Stacked display unit and manufacturing method therefor

Abstract

A stacked display unit and a manufacturing method therefor. The stacked display unit comprises: a driving backplane, provided with a pixel driving array; a pixel layer, comprising a plurality of sub-pixel layers stacked on one pixel region of the driving backplane, wherein the sub-pixel layers comprise sub-pixel units, the sub-pixel units are electrically connected to the pixel driving array, the orthographic projections of the sub-pixel units on the driving backplane do not overlap with each other, and the sub-pixel units in different layers emit light of different colors; and a light reflecting structure, formed in the pixel layer and configured to reflect lateral light emitted from the sub-pixel units, so that the light emitted from the sub-pixel units is directed toward a side away from the driving backplane.

Description

Stacked display unit and its fabrication method

[0001] Cross-reference to related applications

[0002] This application is based on and claims priority to Chinese Patent Application No. 202411854986.9, filed on December 16, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of display technology, and in particular to a stacked display unit and its fabrication method. Background Technology

[0004] Micro-LED (micro-light-emitting diode) display technology has garnered attention for its high brightness, low power consumption, fast response time, and long lifespan, and is considered key to next-generation display technology, particularly in wearable devices, smartphones, televisions, and virtual reality. However, traditional micro-LED display technology requires the horizontal placement of red, green, and blue (RGB) sub-pixels at each pixel point when manufacturing full-color display panels. This leads to a significant increase in manufacturing difficulty and cost in high-pixel-density applications.

[0005] Currently, most Micro-LEDs use a stacked full-color structure to increase pixel density, but the traditional stacked structure is not conducive to bottom light emission, which weakens the light emission reaching the upper surface. Summary of the Invention

[0006] This application aims to at least solve one of the technical problems existing in the prior art. To this end, this application proposes a stacked display unit and its fabrication method, wherein the stacked sub-pixel units do not block each other in the light emission direction, and the lateral light emission is reflected upward through a reflective structure, thereby improving the light emission of the stacked full-color structure.

[0007] In a first aspect, this application provides a stacked display unit, the stacked display unit comprising:

[0008] The driving backplane is equipped with a pixel driving array;

[0009] A pixel layer includes multiple sub-pixel layers stacked on a pixel region of a driving backplane. Each sub-pixel layer includes sub-pixel units, each sub-pixel unit is electrically connected to the pixel driving array, and the orthographic projections of each sub-pixel unit on the driving backplane do not overlap. Sub-pixel units in different layers emit different colors of light.

[0010] The reflective structure is formed within the pixel layer and is used to reflect the lateral light emitted by each sub-pixel unit, so that the light emitted by each sub-pixel unit is emitted toward the side away from the driving backplate.

[0011] According to one embodiment of this application, the reflective structure includes:

[0012] The first reflective cup structure is disposed in each sub-pixel layer, and each first reflective cup structure surrounds the sub-pixel unit in the sub-pixel layer.

[0013] According to one embodiment of this application, the number of first reflector structures in each sub-pixel layer is one. Each first reflector structure surrounds all sub-pixel units in its sub-pixel layer. The orthographic projection of each first reflector structure on the driving backplate surrounds the orthographic projection of all sub-pixel units in each sub-pixel layer on the driving backplate. The centers of the orthographic projection patterns of each first reflector structure on the driving backplate coincide. The area surrounded by each first reflector structure gradually increases in the direction away from the driving backplate.

[0014] According to one embodiment of this application, the number of first reflector cup structures in each sub-pixel layer is the same as the number of sub-pixel units in the same sub-pixel layer, each first reflector cup structure surrounds one sub-pixel unit in the same sub-pixel layer, and the orthographic projections of each first reflector cup structure on the driving backplate do not overlap.

[0015] The reflective structure also includes:

[0016] The second reflector structure is disposed within the sub-pixel layer. The number of second reflector structures in each sub-pixel layer is equal to the sum of the number of sub-pixel units below the sub-pixel layer. The orthographic projection of the second reflector structure on the driving backplate surrounds the orthographic projection of the corresponding sub-pixel unit below the sub-pixel layer on the driving backplate. The orthographic projections of the second reflector structures in the same sub-pixel layer on the driving backplate do not overlap.

[0017] According to one embodiment of this application, the number of first reflector structures in each sub-pixel layer is one, each first reflector structure encloses all sub-pixel units in the sub-pixel layer, and the orthographic projections of each first reflector structure on the driving backplate do not overlap.

[0018] The reflective structure also includes:

[0019] The second reflector structure is disposed in the sub-pixel layer. The number of second reflector structures in each sub-pixel layer is equal to the sum of the number of sub-pixel layers below this sub-pixel layer. The orthographic projection of the second reflector structure on the driving backplane surrounds the orthographic projection of all sub-pixel units in the corresponding sub-pixel layer below this sub-pixel layer on the driving backplane. The orthographic projections of the second reflector structures in the same sub-pixel layer on the driving backplane do not overlap.

[0020] According to one embodiment of this application, the subpixel layer closest to the driving backplane includes a plurality of subpixel units.

[0021] According to one embodiment of this application, the pixel layer includes a first sub-pixel layer, a second sub-pixel layer, and a third sub-pixel layer along the drive backplane. The first sub-pixel layer includes two red sub-pixel units, the second sub-pixel layer includes one green sub-pixel unit, and the third sub-pixel layer includes a blue sub-pixel unit.

[0022] According to one embodiment of this application, the stacked display unit further includes:

[0023] An N-electrode unit is formed within the pixel layer and connected to each sub-pixel unit; or,

[0024] Multiple N-electrode units are formed within the pixel layer, and each sub-pixel unit within the sub-pixel layer is connected to an independent N-electrode unit.

[0025] According to one embodiment of this application, a transparent electrode layer is disposed on the side of each sub-pixel layer away from the driving backplane. The transparent electrode layer is connected to the sub-pixel unit in each sub-pixel layer and to the corresponding N electrode unit.

[0026] According to one embodiment of this application, a transparent electrode layer and a metal electrode layer are disposed on the side of each sub-pixel layer away from the driving backplane. The transparent electrode layer is connected to the sub-pixel unit in each sub-pixel layer, and the metal electrode layer is connected to the corresponding N electrode unit.

[0027] In this configuration, the orthographic projections of each metal electrode layer onto the drive backplate do not overlap.

[0028] According to one embodiment of this application, the stacked display unit further includes:

[0029] The lens unit is located on the side of the pixel layer away from the driving backplate and is used to collimate the light emitted from the pixel layer.

[0030] According to one embodiment of this application, the lens unit includes:

[0031] A lens, the orthographic projection of which onto the driving backplane covers the orthographic projection of each sub-pixel unit onto the driving backplane; or,

[0032] Multiple lenses, the orthographic projection of each lens onto the driving backplane covers the orthographic projection of a sub-pixel unit onto the driving backplane;

[0033] The lens is either a superlens or a microlens.

[0034] According to one embodiment of this application, the orthographic projections of each sub-pixel unit on the driving backplane are uniformly arranged around the center of each pixel region and are adjacent to each other.

