CN116247072B

CN116247072B - Pixel unit, manufacturing method thereof, micro display screen and pixel split device

Info

Publication number: CN116247072B
Application number: CN202310509647.6A
Authority: CN
Inventors: 王亚洲; 杨志祥; 邵明镜
Original assignee: Novos Technology Suzhou Co ltd
Current assignee: Novos Technology Suzhou Co ltd
Priority date: 2023-05-08
Filing date: 2023-05-08
Publication date: 2023-10-20
Anticipated expiration: 2043-05-08
Also published as: CN116247072A

Abstract

The application discloses a pixel unit and a manufacturing method thereof, a micro display screen and a pixel discrete device, wherein the pixel unit comprises a driving backboard and a display unit, the display unit comprises a first device layer, a second device layer and at least one color conversion layer which are vertically stacked in sequence, the first device layer comprises a first sub-pixel and a second sub-pixel, the second device layer comprises a third sub-pixel, and projections of the third sub-pixel, the first sub-pixel and the second sub-pixel on the driving backboard are not overlapped; the at least one color conversion layer is sequentially arranged on one side, far away from the driving backboard, of the first sub-pixel, and the projection of the first sub-pixel on the driving backboard is positioned in the projection of any color conversion layer on the driving backboard; the pixel unit reduces the thickness of the pixel unit and increases the thickness of the color conversion layer on the basis of realizing multicolor display and improving the pixel density, and the brightness and the color purity of the target light source after color conversion are effectively improved.

Description

Pixel unit, manufacturing method thereof, micro display screen and pixel split device

Technical Field

The application relates to the technical field of semiconductor devices, in particular to a pixel unit, a manufacturing method thereof, a micro display screen and a pixel discrete device.

Background

Compared with the current state that the pixel size is in the order of mm in the traditional LED display technology, the pixel size of the Micro-LED display technology is in the order of mum, and the pixel size of the Micro-LED is greatly reduced. While small size pixels offer the advantages of high integration and high energy efficiency, they also offer the potential for reduced external quantum efficiency due to size effects, which can lead to power consumption and performance problems, with the red light behavior of AlGaInP systems being particularly severe. In this regard, those skilled in the art generally adopt a color conversion scheme to implement the target light source, that is, light emitted by a material with higher luminous efficiency passes through the color conversion material to form the target light source, for example, blue light/green light sub-pixel light passes through the color conversion layer to be converted into a red light source, so as to overcome the defects of the AlGaInP system red light source.

In addition, the above-mentioned conventional color conversion scheme is commonly used for medium-sized and large-sized displays, and the pixel density of such medium-sized and large-sized displays is relatively low, and the sensitivity to the thickness of the pixel is relatively low, such as watches, televisions, etc., so that a color conversion layer of tens of micrometers or more can be used. For example, a 50 μm thick quantum dot color conversion layer is used in a television. But for microdisplays, especially those used for AR/MR, the light emitting layer thickness is typically less than 10 μm and the color conversion layer thickness is smaller. Specifically, when the thickness of the light-emitting layer of the pixel unit in the prior art is lower than 10 μm, the thickness of the color conversion layer is only 2-3 μm, and the depth-to-width ratio of the color conversion layer can be generally lower than 1:1. A small color conversion layer thickness will result in a low light absorption conversion rate of the color conversion layer and a low brightness of the resulting target light source. When blue light is adopted to be converted into red light, the color conversion layer formed by the current technology is thinner, the color conversion efficiency is less than 40%, and the brightness can only reach below 100000 nits. Compared with the standard that the color conversion efficiency is 85% under the condition of 10-20 mu m of the color conversion layer in the medium-large display, the color conversion efficiency of the traditional micro display is actually at a lower level under the limit of the structure and the process, and the micro display needs to be improved. Under the condition that the color conversion layer is thinner, the excitation light source is transmitted through the color conversion layer so as to be mixed with the target light source, so that the color purity of the target light source is abnormal when the target light source is lightened, for example, when blue light color is adopted to be converted into red light, a large amount of leaked red light after the blue light is mixed and color-converted can lead to red light to be biased to powder or yellow, and the half-wave width is abnormal so as to lead to colorization abnormality.

Therefore, a pixel unit capable of effectively overcoming the above-mentioned defects is needed.

Disclosure of Invention

The application aims to provide a pixel unit, a manufacturing method thereof, a micro display screen and a pixel discrete device, wherein the pixel unit can be provided with a color conversion layer with a certain thickness on the premise of a thinner luminous layer structure so as to realize color conversion to form a target light source with better brightness.

To achieve the above object, a first aspect of the present application provides a pixel unit, including:

a drive back plate;

the display unit is arranged on the driving backboard, the display unit comprises a first device layer and a second device layer which are vertically stacked in sequence along the direction far away from the driving backboard, the first device layer comprises a first sub-pixel and a second sub-pixel which are arranged at intervals, the second device layer comprises a third sub-pixel, the projection of the third sub-pixel and the first sub-pixel on the driving backboard is not overlapped, and the projection of the third sub-pixel and the second sub-pixel on the driving backboard is not overlapped;

the display unit further comprises at least one color conversion layer, the at least one color conversion layer is sequentially arranged on one side, far away from the driving backboard, of the first sub-pixel, and the projection of the first sub-pixel on the driving backboard is located in the projection of any one of the at least one color conversion layer on the driving backboard.

In a preferred embodiment, the ratio of the sum of the depths of all the color conversion layers in the display unit to the sum of the widths of all the color conversion layers in the display unit is not less than 1:1.

In a preferred embodiment, any one of the first sub-pixel, the second sub-pixel and the third sub-pixel is one of a hemispherical structure and a semi-ellipsoidal structure.

In a preferred embodiment, the first device layer further includes a first passivation layer and a first ohmic layer;

the first passivation layer is covered on the surfaces of the first sub-pixels and the second sub-pixels;

the first ohmic layer is arranged on the surface of the first passivation layer in a covering mode, and the first ohmic layer penetrates through the first passivation layer to be connected with the first sub-pixel and the second sub-pixel respectively.

In a preferred embodiment, the at least one color conversion layer includes a first color conversion layer, and at least a portion of the first color conversion layer is embedded in the first device layer.

In a preferred embodiment, the first sub-pixel is embedded in the first color conversion layer.

In a preferred embodiment, the minimum distance between the first color conversion layer and the driving back plate is greater than the maximum distance between the first ohmic layer and the driving back plate.

In a preferred embodiment, the first color conversion layer extends away from the driving back plate, and a portion of the first color conversion layer is embedded in the second device layer.

In a preferred embodiment, the at least one color conversion layer further includes a second color conversion layer embedded in the second device layer.

In a preferred embodiment, the display unit further comprises at least one enhancement structure;

any reinforcing structure is arranged around the circumference of the first color conversion layer; and/or any reinforcing structure is arranged around the circumference of the second color conversion layer; and/or any reinforcing structure is arranged around the second sub-pixel and/or the third sub-pixel.

In a preferred embodiment, the display unit further includes at least one light screen structure, and any one of the light screen structures is covered on at least one light emitting surface of the first color conversion layer or the second color conversion layer.

In a preferred embodiment, the pixel unit further includes an optical lens, where the optical lens is disposed on a side of the second device layer away from the driving back plate, and at least a portion of the third sub-pixels are embedded in the optical lens.

In a preferred embodiment, any one of the light screen structures cooperates with the reinforcing structure to form an inverted groove structure, and the groove structure wraps the first color conversion layer or the second color conversion layer.

