Ultrasurface dynamic display device based on quantum dot photoresist and preparation method

Abstract

The present application provides a metasurface dynamic display device based on quantum dot photoresist and a preparation method. By combining the metasurface with the quantum dot photoresist, the device can achieve dynamic regulation of the displayed color. The metasurface itself can display structural colors, and the quantum dot photoresist can emit light of a specific color under UV light irradiation. The combination of the two can enhance specific colors or change the original colors, creating a richer and more varied color display effect to meet diverse visual needs. The response of quantum dot photoresist to UV light is reversible, which means that the color change can be repeatedly adjusted by controlling the switch or intensity of UV light, and this process does not damage the material itself, ensuring the long-term stability and durability of the device.

Description

Technical Field

[0001] The present application relates to the field of super-surface technology, and more specifically, to a super-surface dynamic display device based on quantum dot photoresist and a preparation method thereof. Background Art

[0002] The metasurface structure is an artificially designed composite structure. The properties of the metasurface structure do not depend on the intrinsic properties of the material that constitutes it, but on the artificially designed structure. Therefore, if the metasurface structure is set up based on optical display and optical modulation, the intensity, polarization and phase characteristics of the light field can be controlled. The size of this artificially designed structure is usually similar to or smaller than the wavelength of the electromagnetic wave.

[0003] Metasurfaces are mainly used in the fields of beam deflection devices, polarization conversion devices, local field enhancement, high-resolution holographic imaging and structural color display devices. As people have higher and higher demands for display devices, such as improving resolution and reducing device size to increase integration, higher challenges are posed to device design. Once the traditional metasurface structure is processed, the device performance is fixed and lacks good control characteristics. Therefore, it is necessary to seek more extensive and flexible methods to control metasurface display devices.

[0004] The existing technology has proposed a variety of ways to dynamically control metasurface structural color display devices, such as combining metasurfaces with liquid crystals, phase change materials, elastic substrates, etc., to achieve dynamic and flexible adjustment of the color of display devices. However, these solutions have limitations such as cumbersome processing, strict temperature or gas flux control, irreversible adjustment, and limited switching times. Summary of the invention

[0005] The purpose of the embodiments of the present application is to provide a metasurface dynamic display device and a preparation method based on quantum dot photoresist, so as to solve the problems of existing metasurface structural color control schemes, such as complicated processing, strict temperature or gas flux control or irreversible adjustment, and limited switching times.

[0006] An embodiment of the present application provides a metasurface dynamic display device based on quantum dot photoresist, comprising: a metasurface and a quantum dot photoresist; the metasurface is used to display structural color; the quantum dot photoresist is used to: under UV light irradiation, the quantum dot photoresist develops color, thereby realizing dynamic regulation of the metasurface structural color display.

[0007] In the above technical solution, by combining the metasurface with quantum dot photoresist, the device can achieve dynamic regulation of the displayed color. The metasurface itself can display structural colors, and the quantum dot photoresist can emit light of a specific color under UV light irradiation. The combination of the two can enhance specific colors or change the original colors, creating a richer and more varied color display effect to meet diverse visual needs. The response of quantum dot photoresist to UV light is reversible, which means that the color change can be repeatedly adjusted by controlling the switch or intensity of UV light, and this process does not damage the material itself, ensuring the long-term stability and durability of the device. Quantum dot photoresist can be directly spin-coated on the sample surface and combined with the metasurface structure through a graphical process. Compared with other methods for achieving metasurface structural color regulation, the processing flow is simple, the production cycle is greatly reduced, and it helps to reduce production time and economic costs. In addition, since quantum dot photoresist responds very quickly to UV light, the device also has a strong advantage in response speed in color regulation and has more practical application value.

[0008] In some optional embodiments, a transparent substrate is further included; the metasurface is disposed on the front side of the transparent substrate, and the quantum dot photoresist is disposed on the back side of the transparent substrate.

[0009] In some optional embodiments, the distribution of the quantum dot photoresist on the back of the transparent substrate corresponds to the structural color display pattern on the front of the transparent substrate, and the color difference before and after the combination of the metasurface structural color and the luminescent color of the quantum dot photoresist is less than a first threshold;

[0010] The quantum dot photoresist is used to develop color under UV light, thereby enhancing the color intensity and / or brightness and / or color saturation of the color displayed by the metasurface structure itself.

