A through-type wide color gamut all-solid-state electrochromic display and a preparation method thereof

Abstract

The present application relates to a kind of through type wide color gamut full solid-state electrochromic display and preparation method thereof.The structure of the through type wide color gamut full solid-state electrochromic display includes: bottom substrate, bottom electrode, micro-nano processed electrochromic layer, electron blocking layer, ion conducting layer, ion storage layer, second electrode.

Description

Technical Field

[0001] This invention belongs to the technical field of electrochromic functional materials and devices, specifically relating to a transmittance wide color gamut all-solid-state electrochromic display and its preparation method. Background Technology

[0002] The monitor market is showing a diversified development trend, with multiple display technologies coexisting. Cathode ray tube (CRT) monitors were the mainstream for the past few decades, relying on an electron gun to emit an electron beam to excite phosphors to emit light. They offered accurate color reproduction, wide viewing angles, and fast response times, but due to their bulky size, high power consumption, and strong radiation, they are now largely obsolete. Liquid crystal displays (LCDs) have rapidly risen to prominence due to their thinness, portability, low power consumption, and low radiation, becoming the most popular display type. They use liquid crystal molecules to control the light from a backlight under the influence of an electric field to create images, with thin-film transistor (TFT) technology further improving picture quality. Organic light-emitting diode (OLED) monitors stand out for their self-emissive characteristics, requiring no backlight. They offer extremely high contrast, extremely short response times, and can display incredibly vibrant and rich colors, creating a stunning visual effect. They are commonly used in high-end mobile phones, televisions, and other products. However, their high production costs, limited lifespan, and the risk of screen burn-in have limited their widespread adoption. Quantum dot light-emitting diode (QLED) displays, utilizing quantum dot materials to optimize light and color performance, boast a wide color gamut, outstanding brightness, and high color fidelity, offering unique advantages in image quality and gradually gaining prominence in the high-end display field. Plasma displays (PDPs) also once held a certain market share, using gas discharge to excite phosphors for light emission, offering high contrast, good color, and fast response times. However, due to high power consumption, significant heat generation, and short lifespan, they are now less common. Furthermore, displays are categorized by screen size: large screens for professional design and entertainment, medium screens for daily office work, and small screens for portability; by resolution: low, medium-high, and ultra-high resolution to meet different image quality needs; by screen form: flat and curved, with curved screens providing an immersive viewing experience; and by function: general-purpose, gaming, professional design, touchscreen, and 3D displays, each with its own specialization.

[0003] While display technology continues to innovate, numerous challenges remain. First, energy consumption remains a significant issue. LCD backlights consume considerable power, and OLED displays also exhibit substantial energy consumption at high brightness levels, posing a significant challenge to the battery life and energy consumption of mobile devices. Second, color accuracy and uniformity need improvement. Some displays exhibit color deviations and uneven brightness when viewed from different areas and angles, affecting professional design and viewing experiences. Third, eye strain from prolonged viewing is widespread. LED self-emissive displays emit strong blue light, which is highly irritating to the eyes, while some high-refresh-rate gaming monitors can also cause eye discomfort due to flickering frequency changes. Furthermore, the high cost of large-size, high-resolution, and high-performance displays hinders their further penetration into the mass market. The technology's lifespan and reliability also need optimization; for example, the burn-in phenomenon of OLED displays raises concerns among consumers. Summary of the Invention

[0004] To address the aforementioned technical problems, the present invention aims to provide a transmissive wide color gamut all-solid-state electrochromic display and its preparation method.

[0005] In a first aspect, the present invention provides a transmissive wide color gamut all-solid-state electrochromic display, the structure of which includes: a substrate, a bottom electrode, a micro / nano-fabricated electrochromic layer, an electron blocking layer, an ion conducting layer, an ion storage layer, and a second electrode.

[0006] Preferably, the material of the micro / nano-fabricated electrochromic layer includes WO3. 3-x1 MoO 3-x2 TiO 2-x3 It contains at least one of V2O5, with 0≤x1≤0.3, 0≤x2≤0.3, 0≤x3≤0.2, and a thickness of 200~600nm.