[0035] According to one embodiment of this application, adjacent sub-pixel layers are connected by a hybrid bonding layer.

[0036] According to one embodiment of this application, each sub-pixel layer has a wavelength-selective light reflection layer on the side facing the driving backplane. The wavelength-selective light reflection layer is used to reflect the downward light emission of the upper sub-pixel and allows the upward light emission of the lower sub-pixel to pass through.

[0037] Secondly, this application provides a method for fabricating a stacked display unit, the method comprising:

[0038] A driver backplane is provided, which has a pixel driver array.

[0039] The sub-pixel layer is fabricated by sequentially forming a sub-pixel unit, a PV layer, a planarization layer, and a first electrode on a substrate. A reflective cup structure surrounding the sub-pixel unit is formed within the planarization layer.

[0040] Multiple subpixel layers are stacked on the pixel area of ​​the driving backplane, so that each subpixel unit is connected to the pixel driving array. The subpixel units in each subpixel layer emit different colors of light, and the orthographic projections of each subpixel unit on the driving backplane do not overlap.

[0041] According to one embodiment of this application, the fabrication process of the sub-pixel layer further includes fabricating a first hybrid bonding layer on the side of the planarization layer away from the substrate; and,

[0042] After the sub-pixel layer is bonded by the first hybrid bonding layer, the substrate is removed and the second electrode is prepared, or the second electrode and the second hybrid bonding layer are prepared sequentially.

[0043] According to one embodiment of this application, the fabrication process of the second electrode includes:

[0044] A transparent electrode layer, formed on one side of the PV layer using a transparent material, is connected to the N-electrode of the sub-pixel unit. This transparent electrode layer forms a second electrode for connecting the N-electrode unit; or...

[0045] A transparent electrode layer connected to the N-electrode of the sub-pixel unit is formed on one side of the PV layer using a transparent material, and a metal electrode layer connected to the transparent electrode layer is formed on one side of the PV layer using a metal material. The transparent electrode layer and the metal electrode layer form a second electrode for connecting the N-electrode unit.

[0046] According to one embodiment of this application, the fabrication process of the sub-pixel layer further includes forming one or more N-electrode sub-units in the planarization layer and the PV layer;

[0047] After the sub-pixel layers are stacked, each N-electrode sub-unit is connected to form one or more N-electrode units, and the N-electrode units are connected to the second electrode.

[0048] According to one embodiment of this application, the fabrication process of the sub-pixel layer further includes forming a light-reflecting layer between the planarization layer and the first hybrid bonding layer.

[0049] According to one embodiment of this application, after stacking multiple sub-pixel layers on the pixel region of the driving backplane, the method further includes:

[0050] Lens units are fabricated on the side of the stacked subpixel layers away from the driving backplate.

[0051] According to one embodiment of this application, the prepared plurality of sub-pixel layers include a first sub-pixel layer having red sub-pixel units, a second sub-pixel layer having green sub-pixel units, and a third sub-pixel layer having blue sub-pixel units, and are stacked sequentially on a driving backplane in the order of the first sub-pixel layer, the second sub-pixel layer, and the third sub-pixel layer.

[0052] According to the stacked display unit and its fabrication method of this application, the stacked sub-pixel units do not block each other in the light emission direction, and the light emitted from the bottom is not easily blocked during the upward propagation process; at the same time, a reflective structure is used to utilize the lateral light emitted by each sub-pixel unit to achieve upward reflection, thereby improving the light emission of the stacked full-color structure.

[0053] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0054] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0055] Figure 1 is one of the top views of the stacked display unit provided in an embodiment of this application;

[0056] Figure 2 is one of the cross-sectional views of the stacked display unit provided in an embodiment of this application;

[0057] Figure 3 is a second top view of the stacked display unit provided in an embodiment of this application;

[0058] Figure 4 is a second cross-sectional view of the stacked display unit provided in an embodiment of this application;

[0059] Figure 5 is a top view of the stacked display unit provided in the embodiment of this application;

[0060] Figure 6 is a top view of the stacked display unit provided in an embodiment of this application;

[0061] Figure 7 is a top view of the stacked display unit provided in the embodiment of this application;

[0062] Figure 8 is a top view of the stacked display unit provided in the embodiment of this application;

[0063] Figure 9 is a top view of the stacked display unit provided in an embodiment of this application;

[0064] Figure 10 is an eighth top view of the stacked display unit provided in an embodiment of this application;

[0065] Figure 11 is a top view of the stacked display unit provided in an embodiment of this application;

[0066] Figure 12 is a flowchart illustrating the fabrication method of the stacked display unit provided in an embodiment of this application;

[0067] Figures 13-30 are schematic diagrams of the various processes in the preparation method provided in the embodiments of this application.

[0068] Reference numerals: Drive backplane 000, First substrate 001, Second substrate 002, Third substrate 003, First sub-pixel unit 100, First N-electrode unit 102, First epitaxial layer 110, Opening 120, First sub-electrode 131, Second sub-electrode 132, Third sub-electrode 133, Fourth sub-electrode 134, PV layer 140, Planarization layer 150, Reflector cup structure 160, Light reflecting layer 170, Hybrid bonding layer (180, 280), First bonding electrode 181, Second bonding electrode 182, Third bonding electrode 183, Fourth bonding electrode Electrode 184, second sub-pixel unit 200, second N-electrode unit 202, fifth sub-electrode 231, sixth sub-electrode 232, seventh sub-electrode 233, eighth sub-electrode 211, ninth sub-electrode 212, tenth sub-electrode 213, fifth bonding electrode 281, sixth bonding electrode 282, third sub-pixel unit 300, third N-electrode unit 302, eleventh sub-electrode 331, twelfth sub-electrode 332, thirteenth sub-electrode 311, lens unit 400, reflective structure 500, N-electrode unit 600, metal electrode layer 700. Detailed Implementation

[0069] The embodiments of this application are described in detail below, examples of which are illustrated in the accompanying drawings. In the drawings, for clarity, the dimensions of layers, regions, elements, and their relative dimensions may be exaggerated. The same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0070] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, components, areas, layers, and / or portions, these elements, components, areas, layers, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, area, layer, or portion from another element, component, area, layer, or portion. Therefore, without departing from the teachings of this disclosure, the first element, component, area, layer, or portion discussed below may be referred to as a second element, component, area, layer, or portion. And the discussion of a second element, component, area, layer, or portion does not imply that the first element, component, area, layer, or portion necessarily exists in this disclosure.

[0071] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0072] In related technologies, traditional stacked full-color structures are disadvantageous for bottom-emitting light. This is because, during the upward propagation of light emitted from the bottom, it is blocked by the epitaxial layers of other sub-pixels, resulting in additional refraction and reflection. Furthermore, lateral light emission is difficult to utilize effectively, ultimately weakening the light emission reaching the upper surface.

[0073] This application proposes a stacked display unit and its fabrication method. The stacked sub-pixel units do not block each other in the light emission direction, and the light emitted from the bottom is not easily blocked during the upward propagation process. At the same time, a reflective structure is used to utilize the lateral light emitted by each sub-pixel unit to achieve upward reflection, thereby improving the light emission of the stacked full-color structure.

