deposited on the upper and side surfaces of the light-transmitting layer (TPL) of each of the first light-emitting regions (EA1), the upper and side surfaces of the wavelength conversion layer (QDL) of each of the second light-emitting regions (EA2) and third light-emitting regions (EA3), and on the common electrode (CE).

[0144] Then, a mask pattern is formed to cover the optional reflective film (RTF) disposed on the sides of the light-transmitting layer (TPL) of each of the first light-emitting regions (EA1), and on the top and sides of the wavelength conversion layer (QDL) of each of the second light-emitting regions (EA2) and the third light-emitting regions (EA3).

[0145] Then, the selective reflective film (RTF) placed on the upper surface of the light-transmitting layer (TPL) of each of the first light-emitting regions (EA1) not covered by the mask pattern is removed.

[0146] Then, remove the mask pattern.

[0147] Ninth, as shown in FIG. 20, a reflective film (RF) and a plurality of color filters (CF1, CF2, CF3) are formed. (S910 of FIG. 11)

[0148] A reflective layer is deposited to cover the upper surface of the light-transmitting layer (TPL) and the selective reflective film (RTF) of each of the first light-emitting regions (EA1).

[0149] Then, a large voltage difference is formed in the third direction (DR3) without a separate mask, and the reflective layer is etched by the second etching material. In this case, the second etching material moves in the third direction (DR3) by voltage control, that is, moves from top to bottom, and can etch the reflective layer. As a result, the reflective layer placed on the horizontal plane defined by the first direction (DR1) and the second direction (DR2) is removed, whereas the reflective layer placed on the vertical plane defined by the third direction (DR3) may not be removed. Therefore, the reflective layer placed on the upper surface of the light-transmitting layer (TPL) and the upper surface of the wavelength conversion layer (QDL) may be removed. In contrast, the reflective layer placed on the sides of the light-transmitting layer (TPL) and the sides of the wavelength conversion layer (QDL) may not be removed. Thus, the reflective film (RF) can be placed on the selective reflective film (RTF) placed on the sides of the light-transmitting layer (TPL) and the sides of the wavelength conversion layer (QDL).

[0150] The reflective film (RF) may include a highly reflective metallic material such as aluminum (Al). The thickness of the reflective film (RF) may be approximately 0.1 μm.

[0151] Then, a first color filter (CF1) can be formed on the wavelength conversion layer (QDL) in each of the first light-emitting regions (EA1), a second color filter (CF2) can be formed on the wavelength conversion layer (QDL) in each of the second light-emitting regions (EA2), and a third color filter (CF3) can be formed on the wavelength conversion layer (QDL) in each of the third light-emitting regions (EA3).

[0152] FIG. 21 is a cross-sectional view showing another example of a display panel cut along B-B' of FIG. 3. FIG. 22 is an enlarged cross-sectional view showing a light-emitting element, a wavelength conversion layer, a selective reflective film, and a second color filter of the second light-emitting region of FIG. 21. FIG. 23 is an enlarged cross-sectional view showing in detail an example of the light-emitting element and the wavelength conversion layer of FIG. 22.

[0153] The embodiments of FIGS. 21 to 23 differ from the embodiments of FIGS. 5 to 7 in that the wavelength conversion layer (QDL) includes a third semiconductor layer (SEM3) instead of a first base resin (BRS1). In FIGS. 21 to 23, descriptions that overlap with FIGS. 5 to 7 are omitted.

[0154] Referring to FIGS. 21 and 22, in each of the first light-emitting regions (EA1), the second light-emitting regions (EA2), and the third light-emitting regions (EA3), a wavelength conversion layer (QDL_1) may be disposed on the light-emitting element (LE). The wavelength conversion layer (QDL_1) may be in contact with the upper surface of the light-emitting element (LE). The thickness (Tqdl) of the wavelength conversion layer (QDL_1) may be thicker than the thickness of the light-emitting element (LE).

[0155] The wavelength conversion layer (QDL_1) may include a third semiconductor layer (SEM3) and a first wavelength conversion particle (WCP1). Since the first wavelength conversion particle (WCP1) is substantially the same as described in conjunction with FIGS. 5 to 7, a description thereof is omitted.

[0156] The third semiconductor layer (SEM3) may contain the same material as the second semiconductor layer (SEM2). The third semiconductor layer (SEM3) may be doped with a second conductivity type dopant such as Si, Ge, Sn, etc. For example, the third semiconductor layer (SEM3) may be n-GaN doped with n-type Si. The thickness (Tsem3) of the third semiconductor layer (SEM3) may be greater than the thickness (Tsem2) of the second semiconductor layer (SEM2). The thickness (Tsem3) of the third semiconductor layer (SEM3) may be approximately 3 μm. The third semiconductor layer (SEM3) may include a plurality of voids (OP) that accommodate the first wavelength conversion particle (WCP).

[0157] The second insulating layer (INS2) can be placed on the sides of the light-emitting element (LE) and on the sides of the wavelength conversion layer (QDL_1).

[0158] The common electrode (CE) can be disposed on the upper surface of the wavelength conversion layer (QDL_1) and on the second insulating film (INS2). The common electrode (CE) can be disposed to completely cover the light-emitting element (LE) and the wavelength conversion layer (QDL_1). Since the third semiconductor layer (SEM3) of the wavelength conversion layer (QDL_1) is a semiconductor layer doped with a second conductive type dopant, the common voltage of the common electrode (CE) can be supplied to the second semiconductor layer (SEM2) of the light-emitting element (LE) through the third semiconductor layer (SEM3) of the wavelength conversion layer (QDL_1).

