Light-emitting substrate and preparation method therefor, display substrate, and display apparatus

Abstract

A light-emitting substrate. The light-emitting substrate comprises a substrate base and a light-emitting element disposed on the substrate base. The light-emitting element comprises a first semiconductor layer, a light-emitting layer, and a second semiconductor layer which are stacked in the direction away from the substrate base. The light-emitting element further comprises a first optical functional layer. The first optical functional layer is configured to transmit at least part of circularly polarized light in light emitted by the light-emitting element. The first optical functional layer comprises a first portion located on a side of the second semiconductor layer away from the substrate base, and a second portion disposed around the light-emitting layer and the second semiconductor layer.

Description

Luminescent substrate and preparation method thereof, display substrate and display device Technical Field

[0001] The present disclosure relates to the field of display technology, and in particular to a light-emitting substrate and a preparation method thereof, a display substrate, and a display device. Background Art

[0002] With the development of light-emitting diode technology, micro-LEDs (Micro Light Emitting Diodes) have gained widespread application. Micro-LEDs refer to LED chips with a size of less than 50μm. Micro-LEDs offer excellent performance in terms of brightness, lifespan, contrast, response time, energy consumption, viewing angle, and resolution. They also feature self-luminescence, a simple structure, a compact size, and energy efficiency, making them considered the next generation of display technology.

[0003] Summary of the Invention

[0004] In one aspect, a light-emitting substrate is provided. The light-emitting substrate includes a substrate and a light-emitting element disposed on the substrate. The light-emitting element includes a first semiconductor layer, a light-emitting layer, and a second semiconductor layer stacked in a direction away from the substrate. The light-emitting element also includes a first optically functional layer. The first optically functional layer is configured to transmit at least a portion of the circularly polarized light emitted by the light-emitting element. The first optically functional layer includes a first portion located on a side of the second semiconductor layer away from the substrate, and a second portion disposed around the light-emitting layer and the second semiconductor layer.

[0005] In some embodiments, the first optical functional layer further includes a third portion located on a side of the second portion away from the substrate, the third portion is continuously distributed with the first portion, and the third portion is also continuously distributed with the second portion.

[0006] In some embodiments, the first optically functional layer includes a first surface away from the substrate, and the first surface is approximately a flat and continuous surface.

[0007] In some embodiments, the light-emitting layer and the second semiconductor layer are distributed in an island shape, with multiple light-emitting islands and multiple second semiconductor islands, the first semiconductor layer is distributed continuously or in an island shape, and the second portion is further filled between adjacent light-emitting islands and adjacent second semiconductor islands.

[0008] In some embodiments, the first semiconductor layer is distributed in an island shape and has a plurality of first semiconductor islands. The first optical functional layer further includes a fourth portion surrounding the first semiconductor islands and located between adjacent first semiconductor islands, the fourth portion being continuously distributed with the second portion.

[0009] In some embodiments, the material of the first optical functional layer includes cholesteric liquid crystal.

[0010] In some embodiments, the first portion is configured to transmit at least a portion of circularly polarized light emitted by the light-emitting element; and the second portion is configured to scatter at least a portion of the light emitted by the light-emitting element.

[0011] In some embodiments, the cholesteric liquid crystal of the first portion includes a planar state; and the cholesteric liquid crystal of the second portion includes a focal conic state.

[0012] In some embodiments, the first optical function layer includes a first via hole, the orthographic projection of the first via hole on the substrate overlaps with the second semiconductor layer. The light-emitting substrate includes a first connecting electrode, the first connecting electrode is electrically connected to the second semiconductor layer through the first via hole.

[0013] In some embodiments, the light emitting element includes a first electrode located on a side of the second semiconductor island close to the substrate, and the second semiconductor island is electrically connected to the first electrode.

[0014] In some embodiments, the light-emitting substrate includes a second optical functional layer located on a side of the first optical functional layer away from the substrate, wherein the second optical functional layer is configured to convert at least a portion of light transmitted through the first optical functional layer into linearly polarized light.

[0015] In some embodiments, the material of the second optical functional layer includes a liquid crystal mixture, cyclohexanone, and a photopolymerization initiator.

[0016] In some embodiments, the first optically functional layer includes a first via hole, the orthographic projection of the first via hole on the substrate overlapping the second semiconductor layer. The second optically functional layer includes a second via hole, the second via hole communicating with the first via hole. The light-emitting substrate includes a first connecting electrode, the first connecting electrode electrically connected to the second semiconductor layer via the second via hole and the first via hole.

[0017] In some embodiments, the light-emitting substrate further comprises a wire grid layer located on a side of the second optical functional layer away from the base. The wire grid layer comprises a plurality of parallel and spaced wire grids, wherein the extension direction of the plurality of wire grids is parallel to the polarization direction of the polarized light after passing through the second optical functional layer.

[0018] In some embodiments, the substrate includes a circuit layer, at least one wire grid of the wire grid layer is electrically connected to the first connection electrode, and the at least one wire grid electrically connected to the first connection electrode is configured to be connected to the circuit layer of the substrate.

[0019] In some embodiments, the light-emitting substrate further comprises a second substrate and an adhesive layer. The second substrate is located on a side of the wire grid layer away from the base, the wire grid layer being disposed on the second substrate and electrically insulated from the first connecting electrode. The adhesive layer is located between the wire grid layer and the second optically functional layer and is configured to bond the wire grid layer and the second optically functional layer.

[0020] In some embodiments, the light-emitting substrate further comprises a second substrate and an adhesive layer. The second substrate is located on a side of the second optically functional layer away from the base, and the second optically functional layer is disposed on the second substrate. The adhesive layer is located between the second optically functional layer and the second optically functional layer and is configured to bond the first optically functional layer to the second optically functional layer.

[0021] In some embodiments, the light-emitting substrate further comprises a wire grid layer. The wire grid layer is disposed between the second substrate and the second optical functional layer, and comprises a plurality of parallel and spaced wire grids, wherein the extension direction of the plurality of wire grids is parallel to the polarization direction of the polarized light after passing through the second optical functional layer.

[0022] In some embodiments, the light emitting element further comprises a first substrate located on a side of the first semiconductor layer close to the base, wherein the first substrate comprises a reflective layer and a wafer layer stacked in a direction away from the base, and the wafer layer is made of a transparent material.

[0023] In some embodiments, the light emitting element further comprises a first substrate located on a side of the first semiconductor layer close to the base. The first substrate comprises a first substrate and a reflective layer stacked in a direction away from the base, and the material of the first substrate comprises a transparent material or an opaque material.

[0024] In another aspect, a method for preparing a light-emitting substrate is provided. The method comprises: growing an epitaxial layer on a wafer layer; the epitaxial layer comprises a first semiconductor layer, a light-emitting layer, and a second semiconductor layer stacked in sequence; patterning the second semiconductor layer and the light-emitting layer to form a plurality of second semiconductor islands and a plurality of light-emitting islands; and forming a first optically functional layer; the first optically functional layer comprises a first portion located on a side of the second semiconductor island facing away from the first semiconductor layer, and a second portion disposed around the second semiconductor islands and the light-emitting islands.

[0025] In some embodiments, forming the first optically functional layer includes: coating a liquid cholesteric liquid crystal; and solidifying the liquid cholesteric liquid crystal to form the first optically functional layer. The liquid cholesteric liquid crystal is filled between adjacent light-emitting islands and between adjacent second semiconductor islands, covering the second semiconductor islands, and the surface of the liquid cholesteric liquid crystal away from the wafer is a flat surface.

[0026] In some embodiments, curing the cholesteric liquid crystal to form the first optically functional layer includes: shielding a first region of the liquid cholesteric liquid crystal with a light-shielding layer; wherein the orthographic projection of the first region on the first semiconductor layer covers the spaces between the plurality of second semiconductor islands and does not overlap with the second semiconductor islands; curing the region of the liquid cholesteric liquid crystal exposed by the first region using a photocuring process to form a first portion in a planar state; removing the light-shielding layer, and curing the liquid cholesteric liquid crystal in the remaining region to form a second portion and a third portion in a focal-conic state; the second portion, the third portion, and the first portion collectively forming the first optically functional layer.

[0027] In some embodiments, after forming the first optically functional layer, the method further includes: forming a second optically functional layer on a side of the first optically functional layer away from the wafer layer; the second optically functional layer is configured to convert at least a portion of light transmitted through the first optically functional layer into linearly polarized light. A via hole is formed through the second optically functional layer and the first optically functional layer; the orthographic projection of the via hole on the wafer layer overlaps the orthographic projection of the second semiconductor island on the wafer layer. A first connecting electrode is formed within the via hole; the first connecting electrode is connected to the second semiconductor island.

[0028] In some embodiments, after forming the first connecting electrode in the via hole, the preparation method further includes: forming a wire grid layer on the side of the second optical functional layer and the first connecting electrode away from the wafer layer; the wire grid layer includes a plurality of wire grids arranged in parallel and at intervals, and at least one wire grid of the wire grid layer is connected to the first connecting electrode.

[0029] In some embodiments, after forming a wire grid layer on a side of the second optically functional layer and the first connecting electrode away from the wafer layer, the preparation method further comprises: cutting the wafer layer and the epitaxial layer, the first optically functional layer, the second optically functional layer, and the wire grid layer disposed on the wafer layer to form a plurality of light-emitting elements; the light-emitting elements comprising a stacked wafer layer, a first semiconductor layer, at least one light-emitting island and a second semiconductor island, a first optically functional layer, a second optically functional layer, and a wire grid layer. The plurality of light-emitting elements are connected to a substrate to form the light-emitting substrate.

[0030] In some embodiments, after forming the first connecting electrode in the via hole, the preparation method further includes: cutting the wafer layer and the epitaxial layer, the first optical functional layer, and the second optical functional layer disposed thereon to form a plurality of light-emitting elements; the light-emitting elements include a stacked wafer layer, at least one light-emitting island and a second semiconductor island layer, the first optical functional layer, and the second optical functional layer; connecting the light-emitting elements to the substrate to form a first light-emitting substrate; wherein the first connecting electrode is connected to the substrate.

[0031] In some embodiments, the preparation method further includes: preparing a cover plate; the cover plate includes a wire grid layer disposed on a second substrate; the wire grid layer includes a plurality of parallel and spaced wire grids. The cover plate is bonded to the first light-emitting substrate using an adhesive layer to form the light-emitting substrate. The wire grid layer of the cover plate is closer to the second optical functional layer of the first light-emitting substrate than the second substrate, and the plurality of wire grids of the wire grid layer are electrically insulated from the first connecting electrode of the first light-emitting substrate.

[0032] In some embodiments, after forming the first optically functional layer, the method further includes: forming a first via hole extending through the first optically functional layer; the orthographic projection of the first via hole on the wafer layer overlaps the orthographic projection of the second semiconductor island on the wafer layer. A first connecting electrode is formed within the via hole, the first connecting electrode being electrically connected to the second semiconductor island. The wafer layer, the epitaxial layer disposed thereon, and the first optically functional layer are cut to form a plurality of light-emitting elements; the light-emitting elements include a stacked wafer layer, at least one light-emitting island, a second semiconductor island, and the first optically functional layer. The light-emitting elements are connected to a substrate to form a second light-emitting substrate.

[0033] In some embodiments, the preparation method further includes: preparing a cover plate; the cover plate includes a second substrate, and a wire grid layer and a second optical functional layer sequentially stacked on the second substrate; the wire grid layer includes a plurality of parallel and spaced wire grids, and the second optical functional layer is configured to convert at least a portion of light transmitted through the first optical functional layer into linearly polarized light. The cover plate and the second light-emitting substrate are bonded together using an adhesive layer to form the light-emitting substrate; wherein the second optical functional layer of the cover plate is disposed opposite the first optical functional layer of the second light-emitting substrate.

[0034] In some embodiments, after growing the epitaxial layer on the wafer layer and before patterning the second semiconductor layer and the light-emitting layer, the preparation method further includes: forming a transition substrate on a side of the second semiconductor layer away from the wafer layer; removing the wafer layer to expose the first semiconductor layer; forming a reflective layer on a side of the first semiconductor layer away from the transition substrate; forming a first substrate on a side of the reflective layer away from the transition substrate; and removing the transition substrate.

[0035] In some embodiments, the preparation method further comprises: forming a reflective layer on one side of the wafer layer. The light-emitting layer and the epitaxial layer are respectively located on two sides of the wafer layer.

[0036] In another aspect, a display device is provided. The display device includes a liquid crystal display panel and the light-emitting substrate described in any one of the above embodiments. The liquid crystal display panel is disposed on the light-emitting side of the light-emitting substrate.

[0037] In another aspect, a display substrate is provided. The display substrate includes a color conversion layer and the light-emitting substrate described in any one of the above embodiments. The color conversion layer is located on the light-emitting side of the light-emitting substrate.