[0011] In the above technical scheme, when the luminescent color of the quantum dot photoresist is the same as or close to the color displayed by the metasurface structure itself, the metasurface structure color display can achieve the effects of enhanced color intensity, improved brightness and increased color saturation of the device display under the regulation of UV light.

[0012] In some optional embodiments, the distribution of the quantum dot photoresist on the back of the transparent substrate corresponds to the structural color display pattern on the front of the transparent substrate, and the color difference before and after the combination of the metasurface structural color and the luminescent color of the quantum dot photoresist is greater than a second threshold; wherein the second threshold is greater than or equal to the first threshold;

[0013] Quantum dot photoresist is used to develop color under UV light, thereby achieving color change in the color area displayed by the super surface structure.

[0014] In the above technical solution, when the luminescent color of the quantum dot photoresist is different from the color displayed by the metasurface structure itself, the metasurface structure color display can dynamically change and display different colors under the regulation of UV light.

[0015] In some optional embodiments, the quantum dot photoresist is used to develop color under UV light irradiation, thereby changing the super surface structural color display pattern.

[0016] In the above technical solution, the display of the metasurface structural color can be selectively adjusted in the region or pixel range by the patterning process of the quantum dot photoresist. This embodiment can be applied to the field of high-precision anti-counterfeiting and encryption. For example, the metasurface structural color display device is designed as a two-dimensional code graphic display, and the specific color quantum dot photoresist is selectively positioned in a specific area of ​​the metasurface structural color device. By switching on and off the UV light, the partial display color is changed, thereby realizing the switching of the display and hiding of the two-dimensional code graphic.

[0017] A method for preparing a dynamic display device provided in an embodiment of the present application includes:

[0018] Preparing a super surface; wherein the substrate of the super surface is a transparent substrate;

[0019] Uniformly coating a quantum dot photoresist of a specific thickness and a specific color on the back of a transparent substrate;

[0020] The quantum dot photoresist on the back side of the transparent substrate is patterned, leaving the quantum dot photoresist distributed according to the first pattern on the back side of the transparent substrate.

[0021] In the above technical solution, the transparent substrate can be made of quartz glass. Taking the amorphous silicon supersurface as an example, the preparation of the amorphous silicon supersurface includes the steps of depositing an amorphous silicon layer on a transparent substrate and micro-nano processing. A quantum dot photoresist of a specific thickness and a specific color is coated on the back of the transparent substrate to absorb or emit light of a specific wavelength. The quantum dot photoresist will photoluminesce or display bright colors under external stimulation (such as UV light). The quantum dot photoresist is evenly coated on the back of the transparent substrate by spin coating, spray coating or other appropriate coating techniques. According to the expected dynamic display effect, the first pattern of the quantum dot photoresist to be left on the back of the transparent substrate is designed, and then the quantum dot photoresist distributed according to the first pattern is left on the back of the transparent substrate by laser direct writing.

[0022] In some optional embodiments, preparing a metasurface includes:

[0023] Growing a metasurface material layer of a set thickness on the front side of the transparent substrate;

[0024] uniformly coating photoresist on the metasurface material layer;

[0025] Patterning the photoresist on the metasurface material layer to form a second pattern of photoresist;

[0026] Plating a metal mask on the photoresist of the second pattern, stripping the photoresist and the metal mask thereon, leaving the metal mask on the metasurface material;

[0027] Etching away the portion of the metasurface material not covered by the metal mask, leaving an array of columnar metasurface materials distributed according to a third pattern covered by the metal mask;

[0028] The metal mask on the top of the amorphous silicon column is etched away to complete the preparation of the super surface.