[0159] The selective reflective film (RTF) may be disposed on the sides of the wavelength conversion layer (QDL_1) in the first light-emitting region (EA1), whereas it may be disposed on the top surface and sides of the wavelength conversion layer (QDL) in each of the second light-emitting regions (EA2) and the third light-emitting regions (EA3). The selective reflective film (RTF) may be disposed to cover the common electrode (CE) in each of the second light-emitting regions (EA2) and the third light-emitting regions (EA3). In contrast, the selective reflective film (RTF) may not cover the common electrode (CE) disposed on the top surface of the light-transmitting layer (TPL) in the first light-emitting region (EA1).

[0160] As shown in FIG. 22, the selective reflective film (RTF) reflects the first light (LT1) that is not converted by the first wavelength conversion particle (WCP1) of the wavelength conversion layer (QDL) among the first light (LT1) emitted from the light-emitting element (LE) in each of the second light-emitting regions (EA2) and the third light-emitting region (EA3), and transmits the fourth light (LT4) converted by the first wavelength conversion particle (WCP1). Since the first light (LT1) reflected by the selective reflective film (RTF) is re-incident on the wavelength conversion layer (QDL), it can be converted into the fourth light (LT4) by the first wavelength conversion particle (WCP1) of the wavelength conversion layer (QDL). Additionally, since the fourth light (LT4) is light mixed with the second light (LT2) and the third light (LT3), the second light (LT2) can be transmitted through the second color filter (CF2). Therefore, due to the selective reflective film (RTF), the efficiency of converting the first light (LT1) emitted from the light-emitting element (LE) into the fourth light (LT4) by the first wavelength conversion particle (WCP1) of the wavelength conversion layer (QDL) can be increased.

[0161] As described in conjunction with FIGS. 8 and 9, the selective reflective film (RTF) may be a dispersed Bragg reflector to reflect the first light and transmit the fourth light.

[0162] A reflective film (RF) may be disposed on a selective reflective film (RTF) placed on the sides of light-emitting elements (LE), the sides of a light-transmitting layer (TPL), and the sides of a wavelength conversion layer (QDL). Additionally, a reflective film (RF) may be disposed on a common electrode (CE) placed on a first insulating film (INS1). The reflective film (RF) serves to reflect light emitted from the light-emitting elements (LE) that travels in the up, down, left, and right lateral directions, rather than in the upward direction. The reflective film (RF) may include a highly reflective metallic material such as aluminum (Al). The thickness of the reflective film (RF) may be approximately 0.1 μm.

[0163] As shown in FIGS. 21 to 23, the wavelength conversion layer (QDL_1) comprises a material identical to the second semiconductor layer (SEM2) of the light-emitting element (LE) and includes a third semiconductor layer (SEM3) having a plurality of pores (OP) that accommodate the first wavelength conversion particle (WCP1). Additionally, a reflective film (RF) is disposed on the sides of the wavelength conversion layer (QDL_1) in each of the first light-emitting regions (EA1) and on the sides of the wavelength conversion layer (QDL) in each of the second light-emitting regions (EA2) and the third light-emitting regions (EA3). Therefore, among the light emitted from the light-emitting element (LE), light traveling in the up, down, left, and right lateral directions rather than the upward direction can be reflected by the reflective film (RF). Therefore, even without placing a separate partition between the light-emitting elements (LE) of adjacent light-emitting regions (EA1, EA2, EA3), it is possible to prevent the light emitted from the light-emitting elements (LE) of adjacent light-emitting regions (EA1, EA2, EA3) from mixing.

[0164] Additionally, as shown in FIGS. 21 to 23, the selective reflective film (RTF) reflects the first light (LT1) emitted from the light-emitting element (LE) in each of the second light-emitting regions (EA2) and the third light-emitting region (EA3) that is not converted by the first wavelength conversion particle (WCP1) of the wavelength conversion layer (QDL_1), and transmits the fourth light converted by the first wavelength conversion particle (WCP1). Since the first light reflected by the selective reflective film (RTF) is re-incident on the wavelength conversion layer (QDL_1), it can be converted into the fourth light by the first wavelength conversion particle (WCP1) of the wavelength conversion layer (QDL_1). Therefore, due to the selective reflective film (RTF), the efficiency of converting the first light emitted from the light-emitting element (LE) into the fourth light by the first wavelength conversion particle (WCP1) of the wavelength conversion layer (QDL) can be increased.

[0165] FIG. 24a is a cross-sectional view showing another example of a display panel cut along B-B' of FIG. 3.

[0166] The embodiment of FIG. 24a differs from the embodiment of FIG. 21 in that a first wavelength conversion layer (QDL1_1) is disposed in each of the first light-emitting regions (EA1), a second wavelength conversion layer (QDL2_1) is disposed in each of the second light-emitting regions (EA2), and a third wavelength conversion layer (QDL3_1) is disposed in each of the third light-emitting regions (EA3). In FIG. 24a, descriptions that overlap with the embodiment of FIG. 21 are omitted.

[0167] Referring to FIG. 24a, the first wavelength conversion layer (QDL1_1) may be disposed on the light-emitting element (LE) in each of the first light-emitting regions (EA1). The first wavelength conversion layer (QDL1_1) may be in contact with the upper surface of the light-emitting element (LE) in each of the first light-emitting regions (EA1).