[0038] In some embodiments, the color conversion layer includes a dam layer and multiple color conversion sections. The dam layer has multiple openings, and the color conversion sections are located within the openings. The multiple color conversion sections include a first color conversion section, a second color conversion section, and a third color conversion section, each located within a different opening. The first color conversion section converts the light into red light, the second color conversion section converts the light into green light, and the third color conversion section maintains or converts the light into blue light.

[0039] In another aspect, a display device is provided, comprising the above-mentioned display substrate, and a first polarizer, a semi-transmissive and semi-reflective film, a first lens, a second polarizer, a reflective polarizer, and a second lens stacked in sequence on the light-emitting side of the display substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] To more clearly illustrate the technical solutions of the present disclosure, the following briefly introduces the drawings required for use in some embodiments of the present disclosure. Obviously, the drawings described below are only drawings of some embodiments of the present disclosure, and those skilled in the art can also derive other drawings based on these drawings. Furthermore, the drawings described below are schematic diagrams and are not intended to limit the actual dimensions of the products, actual processes of the methods, actual timing of signals, and the like involved in the embodiments of the present disclosure.

[0041] FIG1 is a schematic structural diagram of a display device according to some embodiments;

[0042] FIG2 is a structural diagram of a display device according to some embodiments;

[0043] FIG3 is another structural diagram of a display device according to some embodiments;

[0044] FIG4 is another structural diagram of a display device according to some embodiments;

[0045] FIG5 is a planar structural diagram of a light-emitting substrate according to some embodiments;

[0046] FIG6 is a cross-sectional view along the section line A1-A1 in FIG5;

[0047] FIG7 is a cross-sectional view along the section line A2-A2 in FIG5;

[0048] FIG8 is another cross-sectional view along the section line A1-A1 in FIG5;

[0049] FIG9 is another cross-sectional view taken along the section line A1-A1 in FIG5;

[0050] FIG10 is another cross-sectional view taken along the section line A1-A1 in FIG5;

[0051] FIG11 is a cross-sectional structural diagram of a light-emitting substrate according to some embodiments;

[0052] FIG12A is another cross-sectional structural diagram of a light-emitting substrate according to some embodiments;

[0053] FIG12B is another cross-sectional structural diagram of a light-emitting substrate according to some embodiments;

[0054] FIG13 is another cross-sectional structural diagram of a light-emitting substrate according to some embodiments;

[0055] FIG14 is another cross-sectional structural diagram of a light-emitting substrate according to some embodiments;

[0056] FIG15 is another planar structural diagram of a light-emitting substrate according to some embodiments;

[0057] FIG16 is a cross-sectional view taken along section line A3-A3 in FIG15;

[0058] FIG17A is a cross-sectional view taken along section line A4-A4 in FIG15;

[0059] FIG17B is another cross-sectional view taken along section line A4-A4 in FIG15;

[0060] FIG18 is a structural diagram of a light-emitting substrate according to some embodiments;

[0061] FIG19 is another structural diagram of a light-emitting substrate according to some embodiments;

[0062] 20 to 52 are flow charts of a process for preparing a light-emitting substrate according to some embodiments. DETAILED DESCRIPTION

[0063] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present disclosure. Obviously, the embodiments described are only some embodiments of the present disclosure, not all embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of the present disclosure.

[0064] Unless the context requires otherwise, throughout the specification and claims, the term "comprise" and its other forms, such as the third person singular form "comprises" and the present participle form "comprising", are to be interpreted as open and inclusive, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific example" or "some examples" are intended to indicate that the particular features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the particular features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0065] In the present disclosure, terms such as "lower," "below," "above," and "upper," and the like are used to explain the relationship between components shown in the drawings. These terms may be relative and described based on directions shown in the drawings, or based on the order in which process steps are formed, but are not limited thereto.

[0066] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, "plurality" means two or more.

[0067] When describing some embodiments, the word "connected" and its derivatives may be used. The term "connected" should be understood in a broad sense. For example, "connected" can mean fixed connection, detachable connection, or integration; it can be directly connected or indirectly connected through an intermediate medium.

[0068] “At least one of A, B and C” has the same meaning as “at least one of A, B or C” and both include the following combinations of A, B and C: A only, B only, C only, the combination of A and B, the combination of A and C, the combination of B and C, and the combination of A, B and C.

[0069] “A and / or B” includes the following three combinations: A only, B only, and a combination of A and B.

[0070] The use of "adapted to" or "configured to" herein is intended to be open and inclusive language that does not exclude devices adapted to or configured to perform additional tasks or steps.

[0071] Additionally, the use of “based on” is meant to be open and inclusive, as a process, step, calculation, or other action “based on” one or more stated conditions or values ​​may, in practice, be based on additional conditions or values ​​beyond those stated.

[0072] As used herein, "about," "substantially," or "approximately" includes the stated value and an average value that is within an acceptable range of deviation from the particular value as determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0073] As used herein, "parallel", "perpendicular", and "equal" include the situations described and situations similar to the situations described, and the range of the similar situations is within an acceptable deviation range, wherein the acceptable deviation range is as determined by a person of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the specific quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, wherein the acceptable deviation range of approximate parallelism can be, for example, a deviation within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, wherein the acceptable deviation range of approximate perpendicularity can also be, for example, a deviation within 5°. "Equal" includes absolute equality and approximate equality, wherein the acceptable deviation range of approximate equality can be, for example, that the difference between the two equals is less than or equal to 5% of either one.

[0074] It will be understood that when a layer or element is referred to as being on another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may be present therebetween.

[0075] Exemplary embodiments are described herein with reference to cross-sectional and / or plan views that are idealized exemplary drawings. In the drawings, the thickness of layers and the area of ​​regions are exaggerated for clarity. Therefore, variations in shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are contemplated. Therefore, the exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but rather include deviations in shape due to, for example, manufacturing. For example, an etched region shown as a rectangle will typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shape of regions of the device and are not intended to limit the scope of the exemplary embodiments.

[0076] 1 , an embodiment of the present disclosure provides a display device 1000 , which is a product having an image display function. For example, the display device 1000 can be any device that displays either moving (e.g., video) or fixed (e.g., still images), and whether text or images.

[0077] The display device 1000 can be applied to a variety of electronic devices, such as mobile phones, wireless devices, personal digital assistants (PDAs), wearable devices, augmented reality (AR) devices, virtual reality (VR) devices, handheld or portable computers, GPS receivers / navigators, cameras, MP4 video players, video cameras, game consoles, watches, clocks, calculators, television monitors, flat-panel displays, computer monitors, automotive displays (e.g., odometer displays), cockpit controls and / or displays, camera view displays (e.g., displays for rearview cameras in vehicles), electronic photographs, electronic billboards or signs, projectors, packaging, and aesthetic structures (e.g., displays for images of jewelry). For example, as shown in FIG1 , the display device 1000 can be a mobile phone.

[0078] In some embodiments, the display device 1000 includes a light emitting substrate 1100 configured to emit linearly polarized light.

[0079] Exemplarily, the display device 1000 may be a liquid crystal display (LCD). Referring to FIG2 , in the case where the display device 1000 is a liquid crystal display, the display device 1000 may include a light-emitting substrate 1100, a liquid crystal display panel 1200, and an upper polarizer 1300, which are stacked. In this case, the light-emitting substrate 1100 may be a part of a backlight module. The light-emitting substrate 1100 is located on the non-light-emitting side of the liquid crystal display panel 1200 and is configured to provide a light source to the liquid crystal display panel 1200 and emit linearly polarized light of a specific polarization direction toward the liquid crystal display panel 1200. The liquid crystal display panel 1200 includes a plurality of sub-pixels, each of which is configured to modulate the linearly polarized light incident therein to adjust the polarization direction of the light emitted by the sub-pixel. The upper polarizer 1300 is arranged on the light-emitting side of the liquid crystal display panel 1200, and is configured to filter the linearly polarized light emitted by each sub-pixel so that the light with the polarization direction being the same as the optical axis direction of the polarizer of the upper polarizer 1300 is emitted, and the light with the polarization direction being perpendicular to the optical axis direction of the polarizer of the upper polarizer 1300 is blocked from being emitted, so as to achieve the display of different grayscales and thus realize image display.

[0080] Exemplarily, the display device 1000 can also be a direct display device (such as a Micro-LED display device or a Mini-LED display device). In this case, referring to FIG3 , the display device 1000 can include a display substrate 1400, which can be directly used for screen display. In other words, the display substrate 1400 directly displays images. The display substrate 1400 can include a light-emitting substrate 1100 and a color conversion layer 1500 disposed on the light-emitting side of the light-emitting substrate 1100. The light-emitting substrate 1100 is configured to emit light of one color toward the color conversion layer 1500. The color conversion layer 1500 is configured to convert the color of the light emitted by the light-emitting substrate 1100 toward the color conversion layer to achieve color display.

[0081] 3 , in some embodiments, the color conversion layer 1500 may include a dam layer 510 and a plurality of color conversion portions 520 . The dam layer 510 has a plurality of openings 511 , and the plurality of color conversion portions 520 correspond to the plurality of openings 511 , with one color conversion portion 520 located in one opening 511 .

[0082] As shown in Figure 3, the multiple color conversion sections 520 include a first color conversion section 521, a second color conversion section 522, and a third color conversion section 523, respectively located within different openings 511. The first color conversion section 521 converts light into red light, the second color conversion section 522 converts light into green light, and the third color conversion section 523 maintains or converts light into blue light. For example, if the light-emitting substrate 1100 is configured to emit deep ultraviolet light (wavelength less than 380 nm), the third color conversion section 523 may convert light into blue light. Alternatively, if the light-emitting substrate 1100 is configured to emit blue light, the third color conversion section 523 may maintain the light as blue light.

[0083] Based on the structure of the above-mentioned color conversion layer 1500, the light emitted by the light-emitting substrate 1100 can display red light, green light and blue light after passing through the color conversion layer 1500, and various colors of light can be superimposed according to the brightness difference of red light, green light and blue light, thereby realizing full-color display.

[0084] For example, the material of the dam layer 510 can be a resin material, and the dam layer 510 can have a light-shielding effect to absorb or reflect the light incident on the dam layer 510, thereby avoiding the generation of cross-color between lights of different colors emitted from adjacent color conversion parts 520 of the color conversion layer 1500.

[0085] In other embodiments, the display device 1000 may also be a 3D display device. Referring to FIG. 4 , the display device 1000 may include the display substrate 1400 and an optical module 1600 stacked sequentially on the light-emitting side of the display substrate 1400. For example, the optical module may include a first polarizer 610, a transflective film 620, a first lens 630, a second polarizer 640, a reflective polarizer 650, and a second lens 660, sequentially arranged along the light-emitting direction of the display substrate 1400.

[0086] The first polarizer 610 and the second polarizer 640 may both be quarter-wave plates. The first lens 630 and the second lens 660 may increase the optical path of light emitted from the display substrate 1400 and may amplify the image displayed on the display substrate 1400 .

[0087] The following briefly describes the optical path of light emitted by the display device 1000 and incident on the human eye E. As shown in FIG4 ,

[0088] The light emitted by the light-emitting portion of the display substrate 1400 or the light-emitting substrate 1100 can be linearly polarized light (e.g., TM light). This polarized light is incident on the first polarizer 610, where it is converted into circularly polarized light before being emitted. This circularly polarized light is incident on the transflective film 620, where a portion of the circularly polarized light is transmitted, passes through the first lens 630, and then is emitted to the second polarizer 640. This portion of the circularly polarized light is converted into linearly polarized light (e.g., TE light) by the second polarizer 640, and then is emitted to the reflective polarizer 650. The linearly polarized light is reflected by the reflective polarizer 650 and then incident on the second polarizer 640 again. It is converted into circularly polarized light by the second polarizer 640, then passes through the first lens 630 and is incident on the transflective film 620. This portion of the circularly polarized light is reflected by the transflective film 620 and then is reflected by the second polarizer 640, where it is converted into linearly polarized light (e.g., TM light) before being incident on the reflective polarizer 650. The linearly polarized light passes through the reflective polarizer 650 and the second lens 660 and enters the human eye E. Thus, the human eye E can see a picture composed of polarized light (in FIG. 4 , the dotted line with an arrow represents the propagation path of the light emitted from the display substrate 1400 ).

[0089] It should be understood that the type of display device 1000 provided in the embodiment of the present disclosure is not limited to liquid crystal display devices, direct display devices and 3D display devices, and any other suitable type of display device can be considered as long as the same technical ideas are adopted. The embodiment of the present disclosure will not list them one by one.

[0090] 5, 6 and 7, a light emitting substrate 1100 may include a base 100 and a plurality of light emitting elements 200 disposed on the base 100. In particular, one light emitting element 200 is exemplarily shown in FIG5, 6 and 7.

[0091] The light-emitting element 200 may be an LED light-emitting element. For example, the light-emitting element 200 may be a sub-millimeter light-emitting diode (Mini Light Emitting Diode; Mini-LED for short) with a size of 100 μm to 500 μm; or, the light-emitting element 200 may be a micro light-emitting diode (Micro Light Emitting Diode; Micro-LED for short) with a size less than 100 μm; or, the light-emitting element 200 may be an LED with a larger size (for example, greater than 500 μm).