In a second aspect, there is provided a method of fabricating a pixel cell, the method comprising:

preparing a driving backboard;

manufacturing a display unit, bonding a first target compound semiconductor with the driving backboard, and constructing a first sub-pixel and a second sub-pixel to form a first device layer; bonding a second target compound semiconductor with the first device layer and constructing a third subpixel to form a second device layer; wherein the projection of the third sub-pixel and the first sub-pixel on the driving backboard is not overlapped, and the projection of the third sub-pixel and the second sub-pixel on the driving backboard is not overlapped;

after forming the first device layer, the fabrication method further includes constructing a first color conversion layer, including:

etching the first device layer to form a first groove, wherein the first groove is formed on one side, away from the driving backboard, of the first sub-pixel;

and filling a color conversion material in the first groove to form a first color conversion layer, wherein the projection of the first sub-pixel on the driving backboard is positioned in the projection of the first color conversion layer on the driving backboard.

In a preferred embodiment, after forming the second device layer, the fabrication method further includes constructing a second color conversion layer, including:

etching the second device layer to form a second groove, wherein the second groove is formed on one side of the first color conversion layer away from the driving backboard;

and filling a color conversion material in the second groove to form a second color conversion layer, wherein the projection of the first sub-pixel on the driving backboard is positioned in the projection of the second color conversion layer on the driving backboard.

In a third aspect, a method for fabricating a pixel unit is provided, the method comprising:

preparing a driving backboard;

After forming the second device layer, the fabrication method further includes constructing a first color conversion layer, including:

sequentially etching the second device layer and the first device layer to form a third groove, wherein the third groove is formed on one side, far away from the driving backboard, of the first sub-pixel;

and filling a color conversion material in the third groove to form a first color conversion layer, wherein the projection of the first sub-pixel on the driving backboard is positioned in the projection of the first color conversion layer on the driving backboard.

In a fourth aspect, a method for fabricating a pixel unit is provided, the method comprising:

preparing a driving backboard;

Wherein bonding the first target compound semiconductor with the driving backplate and constructing the first and second sub-pixels to form the first device layer includes:

bonding a first target compound semiconductor with the driving back plate and constructing a first sub-pixel and a second sub-pixel;

forming a first color conversion layer on one side of the first sub-pixel far away from the driving backboard; the projection of the first sub-pixel on the driving backboard is positioned in the projection of the first color conversion layer on the driving backboard;

device layer filling and planarization are performed to form the first device layer.

In a fifth aspect, a micro display is provided, the micro display comprising:

the micro display screen backboard comprises a driving circuit, an input interface and an output interface;

the display area is arranged on the micro display screen backboard, and comprises at least two display units which are arranged in an array mode and are included by the pixel units according to any one of the first aspect;

and the peripheral common cathode is electrically connected with each display unit respectively.

In a sixth aspect, there is provided a pixel-wise separation device including:

A discrete device backplate comprising at least two anode pads and at least one cathode pad;

the device main body is arranged on the discrete device backboard, and comprises at least two display units which are arranged in an array mode and are included in the pixel unit according to any one of the first aspect.

Compared with the prior art, the application has the following beneficial effects:

the application provides a pixel unit and a manufacturing method thereof, a micro display screen and a pixel separation device, wherein the pixel unit comprises a driving backboard and a display unit arranged on the driving backboard, the display unit comprises a first device layer and a second device layer which are vertically stacked in sequence along a direction far away from the driving backboard, the first device layer comprises a first sub-pixel and a second sub-pixel which are arranged at intervals, the second device layer comprises a third sub-pixel, the projection of the third sub-pixel and the first sub-pixel on the driving backboard is not overlapped, and the projection of the third sub-pixel and the second sub-pixel on the driving backboard is not overlapped; the display unit further comprises at least one color conversion layer, the at least one color conversion layer is sequentially arranged on one side, far away from the driving backboard, of the first sub-pixel, and the projection of the first sub-pixel on the driving backboard is positioned in the projection of any one color conversion layer of the at least one color conversion layer on the driving backboard; according to the application, the pixel units realize multicolor display by combining the sub-pixels in the second device layer in a mode of performing color conversion on part of the sub-pixels in the first device layer and reserving part of the sub-pixels, so that the pixel density is improved, and compared with the current situation that the pixel units are thicker or the color purity of the target light source is not ideal after color conversion in the prior art, the pixel units can be effectively reduced in thickness, the thickness of the color conversion layer is increased, the depth-to-width ratio is increased, and the brightness and the color purity of the target light source after color conversion are effectively improved; in the application, the sub-pixels in different device layers are arranged in a staggered manner in the horizontal direction, and compared with the scheme that the sub-pixels are vertically stacked, the problem of color crosstalk caused by photoixcitation can be effectively avoided;

Further, the application provides that the ratio of the sum of the depths of all the color conversion layers in the pixel unit to the sum of the widths of all the color conversion layers in the display unit is not less than 1:1; the pixel unit has a larger depth-to-width ratio, so that the absorption and conversion efficiency of the color conversion layer to the first sub-pixel light can be effectively improved, the brightness of a target light source is improved, the color purity abnormality is avoided, the colorization abnormality caused by light leakage can be effectively avoided, and the miniaturization of the pixel unit is facilitated;

any one of the first sub-pixel, the second sub-pixel and the third sub-pixel in the pixel unit is one of a hemispherical structure and a semi-ellipsoidal structure; the application increases the light extraction efficiency by adopting a hemispherical sub-pixel or a semi-ellipsoidal sub-pixel, and improves the brightness by more than 30 percent;

the application provides a display unit in the pixel unit, which also comprises at least one enhancement structure; any reinforcing structure is arranged around the circumference of the first color conversion layer; and/or, any reinforcing structure is arranged around the circumference of the second color conversion layer; and/or, any reinforcing structure is arranged around the circumference of the second sub-pixel and/or the third sub-pixel; according to the application, the metal shielding among the sub-pixels is realized by arranging at least one enhancement structure, so that the optical crosstalk is effectively avoided, the structural reliability is improved, and the depth-to-width ratio is further improved; on the basis, the light screen structure and the enhancement structure are matched to form the inverted groove type structure, so that the color conversion layer can be fully sealed, light leakage is effectively avoided, and the reliability is further improved;

And when the first color conversion layer is constructed, the first device layer is etched to form the first groove, and the first groove is filled with the color conversion material to form the first color conversion layer.

It should be noted that, the present application only needs to achieve at least one of the above technical effects.

Drawings

Fig. 1 is a top view of a pixel unit in embodiment 1;

FIG. 2 is a cross-sectional view of the section A-B of FIG. 1 in a configuration;

FIG. 3 is a cross-sectional view of section A-B of FIG. 1 in yet another configuration;

FIG. 4 is a cross-sectional view of section A-B of FIG. 1 in yet another configuration;

FIG. 5 is a cross-sectional view of section A-B of FIG. 1 in yet another configuration;

FIG. 6 is a cross-sectional view of section A-B of FIG. 1 in yet another configuration;

FIG. 7 is a cross-sectional view of section A-B of FIG. 1 in yet another configuration;

FIG. 8 is an exemplary driving circuit configuration diagram;

FIG. 9 is an exemplary circuit block diagram corresponding to a device layer;

FIG. 10 is a top view of the drive backplate;

Fig. 11 is a schematic structural diagram of the first target compound semiconductor of example 2 after bonding to a driving back plate;

FIG. 12 is a schematic view of the structure of the first device layer formed in example 2;

fig. 13 is a schematic structural view of the first color conversion layer formed in the constitution of embodiment 2;

fig. 14 is a schematic structural view of the anode electrical connection structure and the reinforcing structure constructed in example 2;

fig. 15 is a schematic structural diagram of the second target compound semiconductor of example 2 after bonding to the first device layer;

fig. 16 is a schematic structural view of the anode electrical connection structure and the reinforcing structure constructed in example 5;

fig. 17 is a schematic structural view of the first color conversion layer in embodiment 5;

FIG. 18 is a schematic view showing the structure of forming the first device layer in example 5;

FIG. 19 is a schematic view showing the structure of a micro display in embodiment 6;

fig. 20 is a schematic diagram of the structure of a pixel-level discrete device in embodiment 7.