[0007] Preferably, the micro / nano-fabricated electrochromic layer is composed of an array of nano-columnar crystals containing nanopores; preferably, the diameter of the columnar crystals is 10-30 nm, the distance between the columnar crystals is 5-20 nm, the pore size of the nanopores is 2-15 nm, and the porosity of the electrochromic layer is 10-30%.

[0008] Preferably, the processing cycle of the micro-nano fabricated electrochromic layer is 0.5-10 μm × 0.5-10 μm, the processing depth is the thickness of the electrochromic layer, and the etching steepness angle is ≥70°; within a single processing cycle, the diameter of the processed pillar pixel is 100-800 nm, the height of the processed pillar pixel is the thickness of the electrochromic layer, and the number of processed pillar pixels is 1-10.

[0009] Preferably, the electron blocking layer material comprises a wide bandgap material with a bandgap width ≥ 3.5 eV, preferably SiO2, Al2O3, or SnO2, with a thickness of 5-20 nm.

[0010] Secondly, the present invention provides a method for fabricating the above-mentioned transmissive wide color gamut all-solid-state electrochromic display, the method comprising the following steps: fabricating an electrochromic layer by magnetron sputtering, and then micro-nano-fabricating the electrochromic layer according to the designed dimensions using an electron beam etching process.

[0011] Preferably, the process parameters for preparing the electrochromic layer by magnetron sputtering include: using tungsten, molybdenum, titanium, or vanadium as the target material; using argon and oxygen as the sputtering gas; a total pressure of 0.3-2.0 Pa; an oxygen partial pressure of 0-50%; a target-to-substrate distance of 10-20 cm; an initial substrate temperature of 50-150 °C; and applying a DC power supply of 200-450 W or a power density of 3.5-9.0 W / cm² to the target. 2 .

[0012] Preferably, the preparation method further includes annealing heat treatment after magnetron sputtering of the electrochromic layer; wherein the annealing heat treatment process includes: heating from room temperature to 375-500℃ at a heating rate of 5-50℃ / s and holding at that temperature for 2-60 minutes, and then naturally cooling to room temperature.

[0013] Preferably, the parameters of the electron beam etching process include: accelerating voltage 30-100 keV, beam current 50-100 pA, and working distance 5-10 mm.

[0014] Beneficial effects

[0015] (1) Based on optical simulation and micro-nano structure design, the present invention utilizes the diffraction of photons in the thin film to form three basic colors: cyan, magenta and yellow. After matrix combination, it can cover seven colors: red, orange, yellow, green, cyan, blue and purple. Based on the above thin film design, a full solid-state electrochromic display can be reversibly changed between color and dark, and has the advantage of wide color gamut display.

[0016] (2) The electrochromic display of this invention not only has low power consumption and good eye protection, but also has the advantage of high overall transmittance. It is suitable for applications such as displays, poster windows and exhibition cabinets. First, it has significant energy-saving advantages. Based on the bistable characteristics of electrochromic materials, static images consume almost no power and do not require backlights, which greatly reduces energy consumption and extends the battery life of mobile devices, in line with the current green energy-saving concept. Second, it has excellent visual experience. It has high contrast, wide viewing angle, no blind corners, natural color transition, and adjusts natural light to reduce eye fatigue. It is more comfortable for office work, watching movies or outdoor use. Third, it has great potential in terms of manufacturing and usage costs. The manufacturing process is relatively simple, reducing complex parts and production costs. Long-term use can save electricity bills due to energy saving, which is cost-effective. Fourth, it has a wide range of applications. It can be flexibly adapted to many fields such as smart windows in buildings, car windows and sunroofs to electronic devices and aerospace, meeting different needs, expanding the boundaries of displays, and is expected to promote display technology to a new level, bringing more convenience and innovation to people's lives. Attached Figure Description

[0017] Figure 1 This is an exemplary structural diagram of the transmissive wide color gamut all-solid-state electrochromic display provided by the present invention;

[0018] Figure 2 This is a cross-sectional SEM image of the electrochromic layer as an example of the present invention;

[0019] Figure 3 This is a schematic diagram of a three-nano-processed columnar pixel structure within an exemplary processing cycle;

[0020] Figure 4 This is an exemplary schematic diagram of a single WO3 nano-processed column pixel structure within a processing cycle, where D represents the diameter of the nano-processed column pixel.