[0029] In the above technical solution, first, a layer of a super surface material layer of a set thickness, such as an amorphous silicon film, is grown on the front side of the selected transparent substrate by chemical vapor deposition (CVD), physical vapor deposition (PVD) or other suitable techniques. The super surface material layer serves as the basis for subsequent micro-nano structure processing. A layer of photoresist is uniformly coated on the surface of the super surface material layer. The selection of the photoresist should be determined based on its resolution, adhesion, etching resistance and other characteristics to ensure the smooth progress of the subsequent processing. The designed pattern (second pattern) is accurately transferred to the photoresist by using graphic techniques such as electron beam exposure. Electron beam exposure technology has the characteristics of high resolution and high precision and is suitable for the processing of micro-nano structures. After exposure, the chemical properties of the photoresist will change, and after development, the photoresist will form a pattern corresponding to the second pattern. A layer of metal (chromium or other suitable metal) mask is deposited on the developed photoresist. Subsequently, the photoresist and the metal mask thereon are stripped off together by an appropriate stripping process (such as wet stripping, dry stripping, etc.), leaving only the metal mask on the super surface material layer. This metal mask will serve as a masking layer for the subsequent etching process. Etching techniques such as reactive ion etching (RIE) are used to etch the portion of the metasurface material that is not blocked by the metal mask. RIE technology can accurately control the etching rate and etching depth to obtain high-quality micro-nano structures. After etching, only the columnar metasurface material array distributed according to the third pattern is left on the original metasurface material layer. Finally, an appropriate wet etchant is used to remove the metal mask on the top of the columnar metasurface material. Wet etching has the advantages of simple operation and low cost. After removing the metal mask, the final structure of the metasurface is presented, that is, a micro-nano structure formed by the columnar metasurface material distributed according to a specific pattern.

[0030] In some optional embodiments, growing a metasurface material layer of a set thickness on the front side of a transparent substrate comprises:

[0031] uniformly coating a photoresist on a transparent substrate;

[0032] Patterning the photoresist on the transparent substrate to obtain a photoresist with a first marking pattern;

[0033] Plating a metal mask on the photoresist of the first mark pattern, stripping the photoresist and the metal mask thereon, leaving the metal mark of the second mark pattern;

[0034] A metasurface material layer of set thickness is grown on a transparent substrate with metal markings.

[0035] In the above technical solution, a layer of photoresist is firstly uniformly coated on the surface of the transparent substrate. Using a graphical technique such as laser direct writing lithography, the designed first marking pattern is accurately transferred to the photoresist. On the first marking pattern formed on the photoresist, a metal mask, such as a metal tungsten mask, is plated by electroplating or other suitable metal deposition techniques. The selection of metal tungsten is based on its good stability and compatibility with subsequent processes. Subsequently, the photoresist and the metal mask attached thereto are removed by a stripping process, but the metal mark directly corresponding to the first marking pattern is retained on the transparent substrate. On the transparent substrate with the metal mark, a layer of super surface material with a set thickness is grown by chemical vapor deposition (CVD), physical vapor deposition (PVD) or other suitable techniques. The metal mark serves as a positioning mark to achieve the correspondence between the super surface layer and the quantum dot photoresist layer pattern.

[0036] In some optional embodiments, the first pattern corresponds to the third pattern, and the color difference before and after the combination of the metasurface structural color and the luminescent color of the quantum dot photoresist is less than a first threshold.

[0037] In some optional embodiments, the first pattern corresponds to the third pattern, and the color difference before and after the combination of the metasurface structural color and the luminous color of the quantum dot photoresist is greater than a second threshold; wherein the second threshold is greater than or equal to the first threshold. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 A schematic diagram of the structure of a super-surface dynamic display device based on quantum dot photoresist provided in an embodiment of the present application;

[0040] Figure 2 This is a schematic diagram of the present embodiment applied to the display of a two-dimensional code graphic;

[0041] Figure 3 A schematic flow chart of a method for preparing a dynamic display device provided in an embodiment of the present application;

[0042] Figure 4 A schematic diagram of the process for preparing an amorphous silicon supersurface provided in an embodiment of the present application.

[0043] Icons: 1-transparent substrate, 2-super surface, 3-quantum dot photoresist, 4-amorphous silicon layer, 5-photoresist, 6-metal chromium mask. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0045] Please refer to Figure 1 , Figure 1 A schematic structural diagram of a dynamic display device based on a metasurface 2 provided in an embodiment of the present application includes: a transparent substrate 1, a metasurface 2 arranged on the front side of the transparent substrate 1, and a quantum dot photoresist 3 arranged on the back side of the transparent substrate 1; the metasurface 2 is used to display structural color; the quantum dot photoresist 3 is used to: under UV light irradiation, the quantum dot photoresist 3 develops color, thereby realizing dynamic regulation of the structural color display of the metasurface 2.