[0168] The first wavelength conversion layer (QDL1_1) may include a third semiconductor layer (SEM3). Since the third semiconductor layer (SEM3) is substantially the same as described in conjunction with FIG. 21, a description thereof is omitted. FIG. 24a illustrates that the first wavelength conversion layer (QDL1_1) does not include wavelength conversion particles, but the embodiments of this specification are not limited thereto. The first wavelength conversion layer (QDL1_1) may include wavelength conversion particles.

[0169] The second wavelength conversion layer (QDL2_1) may be disposed on the light-emitting element (LE) in each of the second light-emitting regions (EA2). The second wavelength conversion layer (QDL2_1) may be in contact with the upper surface of the light-emitting element (LE) in each of the second light-emitting regions (EA2).

[0170] The second wavelength conversion layer (QDL2_1) may include a third semiconductor layer (SEM3) and a second wavelength conversion particle (WCP2). The second wavelength conversion particle (WCP2) can convert a first light emitted from a light-emitting element (LE) into a second light. For example, the second wavelength conversion particle (WCP2) can convert light in the blue wavelength band into light in the green wavelength band.

[0171] The third wavelength conversion layer (QDL3_1) may be disposed on the light-emitting element (LE) in each of the third light-emitting regions (EA3). The third wavelength conversion layer (QDL3_1) may be in contact with the upper surface of the light-emitting element (LE) in each of the third light-emitting regions (EA3).

[0172] The third wavelength conversion layer (QDL3_1) may include a third semiconductor layer (SEM3) and a third wavelength conversion particle (WCP3). The third wavelength conversion particle (WCP3) can convert a first light emitted from a light-emitting element (LE) into a third light. For example, the third wavelength conversion particle (WCP3) can convert light in the blue wavelength band into light in the red wavelength band.

[0173] Among the first light emitted from the light-emitting element (LE) in the second light-emitting region (EA2), the second light converted by the second wavelength conversion particle (WCP2) of the second wavelength conversion layer (QDL2) can pass through the second color filter (CF2). Among the first light emitted from the light-emitting element (LE) in the second light-emitting region (EA2), the first light that is not converted by the second wavelength conversion layer (QDL2) can be absorbed or blocked by the second color filter (CF2). Therefore, the second light-emitting region (EA2) can emit the second light.

[0174] Among the first light emitted from the light-emitting element (LE) in the third light-emitting region (EA3), the third light converted by the third wavelength conversion layer (QDL3) can pass through the third color filter (CF3). Among the first light emitted from the light-emitting element (LE) in the third light-emitting region (EA3), the first light that is not converted by the third wavelength conversion layer (QDL3) can be absorbed or blocked by the third color filter (CF3). Therefore, the third light-emitting region (EA3) can emit the third light.

[0175] FIG. 24b is a cross-sectional view showing another example of a display panel cut along B-B' of FIG. 3.

[0176] The embodiment of FIG. 24b differs from the embodiment of FIG. 21 in that the selective reflective film (RTF) is not placed between adjacent light-emitting regions. In the embodiment of FIG. 24b, the selective reflective film (RTF) is substantially the same as that described in conjunction with FIG. 10b, so a description thereof is omitted.

[0177] FIG. 24c is a cross-sectional view showing another example of a display panel cut along B-B' of FIG. 3.

[0178] The embodiment of FIG. 24c differs from the embodiment of FIG. 21 in that the reflective film (RF) is omitted, and a first lens pattern (LEN1) covering a light-emitting element (LE), a light-transmitting layer (TPL), and a first color filter (CF1) in a first light-emitting region (EA1), a second lens pattern (LEN2) covering a light-emitting element (LE), a wavelength conversion layer (QDL), and a second color filter (CF2) in a second light-emitting region (EA2), and a third lens pattern (LEN3) covering a light-emitting element (LE), a wavelength conversion layer (QDL), and a third color filter (CF3) in a third light-emitting region (EA3) are added. Since the first lens pattern (LEN1), the second lens pattern (LEN2), and the third lens pattern (LEN3) in FIG. 24c are substantially the same as those described in conjunction with FIG. 10c, a description thereof is omitted. FIG. 25 is a flowchart showing a method for manufacturing a display device according to one embodiment. FIGS. 26 to 32 are cross-sectional views illustrating a method for manufacturing a display device according to another embodiment. FIGS. 26 to 32 show cross-sectional views of a display panel cut along B-B' of FIG. 21. Hereinafter, a method for manufacturing a display panel according to one embodiment will be described in detail in conjunction with FIGS. 25 to 32.

[0179] First, as shown in FIG. 26, a first connecting electrode layer (112L1) is formed on the pixel electrodes (111) of the first substrate (SUB1) and on the first insulating film (INS1), and a second connecting electrode layer (112L2) is formed on the light-emitting material layer (LEML) of the second substrate (SUB2). (S120 of FIG. 25)

[0180] Step S120 of FIG. 25 differs from Step S110 of FIG. 11 in that the light-emitting material layer (LEML_1) includes a first semiconductor material layer (LEMD), a second semiconductor material layer (LEMQ), and a third semiconductor material layer (LEMU). In Step S120 of FIG. 25, descriptions that overlap with Step S110 of FIG. 11 are omitted.