[0021] Figure 5 A schematic diagram of a steep right angle etched for a micro / nano-fabricated electrochromic layer. Detailed Implementation

[0022] The present invention will be further illustrated by the following embodiments. It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the present invention.

[0023] First, such as Figure 1 As shown, the present invention provides a transmissive wide color gamut all-solid-state electrochromic display. The structure of the transmissive wide color gamut all-solid-state electrochromic display may include: a substrate, a bottom electrode, a micro / nano-fabricated electrochromic layer, an electron blocking layer, an ion conducting layer, an ion storage layer, and a second electrode, stacked sequentially; or, a substrate, a bottom electrode, an ion storage layer, an ion conducting layer, an electron blocking layer, a micro / nano-fabricated electrochromic layer, and a second electrode, stacked sequentially.

[0024] In some embodiments, the substrate material may include transparent materials such as glass, PMMA, and polycarbonate; the thickness may be 0.05-2 mm; and the transmittance in the visible light range of 380-780 nm wavelength may be ≥75%.

[0025] In some embodiments, the materials of the bottom electrode and the second electrode may include at least one of transparent conductive oxide (such as ITO), MXENE, and metal nanowires, and the sheet resistance may be 10–400 Ω / cm. 2 Preferably, the transmittance of the bottom electrode and the second electrode at wavelengths of 0.38-0.78 μm can be ≥75%, and the thickness of the second electrode can be 400 nm. Sheet resistance determines the device's response capability; excessive sheet resistance makes it difficult to drive the device to change color, while excessive sheet resistance results in excessive instantaneous current during color change, easily causing device breakdown. Setting a minimum transmittance satisfies the device's basic transmittance performance.

[0026] In some embodiments, the material of the micro / nano-fabricated electrochromic layer may include WO3. 3-x1 MoO 3-x2 TiO 2-x3 It contains at least one of V2O5, 0≤x1≤0.3, 0≤x2≤0.3, 0≤x3≤0.2, and the thickness can be 200~600nm.

[0027] Among them, such as Figure 2 As shown, the micro / nano-fabricated electrochromic layer can be composed of an array of nano-columnar crystals containing nanopores; preferably, the diameter of the columnar crystals can be 10-30 nm, the distance between the columnar crystals can be 5-20 nm, the pore size of the nanopores can be 2-15 nm, and the porosity of the electrochromic layer can be 10-30%. The height of the columnar crystals is the thickness of the electrochromic layer.

[0028] It should be noted that the nanopores in the electrochromic layer provided by this invention differ from conventional electrochromic layers with mesoporous structures. The latter primarily utilize the higher contact area of ​​the inorganic electrochromic layer with a mesoporous structure and the fully filled resin-based ion-conducting layer, thereby improving ion migration and transport efficiency and increasing its electrochromic response speed. In contrast, the nanopores disclosed in this invention prevent electrolytes from entering, and the size of the mesopores is smaller than that of conventional mesoporous structures. Furthermore, the main function of the nanopores in this invention is to buffer etching and withstand the size expansion of ions entering the electrochromic layer.

[0029] In some embodiments, the processing cycle of the micro-nano fabricated electrochromic layer can be 0.5-10 μm × 0.5-10 μm, the processing depth can be the thickness of the electrochromic layer, and the etching steepness angle is ≥70°; within a single processing cycle, the diameter of the processed pillar pixel can be 100-800 nm, the height of the processed pillar pixel can be the thickness of the electrochromic layer, and the number of processed pillar pixels can be 1-10.

[0030] like Figure 3 , 4 As shown in Figure 5, Figure 3 , 5 The gray block area in the image represents pixels used for position confirmation and color calibration. The processing cycle is the smallest unit of micro / nano fabrication design; the etching steep angle refers to the angle between the side of the micro / nano structure and the base surface; the more perpendicular the processed side, the larger the angle.