[0046] Among them, the transparent substrate 1 is made of transparent quartz glass material, which is convenient for observing the color of the final experiment and avoiding the color interference of the substrate itself. At the same time, if the quantum dot photoresist 3 that can emit light of different colors is spin-coated on the back, the transparent substrate will not affect the penetration of the color and is convenient for combining with the color of the front metasurface 2. At the same time, quartz glass has high stability, which can avoid over-etching and damaging the integrity of the substrate when etching amorphous silicon.

[0047] The metasurface 2 structure selects metasurfaces 2 such as Si, SiN, and TiO2. Compared with metals such as Au and Ag, dielectric metasurface 2 has smaller loss in the visible light band and is more compatible with CMOS technology, so it has more practical application value.

[0048] On the one hand, quantum dot photoresist 3 can emit light through an efficient quantum dot structure and emit light of a specific wavelength through a specific quantum dot structure. On the other hand, mixing quantum dots in the photoresist can achieve accurate and efficient graphic design through exposure, and can also achieve the assembly of multiple quantum dot photoresists 3 of different colors on the same substrate by layer-by-layer coating.

[0049] In the embodiment of the present application, by combining the super surface 2 with the quantum dot photoresist 3, the device can realize dynamic regulation of the displayed color. The super surface 2 itself can display the structural color of a certain color range, and the quantum dot photoresist 3 can emit light of a specific color under UV light irradiation. The combination of the two can create a richer and more varied color display effect to meet the diverse visual needs. The response of the quantum dot photoresist 3 to UV light is reversible, which means that the change of color can be repeatedly adjusted by controlling the switch or intensity of the UV light, and this process is non-destructive to the material itself, ensuring the long-term stability and durability of the device. The quantum dot photoresist 3 can be directly spin-coated on the sample surface and combined with the super surface 2 structure through a graphical process. Compared with other methods for realizing the regulation of the super surface structural color, the processing flow is simple, the production cycle is greatly reduced, and it helps to reduce the time and economic cost of production. In addition, since the quantum dot photoresist 3 responds very quickly to UV light, the response speed of the device in color regulation also has a strong advantage, and has more practical application value.

[0050] In some optional embodiments, the distribution of the quantum dot photoresist 3 on the back of the transparent substrate 1 corresponds to the structural color display pattern on the front of the transparent substrate 1, and the color difference before and after the combination of the metasurface structural color and the luminescent color of the quantum dot photoresist;

[0051] The quantum dot photoresist 3 is used to develop color under UV light irradiation, thereby enhancing the color intensity and / or brightness and / or color saturation of the color displayed by the metasurface 2 itself.

[0052] In the embodiment of the present application, when the luminescent color of the quantum dot photoresist 3 is the same as or close to the color displayed by the metasurface 2 itself, the structural color display of the metasurface 2 can achieve the effects of enhanced color intensity, improved brightness and increased color saturation of the device display under the regulation of UV light.

[0053] In some optional embodiments, the distribution of the quantum dot photoresist 3 on the back of the transparent substrate 1 corresponds to the structural color display pattern on the front of the transparent substrate 1, and the color difference before and after the combination of the metasurface structural color and the luminescent color of the quantum dot photoresist is greater than a second threshold; wherein the second threshold is greater than or equal to the first threshold;

[0054] The quantum dot photoresist 3 is used to develop color under UV light irradiation, thereby realizing the color change of the color area displayed by the super surface structure.

[0055] In the embodiment of the present application, when the luminescent color of the quantum dot photoresist 3 is different from the color displayed by the metasurface 2 itself, the structural color display of the metasurface 2 can be realized by dynamically changing and displaying different colors under the regulation of UV light.

[0056] In some optional embodiments, the quantum dot photoresist 3 is used to develop color under UV light irradiation, change the color of a specific area, and thereby change the structural color display pattern of the metasurface 2 .