Reference numerals:

100-pixel unit, 10-driving back plate, 11-anode, 20-display unit, 21-first color conversion layer, 22-second color conversion layer, 23-enhancement structure, 24-optical screen structure, 30-first device layer, 31-first sub-pixel, 32-second sub-pixel, 33-first passivation layer, 34-first ohmic layer, 35-first insulating encapsulation layer, 36-first conductive layer, 37-second conductive layer, 40-second device layer, 41-third sub-pixel, 42-second passivation layer, 43-second ohmic layer, 44-second insulating encapsulation layer, 45-anode electrical connection structure, 46-third conductive layer, 50-optical lens, 110-first target compound semiconductor, 111-first P-type ohmic contact layer, 112-first active quantum well layer, 120-second target compound semiconductor, 200-micro display screen, 300-micro display screen, 400-display area, 500-peripheral common cathode, 600-external interface, 700-second insulating encapsulation layer, 45-anode electrical connection structure, 46-third conductive layer, 50-optical lens, 110-first target compound semiconductor, 111-first P-type ohmic contact layer, 112-first P-type ohmic contact layer, 300-micro display screen, 300-micro-display screen, 400-type active display device, and 730-split device.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present application more apparent, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

In the description of the present application, it should be understood that the directions or positional relationships indicated by the terms "upper", "lower", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of description of the present application and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present application. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, unless otherwise indicated, the meaning of "a plurality" is two or more.

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "connected," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art.

Example 1

As shown in fig. 1 to 7, the present embodiment provides a pixel unit 100, and the pixel unit 100 is used for a semiconductor device including, but not limited to, micro-LEDs, micro-lasers, and other optoelectronic devices. The pixel unit 100 includes a driving back plate 10 and a display unit 20 disposed on the driving back plate 10.

Description: fig. 1 is a top view of a pixel unit 100, fig. 2 to 7 are cross-sectional views of a section a-B of the pixel unit 100 in different structures, and subsequent structural views are also top views of the pixel unit in the current structure or corresponding cross-sectional views of the section a-B.

The driving backplate 10 in this embodiment may be one or more active backplates combined with Thin Film Transistors (TFTs), LTPS low temperature polysilicon, CMOS integrated circuits, high mobility transistors (HEMTs), etc. Specifically, the driving back plate 10 is provided with a driving circuit, the driving circuit 10 is provided with at least one anode 11, and an exemplary circuit configuration of the driving circuit is shown in fig. 8. It should be noted that, the circuit diagram shown in the embodiment is only a simple schematic diagram. The driving circuit may comprise an active, passive or semi-passive control circuit, as illustrated in fig. 9, which is an exemplary circuit diagram of any of the device layers. All anodes 11 included in the driving circuit may be arranged linearly or in an array, and any anode 11 is located in the middle or at the edge of the driving back plate 10, which is not limited in this embodiment.

For convenience of description, the number of anodes 11 included in the driving circuit in the driving back plate 10 in this embodiment is three, and the three anodes 11 are arranged linearly as shown in fig. 10.

In some embodiments, the drive backplate 10 comprises at least one Top Metal (Top Metal) covering at least one anode 11; alternatively, the drive backplate 10 includes an in-situ mirror disposed on an upper surface thereof, the in-situ mirror covering or uncovering at least one anode 11. The in-situ mirror may be a metal such as aluminum, gold, silver, etc.; the Bragg reflection layer can also be formed by stacking two or more films with different refractive indexes, such as a lamination of silicon oxide and titanium oxide, a lamination of silicon oxide and aluminum oxide, a lamination of silicon oxide and silicon nitride, and the like; it may also be an ODR total reflection mirror of a metal and dielectric stack, such as at least one combination of silver and silicon oxide, aluminum and aluminum oxide, gold and silicon oxide. Of course, in some embodiments, the driving backplate 10 includes a Top through hole (Top Via) corresponding to each anode 11.

With continued reference to fig. 2-7, the display unit 20 includes two or more device layers vertically stacked in sequence in a direction away from the drive backplate 10. The pixel unit 100 provided in this embodiment is a vertically stacked pixel (Vertically Stacked Pixels, VSP for short), and the VSP can effectively increase the pixel density compared to the pixel units having different pixels arranged in the same horizontal direction. For convenience of description, the embodiment is further exemplified by the display unit 20 including the first device layer 30 and the second device layer 40 vertically stacked in sequence, and the pixel unit 100 can realize multicolor display and white light display, and the structure of the two device layers can effectively reduce the thickness of the display unit 20.

The first device layer 30 includes a first subpixel 31, a second subpixel 32, a first passivation layer 33, and a first ohmic layer 34. The first sub-pixel 31 and the second sub-pixel 32 are arranged at intervals and are respectively connected with different anodes 11 to realize independent electric control. Typically, for ease of production, the first sub-pixel 31 and the second sub-pixel 32 are made of the same luminescent compound material, such as blue or green compound material, typically an InGaN material system. And the first passivation layer 33 is disposed on the surfaces of the first sub-pixel 31 and the second sub-pixel 32. The first ohmic layer 34 is disposed on the surface of the first passivation layer 33, and the first ohmic layer 34 is connected to the first sub-pixel 31 and the second sub-pixel 32 through the first passivation layer 33. Similarly, the second device layer 40 includes a third subpixel 41, a second passivation layer 42, and a second ohmic layer 43. Wherein the third sub-pixel 41 is connected to the corresponding anode 11. The second passivation layer 42 is disposed on the surface of the third sub-pixel 41, the second ohmic layer 43 is disposed on the surface of the second passivation layer 42, and the second ohmic layer 43 is connected to the third sub-pixel 41 through the second passivation layer 42.

The projection of the third sub-pixel 41 and the first sub-pixel 31 on the driving back plate 10 do not overlap, and the projection of the third sub-pixel 41 and the second sub-pixel 32 on the driving back plate 10 do not overlap. Therefore, when the short-wavelength light source with higher energy is independently lighted, the phenomenon of abnormal color purity such as variegation and the like caused by lighting the long-wavelength light source with relatively lower energy in a non-energized state based on the principle of photoexcitation can be effectively avoided.

The display unit 20 further includes at least one color conversion layer, which is sequentially disposed on a side of the first sub-pixel 31 away from the driving back plate 10. And, the projection of the first sub-pixel 31 on the driving back plate 10 is located in the projection of any color conversion layer of the at least one color conversion layer on the driving back plate 10, so that the light emitted by the first sub-pixel 31 basically passes through the at least one color conversion layer and is converted into the target light source.