[0092] For example, the substrate 100 may include a driving circuit layer, and the light emitting element 200 is connected to the driving circuit layer of the substrate 100 and emits light under the control of the driving circuit layer.

[0093] Taking Figures 6 and 7 as examples, the driving circuit layer may include, for example, a thin film transistor (TFT) and a power supply voltage signal line 11. The TFT may include a semiconductor pattern 12, a gate pattern 13, a source pattern 14, and a drain pattern 15. The TFT is used to form a driving circuit to drive the light-emitting element 200 to emit light.

[0094] The substrate 100 may further include an insulating layer between adjacent conductive layers. The conductive layers may be connected via vias penetrating the insulating layer to transmit signals between the different conductive layers. Of course, the structure of the substrate 100 is not limited thereto and may also include other structures, such as data lines DL and gate lines GL. The embodiments of the present disclosure will not be listed one by one, as long as the same technical concept is adopted.

[0095] The light-emitting element 200 can be mounted on the substrate 100 in a face-up manner. For example, as shown in FIG6 , the light-emitting substrate 1100 can further include a first connection line 16, which is configured to connect the light-emitting element 200 and the power supply voltage signal line 11. As shown in FIG7 , the light-emitting substrate 1100 can further include a second connection line 17, which is configured to connect the light-emitting element 200 and the thin film transistor.

[0096] 6 , the light emitting element 200 may include a first semiconductor layer 21 , a light emitting layer 22 , and a second semiconductor layer 23 stacked in a direction away from the substrate 100 .

[0097] The material of the first semiconductor layer 21 can be a P-type semiconductor material, and accordingly, the material of the second semiconductor layer 23 can be an N-type semiconductor material. Alternatively, the material of the first semiconductor layer 21 can be an N-type semiconductor material, and accordingly, the material of the second semiconductor layer 23 can be a P-type semiconductor material. The intrinsic semiconductor material of the above-mentioned P-type semiconductor material and N-type semiconductor material can be any one of gallium nitride (GaN), gallium phosphide (GaP), aluminum gallium arsenide (AlGaAs) and aluminum gallium indium phosphide (AlGaInP), and the intrinsic semiconductor material is P-type doped or N-type doped to obtain the corresponding P-type semiconductor material and N-type semiconductor material. The light-emitting layer 22 can be a multiple quantum well layer (English: Multiple Quantum Well; abbreviated: MQW).

[0098] In some embodiments, as shown in FIG6 , the light-emitting element 200 may further include a first electrode layer 24 located on a side of the second semiconductor layer 23 away from the substrate 100. The material of the first electrode layer 24 includes a transparent conductive material to allow light to pass through the first electrode layer 24 and be emitted in a direction away from the substrate 100. It is understood that a transparent conductive material refers to a material having a light transmittance greater than a preset value (e.g., 80%, 90%, or 95%). For example, the material of the first electrode layer 24 may be indium tin oxide (ITO) or indium zinc oxide (IZO).

[0099] For example, as shown in Figure 6, the light-emitting element 200 also includes a second electrode 25, which is connected to the first semiconductor layer 21. The first semiconductor layer 21 can be electrically connected to the power supply voltage signal line 11 of the substrate 100 through the second electrode 25 and the first connecting line 16 in turn. The power supply voltage signal line 11 is configured to transmit the power supply voltage to the first semiconductor layer 21 through the first connecting line 16 and the second electrode 25.

[0100] For example, as shown in Figure 7, the second semiconductor layer 23 of the light-emitting element 200 can be electrically connected to the drain 15 of the thin film transistor of the substrate 100 through the second connecting line 17, and the thin film transistor is configured to transmit the data signal from the source 14 (connected to the data line DL) to the drain 15 under the control of the gate 13 (gate line GL), and further transmit it to the second semiconductor layer 23 through the second connecting line 17.

[0101] There is a voltage difference between the power supply voltage on the first semiconductor layer 21 and the voltage of the data signal on the second semiconductor layer 23. Under the action of the above voltage difference, the first semiconductor layer 21 and the second semiconductor layer 23 respectively transmit majority carriers and minority carriers to the light-emitting layer. The majority carriers and minority carriers recombine in the light-emitting layer 22 and emit light during the recombination process.

[0102] The light-emitting element 200 further includes a first optically functional layer 26. The first optically functional layer 26 is configured to transmit at least a portion of the circularly polarized light emitted by the light-emitting element. In other words, a portion of the circularly polarized light in the natural light emitted by the light-emitting element 200 toward the first optically functional layer 26 can pass through the first optically functional layer 26. In this way, all light emitted from the first optically functional layer 26 can be circularly polarized light.

[0103] In some embodiments, the material of the first optical functional layer 26 may include cholesteric liquid crystal. The cholesteric liquid crystal molecules are flat and arranged in layers. The molecules in the layers are parallel to each other, and the molecular long axes are parallel to the layer plane. The directions of the molecular long axes of different layers vary slightly, and the molecules are arranged in a spiral structure along the normal direction of the cholesteric liquid crystal layer. The spiral structure is left-handed or right-handed. According to the handedness of the spiral structure, the cholesteric liquid crystal layer can be divided into a left-handed cholesteric liquid crystal layer and a right-handed cholesteric liquid crystal layer.

[0104] Cholesteric liquid crystals can selectively transmit some circularly polarized light. When the cholesteric liquid crystal in the first optically functional layer 26 is a left-handed cholesteric liquid crystal layer, the first optically functional layer 26 can transmit right-handed circularly polarized light and reflect left-handed circularly polarized light. When the cholesteric liquid crystal in the first optically functional layer 26 is a right-handed cholesteric liquid crystal layer, the first optically functional layer 26 can transmit left-handed circularly polarized light and reflect right-handed circularly polarized light.

[0105] The natural light emitted by the light-emitting element 200 includes left-handed circularly polarized light and right-handed circularly polarized light. Thus, if the cholesteric liquid crystal in the first optically functional layer 26 is a left-handed cholesteric liquid crystal layer, the first optically functional layer 26 can transmit the right-handed circularly polarized light emitted by the light-emitting element 200 and reflect the left-handed circularly polarized light back toward the base 100. If the cholesteric liquid crystal in the first optically functional layer 26 is a right-handed cholesteric liquid crystal layer, the first optically functional layer 26 can transmit the left-handed circularly polarized light emitted by the light-emitting element 200 and reflect the right-handed circularly polarized light back toward the base 100.

[0106] As shown in FIG7 , the first optical functional layer 26 includes a first via hole 265, the orthographic projection of the first via hole 265 on the substrate 100 overlapping the second semiconductor layer 23. The light-emitting substrate 1100 also includes a first connecting electrode 27, which is electrically connected to the second semiconductor layer 23 through the first via hole 265. In the case where the light-emitting element 200 includes a first electrode 24, the first connecting electrode 27 can be connected to the second semiconductor layer 23 through the first electrode 24.

[0107] It can be understood that the first connection electrode 27 fills the first via hole 265 , and the boundary of the first connection electrode 27 completely coincides with the boundary of the first via hole. In FIG. 7 , the first via hole 265 refers to the edge of the first connection electrode 27 .

[0108] As shown in FIG6 , in some embodiments, the light-emitting element 200 further includes a first substrate 28, which is located on a side of the first semiconductor layer 21 close to the base 100. The first substrate 28 is used to support other film layers and structures of the light-emitting element 200, for example, the first substrate 200 is used to support the first semiconductor layer 21, the light-emitting layer 22, the second semiconductor layer 23, the first electrode 24, the second electrode 25, and the first optical functional layer 26.

[0109] To improve the luminous efficiency of the light-emitting substrate 1100, in some embodiments, as shown in FIG6 , the first substrate 28 may include a reflective layer 281 and a wafer layer 282 stacked in a direction away from the substrate 100. That is, the reflective layer 281 is closer to the substrate 100 than the wafer layer 282, and the wafer layer 282 is located between the first semiconductor layer 21 and the reflective layer 281. The wafer layer 282 may be made of a transparent material to allow light to pass through it. In this way, circularly polarized light reflected by the first optically functional layer 26 and directed toward the substrate 100 can pass through the wafer layer 282 and enter the reflective layer 281, where it is reflected on the surface of the reflective layer 281. The handedness of the circularly polarized light changes after reflection from the reflective layer 281. For example, left-handed circularly polarized light reflects from the reflective layer 281 to become right-handed circularly polarized light, while right-handed circularly polarized light reflects from the reflective layer 281 to become left-handed circularly polarized light. Taking the first optically functional layer 26 as a left-handed cholesteric liquid crystal layer as an example, the left-handed circularly polarized light reflected by the first optically functional layer 26 is reflected by the reflective layer 281 to form right-handed circularly polarized light. This right-handed circularly polarized light is then directed toward the first optically functional layer 26, which is then able to transmit this portion of the right-handed circularly polarized light. In other words, by providing the reflective layer 281, both the left-handed circularly polarized light and the right-handed circularly polarized light emitted by the light-emitting layer 22 can pass through the first optically functional layer 26 with the same handedness, thereby improving the luminous efficiency and brightness of the light-emitting substrate 1100.

[0110] Exemplarily, the material of the wafer layer 282 can be sapphire (aluminum oxide Al2O3), and the material of the reflective layer 281 can be a metal material, such as one or more of a gold layer (Au), a nickel layer (Ni), an aluminum layer (Al) and a titanium layer (Ti). The material of the above-mentioned reflective layer 281 can be applied to any of the following embodiments.

[0111] In other embodiments, referring to FIG9 , the first substrate 28 includes a first substrate 283 and a reflective layer 281 stacked in a direction away from the base 100. Specifically, the reflective layer 281 is closer to the first semiconductor layer than the wafer layer 282 and is located between the first semiconductor layer 21 and the first substrate 283. Light reflected by the first optically functional layer 26 can be directed directly toward the reflective layer 281 without passing through the first substrate 283. This further reduces propagation loss of light reflected by the first optically functional layer 26, thereby improving the light extraction efficiency of the light-emitting element 200 and the luminous efficiency of the light-emitting substrate 1100. The first substrate 283 is located on the side of the reflective layer 281 closer to the base 100. Light reflected by the first optically functional layer 26 does not pass through the first substrate 283. The material of the first substrate 283 can include a transparent material or an opaque material. For example, the first substrate 283 can be a glass substrate or a silicon-based substrate. However, the embodiments of the present disclosure are not limited thereto, and any other suitable substrate material can also be considered for the first substrate 283.

[0112] Referring to FIG. 6 , in some embodiments, the first optically functional layer 26 includes a first portion 261 located on the side of the second semiconductor layer 23 away from the substrate 100, and a second portion 262 disposed around the light-emitting layer 22 and the second semiconductor layer 23. The first portion 261 can transmit at least a portion of the circularly polarized light emitted by the light-emitting layer 22, thereby enabling the light-emitting element 200 to emit circularly polarized light. The second portion 262 not only provides encapsulation for the light-emitting layer 22 and the second semiconductor layer 23, but also transmits a portion of the light emitted by the light-emitting layer 22, allowing some of the light to be dispersed in all directions, thereby improving the viewing angle of the light-emitting element 200.

[0113] For example, as shown in FIG6 , when the first optical functional layer 26 includes only a first portion 261 and a second portion 262, the first portion 261 and the second portion 262 can be formed separately using two processes. For example, the second portion is first formed on the peripheral side of the light-emitting layer 22 and the second semiconductor layer 23, and then the first portion 261 is formed on the side of the second semiconductor layer 23 away from the substrate 100.

[0114] In some embodiments, the texture state of the cholesteric liquid crystal molecules in the first portion 261 can be the same as the texture state of the second portion 262. In this case, as shown in FIG6 , the cholesteric liquid crystal molecules in the first portion 261 and the second portion 262 both include a planar state, so that the first portion 261 can transmit at least a portion of the circularly polarized light emitted by the light-emitting layer.

[0115] In other embodiments, the cholesteric liquid crystal of the first portion 261 is configured to transmit at least a portion of the circularly polarized light emitted by the light-emitting element 200. The second portion 262 is configured to scatter at least a portion of the light emitted by the light-emitting element 200, thereby allowing some of the light to be dispersed in all directions, thereby improving the viewing angle of the light-emitting element 200.

[0116] Exemplarily, the texture state of the cholesteric liquid crystal molecules of the first portion 261 may also be different from the texture state of the second portion 262. Exemplarily, referring to FIG8 , the cholesteric liquid crystal molecules of the first portion 261 include a planar state, so that the first portion 261 can transmit at least part of the circularly polarized light emitted by the light-emitting layer. The cholesteric liquid crystal molecules of the second portion 262 include a focal conic state, so that the light transmitted by the second portion 262 is natural light, and a wire grid layer 33 can be provided on the side of the first optical functional layer 26 away from the substrate 100. The wire grid layer 33 can transmit part of the linearly polarized light of a specific polarization direction in the natural light transmitted by the second portion 262, so that the light emitted by the light-emitting substrate 1100 is all linearly polarized light. The arrangement of the wire grid layer 33 will be described below and will not be described in detail here.