[0057] In the embodiment of the present application, by means of a patterning process of the quantum dot photoresist 3, the display of the structural color of the metasurface 2 can be selectively adjusted in color in a region or pixel range.

[0058] Please refer to Figure 2 , Figure 2 This is a schematic diagram of the present embodiment applied to the display of a two-dimensional code graphic. The metasurface 2 structural color display device is designed as a two-dimensional code graphic display. The specific color quantum dot photoresist 3 is selectively positioned in a specific area of ​​the metasurface 2 structural color device. By switching on and off the UV light, the partial display color is changed, thereby realizing the switching between displaying and hiding the two-dimensional code graphic. It should be clear that in addition to being applied to the display of two-dimensional code graphics, this embodiment can also be applied to other high-precision anti-counterfeiting and encryption graphic displays.

[0059] Please refer to Figure 3 , Figure 3 A schematic flow chart of a method for preparing a dynamic display device provided in an embodiment of the present application specifically includes:

[0060] Step 100, preparing an amorphous silicon supersurface 2; wherein the substrate of the amorphous silicon supersurface 2 is a transparent substrate 1;

[0061] Step 200, uniformly coating a quantum dot photoresist 3 of a specific thickness and a specific color on the back of a transparent substrate 1;

[0062] Step 300 , performing laser direct writing lithography on the quantum dot photoresist 3 on the back side of the transparent substrate 1 , leaving the quantum dot photoresist 3 distributed according to the first pattern on the back side of the transparent substrate 1 .

[0063] In the embodiment of the present application, the transparent substrate 1 can be made of quartz glass. The preparation of the amorphous silicon super surface 2 includes the steps of depositing an amorphous silicon layer 4 on the transparent substrate 1 and micro-nano processing. The back of the transparent substrate 1 is coated with a quantum dot photoresist 3 of a specific thickness and a specific color so that it can absorb or emit light of a specific wavelength. The quantum dot photoresist 3 will photoluminesce or display bright colors under external stimulation (such as UV light). The quantum dot photoresist 3 is evenly coated on the back of the transparent substrate 1 by spin coating, spray coating or other appropriate coating techniques. According to the expected dynamic display effect, the first pattern of the quantum dot photoresist 3 to be left on the back of the transparent substrate 1 is designed, and then the quantum dot photoresist 3 distributed according to the first pattern is left on the back of the transparent substrate 1 by laser direct writing.

[0064] Please refer to Figure 4 , Figure 4The schematic diagram of the process for preparing the amorphous silicon supersurface 2 provided in the embodiment of the present application, that is, step 100 specifically includes the following steps 110-160:

[0065] Step 110, growing an amorphous silicon layer 4 of a set thickness on the front surface of the transparent substrate 1;

[0066] Step 120, uniformly coating the photoresist 5 on the amorphous silicon layer 4;

[0067] Step 130, forming a second pattern of the photoresist 5 on the amorphous silicon layer 4 by electron beam exposure technology;

[0068] Step 140, plating a chrome mask on the photoresist 5 of the second pattern, stripping the photoresist 5 and the metal chrome mask 6 thereon, leaving the metal chrome mask 6 of amorphous silicon;

[0069] Step 150, etching away the amorphous silicon portion not covered by the metal chromium mask 6 by reactive ion etching, leaving the amorphous silicon pillars covered by the metal chromium mask 6 and distributed according to the third pattern;

[0070] Step 160: Remove the metal chromium mask 6 on the top of the amorphous silicon column by wet etching to complete the preparation of the amorphous silicon super surface 2.