[0181] The light-emitting material layer (LEML_1) may include a first semiconductor material layer (LEMD), a second semiconductor material layer (LEMQ), and a third semiconductor material layer (LEMU). The third semiconductor material layer (LEMU) may be disposed on a buffer film (BF), the second semiconductor material layer (LEMQ) may be disposed on the third semiconductor material layer (LEMU), and the first semiconductor material layer (LEMD) may be disposed on the second semiconductor material layer (LEMQ). The thickness of the second semiconductor material layer (LEMQ) may be greater than the thickness of the first semiconductor material layer (LEMD).

[0182] The first semiconductor material layer (LEMD) may include a first semiconductor layer (SEM1), an electron blocking layer (EBL), an active layer (MQW), a superlattice layer (SLT), and a second semiconductor layer (SEM2) as shown in FIG. 23. The second semiconductor material layer (LEMQ) may include a plurality of voids (OP). The second semiconductor material layer (LEMQ) may include the same material as the second semiconductor layer (SEM2). The third semiconductor material layer (LEMU) may be a semiconductor layer that is not doped with a dopant, i.e., an undoped semiconductor layer. For example, the third semiconductor material layer (LEMU) may be undoped GaN that is not doped with a dopant.

[0183] Secondly, as shown in FIG. 27, the first connecting electrode layer (112L1) and the second connecting electrode layer (112L2) are bonded, and the second substrate (SUB2) is removed. (S220 of FIG. 25)

[0184] A single connecting electrode layer (112L) is formed by melt-bonding the first connecting electrode layer (112L1) and the second connecting electrode layer (112L2) at a predetermined temperature. That is, the connecting electrode layer (112L) is positioned between the pixel electrodes (111) of the first substrate (SUB1) and the light-emitting material layer (LEML_1) of the second substrate (SUB2), and serves as a bonding metal layer that bonds the pixel electrodes (111) of the first substrate (SUB1) and the light-emitting material layer (LEML_1) of the second substrate (SUB2).

[0185] Then, the second substrate (SUB2) and the buffer film (BF) can be removed through a polishing process such as Chemical Mechanical Polishing (CMP) and / or an etching process. Additionally, the third semiconductor material layer (LEMU) of the light-emitting material layer (LEML_1) can be removed through a polishing process such as CMP.

[0186] Third, a mask pattern (MP) is formed on the light-emitting material layer (LEML_1) as shown in FIG. 28. (S320 in FIG. 25)

[0187] A mask pattern (MP) is formed on the upper surface of the light-emitting material layer (LEML_1). The upper surface of the light-emitting material layer (LEML_1) may be the upper surface of the second light-emitting material layer (LEMQ) exposed after the second substrate (SUB2), the buffer film (BF), and the third light-emitting material layer (LEMU) have been removed.

[0188] Fourth, as shown in FIGS. 29a and 29b, the light-emitting material layer (LEML_1) and the connecting electrode layer (112L) are etched according to the mask pattern (MP) to form light-emitting elements (LE) and wavelength conversion layers (QDL_1), and the mask pattern (MP) is removed. (S420 of FIG. 25)

[0189] The mask pattern (MP) may not be etched by the first etching material for etching the light-emitting material layer (LEML_1) and the second etching material for etching the connecting electrode layer (112L) and the planarization insulating film (PINS). As a result, the light-emitting material layer (LEML_1) and the connecting electrode layer (112L) in the area where the mask pattern (MP) is placed may not be etched. Therefore, the connecting electrode (112), the light-emitting element (LE), and the wavelength conversion layer (QDL_1) may be formed on the upper surface of each of the pixel electrodes (111).

[0190] Then, the mask pattern (MP) is removed, and a first wavelength conversion particle (WCP1) is formed within the pores (OP) of the third semiconductor layer (SEM3) of the wavelength conversion layer (QDL_1). When a predetermined organic material containing the first wavelength conversion particle (WCP1) is injected into the pores (OP) of the third semiconductor layer (SEM3), the first wavelength conversion particle (WCP1) may be disposed within the pores (OP) of the third semiconductor layer (SEM3). The first wavelength conversion particle (WCP1) may have a diameter of several to tens of nanometers. For example, the first wavelength conversion particle (WCP1) may be approximately 10 nm.

[0191] Fifth, as shown in FIG. 30, a second insulating film (INS2) is formed on the sides of each of the light-emitting elements (LE) and the wavelength conversion layer (QDL_1), and a common electrode (CE) is formed on the upper surface of each of the light-emitting elements (LE) and on the second insulating film (INS2). (S520 in FIG. 25)

[0192] A second insulating film layer is deposited on the sides of each of the light-emitting elements (LE) and on the top and sides of each of the wavelength conversion layers (QDL_1). The second insulating film layer may be disposed on the top and sides of each of the wavelength conversion layers (QDL_1), on the sides of each of the light-emitting elements (LE), on the sides of each of the connecting electrodes (112), and on the first insulating film (INS1).

[0193] Then, a large voltage difference is formed in the third direction (DR3) without a separate mask, and the second insulating layer is etched by the first etching material. In this case, the first etching material moves in the third direction (DR3), that is, from top to bottom, and can etch the second insulating layer. As a result, the second insulating layer placed on the horizontal plane defined by the first direction (DR1) and the second direction (DR2) is removed, whereas the second insulating layer placed on the vertical plane defined by the third direction (DR3) may not be removed. Therefore, the second insulating layer placed on the upper surface of each of the wavelength conversion layers (QDL_1) and the upper surface of the first insulating layer (INS1) may be removed. In contrast, the second insulating layer placed on the sides of each of the wavelength conversion layers (QDL_1), the sides of each of the light-emitting elements (LE), and the sides of each of the connecting electrodes (112) may not be removed. Accordingly, the second insulating film (INS2) can be formed on each side of the wavelength conversion layers (QDL_1), each side of the light-emitting elements (LE), and each side of the connecting electrodes (112).