[0117] In other embodiments, referring to FIG. 9 , the first optically functional layer 26 further includes a third portion 263 located on a side of the second portion 262 away from the substrate. The third portion 263 is continuous with the first portion 261. That is, the edge of the first portion 261 contacts the edge of the third portion 263, and there is no gap between the third portion 263 and the first portion 261. The third portion 263 is continuous with the second portion 262. That is, the top of the second portion 262 contacts the bottom of the third portion 263, and there is no gap between the third portion 263 and the first portion 261. In other words, the first portion 261, the second portion 262, and the third portion 263 form a continuous, integral structure. Based on this, the first portion 261, the second portion 262, and the third portion 263 can be integrally manufactured using a simultaneous process, which simplifies the manufacturing process of the first optically functional layer 26 and reduces the manufacturing cost of the first optically functional layer 26.

[0118] Continuing with FIG. 9 , the first optically functional layer 26 includes a first surface 266 distal from the substrate 100 . The first surface 266 is substantially flat and continuous. This ensures that the refraction of light on the first surface 266 is substantially uniform, thereby improving the uniformity of light output from the first optically functional layer 26 . This also significantly reduces light divergence, thereby improving light output brightness at normal viewing angles and reducing the risk of cross-coloring between adjacent light-emitting elements 200 .

[0119] For example, the first optical functional layer 26 can be formed by a curing process of liquid cholesteric liquid crystal, utilizing the flow characteristics of the liquid cholesteric liquid crystal to increase the flatness of the first surface 266. The preparation process of the first optical functional layer 26 is described below and is not described in detail here.

[0120] For example, when the first optical functional layer 26 includes the third portion 263, the texture state of the cholesteric liquid crystal molecules in the third portion 263 is the same as the texture state of the cholesteric liquid crystal molecules in the second portion 262. For example, the cholesteric liquid crystal molecules in the second portion 262 and the third portion 263 are both in a planar state, or the cholesteric liquid crystal molecules in the second portion 262 and the third portion 263 are both in a focal conic state.

[0121] Hereinafter, the embodiment of the present disclosure will be exemplarily described by taking the example that the first optical functional layer 26 includes the first portion 261 , the second portion 262 and the third portion 263 .

[0122] In some embodiments, referring again to FIG. 9 , the light-emitting layer 22 and the second semiconductor layer 23 are arranged in an island-like configuration, comprising a plurality of light-emitting islands 221 and a plurality of second semiconductor islands 231. Each light-emitting island 221 has a second semiconductor island 231 on the side facing away from the substrate 100. The stacked first semiconductor layer 21, a light-emitting island 221, and a second semiconductor island 231 constitute a light-emitting portion 201. In other words, the light-emitting element 200 may include a plurality of spaced-apart light-emitting portions 201, with a light-emitting portion 201 being a minimum light-emitting unit. The second portion 262 of the first optically functional layer 26 also fills between adjacent light-emitting islands 221 and adjacent second semiconductor islands 231. If the first optically functional layer 26 also includes a third portion 263, the third portion 263 is also located between adjacent light-emitting islands 221 and adjacent second semiconductor islands 231.

[0123] For example, in the embodiments of the present disclosure, as shown in FIG9 , the light-emitting layer 22 and the second semiconductor layer 23 are taken as an example to include three light-emitting islands 221 and three second semiconductor islands 231. It can be understood that the number of light-emitting islands 221 and second semiconductor islands 231 included in the light-emitting layer 22 and the second semiconductor layer 23 is not limited to this. For example, the light-emitting layer 22 and the second semiconductor layer 23 can include two, four or any other number of light-emitting islands 221 and second semiconductor islands 231, as long as the same technical idea is adopted.

[0124] It can be understood that, as shown in Figure 9, when the light-emitting element 200 includes a first electrode 24, the first electrode 24 is also distributed in an island shape, and the first electrode 24 may include a plurality of first electrode islands 241. A first electrode island 241 is connected to a second semiconductor island 231 to transmit a voltage signal to the second semiconductor island 231.

[0125] As shown in Figure 9, the first semiconductor layer 21 is continuously distributed, that is, the first semiconductor layers 21 of multiple light-emitting parts 201 are connected to each other. In this way, the first semiconductor layer 21 only needs to be connected to the substrate 100 through one second electrode 25, which is beneficial to reduce the number of second electrodes 25, simplify the structure of the light-emitting element 200, and reduce the difficulty of preparing the light-emitting element 200.

[0126] Alternatively, referring to FIG. 10 , the first semiconductor layer 21 may be distributed in an island shape. In this case, the first semiconductor layer 21 includes multiple first semiconductor islands 211, each of which corresponds to a light-emitting island. The stacked first semiconductor island 211, light-emitting island 221, second semiconductor island 231, and first electrode island 241 constitute a light-emitting portion 201. In this manner, the same or different voltage signals can be applied to the first semiconductor islands 211 of each light-emitting portion 201, thereby enhancing the control flexibility of the light-emitting element 200.

[0127] As shown in Figure 10, when the first semiconductor layer 21 is distributed in an island shape, the first optical functional layer 26 further includes a fourth portion 264 surrounding the first semiconductor islands 211 and located between adjacent first semiconductor islands 211. The fourth portion 264 is continuously distributed with the second portion 262. In other words, the fourth portion 264 is located on the side of the second portion 262 close to the substrate 100, and the top surface of the fourth portion 264 contacts the bottom surface of the second portion 262. The fourth portion 264 and the second portion 262 form a continuous, integrated structure. In this way, there is no need to form an additional cushion layer on the side of the second portion 262 close to the substrate 100. The fourth portion 264 and the second portion 262 are integrally formed, which helps simplify the preparation process of the first optical functional layer 26.

[0128] When the first optical functional layer 26 further includes a fourth portion 264, the texture state of the cholesteric liquid crystal molecules in the fourth portion 264 is the same as the texture state of the cholesteric liquid crystal molecules in the second portion 262. For example, the cholesteric liquid crystal molecules in the second portion 262 and the fourth portion 264 are both in a planar state, or the cholesteric liquid crystal molecules in the second portion 262 and the fourth portion 264 are both in a focal conic state.

[0129] In other embodiments, referring to FIG11 , the first semiconductor layer 21, the light-emitting layer 22, the second semiconductor layer 23, and the first electrode layer 24 of the light-emitting element 200 are all continuously distributed. In other words, the light-emitting element 200 includes only one light-emitting portion 201, and within a light-emitting element 200, the first semiconductor layer 21, the light-emitting layer 22, the second semiconductor layer 23, and the first electrode layer 24 are all continuous structures. In this case, as shown in FIG11 , the second portion 262 of the first optically functional layer 26 is disposed around the light-emitting layer 22 and the second semiconductor layer 23, with a gap between the second portions 262 of adjacent light-emitting elements 200. In other words, the second portions 262 of different light-emitting elements 200 are disposed discontinuously.

[0130] Continuing to refer to Figure 11, the orthographic projections of the light-emitting layer 22, the second semiconductor layer 23 and the first electrode layer 24 on the substrate 100 are located within the range of the orthographic projection of the first semiconductor layer 21 on the substrate 100, and at least a portion of the first semiconductor layer 21 extends beyond the edge of the light-emitting layer 22, so that the second electrode 25 is provided on the portion of the first semiconductor layer 21 extending beyond the edge of the light-emitting layer 22.

[0131] In other embodiments, referring to FIG. 12A , the light-emitting element 200 includes a second electrode layer 29 located on the side of the first semiconductor layer 21 closer to the substrate 100, and the light-emitting element 200 does not include the light-reflecting layer 281 and the wafer layer 282. In other words, the light-emitting element 200 includes the second electrode layer 29, the first semiconductor layer 21, the light-emitting layer 22, the second semiconductor layer 23, the first electrode layer 24, and the first connecting electrode 27, which are arranged in a direction away from the substrate 100. The first optically functional layer 26 covers the first electrode layer 24 and the first connecting electrode 27 and is disposed around the second electrode layer 29, the first semiconductor layer 21, the light-emitting layer 22, the second semiconductor layer 23, and the first electrode layer 24.

[0132] Alternatively, referring to FIG. 12B , the light-emitting element 200 includes a second electrode layer 29 located on the side of the first semiconductor layer 21 closest to the substrate 100, and does not include a reflective layer 281, a wafer layer 282, a first electrode layer 24, or a first connecting electrode 27. In other words, the light-emitting element 200 includes the second electrode layer 29, the first semiconductor layer 21, the light-emitting layer 22, and the second semiconductor layer 23, which are arranged away from the substrate 100. One side of the second semiconductor layer 23 extends beyond the edge of the light-emitting layer 22, and the portion of the second semiconductor layer 23 extending beyond the edge of the light-emitting layer 22 is connected to the metal pad layer 102 of the substrate 100 via a connecting electrode 267. The first optically functional layer 26 covers the surface of the second semiconductor layer 23 away from the substrate 100 and is disposed around the second electrode layer 29, the first semiconductor layer 21, the light-emitting layer 22, the second semiconductor layer 23, and the connecting electrode 267.

[0133] In the embodiment of the present disclosure, the structure of the light emitting element 200 is not limited thereto, and any other suitable type of light emitting element may be considered.

[0134] 12A and 12B , the substrate 100 may include a circuit layer 101 and a metal pad layer 102 disposed on the circuit layer 101. The circuit layer 101 is used to provide a driving circuit and signal traces, and the metal pad layer 102 is disposed on a side of the circuit layer 101 near the light-emitting element 200 for connection to the light-emitting element 200. The second electrode layer 29 and / or the metal pad layer 102 may include a metal material so that the second electrode layer 29 and / or the metal pad layer 102 can reflect light directed toward the substrate 100, thereby improving the luminous efficiency of the light-emitting substrate 1100.

[0135] It is understood that in other embodiments, when the substrate 100 is a transparent substrate (such as a glass substrate), the second electrode layer 29 and the metal pad layer 102 may also be transparent conductive layers. In this case, a reflective layer may be provided inside the substrate 100 or on the side of the substrate 100 away from the light-emitting element 200. Alternatively, a DBR reflective layer may be provided inside the light-emitting element 200. In this case, the DBR reflective layer may, for example, cover at least the sidewalls of the second electrode layer 29, the first semiconductor layer 21, and the light-emitting layer 22. This will not be described in detail in the embodiments of the present disclosure.

[0136] In some embodiments, referring to FIG. 13 , the light-emitting substrate 1100 includes a second optically functional layer 31 located on a side of the first optically functional layer 26 that is distal from the substrate. The second optically functional layer 31 is configured to convert at least a portion of the light (circularly polarized light) transmitted through the first optically functional layer 26 into linearly polarized light. In other words, the second optically functional layer 31, which can also be referred to as a phase retardation plate or a λ / 4 glass plate, is capable of converting circularly polarized light into linearly polarized light. The first optically functional layer 26 and the second optically functional layer 31 work together to convert light emitted by the light-emitting layer 22 into linearly polarized light for output.

[0137] In some embodiments, the material of the second optically functional layer 31 may include a liquid crystal mixture, cyclohexanone, a photopolymerization initiator, etc. Of course, the material of the second optically functional layer 31 is not limited thereto, and any other quarter glass may also be considered. The liquid crystal mixture refers to a mixture containing a plurality of cholesteric liquid crystals with different helical pitches, so that the second optically functional layer 31 can transmit light of various wavelengths.

[0138] As shown in FIG13 , in some embodiments, the second optically functional layer 31 can be integrated into the light-emitting element 200. In this case, the second optically functional layer 31 is disposed on the side of the first optically functional layer 26 away from the substrate 100. For example, the second optically functional layer 31 is disposed on the first surface 266 of the first optically functional layer 26. In this case, the orthographic projection of the second optically functional layer 31 on the substrate 100 is within the range of the orthographic projection of the light-emitting element 200 on the substrate 100, which can significantly reduce the amount of consumables for the second optically functional layer 31 and lower the cost of the second optically functional layer 31. Furthermore, compared to separately preparing the second optically functional layer 31 and then laminating it to the light-emitting element 200, in embodiments of the present disclosure, the second optically functional layer 31 can be integrated into the light-emitting element 200, which helps improve the integration of the light-emitting element 200 and reduces the thickness of the light-emitting substrate 1100.

[0139] Continuing with FIG13 , when the second optically functional layer 31 is disposed on the first surface 266, the second optically functional layer 31 may further include a second via 311, the second via 311 communicating with the first via 265, the first connecting electrode 27 passing through the second via 311 and the first via 265, and electrically connected to the second semiconductor island 231 via the first electrode island 241. In FIG13 , to clearly illustrate the second via 311 and the first via 265, the middle first connecting electrode 27 is omitted from the drawing, but this does not mean that the first connecting electrode 27 is not disposed at that location.