[0071] In the embodiment of the present application, first, a layer of amorphous silicon film of a set thickness is grown on the front of the selected transparent substrate 1 by chemical vapor deposition (CVD), physical vapor deposition (PVD) or other suitable techniques. This layer of amorphous silicon film will serve as the basis for subsequent micro-nano structure processing. A layer of photoresist 5 is uniformly coated on the surface of the amorphous silicon layer 4. The selection of the photoresist 5 should be determined based on its resolution, adhesion, etching resistance and other characteristics to ensure the smooth progress of the subsequent processing. The designed pattern (second pattern) is accurately transferred to the photoresist 5 by electron beam exposure technology. Electron beam exposure technology has the characteristics of high resolution and high precision and is suitable for the processing of micro-nano structures. After exposure, the chemical properties of the photoresist 5 will change, and after development, the photoresist will form a pattern corresponding to the second pattern. A layer of metal chromium mask 6 (or other suitable metal) is deposited on the developed photoresist 5 to form a chromium mask. Subsequently, the photoresist 5 and the metal chromium mask 6 thereon are stripped off together by an appropriate stripping process (such as wet stripping, dry stripping, etc.), leaving only the metal chromium mask 6 on the amorphous silicon layer 4. This metal chromium mask 6 will serve as a masking layer for the subsequent etching process. Reactive ion etching (RIE) technology is used to etch the amorphous silicon portion that is not blocked by the metal chromium mask 6. RIE technology can accurately control the etching rate and etching depth to obtain a high-quality micro-nano structure. After etching, what remains on the amorphous silicon layer 4 are amorphous silicon columns distributed according to the third pattern. Finally, a suitable wet etchant is used to remove the metal chromium mask 6 on the top of the amorphous silicon column. Wet etching has the advantages of simple operation and low cost. After removing the metal chromium mask 6, the final structure of the amorphous silicon super surface 2 is presented, that is, a micro-nano structure formed by the amorphous silicon columns distributed according to a specific pattern.

[0072] In some optional implementations, step 110, growing an amorphous silicon layer 4 of a set thickness on the front surface of the transparent substrate 1, specifically includes:

[0073] Step 111, uniformly coating photoresist on the transparent substrate 1;

[0074] Step 112, performing laser direct writing lithography on the photoresist on the transparent substrate 1 to obtain a photoresist with a first marking pattern;

[0075] Step 113, plating metal tungsten on the photoresist of the first marking pattern, stripping the photoresist and the metal tungsten thereon, leaving the metal tungsten mark of the second marking pattern;

[0076] Step 114: growing an amorphous silicon layer 4 of a set thickness on the transparent substrate 1 marked with metal tungsten.

[0077] In the embodiment of the present application, a layer of photoresist is firstly uniformly coated on the surface of the transparent substrate 1. The designed first marking pattern is accurately transferred to the photoresist using laser direct writing lithography technology. On the first marking pattern formed on the photoresist, a layer of metal tungsten is plated by electroplating or other suitable metal deposition technology. The choice of metal tungsten may be based on its good stability and compatibility with subsequent processes. Subsequently, the photoresist and the metal tungsten attached thereto are removed by a stripping process, but the metal tungsten mark directly corresponding to the first marking pattern is retained on the transparent substrate 1. On the transparent substrate 1 with the metal tungsten mark, a layer of amorphous silicon layer 4 of a set thickness is grown by chemical vapor deposition (CVD), physical vapor deposition (PVD) or other suitable technology. The metal tungsten mark serves as a positioning mark to achieve the correspondence between the super surface layer and the quantum dot photoresist layer pattern.

[0078] In some optional embodiments, the first pattern corresponds to the third pattern, that is, the distribution area of ​​the amorphous silicon column is within the corresponding area of ​​the first pattern and is uniformly distributed in the corresponding area, and the color difference between the luminescent color of the quantum dot photoresist 3 and the structural color of the supersurface 2 is less than the first threshold.

[0079] In some optional embodiments, the first pattern corresponds to the third pattern, that is, the distribution area of ​​the amorphous silicon column is within the corresponding area of ​​the first pattern and is uniformly distributed within the corresponding area, and the color difference between the luminescent color of the quantum dot photoresist 3 and the structural color of the supersurface 2 is greater than a second threshold; wherein the second threshold is greater than or equal to the first threshold.

[0080] In a specific embodiment of the present application, a method for preparing a super-surface dynamic display device based on quantum dot photoresist comprises the following steps:

[0081] The photoresist is spin-coated on a transparent glass substrate, and a marker image is formed on the photoresist layer by exposing and developing it through laser direct writing technology. Subsequently, a layer of 80nm thick metal tungsten is deposited through metal magnetron evaporation and then metal stripping is performed to obtain a metal tungsten marker pattern on the transparent glass substrate.