[0074] Referring to Figures 1 and 2, Figure 1 shows a top view of a stacked display unit, and Figure 2 shows a cross-sectional view along section line AA in Figure 1. An embodiment of this application proposes a stacked display unit.

[0075] In this embodiment, the stacked display unit includes a driving backplate 000, a pixel layer, and a reflective structure 500. The driving backplate 000 is provided with a pixel driving array. The pixel layer includes multiple sub-pixel layers stacked on a pixel area of ​​the driving backplate 000. Each sub-pixel layer includes a sub-pixel unit, and each sub-pixel unit is electrically connected to the pixel driving array. The orthographic projections of each sub-pixel unit on the driving backplate 000 do not overlap. Sub-pixel units in different layers emit different colors of light. The reflective structure 500 is formed within the pixel layer and is used to reflect the lateral light emitted by each sub-pixel unit, so that the light emitted by each sub-pixel unit is emitted toward the side away from the driving backplate 000.

[0076] The driving backplane 000 can be a silicon wafer substrate formed using semiconductor technology, on which a pixel driving array is formed. Multiple pixel regions are formed on the driving backplane 000, and the pixel driving array can include pixel circuits disposed in each pixel region. The pixel circuits are connected to pixel units disposed in each pixel region to drive the corresponding pixel units to emit light.

[0077] It should be noted that each pixel region on the driver backplane 000 has stacked pixel layers, and the pixel layers of each part can also be integrated. For ease of explanation of the pixel layer structure, this embodiment uses the pixel layer corresponding to one pixel region as an example for illustration; the pixel layers of the remaining parts can adopt the same structure.

[0078] In some embodiments, adjacent sub-pixel layers are connected by a hybrid bonding layer.

[0079] In this embodiment, the sub-pixel layers are connected using hybrid bonding technology. Hybrid bonding tightly bonds the surfaces of different materials through physical, chemical, and thermal treatments; because it can form efficient connections in a small space, it helps to reduce package size and improve the integration of electronic components. Of course, other methods can also be used to connect the sub-pixel layers.

[0080] The hybrid bonding layer includes an insulating portion and a metal portion, with the metal portion providing signal lines. The upper sub-pixel layer in the stacked structure needs to be connected to the pixel circuitry on the driving backplane 000 via the lower sub-pixel layer; therefore, in addition to the top sub-pixel layer, each sub-pixel layer also contains at least one signal line. The signal lines within the hybrid bonding layer can be connected to sub-pixel units within the upper sub-pixel layer, or to other signal lines within the upper sub-pixel layer.

[0081] A pixel layer may include two, three, or four stacked subpixel layers, and each subpixel layer may include one or more subpixel units. As an example, a pixel layer may include three stacked subpixel layers, and each subpixel layer may include one subpixel unit.

[0082] As shown in Figures 1 and 2, the driving backplate 000 is provided with a first sub-pixel layer, a second sub-pixel layer, and a third sub-pixel layer in a bottom-up direction. The first sub-pixel layer includes a first sub-pixel unit 100, which is used to emit red light; the second sub-pixel layer includes a second sub-pixel unit 200, which is used to emit green light; and the third sub-pixel layer includes a third sub-pixel unit 300, which is used to emit blue light.

[0083] The orthographic projections of the first sub-pixel unit 100, the second sub-pixel unit 200, and the third sub-pixel unit 300 on the driving backplate 000 do not overlap. Therefore, the light emitted from the first sub-pixel unit 100 will not be blocked by the second sub-pixel unit 200 and the third sub-pixel unit 300 during its upward propagation; and the light emitted from the second sub-pixel unit 200 will not be blocked by the third sub-pixel unit 300 during its upward propagation, which is beneficial for the upward light emission of each sub-pixel unit.

[0084] The reflective structure 500 surrounds the sides of each sub-pixel unit. The light emitted from the sides of each sub-pixel unit is reflected by the reflective structure 500 and then emitted from above the pixel layer. This reduces the amount of light emitted from the sides of each sub-pixel unit that exceeds the pixel area, thus improving the utilization rate of light.

[0085] It should be noted that the reflective structure 500 can be a multi-layered structure, with each layer located within its respective sub-pixel layer. This allows the reflective structure 500 to be fabricated simultaneously with the fabrication of each sub-pixel layer. Alternatively, the reflective structure 500 can be a single, integrated structure, fabricated by etching and deposition operations on the pixel layers after the sub-pixel layers are stacked. The reflective cup structure 160 can be made of materials such as aluminum, copper, or silver.

[0086] As an example, a first reflector structure is set within each sub-pixel layer, and each first reflector structure encloses the sub-pixel unit within its own sub-pixel layer.

[0087] In this example, the first reflector structure refers to the reflector structure 160 that surrounds the sub-pixel unit. The reflector structure 160 can be circular, rectangular, or irregular in shape. When the reflector structure 160 is circular, its inner wall surface is smooth, which helps to reduce light scattering and stray light, thereby improving the uniformity of light. The surface of the reflector structure 160 facing the sub-pixel unit is sloped, which facilitates the reflection of light upwards. Its specific slope can be set according to requirements.

[0088] In some embodiments, the orthographic projections of each sub-pixel unit on the driving backplane are uniformly arranged around the center of each pixel region and are adjacent to each other.

[0089] Taking a total of 3 sub-pixel units as an example, the line connecting the center of each sub-pixel unit to the center of the pixel region divides the plane into three equal parts, with an angle of 120° between adjacent lines. Taking a total of 4 sub-pixel units as an example, the angle between adjacent lines is 90°. This results in a more uniform light output within the pixel region. Furthermore, arranging each sub-pixel unit close to the center of the pixel region facilitates central light output and reduces light output beyond the pixel region.

[0090] As an example, the center of the orthographic projection of the reflector structure 160 on the driving backplate can coincide with the center of the pixel region, so that the orthographic projections of each sub-pixel unit on the driving backplate are evenly arranged around the center of the orthographic projection of the reflector structure 160 on the driving backplate, as shown in Figure 1.

[0091] In some embodiments, each sub-pixel layer has a light-reflecting layer 170 on the side facing the driving backplane 000. The light-reflecting layer 170 is used to reflect the light emitted from the lower part of the sub-pixel unit in the corresponding sub-pixel layer, thereby increasing the light output of the stacked structure by reflecting the lower light upward.

[0092] The material of the light-reflecting layer 170 can be determined by the light color of the upper and lower sub-pixel units. It needs to reflect the light emitted by the upper sub-pixel units while minimizing the obstruction of the light emitted by the lower sub-pixel units. For example, if the light emitted by the first sub-pixel unit 100 is red, then the light-reflecting layer 170 of the first sub-pixel layer needs to reflect red; if the light emitted by the second sub-pixel unit 200 is green, then the light-reflecting layer 170 of the second sub-pixel layer needs to reflect green light and minimize the obstruction of red light; if the light emitted by the third sub-pixel unit 300 is blue, then the light-reflecting layer 170 of the third sub-pixel layer needs to reflect blue light and minimize the obstruction of both red and green light.