It will be appreciated that the present embodiment uses the sub-pixel for color conversion in the device layer as the first sub-pixel 31, and any other sub-pixel not used for color conversion as the second sub-pixel 32. It will be appreciated that the number of first sub-pixels 31 includes, but is not limited to, one, and the number of second sub-pixels 32 includes, but is not limited to, one. And, the first sub-pixel 31, the second sub-pixel 32 are located in the same device layer, which may be the first device layer 30 or the second device layer 40. In order to obtain a larger depth-to-width ratio of the pixel unit 100 corresponding to the total of all the color conversion layers included in one target light source, it is preferable that the first sub-pixel 31 and the second sub-pixel 32 are located in the first device layer 30. Under this scheme, the ratio of the sum of the depths of all the color conversion layers for color conversion of the first sub-pixel 31 in the display unit 20 to the sum of the widths of all the color conversion layers in the display unit 20 is not less than 1:1 (the structure shown in fig. 2), preferably not less than 3:1 (the structure shown in fig. 3, 6), further preferably not less than 5:1 (the structure shown in fig. 4, 5), and even not less than 6:1 (the structure shown in fig. 7). Under the depth-to-width ratio, the total thickness of the color conversion layer of the pixel unit 100 in the μm level can reach more than 5 μm, even more than 10 μm, so that the problems of color conversion efficiency and light leakage are effectively overcome.

In addition, it should be noted that, the at least one color conversion layer includes, but is not limited to, a color conversion layer made of a material corresponding to one target light source, and when a plurality of sub-pixels are required to be respectively color-converted to obtain a plurality of different target light sources, only a plurality of corresponding sub-pixel-color conversion layer combinations are required to be provided. Therefore, various combinations of applications as described above are within the scope of the present embodiment. For convenience of description, the embodiment will be further described in detail by taking the example that the first device layer 30 includes the first sub-pixel 31 and the second sub-pixel 32, and at least one color conversion layer is disposed to convert the first sub-pixel 31 into the target light source.

The structure of each sub-pixel is not particularly limited in this embodiment, and a rectangular parallelepiped structure, a column structure, a spherical structure, a hemispherical structure, a semi-ellipsoidal structure, etc. are all within the scope of this embodiment. Preferably, at least one of the first, second and third sub-pixels 31, 32 and 41 is one of hemispherical structure and semi-ellipsoidal structure to increase light extraction efficiency and increase brightness by more than 30%.

The at least one color conversion layer may be located above the first sub-pixel 31, or at least partially cover the first sub-pixel 31. And, the present embodiment does not limit the number of color conversion layers of the same target light source. And, at least one color conversion layer is embedded in the first device layer 30, or partially embedded in the first device layer 30 and partially embedded in the second device layer 40, which are all within the scope of the present embodiment. And a plurality of color conversion layer splitting settings or integrated settings corresponding to the same target light source are all within the implementation range of the scheme.

Specifically, as shown in fig. 2 to 7, at least one color conversion layer includes a first color conversion layer 21, and at least a portion of the first color conversion layer 21 is embedded in the first device layer 30.

Referring further to fig. 2 to 5 and 7, in one embodiment, the first sub-pixel 31 is embedded in the first color conversion layer 21. Of course, the portions of the first passivation layer 33 and the first ohmic layer 34 on the surface of the first subpixel 31 are also embedded in the first color conversion layer 21.

With this structure, as shown in fig. 2 and 3, the display unit 20 includes a first color conversion layer 21, and the first color conversion layer 21 is embedded in the first device layer 30. The first device layer 30 is filled with a transparent dielectric material to form a first insulating encapsulation layer 35, and the first color conversion layer 21 is also embedded in the first insulating encapsulation layer 35. Therefore, the first sub-pixel 31 is embedded in the first color conversion layer 21, and the first color conversion layer 21 is embedded in the first insulating coating layer 35, so that the first insulating coating layer 35 can play a role in protecting the first color conversion layer 21 from moisture, and the reliability of the first color conversion layer 21 is effectively improved. In this embodiment, the first sub-pixel 31 has a hemispherical structure or a semi-ellipsoidal structure, and the first color conversion layer 21 is used to cover the first sub-pixel 31, so that all light rays in all directions of the first sub-pixel 31 can be absorbed and converted, and the absorption conversion rate is effectively improved.

On the basis, as shown in fig. 4 and 5, the display unit 20 further includes a second color conversion layer 22, and the second color conversion layer 22 is embedded in the second device layer 40. The second device layer 40 is filled with a transparent dielectric material to form a second insulating coating layer 44, so that the second color conversion layer 22 is embedded in the second insulating coating layer 44. Preferably, the second color conversion layer 22 is located directly above the first color conversion layer 21, and as a further preferred mode, the projection of the first color conversion layer 21 on the driving back plate 10 is located on the projection of the second color conversion layer 22 on the driving back plate 10, so as to further perform color conversion on the light converted by the first color conversion layer 21, effectively improve the depth-to-width ratio of the color conversion layer corresponding to the target light source, and further improve the absorption conversion efficiency of the light of the first sub-pixel 31.

In another embodiment, as shown in fig. 7, the first color conversion layer 21 extends in a direction away from the driving back plate 10 on the basis of the above-mentioned first color conversion layer 21 only included in the first device layer 30, and a part of the first color conversion layer 21 is embedded in the second device layer 40. With this structure, the color conversion layers included in the first device layer 30 and the second device layer 40 are connected to form a whole, so that the aspect ratio of the color conversion layer corresponding to the target light source is effectively improved, and the absorption conversion efficiency of the light of the first sub-pixel 31 is further improved.

In another embodiment, as shown in fig. 6, the display unit 20 includes a first color conversion layer 21, a portion of the first color conversion layer 21 is located in a first device layer 30, and a portion of the first color conversion layer 21 is located in a second device layer 40. Unlike the above embodiment, the minimum distance between the first color conversion layer 21 and the driving back plate 10 is greater than the maximum distance between the first ohmic layer 34 and the driving back plate 10. That is, the first color conversion layer 21 does not cover the first sub-pixel 31. Through verification, even though the light-emitting layer is not coated, compared with the thickness of the light-emitting layer in the prior art, the structure can obtain better light absorption conversion rate on the premise of having a color conversion layer with a larger depth-to-width ratio.

Of course, the pixel unit 100 further improves the light absorption conversion rate by adopting the aspect ratio, and the display unit 20 further includes at least one enhancement structure 23, wherein one end of any enhancement structure 23 is connected to the ohmic layer of the corresponding device layer, and the other end extends away from the driving back plate 10. In one embodiment, as shown in fig. 2 to 7, any reinforcing structure 23 is disposed around the first color conversion layer 21, and any reinforcing structure 23 is disposed around the second sub-pixel 32 or the third sub-pixel 41. In addition, in another embodiment, as shown in fig. 4 and 5, any reinforcing structure 23 is further disposed around the second color conversion layer 22. The pixel unit 100 in this embodiment effectively avoids optical crosstalk by providing at least one enhancement structure 23 to realize metal shielding between sub-pixels, and effectively avoids light leakage by providing the enhancement structure 23 in the circumferential direction of the color conversion layer, and further improves reliability and aspect ratio. Preferably, the reinforcing structures 23 extend in a direction away from the drive backplate 10 to extend through the respective device layers. Specifically, corresponding to the color conversion layer arrangement mode included in the display unit 20, the enhancement structure 23 extends through the entire first device layer 30, or the enhancement structure 23 extends through the entire second device layer 40, or the enhancement structure 23 extends through both the first device layer 30 and the second device layer 40 (including the second passivation layer 42 and the second ohmic layer 43).