[0082] An amorphous silicon layer with a certain nanometer thickness (the experimental control variable is uniformly 175nm) is grown on a marked glass substrate as the material for making the super surface.

[0083] Spin-coat photoresist on a glass substrate with markings and amorphous silicon grown on it with a certain nanometer thickness, and develop it through electron beam exposure (EBL) technology to form a series of designed specific nanoscale images on the photoresist layer. The specific graphics are circles with different nanometer diameters (not limited to this shape. In addition to the diameter of the circle can be changed to achieve different colors, elliptical, rectangular, and other more complex shapes can also be designed to achieve different colors. Specifically, COMSOL simulation software can be used to simulate and obtain different colors displayed by a metasurface array of a specific shape). Electron beam exposure (EBL) can achieve the exposure of high-precision nanoscale graphics and meet the processing requirements of high-precision structures on metasurfaces.

[0084] After development, a 30nm thick metal chromium is plated on the photoresist with the designed pattern as a mask, and then the photoresist is stripped off and the metal chromium on the surface is taken away, leaving a designed nanoscale image metal mask.

[0085] After metal stripping, the amorphous silicon part not covered by the metal chromium mask is etched away by reactive ion etching (RIE), leaving behind nanoscale amorphous silicon columns masked with metal chromium (or columnar amorphous silicon supersurface arrays with other patterns on the bottom).

[0086] The sample is immersed in a chemical solution by a wet method to etch away the metal chromium mask on the top of the amorphous silicon column, completing the preparation of the amorphous silicon supersurface (the micron-scale color array can be observed through an ordinary optical microscope).

[0087] After the preparation of the amorphous silicon super surface is completed, the quantum dot photoresist is spin-coated on the entire area or a part of the lower surface by spin coating or the like on the back side thereof, specifically comprising the following steps:

[0088] Step S1, turn over the glass substrate on which the amorphous silicon metasurface structure is prepared, and spin-coat a quantum dot photoresist of a certain thickness and specific color on the back surface (the thickness determines the number of quantum dots, thereby affecting the brightness of the back light; at the same time, the quantum dot photoresists that have been put into use in the experiment are red, blue and green. In theory, quantum dot photoresists of other colors can also be combined in the same way, such as blue, orange and other quantum dot photoresists sold on the market).

[0089] Step S2, subjecting the display device coated with quantum dot photoresist of specific thickness and color to laser direct writing exposure according to a specific pattern, and then developing, leaving a stable, difficult to remove photoluminescent quantum dot photoresist pattern of specific color on the back of the glass substrate.

[0090] Step S3, repeating step S2 with quantum dot photoresists of different thicknesses and colors, to obtain a colored quantum dot photoresist pattern on the back.

[0091] Step S4, the pattern of the quantum dot photoresist on the back of the glass substrate is selected according to the color of the front color metasurface array and the desired purpose. By utilizing the characteristics of the quantum dot photoresist being almost colorless when not excited and emitting bright light of a specific color after being excited, it is possible to achieve: enhancing the original color of the metasurface array (making the color more vivid), changing the original array color (making the color of a specific position of the front color metasurface change as specified), thereby achieving the enhancement of the color rendering function, and achieving the change of the pattern observed from the front by whether or not the light is excited. In practical applications, it can achieve functions such as display enhancement and pattern anti-counterfeiting.

[0092] It should be clarified that in this embodiment, the supersurface is prepared first and then the quantum dot photoresist is spin-coated. In other embodiments, the quantum dot photoresist can be spin-coated first and then the supersurface is prepared, or the quantum dot photoresist can be spin-coated and the supersurface is prepared alternately, or the quantum dot photoresist can be spin-coated and the supersurface can be prepared simultaneously.

[0093] In addition, in one or more of the above embodiments, the combination of the metasurface structural color and the quantum dot photoresist color is: the metasurface is on the front side of the transparent substrate, and the quantum dot photoresist is on the back side of the transparent substrate. However, it is not limited to the above combination, and the metasurface and the quantum dot photoresist may be respectively arranged on different layers on the front side of the substrate, or the metasurface and the quantum dot photoresist may be alternately arranged in different areas on the front side of the substrate.

[0094] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of the devices or units can be electrical, mechanical or other forms.