[0093] Referring to FIG2, in some embodiments, the stacked display unit further includes a lens unit 400, which is disposed on the side of the pixel layer away from the driving backplate 000 and is used to collimate the light emitted from the pixel layer.

[0094] Understandably, the lens unit 400 collimates the light rays emitted from each sub-pixel unit from the pixel layer into parallel beams, which helps control the light emission direction. The parallel beams can be perpendicular to the surface of the pixel layer or at an acute angle to it.

[0095] As an example, the lens unit includes a lens whose orthographic projection on the driving backplate 000 covers the orthographic projections of each sub-pixel unit on the driving backplate. Thus, each sub-pixel unit shares a single lens, reducing system complexity, minimizing light emission deviation between sub-pixels, and also saving space.

[0096] As another example, the lens unit includes multiple lenses, and the orthographic projection of each lens onto the driving backplane overlaps the orthographic projection of a sub-pixel unit onto the driving backplane. Thus, each sub-pixel unit uses an independent lens for collimation, which reduces mutual interference between sub-pixel units and facilitates independent optimization of each sub-pixel unit.

[0097] In the above example, the lens can be a meta surface lens or a micro lens.

[0098] Referring again to Figure 2, in some embodiments, the number of first reflector structures in each sub-pixel layer is one. Each first reflector structure encloses all sub-pixel units in its sub-pixel layer. The orthographic projection of each first reflector structure on the driving backplate 000 surrounds the orthographic projection of all sub-pixel units in each sub-pixel layer on the driving backplate 000. The centers of the orthographic projection patterns of each first reflector structure on the driving backplate 000 coincide. The area enclosed by each first reflector structure gradually increases in the direction away from the driving backplate 000.

[0099] In this embodiment, all sub-pixel units within each sub-pixel layer share a reflector structure 160. For example, a first sub-pixel layer includes at least one first sub-pixel unit 100 and a reflector structure 160, which is arranged around all the first sub-pixel units 100 within the layer; a second sub-pixel layer includes at least one second sub-pixel unit 200 and a reflector structure 160, which is arranged around all the second sub-pixel units 200 within the layer; a third sub-pixel layer includes at least one third sub-pixel unit 300 and a reflector structure 160, which is arranged around all the third sub-pixel units 300 within the layer. The reflector structures 160 in each layer can all be circular, and their orthographic projections on the drive backplate 000 are arranged in concentric circles.

[0100] The patterns projected onto the drive backplate 000 by each reflector structure 160 can be identical, and the overlapping arrangement of the patterns' centers is beneficial for improving the uniform reflection of light emitted from each sub-pixel unit. Furthermore, the reflector structures 160 gradually increase in size from bottom to top in a stepped arrangement, which is beneficial for reflecting light from the bottom to the top.

[0101] It should be noted that the orthographic projections of each reflector structure 160 on the drive backplate 000 can partially overlap, and the relatively compact arrangement of each reflector structure 160 helps to save space. In this case, in the top view (as shown in Figure 1), each reflector structure 160 overlaps to form a reflective structure 500. Of course, the orthographic projections of each reflector structure 160 on the drive backplate 000 can also be staggered.

[0102] Referring to Figures 3 and 4, Figure 3 shows a top view of a stacked display unit, and Figure 4 shows a cross-sectional view along section line BB in Figure 3. In some embodiments, the number of first reflector structures in each sub-pixel layer is the same as the number of sub-pixel units in the same sub-pixel layer. Each first reflector structure surrounds one sub-pixel unit in the same sub-pixel layer, and the orthographic projections of each first reflector structure on the driving backplate do not overlap. The reflective structure further includes: a second reflector structure disposed in the sub-pixel layer. The number of second reflector structures in each sub-pixel layer is equal to the sum of the number of sub-pixel units below the same sub-pixel layer. The orthographic projection of the second reflector structure on the driving backplate 000 surrounds the orthographic projection of the corresponding sub-pixel unit below the same sub-pixel layer on the driving backplate 000, and the orthographic projections of each second reflector structure in the same sub-pixel layer on the driving backplate 000 do not overlap.

[0103] In this embodiment, each sub-pixel unit within each sub-pixel layer employs an independent reflector structure 160 to achieve lateral light emission reflection. This facilitates the reflection of lateral light emission from each sub-pixel unit, thereby improving the light emission of each sub-pixel unit. The second reflector structure refers to a reflector structure 160 within each sub-pixel layer that does not obstruct the sub-pixel units within that sub-pixel layer.

[0104] As an example, a first subpixel layer includes a first subpixel unit 100 and a reflector structure 160 arranged around the first subpixel unit 100; a second subpixel layer includes a second subpixel unit 200 and two reflector structures 160, one of which is arranged around the second subpixel unit 200, and the other is orthographically projected onto the first subpixel layer and arranged around the first subpixel unit 100; a third subpixel layer includes a third subpixel unit 300 and three reflector structures 160, one of which is arranged around the third subpixel unit 300, another of which is orthographically projected onto the first subpixel layer and arranged around the first subpixel unit 100, and a third of which is orthographically projected onto the second subpixel layer and arranged around the second subpixel unit 300.

[0105] In this example, the three reflector cup structures 160 projected orthogonally onto the driving backplate 000 surrounding the first sub-pixel unit 100 are arranged in a stepped manner, gradually increasing in size from bottom to top, which facilitates the reflection of light from the bottom to the top. Similarly, the two reflector cup structures 160 projected orthogonally onto the driving backplate 000 surrounding the second sub-pixel unit 200 are arranged in a stepped manner, gradually increasing in size from bottom to top, which also facilitates the reflection of light to the top.

[0106] The orthographic projections of each reflector structure 160 on the drive backplate 000 are complementary and overlapping, and are arranged uniformly and closely around the center. As a result, the amount of light emitted within the pixel area is more uniform, which is beneficial for light emission from the center and reduces light emission beyond the pixel area.

[0107] In some embodiments, the number of first reflective cup structures in each sub-pixel layer is one, and each first reflective cup structure surrounds all sub-pixel units in the sub-pixel layer. The orthographic projections of each first reflective cup structure on the driving backplate 000 do not overlap. The reflective structure also includes second reflective cup structures disposed in the sub-pixel layer. The number of second reflective cup structures in each sub-pixel layer is equal to the sum of the number of sub-pixel layers below the sub-pixel layer. The orthographic projection of the second reflective cup structure on the driving backplate 000 surrounds the orthographic projections of all sub-pixel units in the corresponding sub-pixel layer below the sub-pixel layer on the driving backplate 00. The orthographic projections of each second reflective cup structure in the same sub-pixel layer on the driving backplate 00 do not overlap.

[0108] In this embodiment, each sub-pixel layer adopts an independent reflector structure 160, and sub-pixel units in the same layer share the reflector structure 160 to achieve lateral light emission reflection. This is beneficial for reflecting the lateral light emission of each sub-pixel layer and improving the light emission of each sub-pixel layer. The second reflector structure refers to a reflector structure 160 in each sub-pixel layer that does not enclose the sub-pixel units within that sub-pixel layer.