[0031] The transmissive wide color gamut electrochromic display provided by this invention utilizes the interaction of photons in a thin-film micro / nano structure based on optical simulation and micro / nano structure design. The mechanism of this color display is that light of a certain wavelength in sunlight interacts with the thin film. The periodic structure obtained through micro / nano processing generates a photonic bandgap. Within the photonic bandgap, light waves of a specific frequency are blocked from propagating, while light waves outside the bandgap can propagate, causing reflection of specific wavelengths while most light still passes through. In other words, when incident light irradiates the photonic crystal thin film, light wavelengths within the photonic bandgap are blocked, and only light outside the bandgap can pass through or be reflected, thus exhibiting structural colors and achieving a transmissive color display effect.

[0032] The parameters of the micro / nano fabrication are derived from optical simulations to achieve the widest possible color gamut and saturation. If the etching steepness is too small, the color gamut width of the device will decrease. If the period and diameter of the micro / nano fabrication are too small, the effective electrochromic area in the device will be too small, resulting in weakened color rendering control. If the period and diameter are too large, the light interference effect will be weak, reducing the ability to reflect light of specific wavelengths, thus weakening the color rendering control and significantly reducing the color gamut coverage.

[0033] Furthermore, by controlling the size of micro / nano structures, three primary colors—cyan, magenta, and yellow—can be formed. Using matrix combinations, these can cover seven colors: red, orange, yellow, green, cyan, blue, and violet. Alternatively, by designing micro / nano structures of different shapes within a single processing cycle, the interference of light by these shapes can be utilized, with each independent shape presenting a different color. This means covering the three primary colors within one cycle, and further mixing can achieve full-color mixing. After ion embedding into the micro / nano film layer driven by an external field voltage, the device changes from colored to dark. Assembling these into a complete all-solid-state device yields a transmissive wide-gamut display with dynamic tunability and color mixing design capabilities.

[0034] It should be noted that, unlike conventional techniques that involve inserting metal or structural color layers into the device separately, performing micro- and nano-fabrication, and then fabricating the electrochromic layer on a periodic structure, this invention directly performs micro- and nano-fabrication on the electrochromic layer. This significantly broadens the device's color rendering and control capabilities in the visible light region. Although periodic structures can all form structural colors, conventional techniques often only contain one fixed structure within each period, and the color-changing performance of the device is controlled using transmitted light, clearly lacking the ability for dynamic adjustment and color mixing. In contrast, this invention directly performs micro- and nano-fabrication on the electrochromic layer, utilizing ion entry and exit to change the intrinsic optical constants of the material, thereby switching from one color to another. The technical principle lies in leveraging the intersection of specific micro- and nano-structures with the structural color of photonic crystals, the chemical color of electrochromic materials, and light interference to ultimately achieve flexible multi-color changes and switching capabilities.

[0035] It is also important to note that electrochromic layers prepared using conventional techniques are often difficult to apply to direct etching micro / nano fabrication processes. This is primarily because conventional electrochromic layers typically consist of large (30-50 nm) columnar crystal structures, which are prone to collapse during processing, making high-precision micro / nano fabrication even more challenging. However, the electrochromic layer provided by this invention is composed of a columnar crystal array containing mesopores. This structure exhibits excellent processing performance and can be used for micro / nano fabrication. This is because the columnar crystals in the electrochromic layer of this invention contain numerous mesopores or cavities, resulting in a relatively loose bond between the columnar crystals. During ion beam cutting, each columnar crystal operates independently and does not interfere with the others, facilitating separation between the columnar crystal arrays. This, in turn, is beneficial for obtaining micro / nano structures with high verticality through ion beam cutting, further promoting improved display resolution. Conversely, if the bonding force between adjacent nanopillar arrays is too large during micro / nano fabrication, it will affect the steepness after processing and directly impact the display resolution. Meanwhile, the electrochromic layer with a special structure used in this invention can effectively promote the improvement of device cycling performance. This is because ions repeatedly enter and exit the electrochromic layer during device cycling. The large number of cavities in the electrochromic layer film in this invention can effectively accommodate the volume expansion of ions after entering the film, thereby improving the overall cycling performance of the device.