[0194] Then, a common electrode (CE) is deposited on the upper surface of each of the wavelength conversion layers (QDL_1) and on the second insulating film (INS2).

[0195] Sixth, as shown in FIG. 31, a selective reflective film (RTF) is formed on the wavelength conversion layer (QDL_1) in each of the second light-emitting regions (EA2) and the third light-emitting regions (EA3). (S620 in FIG. 25)

[0196] A selective reflective film (RTF) can be deposited on the upper and side surfaces of the wavelength conversion layer (QDL_1) of each of the first light-emitting regions (EA1), second light-emitting regions (EA2), and third light-emitting regions (EA3), and on the common electrode (CE).

[0197] Then, a mask pattern is formed to cover the optional reflective film (RTF) disposed on the sides of the wavelength conversion layer (QDL_1) of each of the first light-emitting regions (EA1), and on the top and sides of the wavelength conversion layer (QDL_1) of each of the second light-emitting regions (EA2) and the third light-emitting regions (EA3).

[0198] Then, the selective reflective film (RTF) placed on the upper surface of the wavelength conversion layer (QDL_1) of each of the first light-emitting regions (EA1) not covered by the mask pattern is removed.

[0199] Then, remove the mask pattern.

[0200] Seventh, a reflective film (RF) and a plurality of color filters (CF1, CF2, CF3) are formed as shown in FIG. 32. (S720 of FIG. 25)

[0201] A reflective layer is deposited to cover the upper surface of the wavelength conversion layer (QDL_1) of each of the first light-emitting regions (EA1) and the selective reflective film (RTF).

[0202] Then, a large voltage difference is formed in the third direction (DR3) without a separate mask, and the reflective layer is etched by the second etching material. In this case, the second etching material moves in the third direction (DR3) by voltage control, that is, moves from top to bottom, and can etch the reflective layer. As a result, the reflective layer placed on the horizontal plane defined by the first direction (DR1) and the second direction (DR2) is removed, whereas the reflective layer placed on the vertical plane defined by the third direction (DR3) may not be removed. Therefore, the reflective layer placed on the upper surface of the wavelength conversion layer (QDL_1) in each of the first light-emitting regions (EA1), the second light-emitting regions (EA2), and the third light-emitting regions (EA3) may be removed. In contrast, the reflective layer placed on the sides of the wavelength conversion layer (QDL_11) in each of the first light-emitting regions (EA1), the second light-emitting regions (EA2), and the third light-emitting regions (EA3) may not be removed. Accordingly, the reflective film (RF) can be disposed on the optional reflective film (RTF) disposed on the sides of the wavelength conversion layer (QDL_1) in each of the first light-emitting regions (EA1), the second light-emitting regions (EA2), and the third light-emitting regions (EA3).

[0203] Then, a first color filter (CF1) can be formed on the wavelength conversion layer (QDL_1) in each of the first light-emitting regions (EA1), a second color filter (CF2) can be formed on the wavelength conversion layer (QDL_1) in each of the second light-emitting regions (EA2), and a third color filter (CF3) can be formed on the wavelength conversion layer (QDL_1) in each of the third light-emitting regions (EA3).

[0204] FIG. 33 is an exemplary drawing showing a virtual reality device including a display device according to one embodiment. FIG. 33 shows a virtual reality device (1) to which a display device (10_1) according to one embodiment is applied.

[0205] Referring to FIG. 33, a virtual reality device (1) according to one embodiment may be a device in the form of glasses. A virtual reality device (1) according to one embodiment may have a display device (10_1), a left eye lens (10a), a right eye lens (10b), a support frame (20), eyeglass frame legs (30a, 30b), a reflective member (40), and a display device housing (50).

[0206] Although FIG. 33 illustrates a virtual reality device (1) including eyeglass frame temples (30a, 30b), the virtual reality device (1) according to one embodiment may be applied to a head-mounted display that includes a head-mounting band that can be mounted on the head instead of the eyeglass frame temples (30a, 30b). That is, the virtual reality device (1) according to one embodiment is not limited to that shown in FIG. 33 and can be applied in various forms to various other electronic devices.

[0207] The display device housing (50) may include a display device (10_1) and a reflective member (40). An image displayed on the display device (10_1) may be reflected from the reflective member (40) and provided to the user's right eye through the right eye lens (10b). As a result, the user can view the virtual reality image displayed on the display device (10_1) through their right eye.

[0208] FIG. 33 illustrates that the display device housing (50) is positioned at the right end of the support frame (20), but the embodiments of this specification are not limited thereto. For example, the display device housing (50) may be positioned at the left end of the support frame (20), in which case the image displayed on the display device (10_1) may be reflected from the reflective member (40) and provided to the user's left eye through the left eye lens (10a). As a result, the user can view the virtual reality image displayed on the display device (10_1) through the left eye. Alternatively, the display device housing (50) may be positioned at both the left end and the right end of the support frame (20), in which case the user can view the virtual reality image displayed on the display device (10_1) through both the left eye and the right eye.