[0109] As an example, a first subpixel layer includes two first subpixel units 100 and a reflector structure 160 arranged around the two first subpixel units 100; a second subpixel layer includes a second subpixel unit 200 and two reflector structures 160, one of which is arranged around the second subpixel unit 200, and the other is orthographically projected onto the first subpixel layer and arranged around the two first subpixel units 100; a third subpixel layer includes a third subpixel unit 300 and three reflector structures 160, one of which is arranged around the third subpixel unit 300, another of which is orthographically projected onto the first subpixel layer and arranged around the two first subpixel units 100, and a third of which is orthographically projected onto the second subpixel layer and arranged around the second subpixel unit 300.

[0110] In this example, the three reflector cup structures 160 projected onto the driving backplate 000 around the two first sub-pixel units 100 are arranged in a stepped manner, gradually increasing in size from bottom to top, which facilitates the reflection of light from the bottom to the top. Similarly, the two reflector cup structures 160 projected onto the driving backplate 000 around the second sub-pixel unit 200 are arranged in a stepped manner, gradually increasing in size from bottom to top, which also facilitates the reflection of light to the top.

[0111] Of course, in other examples, the first subpixel layer, the second subpixel layer, and the third subpixel layer may each include multiple subpixel units, the first subpixel layer includes one reflector structure 160, the third subpixel layer includes two reflector structures 160, and the third subpixel layer includes three reflector structures 160.

[0112] In some embodiments, the subpixel layer closest to the driving backplane 000 includes a plurality of subpixel units.

[0113] In this embodiment, the number of subpixel units in the lower subpixel layer can be greater than the number of subpixel units in the upper subpixel layer. Increasing the number of subpixel units at the bottom helps to improve the amount of light emitted from the bottom, compensate for light loss at the bottom, and enhance the overall display brightness.

[0114] Referring to Figure 5, which shows a top view of a stacked display unit, as an example, the driving backplate 000 is provided with a first subpixel layer, a second subpixel layer, and a third subpixel layer sequentially from bottom to top. The first subpixel layer includes two first subpixel units 100, which are red subpixel units; the second subpixel layer includes one second subpixel unit 200, which is a green subpixel unit; and the third subpixel layer includes one third subpixel unit 300, which is a blue subpixel unit. This compensates for the red light emitted from the bottom, improving the red light display effect.

[0115] Referring to Figure 6, which shows a top view of a stacked display unit. When the subpixel layer comprises multiple subpixel units, each subpixel unit can also be enclosed by an independent reflector cup structure 160, as detailed in the aforementioned embodiments.

[0116] As shown in Figures 1 to 6, as an example, the stacked display unit further includes an N-electrode unit 600, which is formed within the pixel layer and connected to each sub-pixel unit.

[0117] The N-electrode unit 600 can be composed of signal lines within each sub-pixel layer and signal lines within the hybrid bonding layer. The N-electrode unit 600 provides a reference potential for voltage or current, ensuring that current flow or voltage changes in the stacked display units correctly affect the sub-pixel unit connections. In this example, all sub-pixel units are connected to the same N-electrode unit 600, sharing a single N-electrode unit 600. This reduces the number of N-electrode units 600, saves space, and increases pixel density.

[0118] Referring to Figures 7 to 10, which respectively show a top view of a stacked display unit. As another example, the stacked display unit further includes a plurality of N-electrode units 600, which are formed within a pixel layer, and the sub-pixel units within each sub-pixel layer are respectively connected to an independent N-electrode unit.

[0119] As shown in Figure 7, the stacked display unit includes a first subpixel layer, a second subpixel layer, and a third subpixel layer stacked together. The first subpixel layer includes a first subpixel unit 100, the second subpixel layer includes a second subpixel unit 200, and the third subpixel layer includes a third subpixel unit 300. The first subpixel unit 100, the second subpixel unit 200, and the third subpixel unit 300 share a reflector structure 160.

[0120] The stacked display unit includes a first N-electrode unit 102, a second N-electrode unit 202, and a third N-electrode unit 302. A first sub-pixel unit 100 can be connected to the first N-electrode unit 102, a second sub-pixel unit 200 can be connected to the second N-electrode unit 202, and a third sub-pixel unit 300 can be connected to the third N-electrode unit 302. Each color sub-pixel unit is controlled by an independent N-electrode, enabling more precise brightness adjustment.

[0121] As another example, each sub-pixel layer includes multiple sub-pixel units. The multiple sub-pixel units in the first sub-pixel layer are connected to the first N-electrode unit 102, the multiple sub-pixel units in the second sub-pixel layer are connected to the second N-electrode unit 202, and the multiple sub-pixel units in the third sub-pixel layer are connected to the third N-electrode unit 302.

[0122] As shown in Figure 8, compared to Figure 7, the first sub-pixel unit 100, the second sub-pixel unit 200, and the third sub-pixel unit 300 are enclosed by independent reflector cup structures 160. The first sub-pixel unit 100 can be connected to the first N-electrode unit 102, the second sub-pixel unit 200 can be connected to the second N-electrode unit 202, and the third sub-pixel unit 300 can be connected to the third N-electrode unit 302. Each color sub-pixel unit is controlled by an independent N-electrode, achieving more precise brightness adjustment.

[0123] As shown in Figure 9, compared to Figure 7, the first sub-pixel layer may include two first sub-pixel units 100. The two first sub-pixel units 100 can be connected to a first N-electrode unit 102, the second sub-pixel unit 200 can be connected to a second N-electrode unit 202, and the third sub-pixel unit 300 can be connected to a third N-electrode unit 302. Two red sub-pixels are controlled by one N-electrode, while the other two color sub-pixels are controlled by two other independent N-electrodes, achieving more precise brightness adjustment. Of course, the two first sub-pixel units 100 can also be controlled by two independent N-electrodes.

[0124] As shown in Figure 10, compared to Figure 9, the two first sub-pixel units 100, one second sub-pixel unit 200, and one third sub-pixel unit 300 are enclosed by independent reflector cup structures 160. The two red sub-pixels are controlled by one N-electrode, while the other two color sub-pixels are controlled by two other independent N-electrodes, achieving more precise brightness adjustment.

[0125] In this example, each color sub-pixel unit is controlled by an independent N-electrode. This allows for more precise control of each sub-pixel unit, providing higher display resolution and color control, and improving display quality. The number of sub-pixel units mentioned above is merely an example; other values ​​can be used, and this is not a limitation.

[0126] In some embodiments, a transparent electrode layer is disposed on the side of each sub-pixel layer away from the driving backplane. The transparent electrode layer is connected to the sub-pixel unit in each sub-pixel layer and to the corresponding N electrode unit.

[0127] In this embodiment, the N-electrode of each sub-pixel unit is connected to the corresponding N-electrode unit through a transparent electrode layer. Since the transparent electrode layer blocks less light, the amount of light emitted can be increased. The material of the transparent electrode layer is ITO (Indium Tin Oxide).