Further, the thickness of the enhancement structure 23 increases from the end close to the driving back plate 10 to the end far from the driving back plate 10, so as to form a constraint side wall reflection structure with an inverted trapezoid cross section, and the first sub-pixel 31 is constrained and reduced to form an angle for emitting visible light, so that the collimation for emitting visible light is enhanced. In another preferred embodiment, the thickness of the reinforcing structure 23 decreases from the end near the driving back plate 10 to the end far from the driving back plate 10, forming a bowl-cup shape with a trapezoid-shaped cross section, and effectively supporting the first color conversion layer 21 formed in the reinforcing structure 23.

The display unit 20 further includes at least one light screen structure 24, and any one of the light screen structures 24 is covered on at least one light emitting surface of the first color conversion layer 21 or the second color conversion layer 22. Specifically, the light screen structure 24 is provided on at least one light emitting surface in the color conversion layer farthest from the first subpixel 31. As shown in fig. 5, in one embodiment, the light screen structure 24 is an inverted groove structure, and covers all the light emitting surfaces of the second color conversion layer 22, so as to further avoid the color purity abnormality caused by the light source leakage of the first sub-pixel 31. In another embodiment, as shown in fig. 5 to 7, any light screen structure 24 and the reinforcing structure 23 cooperate to form an inverted groove structure, and the groove structure wraps the first color conversion layer 21 or the second color conversion layer 22, so that color purity abnormality caused by light source leakage of the first sub-pixel 31 can be effectively avoided. Specifically, when the light screen structure 24 is an inverted trough structure, it is embedded in the reinforcing structure 23. When the light screen structure 24 is a plate-like structure, it is disposed on the light emitting surface of the color conversion layer furthest from the first sub-pixel 31 in the vertical direction and the end surface of the reinforcing structure 23, and forms an inverted groove structure in cooperation with the reinforcing structure 23. In the above two structures, the optical screen structure 24 and the reinforcing structure 23 are in a tight state, so as to improve the structural reliability.

Preferably, the first passivation layer 33 and the second passivation layer 42 are formed entirely, so as to avoid unnecessary exposure of the active portion to cause a short circuit. Of course, the openings for electrical connection and the like are necessarily exposed, for example, the portion of any passivation layer located on the surface of the sub-pixel is provided with an opening for connection of the sub-pixel to the ohmic layer in the current device layer, for example, the portion of the first passivation layer 33 located on the surface of the first sub-pixel 31 is provided with an opening through which the first ohmic layer 34 is connected to the first sub-pixel 31. Likewise, the first ohmic layer 34 and the second ohmic layer 43 are preferably of an entire structure having necessary openings so as to realize common cathodes of all sub-pixels in the same pixel unit 100, even common cathodes of semiconductor devices.

As described above, the third subpixel 41 is made of the same or different light-emitting compound material as the first subpixel 31 and the second subpixel 32, and when the materials are the same, a redundant structure is realized, and when the materials are different, multicolor display is realized. Preferably, in the present embodiment, the first sub-pixel 31, the second sub-pixel 32 and the third sub-pixel 41 are all made of InGaN material, and more preferably, the first sub-pixel 31 and the second sub-pixel 32 are both made of blue InGaN compound, and the third sub-pixel 41 is made of green InGaN compound. On the basis of this, the first color conversion layer 21 The second color conversion layers 22 are made of red light quantum dot material or red phosphor material, wherein the red light quantum dot material can be perovskite red light quantum dot (the quantum dot material can be CsPdI) ₃ At least one of a material, inP material, cdSe or CdS material). That is, the blue light source light of the first sub-pixel 31 is converted into a red light source through the first color conversion layer 21 or the combined action of the first color conversion layer 21 and the second color conversion layer 22, so as to realize the RGB full-color display. Moreover, the blue light InGaN compound is adopted as the excitation color conversion light source to form a red light source in combination with the color conversion layer formed by the red light quantum dot material, so that the AlGaInP system red light source with larger external quantum efficiency reduction caused by the size effect can be effectively replaced, and the power is further reduced and the brightness is improved. And, the red light system of the traditional GaAs substrate can be effectively replaced by adopting the mode of forming the red light source by color conversion in the embodiment, and the problem of arsenic related environmental protection brought by the traditional GaAs substrate device is solved.

Further referring to fig. 2 to 7, the first device layer 30 further includes at least one first conductive layer 36 and at least one second conductive layer 37 disposed at intervals, and either the first conductive layer 36 or the second conductive layer 37 is connected to the corresponding anode 11. The first sub-pixel 31 and the second sub-pixel 32 are respectively connected to a first conductive layer 36. The second device layer 40 further includes an anode electrical connection structure 45 and at least one third conductive layer 46, the third sub-pixel 41 is connected to the third conductive layer 46, one end of the anode electrical connection structure 45 is connected to the second conductive layer 37, and the other end passes through the first insulating coating 35 and is connected to the third conductive layer 46, so as to realize anode electrical connection of the third sub-pixel 41. In a preferred embodiment, the projection of the anode electrical connection structure 45 onto the drive backplate 10 is located within the projection of the corresponding third conductive layer 46 onto the drive backplate 10. Therefore, in the embodiment, the anode electrical connection structure 45 is located directly under the third conductive layer 46, and compared with the arrangement mode in the prior art that the electrical connection structure is arranged at the side direction of the sub-pixel to reduce the light emitting area ratio, the arrangement mode of the anode electrical connection structure 45 in the embodiment can effectively improve the light emitting area ratio of the pixel unit 100, thereby improving the pixel density.

The first conductive layer 36 and the second conductive layer 37 are made of transparent conductive materials such as ITO and ZnO, or a laminate or alloy of metal materials such as Ni, au and Ag, and the third conductive layer 46 is preferably made of transparent conductive materials such as ITO and ZnO. And, the first passivation layer 33 and the second passivation layer 42 are made of transparent dielectric materials, respectively. And, the anode electrical connection structure 45 is made of metal simple substance such as Al, ti, cu, tiW or metal composite material.

Further, as shown in fig. 1 to 7, the display unit 20 further includes an optical lens 50 above, and the optical lens 50 is made of an inorganic transparent dielectric material or an organic transparent dielectric material. The optical lens 50 is preferably one of a hemispherical structure or a semi-ellipsoidal structure. The optical lens 50 can further improve the light emission brightness and optimize the light emission angle of the pixel unit 100.

On this basis, referring to fig. 3, in order to further reduce the thickness of the display unit 20, at least a part of the third sub-pixel 41 is embedded in the optical lens 50, and the second device layer 40 is fused with the optical lens 50, preferably the third sub-pixel 41 is completely embedded in the optical lens 50. That is, the second device layer 40 is filled with an inorganic transparent dielectric material and forms the optical lens 50, and the third sub-pixel 41 and the reinforcing structure 23 surrounding the third sub-pixel are embedded in the optical lens 50. Compared to the pixel unit 100 in fig. 2, 4 to 7, the structure further subtracts the thickness of the second device layer 40, so as to further reduce the thickness of the pixel unit 100 while ensuring the thickness of the color conversion layer.