[0095] In addition, the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0096] Furthermore, the functional modules in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0097] In this document, relational terms such as first and second, etc. are used merely to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0098] The above description is only an embodiment of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A super-surface dynamic display device based on quantum dot photoresist, characterized in that: include: substrates, metasurfaces, and quantum dot photoresists; The metasurface is used to display structural color; The quantum dot photoresist is used for: under UV light irradiation, the quantum dot photoresist develops color, thereby realizing dynamic regulation of the super surface structural color display; The substrate comprises a transparent substrate, the metasurface is arranged on the front side of the transparent substrate, and the quantum dot photoresist is arranged on the back side of the transparent substrate; Or, the super surface and the quantum dot photoresist are respectively arranged on different layers on the front side of the substrate; Alternatively, the super surface and the quantum dot photoresist are alternately arranged in different areas on the front side of the substrate.

2. The dynamic display device according to claim 1, characterized in that: The distribution of the quantum dot photoresist on the back of the transparent substrate corresponds to the structural color display pattern on the front of the transparent substrate, and the color difference before and after the combination of the metasurface structural color and the luminescent color of the quantum dot photoresist is less than a first threshold; The quantum dot photoresist is used to develop color under UV light irradiation, thereby achieving color intensity enhancement and / or brightness improvement and / or color saturation increase of the color displayed by the super surface structure itself.

3. The dynamic display device according to claim 1, characterized in that: The distribution of the quantum dot photoresist on the back of the transparent substrate corresponds to the structural color display pattern on the front of the transparent substrate, and the color difference before and after the combination of the metasurface structural color and the luminescent color of the quantum dot photoresist is greater than a second threshold; wherein the second threshold is greater than or equal to the first threshold; The quantum dot photoresist is used to develop color under UV light irradiation, thereby achieving color change in the color area displayed by the super surface structure.

4. The dynamic display device according to claim 1, characterized in that: The quantum dot photoresist is used to develop color under UV light irradiation, thereby changing the super surface structural color display pattern.

5. A method for preparing a dynamic display device, characterized in that: include: preparing a metasurface on the front side of a transparent substrate; Coating quantum dot photoresist on the back side of the transparent substrate; Patterning the quantum dot photoresist on the back side of the transparent substrate, leaving the quantum dot photoresist distributed according to the first pattern on the back side of the transparent substrate; Wherein, the metasurface is used to display structural color; the quantum dot photoresist is used for: under UV light irradiation, the quantum dot photoresist develops color, thereby realizing dynamic regulation of the metasurface structural color display.

6. The method according to claim 5, characterized in that The method of preparing a super surface on the front side of a transparent substrate comprises: Growing a metasurface material layer of a set thickness on the front side of the transparent substrate; Uniformly coating photoresist on the metasurface material layer; Patterning the photoresist on the metasurface material layer to form a photoresist of a second pattern; Plating a metal mask on the photoresist of the second pattern, stripping the photoresist and the metal mask thereon, leaving the metal mask on the metasurface material; Etching away the portion of the metasurface material not covered by the metal mask, leaving an array of columnar metasurface materials distributed according to a third pattern and covered by the metal mask; The metal mask on the top of the amorphous silicon column is etched away to complete the preparation of the super surface.

7. The method according to claim 6, characterized in that The method of growing a super-surface material layer of a set thickness on the front side of the transparent substrate comprises: uniformly coating photoresist on the transparent substrate; Patterning the photoresist on the transparent substrate to obtain a photoresist with a first marking pattern; Plating a metal mask on the photoresist of the first mark pattern, stripping the photoresist and the metal mask thereon, leaving the metal mark of the second mark pattern; A metasurface material layer with a set thickness is grown on the transparent substrate with the metal mark.

8. The method according to claim 6, characterized in that The first pattern corresponds to the third pattern, and the color difference before and after the combination of the metasurface structural color and the luminescent color of the quantum dot photoresist is less than a first threshold.

9. The method according to claim 6, characterized in that The first pattern corresponds to the third pattern, and the color difference before and after the combination of the metasurface structural color and the luminous color of the quantum dot photoresist is greater than a second threshold; wherein the second threshold is greater than or equal to the first threshold.

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