[0128] Referring to FIG11, FIG11 shows a top view of a stacked display unit. In some embodiments, a transparent electrode layer and a metal electrode layer 700 are disposed on the side of each sub-pixel layer away from the driving backplate 000, which are interconnected. The transparent electrode layer is connected to the sub-pixel unit in each sub-pixel layer, and the metal electrode layer 700 is connected to the corresponding N electrode unit 600; wherein the orthographic projections of each metal electrode layer 700 on the driving backplate do not overlap.

[0129] In this embodiment, a metal electrode layer 700 is used to realize the signal transmission of the N electrode, which has higher conductivity than the ITO electrode and improves signal accuracy. Furthermore, the N electrode of the sub-pixel unit is connected to the transparent electrode layer, using the ITO electrode process to reduce obstruction of light above the sub-pixel unit. In addition, the metal electrode layers 700 are staggered in the stacking direction, reducing parasitic capacitance effects, lowering signal interference, and improving signal integrity. The material of the metal electrode layer 700 can be copper, silver, or aluminum, etc.

[0130] As an example, one end of the metal electrode layer 700 is arranged around the transparent electrode layer. For instance, the orthographic projection of the transparent electrode layer on the drive backplate 000 is circular, and one end of the metal electrode layer 700 is annular, with the transparent electrode layer in contact with the inner surface of the corresponding annular connection of the metal electrode layer 700.

[0131] Referring to Figure 12, which illustrates a fabrication process for a stacked display unit, an embodiment of this application also proposes a method for fabricating a stacked display unit. In this embodiment, the fabrication method includes steps 10, 20, and 30.

[0132] Step 10: Provide a driving backplane 000, which is provided with a pixel driving array;

[0133] Step 20: Sub-pixel units, PV layer 140, planarization layer 150 and first electrode are sequentially formed on the substrate to prepare the sub-pixel layer. A reflector cup structure 160 surrounding the sub-pixel unit is formed in the planarization layer 150.

[0134] Step 30: Stack multiple sub-pixel layers on the pixel area of ​​the driving backplane 000, so that each sub-pixel unit is connected to the pixel driving array, the sub-pixel units in each sub-pixel layer emit different colors of light, and the orthographic projections of each sub-pixel unit on the driving backplane 000 do not overlap.

[0135] The driving backplane 000 can be a silicon wafer substrate formed using semiconductor technology. The silicon wafer is divided into multiple pixel regions through processes such as film deposition and etching, and pixel circuits are formed in each pixel region to form a pixel driving array.

[0136] In this embodiment, each sub-pixel layer is fabricated independently and then stacked sequentially on the driving backplane 000. For example, the multiple sub-pixel layers may include a first pixel layer, a second pixel layer, and a third pixel layer. The stacking process can be as follows: first, connect the first side of the first pixel layer to the driving backplane 000; then, connect the first side of the second pixel layer to the second side of the first pixel layer; and finally, connect the first side of the third pixel layer to the second side of the second pixel layer.

[0137] As an example, the first pixel layer may include at least one red sub-pixel unit, the second pixel layer may include at least one green sub-pixel unit, and the third pixel layer may include at least one blue sub-pixel unit.

[0138] In this embodiment, a reflector structure 160 is fabricated within each sub-pixel layer. The reflector structure 160 surrounds the side of each sub-pixel unit. Light emitted from the side of each sub-pixel unit is reflected by the reflector structure 160 and then exits the pixel layer from above each sub-pixel unit. This reduces the amount of light emitted from the side of each sub-pixel unit that exceeds the pixel area, thus improving light utilization.

[0139] In some embodiments, after stacking multiple subpixel layers on the pixel region of the driving backplane 000, a lens unit 400 is further prepared on the side of the stacked multiple subpixel layers away from the driving backplane.

[0140] Based on the above embodiments, the first side of the third pixel layer can be connected to the second side of the second pixel layer, and a lens unit 400 can also be fabricated on the second side of the third pixel layer. By using the lens unit 400 to collimate the light rays emitted from each sub-pixel unit from the pixel layer into parallel beams, it is beneficial to control the light emission direction. The specific structure of the lens unit 400 can be referred to in the foregoing embodiments, and will not be repeated here.

[0141] Referring to Figures 13-30, which illustrate the structure of each step in a method for fabricating a stacked display unit, this application provides an example of a fabrication process to more clearly explain the fabrication method of this embodiment.

[0142] First, a first epitaxial layer 110 corresponding to the first sub-pixel unit 100 is formed on the first substrate 001, and then the first sub-pixel unit 100 is processed by etching. The first sub-pixel unit 100 can be a red sub-pixel, and its specific material can be selected according to requirements. Then, a PV layer 140 and a planarization layer 150 are formed on the first sub-pixel unit 100. Then, an opening 120 is made in the planarization layer 150, and metal is deposited in the opening 120 to form a reflector cup structure 160. The specific structure and shape of the reflector cup structure 160 can be referred to the aforementioned embodiments, and will not be repeated here.

[0143] In some embodiments, a light-reflecting layer 170 is provided on the planarization layer 150. The side with the light-reflecting layer 170 will be subsequently connected to the side facing the driving backplate 000, so that the light-reflecting layer 170 can reflect the light emitted by the first sub-pixel unit 100 toward the driving backplate 000. By reflecting the light emitted in this direction toward the side away from the driving backplate 000, the light output of the stacked structure is increased.

[0144] An opening is formed in the light-reflecting layer 170 to fabricate a first electrode. In this embodiment, the first electrode includes a first sub-electrode 131, a second sub-electrode 132, a third sub-electrode 133, and a fourth sub-electrode 134. The first sub-electrode 131 is connected to the first sub-pixel unit 100, and the second, third, and fourth sub-electrodes 132 and 133 are connected to signal lines penetrating the planarization layer 150. The second sub-electrode 132 is used to connect to the second sub-pixel layer, the third sub-electrode 133 is used to connect to the third sub-pixel layer, and the fourth sub-electrode 134 is used to form the N-electrode unit 600.

[0145] In some embodiments, adjacent sub-pixel layers are connected by a hybrid bonding layer. The fabrication process of the sub-pixel layer further includes fabricating a first hybrid bonding layer on the side of the planarization layer 150 away from the substrate; and after the sub-pixel layers are bonded by the first hybrid bonding layer, removing the substrate and fabricating a second electrode, or sequentially fabricating a second electrode and a second hybrid bonding layer.

[0146] In this embodiment, a first hybrid bonding layer 180 is prepared on the side of the planarization layer 150 away from the substrate 000. This hybrid bonding layer 180 includes a first bonding electrode 181, a second bonding electrode 182, a third bonding electrode 183, and a fourth bonding electrode 184. The first bonding electrode 181 is connected to the first sub-electrode 131, the second bonding electrode 182 is connected to the second sub-electrode 132, the third bonding electrode 183 is connected to the third sub-electrode 133, and the fourth bonding electrode 184 is connected to the fourth sub-electrode 134.