[0140] Referring to FIG. 14 , in some other embodiments, the light-emitting substrate 1100 further includes a second substrate 32, which is located on a side of the first optically functional layer 26 away from the base 100. The second optically functional layer 31 is disposed on the second substrate 32, and the second optically functional layer 31 is closer to the base 100 than the second substrate 32. The second optically functional layer 31 can be connected to the light-emitting element 200 via an adhesive layer 41. The adhesive layer 41 can include a portion located between the light-emitting element 200 and the second optically functional layer 31, as well as a portion (not shown) filling between adjacent light-emitting elements 200.

[0141] That is, during the preparation of the light-emitting substrate 1100, the second optically functional layer 31 can be formed on the second substrate 32, and after the light-emitting element is connected to the base 100, the entirety of the second substrate 32 and the second optically functional layer 31 (the cover plate 300) is bonded to the entirety of the light-emitting element 200 and the base 100 via the adhesive layer 41. The second optically functional layer 31 and the light-emitting element 200 are prepared separately. In this way, the light-emitting element 200 and the second optically functional layer 31 can be prepared simultaneously in different locations, and the preparation is not limited to the second optically functional layer 31 being prepared after the first optically functional layer 26 is completed. This helps to improve the overall preparation efficiency of the light-emitting substrate 1100.

[0142] When the second optically functional layer 31 is disposed on the second substrate 32, the orthographic projection of the second optically functional layer 31 on the base 100 covers the orthographic projection of the light-emitting element 200 on the base 100, and is partially located between adjacent light-emitting elements 200. The area enclosed by the line connecting the outer edges of the outermost plurality of light-emitting elements 200 included in the light-emitting substrate 1100 is defined as the light-emitting area of ​​the light-emitting substrate 1100. The orthographic projection of the second optically functional layer 31 on the base 100 at least covers the light-emitting area.

[0143] In some embodiments, referring to Figures 15 and 16, the light-emitting substrate 1100 also includes a wire grid layer 33 located on the side of the second optical functional layer 31 away from the substrate. The wire grid layer 33 includes a plurality of parallel and spaced wire grids 331. The extension direction of the plurality of wire grids 331 is parallel to the polarization direction of the linearly polarized light after passing through the second optical functional layer 31. In this way, the linearly polarized light after passing through the second optical functional layer 31 can pass through the wire grid layer 33, which is beneficial to improving the polarization degree of the light emitted by the light-emitting substrate 1100.

[0144] For example, when the material of the first optical functional layer 26 is right-handed cholesteric liquid crystal, the optical axis of the second optical functional layer 31 may be 45°, and accordingly, the extension direction of the wire grid 331 may be set to 90°; alternatively, the optical axis of the second optical functional layer 31 may be -45°, and accordingly, the extension direction of the wire grid 331 may be set to 0°. When the material of the first optical functional layer 26 is left-handed cholesteric liquid crystal, the optical axis of the second optical functional layer 31 may be 45°, and accordingly, the extension direction of the wire grid 331 may be set to 0°; alternatively, the optical axis of the second optical functional layer 31 may be -45°, and accordingly, the extension direction of the wire grid 331 may be set to 90°.

[0145] For example, as shown in FIG14 , when the light-emitting substrate 1100 includes a first optical functional layer 26, a second optical functional layer 31, and a wire grid layer 33, the light propagation of the light-emitting element 200 of the present application is exemplified by taking the material of the first optical functional layer 26 as a right-handed cholesteric liquid crystal as an example. The light emitted from the light-emitting layer 22 in a direction away from the substrate 100 includes left-handed circularly polarized light and right-handed circularly polarized light. The left-handed circularly polarized light emitted by the light-emitting layer 22 can pass through the first optical functional layer 26 and be emitted to the second optical functional layer 31. The second optical functional layer 31 converts the left-handed circularly polarized light into linearly polarized light and then emits it to the wire grid layer 33. The wire grid layer 33 can increase the polarization degree of the above-mentioned linearly polarized light and transmit most of the linearly polarized light so that it can be emitted from the light-emitting element 200. The right-handed circularly polarized light emitted by the light-emitting layer 22 is reflected on the first optical functional layer 26, then emitted to one side of the substrate 100 and into the reflective layer 281. The right-handed circularly polarized light is reflected on the reflective layer 281 and converted into left-handed circularly polarized light. The left-handed circularly polarized light is emitted toward the second optically functional layer 31. The second optically functional layer 31 converts the left-handed circularly polarized light into linearly polarized light, which is then emitted toward the wire grid layer 33. The wire grid layer 33 can increase the polarization degree of the linearly polarized light and transmit most of the linearly polarized light so that it can be emitted from the light-emitting element 200. In other words, in the light-emitting element 200 provided by the embodiment of the present disclosure, both the left-handed polarized light and the right-handed circularly polarized light emitted by the light-emitting layer 22 can be emitted from the light-emitting element 200, which is beneficial to improving the luminous efficiency of the light-emitting element 200.

[0146] In some embodiments, referring to Figures 15 and 16 , the wire grid layer 33 can be integrated into the light-emitting element 200, that is, the wire grid layer 33 is provided in the light-emitting element 200, for example, the wire grid layer 33 is directly provided on the surface of the second optical functional layer 31 away from the substrate 100. In this way, the orthographic projection of the wire grid layer 33 on the substrate 100 is located within the range of the orthographic projection of the light-emitting element 200 on the substrate 100, and there is no wire grid layer 33 in the interval between adjacent light-emitting elements 200, which can greatly reduce the amount of consumables of the wire grid layer 33 and reduce the cost of the wire grid layer 33. Moreover, compared with preparing the wire grid layer 33 separately and bonding the wire grid layer 33 to the light-emitting element 200, in the embodiment of the present disclosure, the wire grid layer 33 is integrated into the light-emitting element 200, which is conducive to improving the integration of the light-emitting element 200, reducing the thickness of the light-emitting substrate 1100, and realizing the light-weight and thinning of the light-emitting substrate 1100.

[0147] Referring to FIG. 16 , when the light-emitting substrate 1100 includes a wire grid layer 33, the light-emitting substrate 1100 may further include a protective layer 34. The protective layer 34 is disposed on a side of the wire grid layer 33 away from the substrate 100 and covers the wire grid layer 33. The protective layer 34 is configured to protect the wire grid layer 33 and reduce the risk of wear or other damage to the wire grid layer 33. The surface of the protective layer 34 away from the substrate 100 is a substantially continuous, flat surface. In other words, the protective layer 34 may also serve to flatten the surface of the light-emitting element 200.

[0148] Exemplarily, as shown in Figures 15 and 17A, at least one wire grid 331 of the wire grid layer 33 is electrically connected to the first connecting electrode 27, and at least one wire grid 331 electrically connected to the first connecting electrode 27 is configured to be electrically connected to the circuit layer (TFT) of the substrate 100. That is to say, the at least one wire grid 331 is reused as a metal trace. Along the extension direction of the wire grid 331 (the vertical direction in Figure 15), the size of the first connecting electrode 27 is smaller than the size of the wire grid 331, and the second connecting line 17 is connected to the first connecting electrode 27 through the wire grid 331. On the one hand, it is beneficial to shorten the length of the second connecting line 17 and reduce the consumables of the second connecting line 17. On the other hand, it is beneficial to increase the contact area between the second connecting line 17 and the wire grid 331 and reduce the contact resistance between the second connecting line 17 and the wire grid 331.

[0149] In other embodiments, referring to FIG. 17B , the light-emitting element 200 may not be provided with the first connecting electrode 27. The wire grid 331 passes through the second via 311 and the first via 265 to directly connect to the first electrode island 241, and further to the second semiconductor island 231. In other words, the wire grid 331 can be reused as the first connecting electrode 27. This can effectively simplify the manufacturing process of the light-emitting element 200 and reduce the manufacturing cost of the light-emitting element 200.

[0150] In other embodiments, referring to FIG18 , when the light-emitting substrate 1100 includes a wire grid layer 33, the light-emitting substrate 1100 further includes a second substrate 32 and an adhesive layer 41. The second substrate 32 is located on the side of the wire grid layer 33 away from the substrate 100, and the wire grid layer 33 is arranged on the second substrate 32. The adhesive layer 41 is located between the wire grid layer 33 and the second optical functional layer 31 and is configured to bond the wire grid layer 33 to the second optical functional layer 31. The wire grid layer 33 is electrically insulated from the first connecting electrode 27. The first connecting electrode 27 can be directly connected to the substrate 100 through the second connecting line 17. For example, in the process of preparing the light-emitting substrate 1100, the light-emitting element 200 can be first installed on the substrate 100, and a second connecting line can be formed on the light-emitting element 200 and the substrate 100, and then the wire grid layer 33 and the second substrate 32 can be bonded to the light-emitting element 200.

[0151] When the wire grid layer 33 is provided on the second substrate 32, the orthographic projection of the wire grid layer 33 on the substrate 100 covers the orthographic projection of the light-emitting element 200 on the substrate 100, and is partially located between adjacent light-emitting elements 200. In other words, the wire grid layer 33 can be a continuous whole-layer structure. Among the multiple light-emitting elements 200 included in the light-emitting substrate 1100, the area enclosed by the lines connecting the outer boundaries of the multiple light-emitting elements 200 located at the outermost periphery is the light-emitting area of ​​the light-emitting substrate 1100, and the orthographic projection of the wire grid layer 33 on the substrate 100 at least covers the light-emitting area.

[0152] As shown in Figure 18, when the light-emitting substrate 1100 includes a wire grid layer 33, the light-emitting substrate 1100 may further include a protective layer 34. The protective layer 34 is arranged on the side of the wire grid layer 33 close to the substrate 100 and covers the wire grid layer 33. The protective layer 34 is configured to protect the wire grid layer 33 and reduce the risk of wear or other damage to the wire grid layer 33.

[0153] For example, after the wire grid layer 33 is formed on the second substrate 32, a protective layer 34 is formed on the wire grid layer 33. Then, the whole (cover plate 300) consisting of the second substrate 32, the wire grid layer 33 and the protective layer 34 is connected to the whole consisting of the light emitting element 200 and the base 100 through the adhesive layer 41.

[0154] During the preparation of the light-emitting substrate 1100, a second optically functional layer 31 can be formed on the second substrate 32. After the light-emitting element is connected to the base 100, the second substrate 32, along with the second optically functional layer 31, is bonded (assembled) to the entire assembly consisting of the light-emitting element 200 and the base 100. The second optically functional layer 31 and the light-emitting element 200 are prepared separately. This allows the light-emitting element 200 and the second optically functional layer 31 to be prepared simultaneously in different locations, rather than being limited to preparing the second optically functional layer 31 after completing the first optically functional layer 26. This improves the overall preparation efficiency of the light-emitting substrate 1100.

[0155] In some embodiments, referring to FIG. 19 , when the light-emitting substrate 1100 includes both the second optical functional layer 31 and the wire grid layer 33, the light-emitting substrate 1100 may further include a second substrate 32, which is disposed on a side of the wire grid layer 33 away from the base 100, and both the second optical functional layer 31 and the wire grid layer 33 are disposed on the second substrate 21. It can also be understood that, under the premise that the second optical functional layer 31 is disposed on the second substrate 32, the wire grid layer 33 must also be disposed on the second substrate 32, and the wire grid layer 33 is disposed between the second substrate 32 and the second optical functional layer 31. The light-emitting substrate 1100 may further include a protective layer 34, which is disposed between the wire grid layer 33 and the second optical functional layer 31.

[0156] It is understandable that the above embodiments of the present disclosure are not all embodiments, and the above different embodiments can be implemented in any combination or separately without conflict. The implementation plans formed by splitting and combining the embodiments all fall within the scope of protection of the present disclosure.

[0157] On the other hand, the embodiment of the present disclosure further provides a method for preparing a light-emitting substrate 1100. The method for preparing the light-emitting substrate 1100 may include the following steps S100 to S560.

[0158] Exemplarily, as shown in FIG. 19 , when the light-emitting substrate 1100 includes a first substrate 28 , and the first substrate 28 includes a light-reflecting layer 281 and a wafer layer 282 that are stacked, the method for preparing the light-emitting substrate 1100 includes S100 .

[0159] S100 , referring to FIG. 20 , a light reflecting layer 281 is formed on one side of the wafer layer 282 .

[0160] The material of the wafer layer 282 can be sapphire (aluminum oxide Al2O3). The material of the reflective layer 281 can be a metal material, such as one or more of gold (Au), nickel (Ni), aluminum (Al), and titanium (Ti). The wafer layer 282 and the reflective layer 281 together form the first substrate 28.

[0161] Illustratively, the orthographic projection of the reflective layer 281 on the wafer layer 282 covers the surface of the wafer layer 282. The reflective layer 281 can be formed on one side of the wafer layer 282 by electroplating, sputtering, evaporation or any other process, which is not specifically limited in the embodiments of the present disclosure.

[0162] S110 : Referring to FIG. 21 , an epitaxial layer 20 is grown on the wafer layer 282 .