[0036] Furthermore, excessively large diameters of the nanopillar crystals can affect the steepness of the ion beam etching angle, thus impacting the display's resolution; conversely, excessively small diameters can lead to structural collapse and instability. Similarly, excessively large nanopores can cause structural instability, while excessively small nanopores result in strong bonding forces between the nanopillars, also affecting the ion beam etching process and its subsequent precision.

[0037] In some embodiments, the electron blocking layer material may include a wide bandgap material with a bandgap width ≥ 3.5 eV, preferably SiO2, Al2O3, or SnO2, and the thickness may be 5-20 nm.

[0038] Since some electrolyte may come into direct contact with the electrode after etching, posing a short-circuit risk, a wide bandgap semiconductor can effectively prevent electrons from recombinating directly with cations in the electrolyte layer (ion-conducting layer), forming irreversible defects. The wider the bandgap, the stronger the electron blocking ability; the thicker the layer, the stronger the electron blocking ability. However, excessive thickness will affect the period and diameter of the electrochromic layer after micro / nano fabrication, thereby affecting its optical modulation performance.

[0039] In some embodiments, the material of the ion-conducting layer may include LiTaO3, LiNbO3, Li 0.35 La 0.65 At least one of TiO3 and Li2Ti2O5, with a thickness of 10-50 nm.

[0040] In some embodiments, the material of the ion storage layer may include NiO. x V2O5, CoO x At least one of them, the thickness can be 20-120 nm.

[0041] In some embodiments, the color display of the transmissive wide color gamut all-solid-state electrochromic display covers red, yellow and blue, and after matrix combination, the human eye can recognize seven colors: red, orange, yellow, green, cyan, blue and purple; the electrochromic display has a response speed of ≤10s, a cycle life of ≥10,000 times, and a visible light transmittance of ≥50% before coloring.

[0042] Compared with LED displays, the electrochromic display provided by this invention has the following advantages: 1. Good energy saving: (1) Bistable characteristics: Electrochromic materials have bistable properties. After displaying static images, as long as the displayed content does not change, no power will be consumed. For example, electronic paper uses electrochromic technology. When displaying static information such as text, it consumes almost no power and can maintain the display state for a long time, which greatly saves power. LED displays need to be continuously powered to maintain light emission when working. Even when displaying static images, they will consume a certain amount of power. (2) No backlight required: Electrochromic displays do not need backlights. They display content by adjusting their own optical properties, which further reduces energy consumption. In contrast, LED displays usually need LED backlights to illuminate the screen, and backlights consume more power. 2. Good visual experience: (1) No blind angle: Electrochromic displays can maintain a good display effect when viewed from different angles. The viewing angle is wide and there is no obvious blind spot. Although LED displays also have a relatively wide viewing angle, they may experience reduced brightness and color distortion at some extreme angles. (2) High contrast: Electrochromic materials exhibit significant color changes during oxidation-reduction processes, achieving high optical contrast, making bright areas of the image brighter and dark areas darker, resulting in a more vivid, clear, and detailed picture; while LED displays can also achieve a certain level of contrast, they are generally not as high as electrochromic displays. (3) Reduced eye fatigue: Non-emissive transmissive electrochromic displays display content by adjusting natural light rather than emitting light, resulting in softer light, similar to the feeling of viewing objects under natural light, reducing eye stimulation, and making it less likely to cause eye fatigue after prolonged viewing; LED displays are self-emissive displays, emitting relatively strong light, which may cause eye discomfort after prolonged viewing.

[0043] The following describes, by way of example, a method for fabricating a transmittance wide color gamut all-solid-state electrochromic display provided by the present invention. The fabrication method may include the following steps:

[0044] (1) The bottom electrode and the electrochromic layer were sequentially prepared on the surface of the substrate by magnetron sputtering;

[0045] (2) The electrochromic layer film is micro- or nano-fabricated according to the designed size using electron beam etching process to obtain a micro- or nano-fabricated electrochromic layer;

[0046] (3) An electron blocking layer is prepared on the surface of the micro / nano-fabricated electrochromic layer using atomic layer deposition (ALD).