[0147] It should be noted that the fourth bonding electrode 184 and the fourth sub-electrode 134 serve as N-electrode sub-units, and the N-electrode sub-units of each layer are connected to form an N-electrode unit 600. When each sub-pixel unit adopts a common N-level driving method, the number of N-electrode units 600 is one, and the number of the fourth bonding electrode 184 and the fourth sub-electrode 134 is also one. When each sub-pixel unit adopts an independent N-level driving method, the number of N-electrode units 600 is the same as the number of sub-pixel units, and the number of the fourth bonding electrode 184 and the fourth sub-electrode 134 is the same as the number of sub-pixel units. The specific arrangement of the N-electrode units 600 can be referred to in the foregoing embodiments, and will not be repeated here.

[0148] The hybrid bonding layer 180 and the driving backplane 000 are connected using a hybrid bonding process to achieve the connection between the first sub-pixel layer and the driving backplane 000. After the hybrid bonding layer 180 is formed, the first substrate 001 and excess first epitaxial layer 110 are removed and CMP (chemical mechanical polishing) is performed to smooth them out; then the second electrode and the second hybrid bonding layer are fabricated.

[0149] The fabrication process of the second electrode includes: forming a transparent electrode layer connected to the N pole of the sub-pixel unit on one side of the PV layer 140 using a transparent material, and the transparent electrode layer forming the second electrode for connecting the N electrode unit 600; or, forming a transparent electrode layer connected to the N pole of the sub-pixel unit on one side of the PV layer 140 using a transparent material, and forming a metal electrode layer 700 connected to the transparent electrode layer on one side of the PV layer using a metal material, and the transparent electrode layer and the metal electrode layer forming the second electrode for connecting the N electrode unit 600.

[0150] It should be noted that the second electrode mentioned in this embodiment mainly refers to the electrode portion connected to the first sub-pixel unit 100. Using a transparent electrode layer to connect to the N electrode unit 600 reduces the light emission impedance to each sub-pixel unit, which is beneficial for overall light emission. Using a metal electrode layer 700 to connect to the N electrode unit 600 reduces parasitic capacitance effects, lowers signal interference, and improves signal integrity. The specific structure of the metal electrode layer 700 can be referred to in the foregoing embodiments.

[0151] In addition, on the side of the planarization layer 150 away from the first substrate 001, an electrode portion is formed that is connected to the second bonding electrode 182, the third bonding electrode 183 and the fourth bonding electrode 184. This portion can be fabricated using ITO.

[0152] It should be noted that for the intermediate bonded sub-pixel layers, a second hybrid bonding layer needs to be prepared because further bonding is required; for the last bonded sub-pixel layer, a second hybrid bonding layer does not need to be prepared because further bonding is not required.

[0153] The fabrication of the second sub-pixel layer is the same as that of the first sub-pixel layer. A second sub-pixel unit 200, a light-reflecting layer 170, and a hybrid bonding layer are fabricated on the second substrate 002. The second sub-pixel layer includes a fifth sub-electrode 231, a sixth sub-electrode 232, and a seventh sub-electrode 233, with the fifth sub-electrode 231 connected to the second sub-pixel unit 200.

[0154] The hybrid bonding layer of the second sub-pixel layer is hybrid bonded to the second hybrid bonding layer of the first sub-pixel layer; then, the second substrate 002 and excess epitaxial layer are removed to fabricate the third electrode and the hybrid bonding layer 280 of the third layer. The third electrode includes an eighth sub-electrode 211, a ninth sub-electrode 212, and a tenth sub-electrode 213. The eighth sub-electrode 211 is connected to the second sub-pixel unit 200, the ninth sub-electrode 212 is connected to the sixth sub-electrode 232, and the tenth sub-electrode 213 is connected to the seventh sub-electrode 233. The hybrid bonding layer 280 includes a fifth bonding electrode 281 and a sixth bonding electrode 282. The fifth bonding electrode 281 is connected to the ninth sub-electrode 212, and the sixth bonding electrode 282 is connected to the tenth sub-electrode 213.

[0155] The eighth sub-electrode 211 can be prepared with reference to the aforementioned description of the second electrode. It can be prepared using a transparent conductive material or a combination of a transparent conductive material and a metallic material.

[0156] After the first sub-pixel layer and the second sub-pixel layer are bonded, the fifth sub-electrode 231 is connected to the second sub-electrode 132, the sixth sub-electrode 232 is connected to the third sub-electrode 133, and the seventh sub-electrode 233 is connected to the fourth sub-electrode 134. The number of seventh sub-electrodes 233 is the same as the number of fourth sub-electrodes 134.

[0157] The fabrication of the third sub-pixel layer is the same as that of the first and second sub-pixel layers. A third sub-pixel unit 300, an eleventh sub-electrode 331, a twelfth sub-electrode 332, and a hybrid bonding layer are fabricated on the third substrate 003. The eleventh sub-electrode 331 is connected to the third sub-pixel unit 300. A light-reflecting layer 170 can also be fabricated before the hybrid bonding layer.

[0158] After the third sub-pixel layer is hybrid-bonded to the second sub-pixel through a hybrid bonding layer, the third substrate 003 and excess epitaxial layer are removed. Since no further sub-pixels are stacked, no hybrid bonding layer is fabricated; instead, a thirteenth sub-electrode 311 is fabricated. The thirteenth sub-electrode 311 is connected to the third sub-pixel unit 300 and the twelfth sub-electrode 332. After bonding, the twelfth sub-electrode 332 is connected to the sixth bonding electrode 282 to form the N-electrode unit 600.

[0159] The preparation of the thirteenth sub-electrode 311 can refer to the aforementioned description of the second electrode. It can be prepared using a transparent conductive material, or it can be prepared using a combination of transparent conductive material and metallic material.

[0160] Finally, a lens unit 400 is fabricated on the thirteenth sub-electrode 311. The specific structure of the lens unit 400 can be referred to in the aforementioned embodiments, and will not be repeated here.

[0161] In this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0162] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A stacked display unit, wherein, The stacked display unit includes: The driving backplane is equipped with a pixel driving array; A pixel layer includes multiple sub-pixel layers stacked on a pixel region of the driving backplane. Each sub-pixel layer includes sub-pixel units, each sub-pixel unit is electrically connected to the pixel driving array, and the orthographic projections of each sub-pixel unit on the driving backplane do not overlap. Sub-pixel units in different layers emit different colors of light. A reflective structure is formed within the pixel layer and is used to reflect the lateral light emitted by each of the sub-pixel units, so that the light emitted by each of the sub-pixel units is emitted toward the side away from the driving backplate.

2. The stacked display unit according to claim 1, wherein, The reflective structure includes: A first reflective cup structure is disposed within each of the sub-pixel layers, and each first reflective cup structure encloses the sub-pixel unit within the sub-pixel layer.

3. The stacked display unit according to claim 2, wherein, The number of first reflector structures in each sub-pixel layer is one. Each first reflector structure encloses all the sub-pixel units in the sub-pixel layer. The orthographic projection of each first reflector structure on the driving backplate surrounds the orthographic projection of all the sub-pixel units in the sub-pixel layer on the driving backplate. The centers of the orthographic projection patterns of each first reflector structure on the driving backplate coincide. The area enclosed by each first reflector structure gradually increases in the direction away from the driving backplate.