[0163] For example, an epitaxial layer 20 can be grown on the wafer layer 282 using an epitaxial growth process. As shown in FIG22 , when a reflective layer 281 is formed on one side of the wafer layer 282, the epitaxial layer 20 is grown on the side of the wafer layer 282 away from the reflective layer 281. The epitaxial layer 20 includes a first semiconductor layer 21, a light-emitting layer 22, and a second semiconductor layer 23, which are stacked in sequence in a direction away from the wafer layer 282. The material of the first semiconductor layer 21 can be a P-type semiconductor material, and correspondingly, the material of the second semiconductor layer 23 can be an N-type semiconductor material. Alternatively, the material of the first semiconductor layer 21 can be an N-type semiconductor material, and correspondingly, the material of the second semiconductor layer 23 can be a P-type semiconductor material. The light-emitting layer 22 can be a multi-quantum well layer, and the materials of the first semiconductor layer 21, the light-emitting layer 22, and the second semiconductor layer 23 can all include gallium nitride.

[0164] In some embodiments, the method for preparing the light-emitting substrate 1100 further includes step S111 after the above step S110 .

[0165] S111 , referring to FIG. 22 , a first electrode layer 24 is formed on a side of the epitaxial layer 20 away from the wafer layer 282 .

[0166] For example, the first electrode layer 24 can be formed using processes such as magnetron sputtering and evaporation. Of course, the embodiments of the present disclosure are not limited thereto, and the first electrode layer 24 can also be formed using other processes. The material of the first electrode layer 24 includes a transparent conductive material to allow light to pass through the first electrode layer 24 and be emitted in a direction away from the reflective layer 281. For example, the material of the first electrode layer 24 can be ITO or IZO.

[0167] In all the following embodiments, the light-emitting substrate 1100 including the first electrode layer 24 is used as an example to illustrate the method for preparing the light-emitting substrate of the embodiment of the present disclosure. It is understood that in the following embodiments, different implementations can be obtained by removing the first electrode layer 24.

[0168] In some embodiments, as shown in FIG9 , when the light-emitting substrate 1100 includes a first substrate 28, and the first substrate 28 includes a laminated light-reflecting layer 281 and a first underlayer 283, the method for preparing the light-emitting substrate 1100 does not include the aforementioned step S100, and after the aforementioned step S110 or step S111, the method for preparing the light-emitting substrate 1100 further includes the following steps S112 to S116. In other words, the method for preparing the same light-emitting substrate 1100 includes only one of step S100 and steps S112 to S116.

[0169] S112 , referring to FIG. 23 , a transition substrate 310 is formed on a side of the second semiconductor layer 23 away from the wafer layer 282 .

[0170] As shown in FIG23 , since step S100 is not performed, the side of the wafer layer 282 away from the epitaxial layer 20 lacks the reflective layer 281 . For example, the transition substrate 310 may be a glass substrate, a silicon substrate, or any other suitable substrate. The transition substrate 310 may be bonded to the first electrode layer 24 via an adhesive layer.

[0171] S113 , referring to FIG. 24 , the wafer layer 282 is removed to expose the first semiconductor layer 21 .

[0172] For example, the wafer layer 282 may be removed by a grinding process such as chemical mechanical grinding.

[0173] S114 , referring to FIG. 25 , a light reflecting layer 281 is formed on a side of the first semiconductor layer 21 away from the transition substrate 310 .

[0174] Illustratively, the reflective layer 281 may be formed by magnetron sputtering or evaporation. The material of the reflective layer 281 is as described above and will not be described again here.

[0175] S115 , referring to FIG. 26 , a first substrate 283 is formed on a side of the light reflecting layer 281 away from the transition substrate 310 .

[0176] The light reflecting layer 281 and the first substrate 283 together form the first base plate 28 .

[0177] S116 , referring to FIG. 27 , the transition substrate 310 is removed.

[0178] For example, the transition substrate 310 may be removed by a grinding process.

[0179] In the following embodiments of the present disclosure, the first substrate 28 can be formed by the aforementioned step S100 and including a laminated light-reflecting layer 281 and a wafer layer 282, or formed by the aforementioned steps S112 to S115 and including a laminated first substrate 283 and a light-reflecting layer 281. The embodiments of the present disclosure are not limited to this. The following uses the first substrate 28 formed by the aforementioned step S100 and including a laminated light-reflecting layer 281 and a wafer layer 282 as an example to exemplify the embodiments of the present disclosure.

[0180] After the above step S116 , or after the above step S110 , the method for preparing the light-emitting substrate 1100 further includes steps S120 and S130 .

[0181] S120 : Referring to FIG. 28 , the first electrode layer 24 , the second semiconductor layer 23 and the light emitting layer 22 are patterned to form a first electrode island 241 , a plurality of second semiconductor islands 231 and a plurality of light emitting islands 221 .

[0182] For example, a dry or wet etching process may be used to remove portions of the first electrode layer 24 , the second semiconductor layer 23 and the light emitting layer 22 to complete the patterning of the first electrode layer 24 , the second semiconductor layer 23 and the light emitting layer 22 .

[0183] A light emitting island 221, a second semiconductor island 231 and a first electrode island 241 stacked together form a light emitting portion 201. There is a gap between adjacent light emitting portions 201.

[0184] In some other embodiments, as shown in FIG29 , after patterning the first electrode layer 24, the second semiconductor layer 23, and the light-emitting layer 22 in step S120, the first semiconductor layer 21 may be patterned to form a plurality of first semiconductor islands 211. A stacked first semiconductor island 211, a light-emitting island 221, a second semiconductor island 231, and a first electrode island 241 together constitute a light-emitting portion 201. Adjacent light-emitting portions 201 are spaced apart. The following describes embodiments of the present disclosure using the first semiconductor layer 21 as an example of a continuous, integral layer structure.

[0185] S130 , referring to FIG. 30 to FIG. 34 , a first optical functional layer 26 is formed.

[0186] The first optical functional layer 26 at least includes a first portion 261 located on a side of the second semiconductor island 231 away from the first semiconductor layer 21 (or the first substrate 28 ), and a second portion 262 disposed around the second semiconductor island 231 and the light emitting island 221 .

[0187] For example, when the first optical functional layer 26 includes only the first portion 261 and the second portion 262, the first portion 261 and the second portion 262 can be separately formed through two processes. For example, first, liquid cholesteric liquid crystal is filled and solidified in the gap between the second semiconductor island 231 and the light-emitting island 221 to form the first portion 261. Then, a barrier layer is disposed on the side of the first electrode island 241 and the first portion 261 away from the wafer layer 282. The orthographic projection of the barrier layer on the wafer layer covers the orthographic projection of the first portion on the wafer layer. The barrier layer includes multiple first openings, each first opening exposing one first electrode island 241. Then, the liquid cholesteric liquid crystal can be filled and solidified in the first openings to form the second portion.

[0188] In some embodiments, when the first optical functional layer 26 further includes a third portion 263, the third portion 263 is located on a side of the second portion 262 away from the wafer layer 282, and the third portion 263 is continuously distributed with the first portion 261, and the third portion 263 is continuously distributed with the second portion 262. In this case, the above step S130 of forming the first optical functional layer 26 may include steps S131 and S132.

[0189] S131, referring to FIG. 30, coating liquid cholesteric liquid crystal 260.

[0190] For example, a spin coating process can be used to apply the liquid cholesteric liquid crystal. The liquid cholesteric liquid crystal 260 is filled between adjacent light-emitting islands 221 and between adjacent second semiconductor islands 231. The liquid cholesteric liquid crystal 260 also covers the second semiconductor islands 231 (or covers the first electrode islands 241). The surface of the liquid cholesteric liquid crystal 260 away from the wafer 282 is flat. This facilitates the subsequent formation of a flat first optical functional layer 26.

[0191] S132 , referring to FIG. 31 , or referring to FIG. 32 to FIG. 34 , solidifying the liquid cholesteric liquid crystal to form a first optical functional layer 26 .

[0192] In some embodiments, as shown in FIG31 , all liquid cholesteric liquid crystals can be solidified simultaneously in the same process to form the first optical functional layer 26. In this way, the cholesteric liquid crystals of the first portion 261 and the second portion 262 of the first optical functional layer 26 both include a planar state.

[0193] In other embodiments, referring to FIG. 32 to FIG. 34 , the above-mentioned step S132 may include steps S1321 to S1323 .

[0194] S1321 , referring to FIG. 32 , the light shielding layer 400 is used to expose the first region 2610 of the liquid cholesteric liquid crystal 260 . The orthographic projection of the first region 2610 on the first semiconductor layer 21 coincides with the orthographic projection of the second semiconductor island 231 on the first semiconductor layer 21 .

[0195] S1322 , referring to FIG. 33 , a light curing process is used to cure the first region 2610 of the liquid cholesteric liquid crystal 260 to form a planar first portion 261 .

[0196] S1323 , referring to FIG. 34 , the light shielding layer 400 is removed, and the liquid cholesteric liquid crystal 260 in the remaining area is solidified to form the second portion 262 and the third portion 263 in a focal conic state.

[0197] For example, the liquid cholesteric liquid crystal in the remaining area can be heated (to 140° C.) and then rapidly cooled to form the second portion 262 and the third portion 263 in the focal conic state. The second portion 262, the third portion 263, and the first portion 261 together form the first optical functional layer 26.

[0198] In some embodiments, after step S130, the method for preparing the light-emitting substrate 1100 includes steps S210 to S230. In other embodiments, after step S130, the method for preparing the light-emitting substrate 1100 includes steps S510 to S560. The following describes the method for preparing the light-emitting substrate of the present disclosure, taking the example of the first portion 261, the second portion 262, and the third portion 263 of the first optical functional layer 26 formed in step S130 as examples in which the cholesteric liquid crystals of the first portion 261, the second portion 262, and the third portion 263 all comprise a planar state.

[0199] S210 , referring to FIG. 35 , a second optical function layer 31 is formed on a side of the first optical function layer 26 away from the wafer layer 282 .

[0200] 35 , the second optical functional layer 31 is disposed on the first optical functional layer 26 and covers the first optical functional layer 26. The second optical functional layer 31 is configured to convert at least a portion of light transmitted through the first optical functional layer 26 into linearly polarized light.

[0201] Illustratively, forming the second optical functional layer 31 on the side of the first optical functional layer 26 away from the wafer layer 282 can include spin coating a second optical functional layer material solution on the side of the first optical functional layer 26 away from the wafer layer 282, and curing the second optical functional layer material solution to form the second optical functional layer 31.

[0202] S220 , referring to FIG. 36 , forming a via hole 202 penetrating the second optical function layer 31 and the first optical function layer 26 .

[0203] For example, a photolithography process can be used to form a via 202 that penetrates the second optical functional layer 31 and the first optical functional layer 26. The via 202 includes a second via 311 located in the second optical functional layer 31 and a first via 265 located in the first optical functional layer 26. For example, the second via 311 and the first via 265 are formed simultaneously through a single etching process. The second via 311 and the first via 265 are interconnected, and a smooth transition is formed at the junction of the second via 311 and the first via 265.

[0204] The orthographic projection of the via hole 202 on the wafer layer 282 overlaps with the orthographic projection of the second semiconductor island 231 on the wafer layer 282, so that the first connection electrode 27 subsequently formed in the via hole 202 can be electrically connected to the second semiconductor island 231 (first electrode 241).

[0205] After the above step S220, the method for preparing the light-emitting substrate 1100 further includes step S230. Alternatively, in some other embodiments, after the above step S220, the method for preparing the light-emitting substrate 1100 further includes step S240.

[0206] S230 , referring to FIG. 37 , a first connection electrode 27 is formed in the via hole 202 .

[0207] Illustratively, the first connection electrode 27 may be formed by a film deposition process. The material of the first connection electrode 27 may be, for example, a metal material or a transparent conductive material. The first connection electrode 27 may be electrically connected to the second semiconductor island 231 through the first electrode island 241 .

[0208] S240 , forming a wire grid layer 33 on a side of the second optical function layer 31 away from the wafer layer 282 .

[0209] The wire grid layer 33 includes a plurality of wire grids 331 arranged in parallel and at intervals. At least one wire grid 331 of the wire grid layer 33 is filled in the via hole 202 and is electrically connected to the first electrode island 241 .

[0210] The following describes an exemplary embodiment of the present disclosure, taking the method for preparing the light-emitting substrate 1100 including step S230 as an example. In some embodiments, after step S230, the method for preparing the light-emitting substrate 1100 further includes steps S310 to S330. Alternatively, in other embodiments, after step S230, the method for preparing the light-emitting substrate 1100 further includes steps S410 to S440.

[0211] S310, referring to FIG38, a wire grid layer 33 is formed on the side of the second optical functional layer 31 and the first connection electrode 27 away from the wafer layer 282.