In summary, the pixel unit in this embodiment performs color conversion on a part of the sub-pixels in the first device layer and retains a part of the sub-pixels for color conversion, and combines with the sub-pixels in the second device layer to realize multicolor display, so that the thickness of the pixel unit is reduced and the color conversion layer is increased on the basis of realizing multicolor display and improving the pixel density, and the brightness and color purity of the target light source after color conversion are effectively improved; in the application, the sub-pixels in different device layers are arranged in a staggered manner in the horizontal direction, and compared with the scheme that the sub-pixels are vertically stacked, the problem of color crosstalk caused by photoixcitation can be effectively avoided;

the pixel unit in the embodiment has a larger depth-to-width ratio, so that the absorption and conversion efficiency of the color conversion layer to the first sub-pixel light can be effectively improved, the brightness of the target light source is improved, the color purity abnormality is avoided, the color abnormality caused by light leakage can be effectively avoided, and the miniaturization of the pixel unit is facilitated;

in addition, the light extraction efficiency is increased by adopting a hemispherical sub-pixel or a semi-ellipsoidal sub-pixel, and the brightness is improved by more than 30%;

in addition, the embodiment realizes metal shielding among the sub-pixels by arranging at least one enhancement structure so as to effectively avoid optical crosstalk, improve the structure reliability and further improve the depth-to-width ratio; on the basis, the light screen structure and the enhancement structure are matched to form the inverted groove type structure, so that the color conversion layer can be fully sealed, light leakage is effectively avoided, and the reliability can be further improved.

Example 2

Corresponding to the pixel unit 100 in the above embodiment 1, the present embodiment provides a method for manufacturing a pixel unit, and the structure of the pixel unit 100 manufactured by the method is shown in fig. 2.

The manufacturing method comprises the following steps:

s10, preparing to drive the backboard 10. As shown in fig. 10, the surface of the driving back plate 10 is provided with at least one anode 11.

S20, manufacturing a display unit 20. Step S20 includes:

s201, the first target compound semiconductor 110 is bonded to the driving backplate 10 and the first sub-pixel 31 and the second sub-pixel 32 are configured to form the first device layer 30.

First, a first target compound semiconductor 110 is prepared, and the first target compound semiconductor 110 is typically a compound wafer or a wafer area of a predetermined size cut from the compound wafer. The compound wafer refers to a compound formed by two or more elements according to a definite atomic ratio, has definite forbidden band width and energy band structure and other semiconductor properties, and comprises crystalline inorganic compounds (such as III-V group and II-VI group compound semiconductors), organic compounds (such as organic semiconductors) and oxide semiconductors. In this embodiment, the green/blue InGaN ternary material system is mainly involved, and the substrate material may be GaN, si, siC, sapphire or the like.

The P-contact surface of the first target compound semiconductor 110 is prepared to form a first P-type ohmic contact layer 111. The first target compound semiconductor 110 includes a substrate and a first active quantum well layer 112, wherein a P contact surface is on a side of the first active quantum well layer 112 away from the substrate, and a first N-type ohmic contact surface is on a side of the first active quantum well layer close to the substrate.

Specifically, in the case of preparing an ohmic contact layer on the P contact surface of the first target compound semiconductor 110, the contact material may be a transparent conductive material such as ITO or ZnO, or may be a laminate or alloy of metal materials such as Ni, au, ag, be, zn. In one embodiment, a GaN-based blue InGaN compound or a GaN-based green InGaN compound is selected, and AuBe alloy film is coated by vapor deposition, sputtering and the like, wherein the AuBe alloy film thickness is 60nm and N is used for coating the alloy film ₂ And annealing at 410 ℃ in the environment to form ohmic contact and form the first P-type ohmic contact layer 111, wherein the thickness of the compound surface coating contact layer and the contact forming conditions can be adjusted and changed according to requirements.

Then, bonding materials are respectively plated on the surfaces of the first P-type ohmic contact layer 111 of the first target compound semiconductor 110 and the driving back plate 10. The bonding material is conductive material, such as ITO, znO, or Au, al, cu, sn, or alloy, or adhesion layer comprising Cr, ti, or other metal structure. For example, a metal composite layer formed by sputtering or vapor plating Cr10nm and Au50nm is formed on the surfaces of the first P-type ohmic contact layer 111 of the first target compound semiconductor 110 and the driving back plate 10, respectively. In a preferred embodiment, after a surface planarization process, first using CMP, the bonding layer surface is activated with a plasma surface to render the surface hydrophilic, prior to bonding. Wherein, the surface roughness after CMP planarization treatment is less than or equal to 5nm, and the power is 200W O during plasma activation ₂ The treatment in the plasma atmosphere is completed for 60 s.

Next, the first target compound semiconductor 110 is bonded to the driving backplate 10, and the substrate of the first target compound semiconductor 110 is removed, exposing the first active quantum well layer 112, as shown in fig. 11. Specifically, the bonding of the first target compound semiconductor 110 to the drive back plate 10 is performed at a low temperature. And then removing the substrate by wet etching at 150 ℃.

The bonding material after bonding is combined with the first P-type ohmic contact layer 111 to form a conductive layer.

When the first active quantum well layer 112 is a blue compound epitaxial layer or a green compound epitaxial layer, the specific structure of the first target compound semiconductor 110 is shown in table 1 or table 2 below, and the common substrate may include materials such as sapphire, silicon carbide, gallium nitride, etc.:

TABLE 1

Layer name	Material of material
		First P-type ohmic contact layer	P-GaN
First active quantum well layer	InGaN&GaN
		First N-type ohmic contact layer	N-GaN
Substrate and method for manufacturing the same	Sapphire

TABLE 2

Layer name	Material of material
		First P-type ohmic contact layer	P-GaN
First active quantum well layer	InGaN&GaN
		First N-type ohmic contact layer	GaN
Substrate and method for manufacturing the same	Si

Then, the first active quantum well layer 112 is subjected to patterned exposure or patterned mask to form a first sub-pixel 31 and a second sub-pixel 32, wherein the first sub-pixel 31 and the second sub-pixel 32 have a hemispherical structure or a semi-ellipsoidal structure. And patterning and etching the conductive layers to form at least two first conductive layers 36 and at least one second conductive layer 37, wherein the first conductive layers and the second conductive layers 32 are respectively positioned on different first conductive layers 36, and the second conductive layers 37 are used for electric connection of upper device layers.

Next, the transparent dielectric material is plated on the sides of the first sub-pixel 31 and the second sub-pixel 32 to form a first passivation layer 33, and openings corresponding to the first sub-pixel 31, the second sub-pixel 32 and the second conductive layer 37 are formed by patterning etching. Specifically, the first passivation layer 33 is prepared by ALD, CVD, PVD and the like, and the first passivation layer 33 includes, but is not limited to, a single transparent dielectric layer formed of aluminum oxide, silicon nitride, aluminum nitride, or a composite layer of multiple layers. Then, a transparent conductive material is coated on the surface of the first passivation layer 33 to form a first ohmic layer 34, and at least one opening corresponding to the openings of the first passivation layer 33 and the second conductive layer 37 is formed by using patterned etching. Specifically, a transparent conductive film is prepared as the first ohmic layer 34 by means of electron beam, ion beam, sputtering, or the like. The material of the first ohmic layer 34 may be transparent conductive metal oxide such as ITO, znO, or a thin alloy or laminate of metal such as Al, au, ge, ni, cr, or a mixture of metal oxide and metal such as a mixture of ITO and Al, a mixture of ITO and Au, or a mixture of ITO and Ag. By the preparation of the first ohmic layer 34, a common cathode is formed. Next, a transparent dielectric material is filled and the surface is planarized to form a first insulating layer 35, and the specific structure is shown in fig. 12.

After forming the first device layer 30, the method further includes a step S202 of structuring the first color conversion layer 21. Specifically, step S202 includes:

s202a, performing patterned etching on the first device layer 30 to form a first groove, where the first groove is formed on a side of the first sub-pixel 31 away from the driving backplate 10.