4. The stacked display unit according to claim 2, wherein, The number of first reflector cup structures in each sub-pixel layer is the same as the number of sub-pixel units in the sub-pixel layer. Each first reflector cup structure encloses one sub-pixel unit in the sub-pixel layer. The orthographic projections of each first reflector cup structure on the driving backplate do not overlap. The reflective structure also includes: The second reflector structure disposed within the sub-pixel layer has the number of second reflector structures in each sub-pixel layer equal to the sum of the number of sub-pixel units below the sub-pixel layer. The orthographic projection of the second reflector structure on the driving backplate surrounds the orthographic projection of the corresponding sub-pixel unit below the sub-pixel layer on the driving backplate. The orthographic projections of each second reflector structure in the same sub-pixel layer on the driving backplate do not overlap.

5. The stacked display unit according to claim 2, wherein, The number of the first reflective cup structure in each sub-pixel layer is one, and each first reflective cup structure encloses all the sub-pixel units in the sub-pixel layer. The orthographic projections of each first reflective cup structure on the driving backplate do not overlap. The reflective structure also includes: The second reflector structure disposed within the sub-pixel layer has a number equal to the sum of the number of sub-pixel layers below it. The orthographic projection of the second reflector structure on the driving backplate surrounds the orthographic projections of all the sub-pixel units in the corresponding sub-pixel layer below it on the driving backplate. The orthographic projections of the second reflector structures in the same sub-pixel layer on the driving backplate do not overlap.

6. The stacked display unit according to any one of claims 1-5, wherein, The subpixel layer closest to the driving backplane includes a plurality of subpixel units.

7. The stacked display unit according to claim 6, wherein, The pixel layer includes a first sub-pixel layer, a second sub-pixel layer, and a third sub-pixel layer along the drive backplane. The first sub-pixel layer includes two red sub-pixel units, the second sub-pixel layer includes one green sub-pixel unit, and the third sub-pixel layer includes a blue sub-pixel unit.

8. The stacked display unit according to any one of claims 1-7, wherein, The stacked display unit further includes: An N-electrode unit is formed within the pixel layer and connected to each of the sub-pixel units; or, Multiple N-electrode units are formed within the pixel layer, and each sub-pixel unit within the sub-pixel layer is connected to an independent N-electrode unit.

9. The stacked display unit according to claim 8, wherein, A transparent electrode layer is disposed on the side of each sub-pixel layer away from the driving backplate. The transparent electrode layer is connected to the sub-pixel unit in each sub-pixel layer and to the corresponding N electrode unit.

10. The stacked display unit according to claim 8, wherein, Each sub-pixel layer has a transparent electrode layer and a metal electrode layer connected to each other on the side away from the driving backplate. The transparent electrode layer is connected to the sub-pixel unit in each sub-pixel layer, and the metal electrode layer is connected to the corresponding N electrode unit. The orthographic projections of each of the metal electrode layers on the drive backplate do not overlap.

11. The stacked display unit according to any one of claims 1-10, wherein, The stacked display unit further includes: A lens unit is disposed on the side of the pixel layer away from the driving backplate, and is used to collimate the light emitted from the pixel layer.

12. The stacked display unit according to claim 11, wherein, The lens unit includes: A lens, the orthographic projection of which onto the driving backplate covers the orthographic projection of each of the sub-pixel units onto the driving backplate; or, Multiple lenses, the orthographic projection of each lens on the driving backplate covers the orthographic projection of one of the sub-pixel units on the driving backplate; The lens is either a superlens or a microlens.

13. The stacked display unit according to any one of claims 1-12, wherein, The orthographic projections of each of the sub-pixel units on the driving backplate are uniformly arranged around the center of each pixel region and are adjacent to each other.

14. The stacked display unit according to any one of claims 1-13, wherein, The adjacent sub-pixel layers are connected by a hybrid bonding layer.

15. The stacked display unit according to any one of claims 1-14, wherein, Each of the sub-pixel layers has a wavelength-selective light reflection layer on the side facing the moving backplate. The wavelength-selective light reflection layer is used to reflect the downward light emission of the upper sub-pixel and allows the upward light emission of the lower sub-pixel to pass through.

16. A method for manufacturing a stacked display unit as described in any one of claims 1-15, wherein, The preparation method includes: A driving backplane is provided, wherein the driving backplane is provided with a pixel driving array; A sub-pixel layer is fabricated by sequentially forming a sub-pixel unit, a PV layer, a planarization layer, and a first electrode on a substrate. A reflective cup structure surrounding the sub-pixel unit is formed within the planarization layer. Multiple sub-pixel layers are stacked on the pixel area of ​​the driving backplane, so that each sub-pixel unit is connected to the pixel driving array. The sub-pixel units in each sub-pixel layer emit different colors of light, and the orthographic projections of each sub-pixel unit on the driving backplane do not overlap.

17. The preparation method according to claim 16, wherein, The fabrication process of the sub-pixel layer further includes fabricating a first hybrid bonding layer on the side of the planarization layer away from the substrate; and, After the sub-pixel layer is bonded through the first hybrid bonding layer, the substrate is removed and a second electrode is prepared, or the second electrode and the second hybrid bonding layer are prepared sequentially.

18. The preparation method according to claim 17, wherein, The fabrication process of the second electrode includes: A transparent electrode layer, formed on one side of the PV layer using a transparent material, is connected to the N-electrode of the sub-pixel unit. This transparent electrode layer forms a second electrode for connecting to the N-electrode unit; or... A transparent electrode layer is formed on one side of the PV layer using a transparent material and connected to the N electrode of the sub-pixel unit. A metal electrode layer is formed on one side of the PV layer using a metal material and connected to the transparent electrode layer. The transparent electrode layer and the metal electrode layer form a second electrode for connecting the N electrode unit.

19. The preparation method according to claim 18, wherein, The fabrication process of the sub-pixel layer also includes forming one or more N-electrode sub-units in the planarization layer and the PV layer; After the sub-pixel layers are stacked, the N-electrode sub-units are connected to form one or more N-electrode units, and the N-electrode units are connected to the second electrode.

20. The preparation method according to claim 17, wherein, The fabrication process of the sub-pixel layer also includes forming a light-reflecting layer between the planarization layer and the first hybrid bonding layer.

21. The preparation method according to any one of claims 16-20, wherein, After stacking the multiple sub-pixel layers on the pixel region of the driving backplane, the method further includes: Lens units are fabricated on the side of the stacked sub-pixel layers away from the driving backplate.

22. The preparation method according to any one of claims 16-21, wherein, The prepared sub-pixel layers include a first sub-pixel layer with red sub-pixel units, a second sub-pixel layer with green sub-pixel units, and a third sub-pixel layer with blue sub-pixel units, and are stacked sequentially on the driving backplate in the order of the first sub-pixel layer, the second sub-pixel layer, and the third sub-pixel layer.

Images