[0209] FIG. 34 is an example drawing showing a smart device including a display device according to one embodiment.

[0210] Referring to FIG. 34, a display device (10_2) according to one embodiment can be applied to a smart watch (2), which is one of the smart devices.

[0211] FIG. 35 is an exemplary drawing showing an automobile instrument panel and a center fascia including a display device according to one embodiment. FIG. 35 shows an automobile to which display devices (10_a, 10_b, 10_c, 10_d, 10_e) according to one embodiment are applied.

[0212] Referring to FIG. 35, display devices (10_a, 10_b, 10_c) according to one embodiment may be applied to an instrument panel of a vehicle, applied to a center fascia of a vehicle, or applied to a Center Information Display (CID) placed on the dashboard of a vehicle. Alternatively, they may be used as a display device (10C). Additionally, display devices (10_d, 10_e) according to one embodiment may be applied to a room mirror display that replaces a side mirror of a vehicle.

[0213] FIG. 36 is an exemplary drawing showing a transparent display device including a display device according to one embodiment.

[0214] Referring to FIG. 36, a display device (10_3) according to one embodiment can be applied to a transparent display device. The transparent display device can display an image (IM) and transmit light at the same time. Therefore, a user located in front of the transparent display device can not only view the image (IM) displayed on the display device (10_3), but also see an object (RS) or background located on the back of the transparent display device. When the display device (10_3) is applied to a transparent display device, the first substrate (SUB1) of the display device (10_3) shown in FIG. 5 may include a light-transmitting portion capable of transmitting light, or may be formed of a material capable of transmitting light.

[0215] FIG. 37 is a circuit diagram of a pixel circuit and a light-emitting element according to one embodiment.

[0216] Figure 37 shows an example of the pixel circuit (PXC) and light-emitting element (LE) of Figure 5.

[0217] Referring to FIG. 37, the light-emitting element (LE) emits light according to the driving current (Ids). The amount of light emitted by the light-emitting element (LE) may be proportional to the driving current (Ids). The light-emitting element (LE) may be an inorganic light-emitting element comprising an anode electrode, a cathode electrode, and an inorganic semiconductor disposed between the anode electrode and the cathode electrode. For example, the light-emitting element (LE) may be a micro light-emitting diode.

[0218] The anode electrode of the light-emitting element (EL) is connected to the source electrode of the driving transistor (DT), and the cathode electrode can be connected to a second power line (VSL) to which a low potential voltage lower than the high potential voltage is supplied.

[0219] The driving transistor (DT) adjusts the current flowing from the first power line (VDL), to which the first power supply voltage is supplied, to the light-emitting element (EL) according to the voltage difference between the gate electrode and the source electrode. The gate electrode of the driving transistor (DT) is connected to the first electrode of the first transistor (ST1), the source electrode is connected to the anode electrode of the light-emitting element (EL), and the drain electrode can be connected to the first power line (VSL), to which a high potential voltage is applied.

[0220] The first transistor (ST1) is turned on by a scan signal of the scan line (SL) to connect the data line (DL) to the gate electrode of the driving transistor (DT). The gate electrode of the first transistor (ST1) is connected to the scan line (SL), the first electrode is connected to the gate electrode of the driving transistor (DT), and the second electrode can be connected to the data line (DL).

[0221] The second transistor (ST2) is turned on by the sensing signal of the sensing signal line (SSL) to connect the initialization voltage line (VIL) to the source electrode of the driving transistor (DT). The gate electrode of the second transistor (ST2) is connected to the sensing signal line (SSL), the first electrode is connected to the initialization voltage line (VIL), and the second electrode can be connected to the source electrode of the driving transistor (DT).

[0222] It should be noted that the first electrode of each of the first and second transistors (ST1, ST2) may be a source electrode and the second electrode may be a drain electrode, but is not limited thereto. That is, the first electrode of each of the first and second transistors (ST1, ST2) may be a drain electrode and the second electrode may be a source electrode.

[0223] A capacitor (Cst) is formed between the gate electrode and the source electrode of the driving transistor (DT). The capacitor (Cst) stores the voltage difference between the gate voltage and the source voltage of the driving transistor (DT).

[0224] In FIG. 37, the driving transistor (DT) and the first and second transistors (ST1, ST2) are formed as N-type MOSFETs (Metal Oxide Semiconductor Field Effect Transistors), but it should be noted that this is not limited thereto. The driving transistor (DT) and the first and second transistors (ST1, ST2) may also be formed as P-type MOSFETs.

[0225] FIG. 38 is a circuit diagram of a pixel circuit and a light-emitting element according to another embodiment.

[0226] Figure 38 shows another example of the pixel circuit (PXC) and light-emitting element (LE) of Figure 5.

[0227] Referring to FIG. 38, the light-emitting element (LE) emits light according to the driving current (Ids). The amount of light emitted by the light-emitting element (LE) may be proportional to the driving current (Ids). The light-emitting element (LE) may be an inorganic light-emitting element comprising an anode electrode, a cathode electrode, and an inorganic semiconductor disposed between the anode electrode and the cathode electrode. For example, the light-emitting element (LE) may be a micro light-emitting diode.

[0228] The anode electrode of the light-emitting element (LE) is connected to the first electrode of the fourth transistor (ST4) and the second electrode of the sixth transistor (ST6), and the cathode electrode can be connected to the first power line (VSL). A parasitic capacitance (Cel) may be formed between the anode electrode and the cathode electrode of the light-emitting element (LE).