[0212] For example, the wire grid layer 33 can be formed using nanoimprint technology. Forming the wire grid layer 33 using nanoimprint technology may include: forming a continuous metal layer on the surface of the second optically functional layer 31 and the first connection electrode 27 away from the wafer layer 282; forming an imprinted pattern layer on the metal layer using nanoimprint technology; and etching the metal layer according to the imprinted pattern layer to form the wire grid layer. The wire grid layer 33 includes a plurality of parallel and spaced wire grids 331, with at least one wire grid 331 of the wire grid layer 33 being connected to the first connection electrode 27.

[0213] After step S310 , the method for preparing the light-emitting substrate 1100 may further include step S311 .

[0214] S311 , referring to FIG. 39 , a protection layer 34 is formed on a side of the wire grid layer 33 away from the wafer layer 282 .

[0215] For example, the protective layer 34 can be formed by a coating process and a curing process. The material of the protective layer 34 can be, for example, OA glue. The OA glue is first coated on the side of the wire grid layer 33 away from the second substrate 32, and then the OA glue is cured to form the protective layer 34. The protective layer 34 is used to protect the wire grid layer 33 and reduce the risk of wear or other damage to the wire grid layer 33. The surface of the protective layer 34 away from the second substrate 32 is an approximately continuous flat surface, that is, the protective layer 34 can also play the role of flattening the surface of the cover plate 300.

[0216] S320 , referring to FIG. 39 or FIG. 40 , the wafer layer 282 and the epitaxial layer 20 , the first optical function layer 26 , the second optical function layer 31 and the wire grid layer 33 disposed on the wafer layer 282 are cut to form a plurality of light emitting elements 200 .

[0217] The light emitting element 200 includes a stacked wafer layer 282 , a first semiconductor layer 21 , at least one light emitting island 221 and a second semiconductor island 231 , at least one first electrode island 241 , a first optical functional layer 26 , a second optical functional layer 31 and a wire grid layer 33 .

[0218] 39 , the light-emitting element 200 includes a continuously distributed first semiconductor layer 21, three light-emitting islands 221 and three second semiconductor islands 231 disposed on a side of the first semiconductor layer 21 away from the wafer layer 282, and a first optical functional layer 26, a second optical functional layer 31, a wire grid layer 33, and a protective layer 34 disposed on a side of the second semiconductor islands 231 away from the wafer layer 282. Furthermore, in the following embodiments, the light-emitting element shown in FIG. 39 is used as an example to further describe the method for preparing the light-emitting substrate 1100.

[0219] It is understandable that, in some other embodiments, as shown in FIG. 40 , a light-emitting element 200 may also include only one light-emitting island 221 and one second semiconductor island 231 .

[0220] For example, the wafer layer 282 and the epitaxial layer 20 , the first optical function layer 26 , the second optical function layer 31 and the wire grid layer 33 disposed on the wafer layer 282 may be cut by a cutter or a laser.

[0221] S330 , referring to FIG. 41 , a plurality of light emitting elements 200 are connected to the base 100 to form a light emitting substrate 1100 .

[0222] For example, a plurality of light-emitting elements 200 can be transferred and fixed to the substrate 100 using mass transfer technology. The light-emitting elements 200 can be connected and fixed to the substrate 100 in a positive manner. For example, after the plurality of light-emitting elements 200 are fixedly connected to the substrate 100, a sputtering process and an etching process can be used to form first and second connecting wires on the surfaces of the light-emitting elements 200 and the substrate 100, and the light-emitting elements 200 are electrically connected to the substrate 100 through the first and second connecting wires.

[0223] In some other embodiments, after the above step S230 , the method for preparing the light-emitting substrate 1100 further includes steps S410 to S440 .

[0224] S410 , referring to FIG. 42 , the wafer layer 282 and the epitaxial layer 20 , the first optical function layer 26 , and the second optical function layer 31 disposed on the wafer layer 282 are cut to form a plurality of light emitting elements 200 .

[0225] FIG42 only illustrates one light-emitting element 200. As shown in FIG42 , the light-emitting element 200 includes a continuously distributed first semiconductor layer 21, three light-emitting islands 221 and three second semiconductor islands 231 disposed on the side of the first semiconductor layer 21 away from the wafer layer 282, and a first optical functional layer 26, a second optical functional layer 31, a wire grid layer 33, and a protective layer 34 disposed on the side of the second semiconductor islands 231 away from the wafer layer 282. In actual production, multiple light-emitting elements 200 can be prepared on a wafer layer at one time, and the multiple light-emitting elements 200 are cut to form individual independent light-emitting elements.

[0226] Compared with the above embodiment (steps S310 to S330), the wire grid layer 33 of this embodiment is not directly formed on the light-emitting element 200, that is, the light-emitting element 200 does not include the wire grid layer 33. At this time, the light-emitting element 200 includes a stacked wafer layer 282, at least one light-emitting island 221 and a second semiconductor island layer 231, at least one first electrode island 241, a first optical functional layer 26, and a second optical functional layer 31.

[0227] For example, the wafer layer 282 and the epitaxial layer 20 , the first optical function layer 26 and the second optical function layer 31 disposed on the wafer layer 282 may be cut by a cutter or a laser.

[0228] S420 , referring to FIG. 43 , the light emitting element 200 is connected to the base 100 to form a first light emitting substrate 210 .

[0229] For example, a plurality of light-emitting elements 200 can be transferred and fixed on the substrate 100 by mass transfer technology. The light-emitting element 200 can be connected and fixed to the substrate 100 in a positive manner. For example, after the plurality of light-emitting elements 200 are fixedly connected to the substrate 100, a first connecting wire and a second connecting wire can be formed on the surface of the light-emitting element 200 and the substrate 100 by a sputtering process and an etching process, and the light-emitting element 200 is electrically connected to the substrate 100 through the first connecting wire and the second connecting wire. Among them, the first connecting electrode 27 of the light-emitting element 200 is connected to the substrate 100 through the second connecting wire 17 (as shown in Figure 17A).

[0230] S430 , referring to FIG. 44 to FIG. 46 , prepare the cover plate 300 .

[0231] In some embodiments, S430 of preparing the cover plate 300 may include steps S431 to S433 .

[0232] S431 , referring to FIG. 44 , a wire grid metal layer 330 is deposited on the second substrate 32 .

[0233] For example, the wire grid metal layer 330 may be formed on the second substrate 32 by a process such as sputtering or evaporation, and the wire grid metal layer 330 is a continuous whole layer structure.

[0234] S432 , referring to FIG. 45 , patterning the wire grid metal layer 330 to form a wire grid layer 33 .

[0235] For example, nano-imprinting technology may be used to pattern the wire grid metal layer 330. The wire grid layer 33 includes a plurality of wire grids 331 that are arranged in parallel and at intervals.

[0236] S433 , referring to FIG. 46 , a protection layer 34 is formed on a side of the wire grid layer 33 away from the second substrate 32 .

[0237] For example, the protective layer 34 can be formed by a coating process and a curing process. The material of the protective layer 34 can be, for example, OA glue. The OA glue is first coated on the side of the wire grid layer 33 away from the second substrate 32, and then the OA glue is cured to form the protective layer 34. The protective layer 34 is used to protect the wire grid layer 33 and reduce the risk of wear or other damage to the wire grid layer 33. The surface of the protective layer 34 away from the second substrate 32 is an approximately continuous flat surface, that is, the protective layer 34 can also play the role of flattening the surface of the cover plate 300.

[0238] It is understood that the above steps S430 to S433 can be performed independently from the above steps (eg, S100 to S330) and are not affected by the order of the processes. In other words, the cover plate 300 and the first light-emitting substrate 210 can be manufactured independently.

[0239] S440 , referring to FIG. 47 , the cover plate 300 and the first light-emitting substrate 210 are bonded together using the adhesive layer 41 to form the light-emitting substrate 1100 .

[0240] Among them, the wire grid layer 33 of the cover plate 300 is closer to the second optical functional layer 31 of the first light-emitting substrate 210 than the second substrate 32, and the multiple wire grids 331 of the wire grid layer 33 and the first connecting electrode 27 of the first light-emitting substrate 210 include at least an adhesive layer 41, that is, the multiple wire grids 331 are electrically insulated from the first connecting electrode 27.

[0241] In other embodiments, referring to FIG. 48 to FIG. 52 , after the above step S130 , the method for preparing the light-emitting substrate 110 further includes steps S510 to S560 .

[0242] S510 , referring to FIG. 48 , forming a first via hole 265 penetrating the first optical function layer 26 .

[0243] For example, the first via hole 265 can be formed by an etching process. The orthographic projection of the first via hole 265 on the wafer layer 282 overlaps with the orthographic projection of the second semiconductor island 231 on the wafer layer 282. For example, the first via hole 265 exposes a portion of the first electrode island 241.

[0244] S520 , referring to FIG. 49 , a first connecting electrode 27 is formed in the first via hole 265 . The first connecting electrode 27 is electrically connected to the second semiconductor island 231 through the first electrode island 241 .

[0245] Illustratively, the first connection electrode 27 may be formed by a film deposition process. The material of the first connection electrode 27 may be, for example, a metal material or a transparent conductive material. The first connection electrode 27 may be electrically connected to the second semiconductor island 231 through the first electrode island 241 .

[0246] S530 , cutting the wafer layer 282 and the epitaxial layer 20 and the first optical function layer 26 disposed on the wafer layer 282 to form a plurality of light emitting elements 200 .

[0247] Figure 49 illustrates only one example of a light-emitting element 200. The structure of the light-emitting element obtained by cutting in step S530 can be seen in Figure 49. The light-emitting element 200 includes a continuously distributed first semiconductor layer 21, three light-emitting islands 221 and three second semiconductor islands 231 disposed on a side of the first semiconductor layer 21 away from the wafer layer 282, and a first optically functional layer 26 and a first connecting electrode 27 disposed on a side of the second semiconductor islands 231 away from the wafer layer 282.

[0248] For example, the wafer layer 282 and the epitaxial layer 20 disposed on the wafer layer 282 can be cut by a cutter or laser. The difference from the aforementioned steps (S310 and S320) is that the light-emitting element 200 formed in this embodiment does not include the second optical functional layer 31, and the second optical functional layer 31 can be formed on the cover plate 300. The light-emitting element 200 includes a stacked wafer layer 282, at least one light-emitting island 221 and a second semiconductor island 231, and a first optical functional layer 26.

[0249] S540 , referring to FIG. 50 , the light emitting element 200 is connected to the base 100 to form a second light emitting substrate 220 .

[0250] For example, a plurality of light-emitting elements 200 can be transferred and fixed on the substrate 100 by mass transfer technology. The light-emitting element 200 can be connected and fixed to the substrate 100 in a formal manner. For example, after the plurality of light-emitting elements 200 are fixedly connected to the substrate 100, a first connecting wire and a second connecting wire can be formed on the surface of the light-emitting element 200 and the substrate 100 by a sputtering process and an etching process, and the light-emitting element 200 is electrically connected to the substrate 100 through the first connecting wire and the second connecting wire. Among them, the first connecting electrode 27 of the light-emitting element 200 is connected to the substrate 100 through the second connecting wire 17 (as shown in Figure 7).

[0251] S550 , referring to FIG. 51 , prepare the cover plate 300 .

[0252] In some embodiments, S550 preparing the cover plate 300 may include steps S551 to S554.

[0253] S551 , depositing a wire grid metal layer 330 on the second substrate 32 .

[0254] For example, the wire grid metal layer 330 may be formed on the second substrate 32 by a process such as sputtering or evaporation, and the wire grid metal layer 330 is a continuous whole layer structure.

[0255] S552 , patterning the wire grid metal layer 330 to form a wire grid layer 33 .

[0256] For example, nano-imprinting technology may be used to pattern the wire grid metal layer 330. The wire grid layer 33 includes a plurality of wire grids 331 that are arranged in parallel and at intervals.

[0257] S553 , forming a protection layer 34 on a side of the wire grid layer 33 away from the second substrate 32 .

[0258] For example, the protective layer 34 can be formed by a coating process and a curing process. The material of the protective layer 34 can be, for example, OA glue. The OA glue is first coated on the side of the wire grid layer 33 away from the second substrate 32, and then the OA glue is cured to form the protective layer 34. The protective layer 34 is used to protect the wire grid layer 33 and reduce the risk of wear or other damage to the wire grid layer 33. The surface of the protective layer 34 away from the second substrate 32 is an approximately continuous flat surface, that is, the protective layer 34 can also play the role of flattening the surface of the cover plate 300.

[0259] S554 , forming a second optical function layer 31 on a side of the protective layer 34 away from the second substrate 32 .

[0260] The second optical functional layer 31 is configured to convert at least a portion of light transmitted through the first optical functional layer into linearly polarized light.

[0261] S560 , referring to FIG. 52 , the cover plate 300 and the second light-emitting substrate 220 are bonded together using the adhesive layer 41 to form the light-emitting substrate 1100 .

[0262] The second optical function layer 31 of the cover plate 300 is closer to the first optical function layer 26 than the second substrate 32 , and the second optical function layer 31 of the cover plate 300 is disposed opposite to the first optical function layer 26 of the second light-emitting substrate 220 .