[0047] (4) An ion-conducting layer, an ion-storage layer, and a second electrode are deposited on the surface of the electron blocking layer using magnetron sputtering to obtain the transmissive wide color gamut all-solid-state electrochromic display; or,

[0048] (1) A bottom electrode, an ion storage layer, and an ion conduction layer were sequentially fabricated on the surface of a substrate by magnetron sputtering;

[0049] (2) An electron blocking layer is prepared on the surface of the ion-conducting layer using atomic layer deposition (ALD).

[0050] (3) An electrochromic layer is deposited on the surface of the electron blocking layer using a magnetron sputtering process;

[0051] (4) The electrochromic layer film is micro-nano-fabricated according to the designed size using electron beam etching process to obtain a micro-nano-fabricated electrochromic layer;

[0052] (5) A second electrode is deposited on the surface of the micro-nano fabricated electrochromic layer using magnetron sputtering to obtain the transmissive wide color gamut all-solid-state electrochromic display.

[0053] In some embodiments, the process parameters for preparing the electrochromic layer by magnetron sputtering may include: using tungsten, molybdenum, titanium, or vanadium as the target material; using argon and oxygen as the sputtering gas; a total pressure of 0.3-2.0 Pa; an oxygen partial pressure of 0-50%; a target-to-substrate distance of 10-20 cm; an initial substrate temperature of 50-150 °C; and a DC power applied to the target of 200-450 W or a power density of 3.5-9.0 W / cm². 2 The preferred initial substrate temperature is 90℃, and the DC power supply is 350W.

[0054] This invention increases the initial sputtering temperature, enabling sputtered particles to move rapidly on the substrate, forming more nucleation sites rather than layered growth. Furthermore, appropriately increasing the sputtering temperature helps improve the growth rate of nanopillars, promoting vertical growth of the nanoarray rather than lateral growth. If the initial substrate temperature is too low, nanoparticles tend to grow into islands, resulting in larger nanopillars and decreased device performance. If the initial substrate temperature is too high, the film crystallizes, resulting in a large number of crystalline particles, affecting subsequent high-precision processing capabilities. The DC power supply used for deposition affects the growth rate of the nanopillars. Insufficient power leads to a low growth rate, resulting in tightly bound nanopillars that hinder the formation of independent nanopillars, thus affecting film processing capabilities. Excessive power results in an overly dense film, similarly impacting processing capabilities.

[0055] In some embodiments, the preparation method may further include magnetron sputtering of an electrochromic layer followed by annealing heat treatment; wherein the annealing heat treatment process may include: heating from room temperature to 375-500°C at a heating rate of 5-50°C / s and holding at that temperature for 2-60 minutes, and then naturally cooling to room temperature.

[0056] This invention utilizes a magnetron sputtering process to control power and atmosphere to obtain a porous film material. A rapid heat treatment process is then employed to preferentially grow nanopillars within the film, with different heating rates and holding temperatures corresponding to different film growth directions. The invention sets appropriate heat treatment conditions to induce close-packed growth, meaning the film material undergoes in-plane shrinkage, thereby randomly generating a large number of pores.

[0057] More specifically, the DC magnetron sputtering system used in this invention for magnetron sputtering deposition may include a deposition chamber, a sample inlet chamber, several target heads, a substrate, a DC current source, and a series of mechanical pumps and vacuum pumps. The target head is at a certain angle to the substrate and separated by a certain distance, and the DC power supply is connected to the target head. The substrate is ultrasonically cleaned with acetone, anhydrous ethanol, and deionized water for 20 minutes each, and then dried with compressed air. A portion of the conductive substrate is covered with high-temperature tape as an electrode and fixed to the substrate tray. The substrate is placed in the sample inlet chamber, and the mechanical pump is turned on to pump the pressure to below 5 Pa. Then, the baffle valve is opened, and the vacuum level (baseline vacuum) reaches 10 Pa. -4 Splash chambers with Pa and below.

[0058] The specific sputtering deposition process is as follows: High-purity argon and oxygen are introduced into the sputtering chamber, with the purity of the argon and oxygen being 99.99% or higher. The total pressure and oxygen partial pressure in the chamber are controlled within the range of 0.3-2.0 Pa and 0-50%, respectively, with the oxygen partial pressure preferably being 0-25%. The vertical distance between the target and the substrate is controlled to be 10-20 cm, and the initial substrate temperature is room temperature - 150℃. The DC power supply is turned on, with the power controlled to be 30-450 W. The pre-sputtering time is 5-30 min, the sputtering time is 10-60 min, and the substrate temperature is room temperature. After sputtering, the substrate is removed after the substrate temperature has cooled to room temperature.