[0229] The pixel circuit (PXC) includes a driving transistor (DT), switching elements, and a capacitor (C1). The switching elements include first to sixth transistors (ST1, ST2, ST3, ST4, ST5, ST6).

[0230] The driving transistor (DT) includes a gate electrode, a first electrode, and a second electrode. The driving transistor (DT) controls the drain-source current (Ids, hereinafter referred to as "driving current") flowing between the first electrode and the second electrode according to the data voltage applied to the gate electrode.

[0231] A capacitor (C1) is formed between the second electrode of the driving transistor (DT) and the second power line (VSL). One electrode of the capacitor (C1) is connected to the second electrode of the driving transistor (DT), and the other electrode can be connected to the second power line (VSL).

[0232] If the first electrode of each of the first to sixth transistors (ST1, ST2, ST3, ST4, ST5, ST6) and the driving transistor (DT) is a source electrode, the second electrode may be a drain electrode. Alternatively, if the first electrode of each of the first to sixth transistors (ST1, ST2, ST3, ST4, ST5, ST6) and the driving transistor (DT) is a drain electrode, the second electrode may be a source electrode.

[0233] The active layer of each of the first to sixth transistors (ST1, ST2, ST3, ST4, ST5, ST6) and the driving transistor (DT) may be formed of any one of polysilicon, amorphous silicon, and oxide semiconductor. When the semiconductor layer of each of the first to sixth transistors (ST1, ST2, ST3, ST4, ST5, ST6) and the driving transistor (DT) is formed of polysilicon, the process for forming it may be a low-temperature polysilicon (LTPS) process.

[0234] In addition, FIG. 38 describes the first to sixth transistors (ST1, ST2, ST3, ST4, ST5, ST6) and the driving transistor (DT) as being formed as P-type MOSFETs (Metal Oxide Semiconductor Field Effect Transistors), but is not limited thereto and may be formed as N-type MOSFETs.

[0235] Furthermore, the first power supply voltage of the first power supply line (VSL), the second power supply voltage of the second power supply line (VSL), and the third power supply voltage of the third power supply line (VIL) can be set by taking into account the characteristics of the driving transistor (DT), the characteristics of the light-emitting element (LE), etc.

[0236] FIG. 39 is a circuit diagram of a pixel circuit and a light-emitting element according to another embodiment.

[0237] Figure 39 shows another example of the pixel circuit (PXC) and light-emitting element (LE) of Figure 6.

[0238] The embodiment of FIG. 39 differs from the embodiment of FIG. 39 in that the driving transistor (DT), the second transistor (ST2), the fourth transistor (ST4), the fifth transistor (ST5), and the sixth transistor (ST6) are formed as P-type MOSFETs, and the first transistor (ST1) and the third transistor (ST3) are formed as N-type MOSFETs.

[0239] Referring to FIG. 39, the active layer of each of the driving transistor (DT), second transistor (ST2), fourth transistor (ST4), fifth transistor (ST5), and sixth transistor (ST6), which are formed as P-type MOSFETs, is formed of polysilicon, and the active layer of each of the first transistor (ST1) and third transistor (ST3), which are formed as N-type MOSFETs, can be formed of oxide semiconductor.

[0240] In FIG. 39, the gate electrode of the second transistor (ST2) and the gate electrode of the fourth transistor (ST4) are connected to the write scan line (GWL), and the gate electrode of the first transistor (ST1) is connected to the control scan line (GCL), which is different from the embodiment of FIG. 38. Additionally, in FIG. 39, since the first transistor (ST1) and the third transistor (ST3) are formed as N-type MOSFETs, a scan signal of gate high voltage can be applied to the control scan line (GCL) and the initialization scan line (GIL). In contrast, since the second transistor (ST2), the fourth transistor (ST4), the fifth transistor (ST5), and the sixth transistor (ST6) are formed as P-type MOSFETs, a scan signal of gate low voltage can be applied to the write scan line (GWL) and the light-emitting line (EL).

[0241] Meanwhile, it should be noted that the pixel circuit (PXC) according to the embodiment of the present specification is not limited to that shown in FIGS. 37 to 39. The pixel circuit (PXC) according to the embodiment of the present specification may be formed with other known circuit structures that can be employed by those skilled in the art, in addition to the embodiment shown in FIGS. 37 to 39.

[0242] Although embodiments of the present invention have been described above with reference to the attached drawings, those skilled in the art will understand that the present invention may be implemented in other specific forms without changing the technical concept or essential features thereof. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. Explanation of the symbols

[0243] 10: Display device 100: Display panel 110: Semiconductor circuit board 111: Pixel electrode 112: Connecting electrode 120: Light-emitting element layer LE: Light-emitting element QDL: Wavelength conversion layer