[0263] The above description is merely a specific embodiment of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Any changes or substitutions that a person skilled in the art can conceive within the technical scope disclosed in the present disclosure should be included within the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection of the claims.

Claims

1. A light-emitting substrate comprising a base and a light-emitting element disposed on the base; the light-emitting element comprises a first semiconductor layer, a light-emitting layer, a second semiconductor layer stacked in a direction away from the base, and a first optical functional layer configured to transmit at least a portion of circularly polarized light emitted by the light-emitting element; in, The first optical functional layer includes a first portion located on a side of the second semiconductor layer away from the substrate, and a second portion disposed around the light emitting layer and the second semiconductor layer.

2. The light-emitting substrate according to claim 1, wherein The first optical functional layer further includes a third portion located on a side of the second portion away from the substrate. The third portion is continuously distributed with the first portion, and the third portion is also continuously distributed with the second portion.

3. The light-emitting substrate according to claim 2, wherein The first optical functional layer includes a first surface away from the substrate, and the first surface is approximately a flat and continuous surface.

4. The light-emitting substrate according to any one of claims 1 to 3, wherein The light-emitting layer and the second semiconductor layer are distributed in an island shape, with a plurality of light-emitting islands and a plurality of second semiconductor islands, and the first semiconductor layer is distributed continuously or in an island shape; The second portion is also filled between adjacent light emitting islands and adjacent second semiconductor islands.

5. The light-emitting substrate according to claim 4, wherein The first semiconductor layer is distributed in an island shape and has a plurality of first semiconductor islands. The first optical functional layer further includes a fourth portion surrounding the first semiconductor islands and located between adjacent first semiconductor islands. The fourth portion is continuously distributed with the second portion.

6. The light-emitting substrate according to any one of claims 1 to 5, wherein The material of the first optical functional layer includes cholesteric liquid crystal.

7. The light-emitting substrate according to claim 6, wherein The first portion is configured to transmit at least a portion of the circularly polarized light emitted by the light-emitting element; and the second portion is configured to scatter at least a portion of the light emitted by the light-emitting element.

8. The light-emitting substrate according to claim 7, wherein The cholesteric liquid crystal of the first portion includes a planar state; and the cholesteric liquid crystal of the second portion includes a focal conic state.

9. The light-emitting substrate according to any one of claims 1 to 8, wherein The first optical functional layer includes a first via hole, and an orthographic projection of the first via hole on the substrate overlaps with the second semiconductor layer; The light emitting substrate includes a first connecting electrode, and the first connecting electrode is electrically connected to the second semiconductor layer through the first via hole.

10. The light emitting substrate according to claim 5, wherein The light emitting element includes a first electrode located on a side of the second semiconductor island close to the substrate, and the second semiconductor island is electrically connected to the first electrode.

11. The light-emitting substrate according to any one of claims 1 to 10, wherein The light-emitting substrate includes a second optical functional layer located on a side of the first optical functional layer away from the base, and the second optical functional layer is configured to convert at least a portion of light transmitted through the first optical functional layer into linearly polarized light.

12. The light-emitting substrate according to claim 11, wherein The material of the second optical functional layer includes a liquid crystal mixture, cyclohexanone and a photopolymerization initiator.

13. The light-emitting substrate according to claim 11 or 12, wherein The first optical functional layer includes a first via hole, and an orthographic projection of the first via hole on the substrate overlaps with the second semiconductor layer; The second optical function layer includes a second via hole, and the second via hole is connected to the first via hole; The light emitting substrate includes a first connecting electrode, and the first connecting electrode is electrically connected to the second semiconductor layer through the second via hole and the first via hole. The light-emitting substrate according to claim 13 , wherein: The light-emitting substrate also includes a wire grid layer located on the side of the second optical functional layer away from the base, the wire grid layer includes a plurality of parallel and spaced wire grids, and the extension direction of the plurality of wire grids is parallel to the polarization direction of the polarized light after passing through the second optical functional layer.

15. The light-emitting substrate according to claim 14, wherein The substrate includes a circuit layer; at least one wire grid of the wire grid layer is electrically connected to the first connection electrode, and at least one wire grid electrically connected to the first connection electrode is configured to be connected to the circuit layer of the substrate.

16. The light-emitting substrate according to claim 14, wherein The light-emitting substrate further includes: a second substrate, located on a side of the wire grid layer away from the base, the wire grid layer being disposed on the second substrate and electrically insulated from the first connecting electrode; The bonding layer is located between the wire grid layer and the second optical functional layer, and is configured to bond the wire grid layer and the second optical functional layer.

17. The light-emitting substrate according to claim 11 or 12, wherein The light-emitting substrate further includes: a second substrate, located on a side of the second optical functional layer away from the base, wherein the second optical functional layer is disposed on the second substrate; The adhesive layer is located between the second optical functional layer and the second optical functional layer, and is configured to adhere the first optical functional layer and the second optical functional layer.

18. The light-emitting substrate according to claim 17, wherein The light-emitting substrate further includes: The wire grid layer is arranged between the second substrate and the second optical functional layer, and includes a plurality of wire grids arranged in parallel and at intervals. The extension direction of the plurality of wire grids is parallel to the polarization direction of the polarized light after passing through the second optical functional layer.

19. The light emitting substrate according to any one of claims 1 to 18, wherein The light emitting element further comprises a first substrate located on a side of the first semiconductor layer close to the base; the first substrate comprises a reflective layer and a wafer layer stacked in a direction away from the base, and the wafer layer is made of a transparent material.

20. The light emitting substrate according to any one of claims 1 to 18, wherein The light emitting element further comprises a first substrate located on a side of the first semiconductor layer close to the base; the first substrate comprises a first underlayer and a reflective layer stacked in a direction away from the base, and the material of the first substrate comprises a transparent material or an opaque material.

21. A method for preparing a light-emitting substrate, comprising: Growing an epitaxial layer on the wafer layer, wherein the epitaxial layer includes a first semiconductor layer, a light-emitting layer, and a second semiconductor layer stacked in sequence; patterning the second semiconductor layer and the light-emitting layer to form a plurality of second semiconductor islands and a plurality of light-emitting islands; A first optical functional layer is formed; the first optical functional layer includes a first portion located on a side of the second semiconductor island away from the first semiconductor layer, and a second portion arranged around the second semiconductor island and the light emitting island.

22. The preparation method according to claim 21, wherein The forming of the first optical functional layer comprises: Coating liquid cholesteric liquid crystal; the liquid cholesteric liquid crystal is filled between adjacent light-emitting islands and between adjacent second semiconductor islands, covering the second semiconductor islands, and the surface of the liquid cholesteric liquid crystal away from the wafer layer is a flat surface; The liquid cholesteric liquid crystal is solidified to form the first optical functional layer.

23. The preparation method according to claim 22, wherein The solidifying of the cholesteric liquid crystal to form the first optical functional layer comprises: A light shielding layer is used to shield a first region of the liquid cholesteric liquid crystal, wherein an orthographic projection of the first region on the first semiconductor layer covers intervals between the plurality of second semiconductor islands and has no overlap with the second semiconductor islands; curing the area of the liquid cholesteric liquid crystal exposed by the first area using a light curing process to form a first portion in a planar state; The light shielding layer is removed, and the liquid cholesteric liquid crystal in the remaining area is solidified to form a second portion and a third portion in a focal conic state. The second portion, the third portion and the first portion together form the first optical functional layer.

24. The preparation method according to any one of claims 21 to 23, wherein After forming the first optical functional layer, the method further includes: forming a second optical functional layer on a side of the first optical functional layer away from the wafer layer, wherein the second optical functional layer is configured to convert at least a portion of light transmitted through the first optical functional layer into linearly polarized light; forming a via hole penetrating the second optical functional layer and the first optical functional layer, wherein an orthographic projection of the via hole on the wafer layer overlaps with an orthographic projection of the second semiconductor island on the wafer layer; A first connecting electrode is formed in the via hole; the first connecting electrode is connected to the second semiconductor island.

25. The preparation method according to claim 24, wherein After forming the first connecting electrode in the via hole, the preparation method further includes: A wire grid layer is formed on a side of the second optical functional layer and the first connecting electrode away from the wafer layer; the wire grid layer includes a plurality of wire grids arranged in parallel and at intervals, and at least one wire grid of the wire grid layer is connected to the first connecting electrode.

26. The preparation method according to claim 25, wherein After forming a wire grid layer on a side of the second optical functional layer and the first connecting electrode away from the wafer layer, the preparation method further includes: Cutting the wafer layer and the epitaxial layer, the first optical functional layer, the second optical functional layer and the wire grid layer disposed on the wafer layer to form a plurality of light-emitting elements, wherein the light-emitting elements include a stacked wafer layer, a first semiconductor layer, at least one light-emitting island and a second semiconductor island, a first optical functional layer, a second optical functional layer and a wire grid layer; A plurality of light-emitting elements are connected to a base to form the light-emitting substrate.

27. The preparation method according to claim 24, wherein After forming the first connecting electrode in the via hole, the preparation method further includes: Cutting the wafer layer and the epitaxial layer, the first optical functional layer, and the second optical functional layer disposed on the wafer layer to form a plurality of light-emitting elements, wherein the light-emitting elements include a stacked wafer layer, at least one light-emitting island and a second semiconductor island layer, a first optical functional layer, and a second optical functional layer; The light-emitting element is connected to the base to form a first light-emitting substrate; wherein the first connecting electrode is connected to the base.

28. The preparation method according to claim 27, further comprising: Prepare a cover plate, the cover plate comprising a wire grid layer provided on a second substrate; the wire grid layer comprising a plurality of wire grids provided in parallel and at intervals; The cover plate is bonded to the first light-emitting substrate using an adhesive layer to form a light-emitting substrate; wherein the wire grid layer of the cover plate is closer to the second optical functional layer of the first light-emitting substrate than the second substrate, and the multiple wire grids of the wire grid layer are electrically insulated from the first connecting electrode of the first light-emitting substrate.

29. The preparation method according to any one of claims 21 to 23, wherein After forming the first optical functional layer, the method further includes: forming a first via hole penetrating the first optical functional layer, wherein an orthographic projection of the first via hole on the wafer layer overlaps with an orthographic projection of the second semiconductor island on the wafer layer; forming a first connecting electrode in the via hole, wherein the first connecting electrode is electrically connected to the second semiconductor island; Cutting the wafer layer and the epitaxial layer and the first optical functional layer disposed on the wafer layer to form a plurality of light-emitting elements, wherein the light-emitting elements include stacked wafer layers, at least one light-emitting island and a second semiconductor island, and the first optical functional layer; The light-emitting element is connected to a base to form a second light-emitting substrate.

30. The preparation method according to claim 29, wherein The preparation method further comprises: A cover plate is prepared, the cover plate comprising a second substrate and a wire grid layer and a second optical functional layer sequentially stacked on the second substrate; the wire grid layer comprises a plurality of wire grids arranged in parallel and spaced apart, and the second optical functional layer is configured to convert at least a portion of light transmitted through the first optical functional layer into linearly polarized light; The cover plate and the second light-emitting substrate are bonded together using an adhesive layer to form the light-emitting substrate; wherein the cover plate The second optical function layer of the plate is arranged opposite to the first optical function layer of the second light-emitting substrate.

31. The preparation method according to any one of claims 21 to 30, wherein After growing the epitaxial layer on the wafer layer and before patterning the second semiconductor layer and the light-emitting layer, the preparation method further includes: forming a transition substrate on a side of the second semiconductor layer away from the wafer layer; removing the wafer layer to expose the first semiconductor layer; forming a light reflecting layer on a side of the first semiconductor layer away from the transition substrate; forming a first substrate on a side of the light reflecting layer away from the transition substrate; The transition substrate is removed.

32. The preparation method according to any one of claims 21 to 30, further comprising: forming a reflective layer on one side of the wafer layer; The light emitting layer and the epitaxial layer are respectively located on two sides of the wafer layer.

33. A display device comprising a liquid crystal display panel and the light-emitting substrate according to any one of claims 1 to 20; the liquid crystal display panel is arranged on the light-emitting side of the light-emitting substrate.

34. A display substrate comprising a color conversion layer and the light-emitting substrate according to any one of claims 1 to 20; the color conversion layer is located on the light-emitting side of the light-emitting substrate.

35. The display substrate according to claim 34, wherein the color conversion layer comprises a dam layer and a plurality of color conversion portions, the dam layer having a plurality of openings, and the color conversion portions are located in the openings; The plurality of color conversion portions include a first color conversion portion, a second color conversion portion, and a third color conversion portion, each of which is located in a different opening; wherein, The first color conversion unit converts the light into red light, the second color conversion unit converts the light into green light, and the third color conversion unit maintains or converts the light into blue light.

36. A display device comprising: A display substrate as described in claim 34 or 35, and a first polarizer, a semi-transmissive and semi-reflective film, a first lens, a second polarizer, a reflective polarizer and a second lens stacked in sequence on the light-emitting side of the display substrate.

Images