Specifically, the first insulating encapsulation layer 35 is patterned and etched to form a first groove, where the aspect ratio of the first groove is the aspect ratio of the first color conversion layer 21. The first recess extends below to the first ohmic layer 34.

S202b, filling the first groove with a color conversion material to form the first color conversion layer 21, where the projection of the first sub-pixel 31 on the driving back plate 10 is located in the projection of the first color conversion layer 21 on the driving back plate 10. When the first sub-pixel 31 has a hemispherical structure or a semi-ellipsoidal structure, the first color conversion layer 21 is coated on the circumference of the first sub-pixel 31 to fully absorb the visible light emitted from the light emitting surface of the first sub-pixel 31.

The specific structure after this step is performed as described above with reference to fig. 13.

Preferably, after step S202b, further step S202c is performed to planarize the first insulating layer 35 again, so as to form a transparent dielectric material with a certain thickness on the upper surface of the first color conversion layer 21, so as to form protection such as moisture isolation for the first color conversion layer 21, and improve the reliability of the first color conversion layer 21.

After the above step S202 is completed, step S20 further includes:

s203, constructing at least one anode electrical connection structure 45 and at least one reinforcing structure 23.

Specifically, the through holes corresponding to the at least one anode electrical connection structure 45 and the at least one reinforcing structure 23 are respectively configured by patterning etching, and then the through holes are filled with metal to configure the corresponding at least one anode electrical connection structure 45 and the at least one reinforcing structure 23. In the pixel unit 100 formed in this way, the thickness of the reinforcing structure 23 increases gradually from one end close to the driving back plate 10 to one end far away from the driving back plate 10, so as to form a constraint type side wall reflecting structure with an inverted trapezoid cross section, and the constraint reduces the angle emitted by visible light, so that the optical crosstalk between pixels can be shielded more thoroughly. The anode electrical connection structure 45 is used for anode electrical connection of the upper device layer, and the anode electrical connection structure 45 is connected with the second conductive layer 37, and the other end extends toward a direction away from the driving back plate 10.

Specifically, a metal material is deposited in the through hole through sputtering, electroplating and other processes to fill the through hole, and then a CMP scheme is used to polish the redundant metal to expose the channel, so as to form at least one penetrating reinforcing structure 23 and at least one anode electrical connection structure 45, so as to thoroughly shield the optical crosstalk between the sub-pixels. The specific structure after this step is performed as described above with reference to fig. 14.

S203, bonding the second target compound semiconductor 120 with the first device layer 30 and configuring the third sub-pixel 41 to form the second device layer 40, as shown in fig. 15. Wherein the projection of the third sub-pixel 41 and the first sub-pixel 31 on the driving back plate 10 are not overlapped, and the projection of the third sub-pixel 41 and the second sub-pixel 32 on the driving back plate 10 are not overlapped. The fabrication of the second device layer 40 refers to the foregoing fabrication process of the first device layer 30, and will not be described herein.

S30, constructing an optical lens 50. A transparent dielectric material fill and patterned mask is performed on the side of the second device layer 40 remote from the first device layer 30 to form a hemispherical optical lens 50. The specific structure after this step is performed is shown with reference to fig. 2.

In the pixel unit 100 manufactured in this embodiment, the aspect ratio of the first color conversion layer 21 is not less than 1:1, which is compared with the prior art, the aspect ratio of the first color conversion layer 21 is increased while the thickness of the pixel is reduced.

Therefore, when the first color conversion layer is constructed, the method for manufacturing the pixel unit provided by the embodiment adopts the mode that the first device layer is etched to form the first groove, and the first groove is filled with the color conversion material to form the first color conversion layer.

Example 3

The present embodiment provides a further method for fabricating a pixel unit, which is used to fabricate the pixel unit 100 shown in fig. 4 or fig. 5. The manufacturing method in this embodiment is different from that in embodiment 2 only in that:

after step S203, step S20 further includes S204, constructing the second color conversion layer 22. Specifically, step S204 includes:

s204a, etching the second device layer 40 to form a second groove, wherein the second groove is formed on one side of the first color conversion layer 21 away from the driving backboard 10;

s204b, filling the second groove with a color conversion material to form a second color conversion layer 22, where the projection of the first sub-pixel 31 on the driving back plate 10 is located in the projection of the second color conversion layer 22 on the driving back plate 10. The second color conversion layer 22 is also made of red light quantum dot material or red phosphor material.

Preferably, as shown in fig. 4, a light screen structure 24 is formed on the surface of the second color conversion layer 22, and the light screen structure 24 is an inverted groove structure, so as to further prevent light leakage.

In the pixel unit 100 manufactured in this embodiment, the integrated depth-to-width ratio of the first color conversion layer 21 and the second color conversion layer 22 is not less than 5:1, which greatly increases the depth-to-width ratio of the color conversion layer while reducing the pixel thickness compared with the prior art.

Example 4

The present embodiment provides a further method for fabricating a pixel unit, which is used to fabricate the pixel unit 100 shown in fig. 6 or fig. 7. The manufacturing method in this embodiment is different from that in embodiment 2 only in that:

s20, manufacturing a display unit 20.

Step S20 includes:

S202, the second target compound semiconductor 120 is bonded to the first device layer 30 and the third subpixel 41 is configured to form the second device layer 40.

S203, constructing the first color conversion layer 21, including:

s203a, sequentially etching the second device layer 40 and the first device layer 30 to form a third groove, where the third groove is formed on a side of the first sub-pixel 31 away from the driving backplate 10.

S203b, filling the third groove with a color conversion material to form the first color conversion layer 21, where the projection of the first sub-pixel 31 on the driving back plate 10 is located in the projection of the first color conversion layer 21 on the driving back plate 10.

In step S203a, the first color conversion layer 21 formed when the third recess is not etched to the first ohmic layer 34 is shown in fig. 6, and the first color conversion layer 21 formed when the third recess is etched to the first ohmic layer 34 is shown in fig. 7. It is apparent that, in the pixel unit 100 shown in fig. 7, the aspect ratio of the first color conversion layer 21 is larger and not smaller than 6:1.

Example 5

The present embodiment provides a further method for fabricating a pixel unit, which is used to fabricate the pixel unit 100 shown in fig. 3. The manufacturing method in this embodiment is different from that in embodiment 2 only in that:

s20, manufacturing a display unit 20. Step S20 includes:

Specifically, step S201 includes:

s201a, bonding the first target compound semiconductor 110 to the driving backplate 10 and constructing the first sub-pixel 31 and the second sub-pixel 32, and forming the corresponding first passivation layer 33 and the first ohmic layer 34.

S201b, forming the reinforcing structure 23 and the anode electrical connection structure 45 by adopting the patterned coating. The specific structure after this step is performed is shown with reference to fig. 16.

S201c, the first color conversion layer 21 is formed by patterning or fixed-point inkjet printing. The cross section of the reinforcing structure 23 constructed in S201b is a trapezoid structure, so that the first color conversion layer 21 formed in the reinforcing structure 23 can be effectively supported, and the structural reliability is improved. The specific structure after this step is performed is shown with reference to fig. 17.

S201d, performing device layer filling and planarization by using a transparent dielectric material, forming a first insulating encapsulation layer 35, and forming a first device layer 30. The specific structure after this step is performed is shown with reference to fig. 18.

S202, the second target compound semiconductor 120 is bonded to the first device layer 30 and the third subpixel 41 is configured.