[0059] In some embodiments, the parameters of the electron beam etching process may include: accelerating voltage 30-100 keV (to reduce proximity effect), beam current 50-100 pA, and working distance 5-10 mm (to avoid image distortion).

[0060] In some embodiments, the parameters of the atomic layer deposition process may include: the silicon source is bis(dimethylamino)silane (BDEAS) or trichlorosilane (SiCl3H); the oxidant is ozone (O3) (a 15% O3 / O2 mixed gas) or water (H2O) (high-purity deionized water); the deposition temperature is 200-300°C; and the number of cycles is 50-200.

[0061] The fabrication process involved in this invention is simple, low-cost, and easy to promote. The high-performance electrochromic device developed by this invention has a wider range of application prospects.

[0062] The following examples further illustrate the present invention in detail. It should also be understood that the following examples are only for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above description of the present invention are within the scope of protection of the present invention. The specific process parameters, etc., in the following examples are merely examples within a suitable range; that is, those skilled in the art can make appropriate selections within the range based on the description herein, and are not intended to be limited to the specific values ​​in the examples below. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art.

[0063] Example 1

[0064] The fabrication method of the transmittance wide color gamut all-solid-state electrochromic display provided in this embodiment includes the following steps:

[0065] (1) First, glass was used as a transparent substrate, and a bottom electrode was prepared on the surface by magnetron sputtering. Then, an electrochromic layer was deposited on the surface of the bottom electrode by magnetron sputtering: tungsten metal was used as the target material, argon and oxygen were used as the sputtering gases, the total pressure was 2.0 Pa, the oxygen partial pressure was 6%, the distance between the target and the substrate was 15 cm, the initial substrate temperature was 90℃, and the DC power applied to the target was 350 W or the power density was 3.5 W / cm². 2 A 400 nm electrochromic layer film is deposited; wherein the material of the micro-nano fabricated electrochromic layer is WO3; it is composed of an array of nano-columnar crystals containing nanopores, the diameter of the nano-columnar crystals is 20 nm, the distance between the columnar crystals is 15 nm, the pore size of the nano-columnar crystals is 10 nm, and the porosity of the electrochromic layer is 20%; after magnetron sputtering the electrochromic layer, an annealing heat treatment is performed, the annealing heat treatment process includes: heating from room temperature to 400 °C at a heating rate of 10 °C / s and holding at that temperature for 5 minutes, and then naturally cooling to room temperature;

[0066] (2) The thin film was micro-nano-processed according to the designed size using EBL, with a cycle of 1 μm × 1 μm, a processing depth of 400 nm, and an etching steepness angle of 85°; within a single processing cycle, the diameter of the processed column pixel was 500 nm, the height of the processed column pixel was 400 nm, and the number of processed column pixels was 1, thus obtaining a micro-nano-processed electrochromic layer.

[0067] (3) An electron blocking layer of SiO2 with a thickness of 10 nm was deposited on the surface of the processed electrochromic layer by atomic layer deposition;

[0068] (4) On the above structure, using a LiTaO3 ceramic target, with a total pressure of 2.0 Pa, a pure argon atmosphere, a vertical distance of 15 cm between the target and the substrate, and a radio frequency power of 180 W, an ion conduction layer with a thickness of 40 nm is deposited; using metallic Ni as the target, with a total pressure of 1.0 Pa, an oxygen partial pressure of 20%, a vertical distance of 15 cm between the target and the substrate, and a DC power of 100 W, an ion storage layer with a thickness of 80 nm is deposited; then, a visible light highly transparent ITO second electrode is deposited, with sputtering parameters of ITO as the target, a total pressure of 0.3 Pa, a pure argon atmosphere, a vertical distance of 15 cm between the target and the substrate, a DC power of 80 W, and a surface deposition thickness of 400 nm using a medium frequency power supply, to obtain the transparent wide color gamut all-solid-state electrochromic display.