Claims

Claim 1 A display device comprising: a substrate; a pixel electrode disposed on the substrate; a light-emitting element disposed on the pixel electrode and extending in the thickness direction of the substrate; a common electrode disposed on the light-emitting element; a wavelength conversion layer disposed on the common electrode and including wavelength conversion particles that convert a first light emitted from the light-emitting element into a second light; and a selective reflective film disposed on the upper surface and sides of the wavelength conversion layer, which reflects the first light and transmits the second light, wherein the common electrode is in contact with the wavelength conversion layer, and the selective reflective film comprises a plurality of odd layers having a first refractive index and a plurality of excellent layers having a second refractive index higher than the first refractive index, wherein the plurality of odd layers and the plurality of excellent layers are alternately disposed in the thickness direction of the substrate. Claim 2 delete Claim 3 A display device according to claim 1, further comprising a color filter disposed on the selective reflective film, which blocks or absorbs the first light and transmits at least a portion of the second light. Claim 4 A display device according to claim 1, further comprising a reflective film disposed on the sides of the selective reflective film. Claim 5 A display device having, in claim 4, a connecting electrode disposed between the pixel electrode and the light-emitting element. Claim 6 In claim 5, the common electrode is a display device disposed on the upper surface and sides of the light-emitting element and on the sides of the connecting electrode. Claim 7 In claim 6, the display device further comprises a first insulating film disposed on the substrate, and the common electrode disposed on the first insulating film. Claim 8 In claim 7, the selective reflective film is a display device disposed on the common electrode disposed on the first insulating film. Claim 9 A display device according to claim 6, further comprising a second insulating film disposed between the sides of the light-emitting element and the common electrode. Claim 10 A display device comprising: a substrate; a pixel electrode disposed on the substrate; a light-emitting element disposed on the pixel electrode and extending in the thickness direction of the substrate; a wavelength conversion layer disposed on the light-emitting element and including wavelength conversion particles that convert a first light emitted from the light-emitting element into a second light; a common electrode disposed on the wavelength conversion layer; and a selective reflective film disposed on the common electrode, which reflects the first light and transmits the second light, wherein the common electrode is in contact with the wavelength conversion layer, and the selective reflective film comprises a plurality of odd layers having a first refractive index and a plurality of excellent layers having a second refractive index higher than the first refractive index, wherein the plurality of odd layers and the plurality of excellent layers are alternately disposed in the thickness direction of the substrate. Claim 11 In claim 10, the light-emitting element comprises: a first semiconductor layer disposed on the pixel electrode; an active layer disposed on the first semiconductor layer; and a second semiconductor layer disposed on the active layer, forming a display device. Claim 12 In claim 11, the wavelength conversion layer comprises a third semiconductor layer including a plurality of voids that accommodate the wavelength conversion particles, in a display device. Claim 13 In claim 12, the display device wherein the third semiconductor layer comprises the same material as the second semiconductor layer. Claim 14 A display device according to claim 12, wherein the first semiconductor layer comprises p-GaN doped with a first conductivity type dopant, and the second semiconductor layer and the third semiconductor layer each comprise n-GaN doped with a second conductivity type dopant. Claim 15 In claim 10, a display device in which the thickness of the wavelength conversion layer is greater than the thickness of the light-emitting element. Claim 16 In claim 10, the common electrode is a display device disposed on the upper surface and sides of the wavelength conversion layer and on the sides of the light-emitting element. Claim 17 A display device comprising: a light-emitting element disposed in each of a first light-emitting region emitting a first light, a second light-emitting region emitting a second light, and a third light-emitting region emitting a third light; a light-transmitting layer disposed on the light-emitting element in the first light-emitting region; a wavelength conversion layer disposed on the light-emitting element in each of the second light-emitting region and the third light-emitting region; and a selective reflective film disposed on the sides of the light-transmitting layer in the first light-emitting region and disposed on the upper surfaces and sides of the wavelength conversion layer in the second light-emitting region, wherein the selective reflective film reflects the first light incident from the wavelength conversion layer and transmits the second light, and the selective reflective film is not disposed on the upper surface of the light-transmitting layer in the first light-emitting region. Claim 18 In claim 17, the selective reflective film is disposed on the upper and side surfaces of the wavelength conversion layer in the third light-emitting region, and the selective reflective film is a display device that transmits the third light. Claim 19 A display device according to claim 18, further comprising: a first color filter disposed on the light-transmitting layer in the first light-emitting region, which transmits the first light and absorbs or blocks the second light and the third light; a second color filter disposed on the wavelength-converting layer in the second light-emitting region, which transmits the second light and absorbs or blocks the first light and the third light; and a third color filter disposed on the wavelength-converting layer in the third light-emitting region, which transmits the third light and absorbs or blocks the first light and the second light. Claim 20 A step of forming a first connecting electrode layer on a first substrate and forming a second connecting electrode layer on a light-emitting material layer of a second substrate; a step of forming a connecting electrode layer by bonding the first connecting electrode layer and the second connecting electrode layer and removing the second substrate; a step of forming a mask pattern on the light-emitting material layer and etching the light-emitting material layer and the connecting electrode layer according to the mask pattern to form light-emitting elements; a step of forming an insulating film on the sides of each of the light-emitting elements and forming a common electrode on the upper surface of each of the light-emitting elements and on the insulating film; a step of forming a light-transmitting layer on the common electrode in a first light-emitting region; a step of forming a wavelength conversion layer that contacts the common electrode in a second light-emitting region and a third light-emitting region and converts a first light emitted from the light-emitting element into a second light. A method for manufacturing a display device comprising the step of forming a selective reflective film that reflects the first light and transmits the second light on a wavelength conversion layer of each of the second light-emitting region and the third light-emitting region, wherein the selective reflective film comprises a plurality of odd layers having a first refractive index and a plurality of excellent layers having a second refractive index higher than the first refractive index, and wherein the plurality of odd layers and the plurality of excellent layers are alternately arranged in the thickness direction of the substrate.

Images