S30, constructing an optical lens 50. A transparent dielectric material fill and patterning mask is performed on the side of the third sub-pixel 41 remote from the first device layer 30 to form a hemispherical optical lens 50. The specific structure after this step is performed is shown with reference to fig. 3.

In contrast to the foregoing embodiment, in this embodiment, the pixel unit 100 is configured by first configuring the enhancement structure 23 and the first color conversion layer 21 and then performing device layer filling, and the configured third sub-pixel 41 is embedded in the optical lens 50, so that the thickness of the display unit 20 is further reduced, the thickness of the first device layer 30 can be greatly increased, and the aspect ratio of the first color conversion layer 21 is correspondingly increased, where the aspect ratio is not less than 3:1.

example 6

The present embodiment provides a micro display 200, as shown in fig. 19, the micro display 200 includes:

the micro display screen backboard 300, the micro display screen backboard 300 comprises at least two driving circuits, an input interface and an output interface;

the display area 400 is disposed on the micro display back plate 300, and the display area 400 includes at least two display units 20 of the pixel units 100 as in embodiment 1, and at least two display units 20 are arranged in an array;

The peripheral common cathode 500, the peripheral common cathode 500 is electrically connected to any one of the ohmic layers included in each of the display units 20, respectively, so that the entire micro display 200 is common to the cathodes. It should be noted that, the peripheral common cathode 500 is a metal frame structure surrounding the display area 400.

The external IO interface 600 is located at an arbitrary position of the micro display screen backboard 300.

Further, the arrangement direction of each pixel unit 100 in the micro display 200 that is arranged adjacently is not limited in this embodiment.

The specific structure and corresponding technical effects of the micro display in this embodiment are described in detail with reference to embodiment 1, which will not be described in further detail.

Example 7

As shown in fig. 20, the present embodiment provides a pixel-level discrete device 700, the pixel-level discrete device 700 including:

a discrete device backplane 710, the discrete device backplane 710 comprising at least three anode pads 730 and at least one cathode pad (not shown);

the device body 720, the device body 720 is disposed on the discrete device back plane 710, and the device body 720 includes at least two display units 20 as the pixel unit 100 in embodiment 1, and the at least two display units 20 are arranged in an array. And, either the first conductive layer 36 or either the second conductive layer 37 is connected to a corresponding anode pad 730, and the ohmic layer of either device layer is connected to a corresponding cathode pad.

All the above optional technical solutions can be combined to form an optional embodiment of the present application, and any multiple embodiments can be combined, so as to obtain the requirements of coping with different application scenarios, which are all within the protection scope of the present application, and are not described in detail herein.

It should be noted that the above-mentioned embodiments are only preferred embodiments of the present application, and are not intended to limit the present application, and any modifications, equivalent substitutions, improvements, etc. within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A pixel cell, wherein the pixel cell comprises:

a drive back plate;

The display unit further comprises at least one color conversion layer, the at least one color conversion layer is sequentially arranged on one side, far away from the driving backboard, of the first sub-pixel, and the projection of the first sub-pixel on the driving backboard is positioned in the projection of any one of the at least one color conversion layer on the driving backboard;

any one of the first sub-pixel, the second sub-pixel and the third sub-pixel is one of a hemispherical structure and a semi-ellipsoidal structure;

the first device layer further comprises a first passivation layer and a first ohmic layer; the first passivation layer is covered on the surfaces of the first sub-pixels and the second sub-pixels; the first ohmic layer is covered on the surface of the first passivation layer and penetrates through the first passivation layer to be respectively connected with the first sub-pixel and the second sub-pixel;

the at least one color conversion layer comprises a first color conversion layer, and at least part of the first color conversion layer is embedded in the first device layer; the first sub-pixel is embedded in the first color conversion layer.

2. The pixel cell of claim 1, wherein the ratio of the sum of the depths of all of the color conversion layers in the display cell to the sum of the widths of all of the color conversion layers in the display cell is not less than 1:1.

3. The pixel cell of claim 1, wherein a minimum distance between the first color conversion layer and the drive backplate is greater than a maximum distance between the first ohmic layer and the drive backplate.

4. The pixel cell of claim 1, wherein the first color conversion layer extends away from the drive back plate and a portion of the first color conversion layer is embedded in the second device layer.

5. The pixel cell of claim 1, wherein the at least one color conversion layer further comprises a second color conversion layer embedded within the second device layer.

6. The pixel cell of claim 5, wherein the display cell further comprises at least one enhancement structure;

7. The pixel cell of claim 6, wherein the display unit further comprises at least one light screen structure, any one of the light screen structures overlying at least one light emitting surface of the first color conversion layer or the second color conversion layer.

8. The pixel cell of claim 7, wherein any one of the light screen structures cooperates with the reinforcing structure to form an inverted channel structure, the channel structure encasing the first color conversion layer or the second color conversion layer.

9. The pixel cell of claim 1, further comprising an optical lens disposed on a side of the second device layer away from the drive back plate, at least a portion of the third sub-pixel being embedded within the optical lens.

10. The manufacturing method of the pixel unit is characterized by comprising the following steps:

preparing a driving backboard;

manufacturing a display unit, bonding a first target compound semiconductor with the driving backboard, and constructing a first sub-pixel and a second sub-pixel to form a first device layer; bonding a second target compound semiconductor with the first device layer and constructing a third subpixel to form a second device layer; the projection of the third sub-pixel and the projection of the first sub-pixel on the driving backboard are not overlapped, the projection of the third sub-pixel and the projection of the second sub-pixel on the driving backboard are not overlapped, and any one sub-pixel of the first sub-pixel, the second sub-pixel and the third sub-pixel is in one of a hemispherical structure and a semi-ellipsoidal structure; the first device layer further comprises a first passivation layer and a first ohmic layer; the first passivation layer is covered on the surfaces of the first sub-pixels and the second sub-pixels; the first ohmic layer is covered on the surface of the first passivation layer and penetrates through the first passivation layer to be respectively connected with the first sub-pixel and the second sub-pixel;

filling a color conversion material in the first groove to form a first color conversion layer, wherein the projection of the first sub-pixel on the driving backboard is positioned in the projection of the first color conversion layer on the driving backboard; at least part of the first color conversion layer is embedded in the first device layer; the first sub-pixel is embedded in the first color conversion layer.

11. The method of fabricating of claim 10, wherein after forming the second device layer, the method further comprises constructing a second color conversion layer comprising:

12. The manufacturing method of the pixel unit is characterized by comprising the following steps:

preparing a driving backboard;

filling a color conversion material in the third groove to form a first color conversion layer, wherein the projection of the first sub-pixel on the driving backboard is positioned in the projection of the first color conversion layer on the driving backboard; at least part of the first color conversion layer is embedded in the first device layer; the first sub-pixel is embedded in the first color conversion layer.

13. The manufacturing method of the pixel unit is characterized by comprising the following steps:

preparing a driving backboard;

performing device layer filling and planarization to form the first device layer; at least part of the first color conversion layer is embedded in the first device layer; the first sub-pixel is embedded in the first color conversion layer.

14. The micro display screen, its characterized in that, micro display screen includes:

the display area is arranged on the micro display screen backboard, and comprises at least two display units which are arranged in an array mode and are included by the pixel units according to any one of claims 1 to 9;

15. A pixel level discrete device, characterized in that the pixel level discrete device comprises:

the device main body is arranged on the discrete device backboard, and comprises at least two display units which are arranged in an array mode and are included in the pixel unit according to any one of claims 1 to 9.