[0069] Example 2

[0070] The fabrication method of the transmissive wide color gamut all-solid-state electrochromic display provided in this embodiment is the same as that in Embodiment 1, with the main difference being:

[0071] In step (1), the electrochromic layer thickness is 200 nm;

[0072] In step (2), the processing depth is 200 nm and the height of the processed columnar pixel is 200 nm in a single processing cycle.

[0073] Example 3

[0074] The fabrication method of the transmissive wide color gamut all-solid-state electrochromic display provided in this embodiment is the same as that in Embodiment 1, with the main difference being:

[0075] In step (1), the electrochromic layer thickness is 600 nm;

[0076] In step (2), the processing depth is 600 nm and the height of the processed columnar pixel is 600 nm in a single processing cycle.

[0077] Example 4

[0078] The fabrication method of the transmissive wide color gamut all-solid-state electrochromic display provided in this embodiment is the same as that in Embodiment 1, with the main difference being:

[0079] In step (2), the micro / nano fabrication cycle is 0.5 μm × 0.5 μm.

[0080] Example 5

[0081] The fabrication method of the transmissive wide color gamut all-solid-state electrochromic display provided in this embodiment is the same as that in Embodiment 1, with the main difference being:

[0082] In step (2), the micro / nano fabrication cycle is 10 μm × 10 μm.

[0083] Example 6

[0084] The fabrication method of the transmissive wide color gamut all-solid-state electrochromic display provided in this embodiment is the same as that in Embodiment 1, with the main difference being:

[0085] In step (2), the diameter of the micro / nano fabrication is 200 nm.

[0086] Example 7

[0087] The fabrication method of the transmissive wide color gamut all-solid-state electrochromic display provided in this embodiment is the same as that in Embodiment 1, with the main difference being:

[0088] In step (2), the diameter of the micro / nano fabrication is 400 nm.

[0089] Example 8

[0090] The fabrication method of the transmissive wide color gamut all-solid-state electrochromic display provided in this embodiment is the same as that in Embodiment 1, with the main difference being:

[0091] In step (2), the diameter of the micro / nano fabrication is 600 nm.

[0092] Example 9

[0093] The fabrication method of the transmissive wide color gamut all-solid-state electrochromic display provided in this embodiment is the same as that in Embodiment 1, with the main difference being:

[0094] In step (2), the etching steep angle of the micro / nano fabrication is 70°.

[0095] Example 10

[0096] The fabrication method of the transmissive wide color gamut all-solid-state electrochromic display provided in this embodiment is the same as that in Embodiment 1, with the main difference being:

[0097] In step (3), the electron blocking layer has a thickness of 5 nm.

[0098] Example 11

[0099] The fabrication method of the transmissive wide color gamut all-solid-state electrochromic display provided in this embodiment is the same as that in Embodiment 1, with the main difference being:

[0100] In step (3), the electron blocking layer has a thickness of 20 nm.

[0101] Example 12

[0102] The fabrication method of the transmittance wide color gamut all-solid-state electrochromic display provided in this embodiment includes the following steps:

[0103] (1) First, a bottom electrode is prepared on the surface of a transparent glass substrate by magnetron sputtering. Then, an ion storage layer is deposited on the surface of the bottom electrode by magnetron sputtering: using metallic Ni as the target material, the total pressure is 1.0 Pa, the oxygen partial pressure is 20%, the distance between the target material and the substrate is 15 cm, the DC power supply is 100 W, and the deposition thickness is 80 nm. On the surface of the ion storage layer, using a LiTaO3 ceramic target, the total pressure is 2.0 Pa, the pure argon atmosphere is used, the distance between the target material and the substrate is 15 cm, the RF power supply is 180 W, and an ion conduction layer with a thickness of 40 nm is deposited.

[0104] (2) An electron blocking layer of SiO2 with a thickness of 10 nm is deposited on the surface of the processed ion-conducting layer by atomic layer deposition;

[0105] (3) Subsequently, using tungsten metal as the target material, the sputtering gases were argon and oxygen, the total pressure was 2.0 Pa, the oxygen partial pressure was 6%, the distance between the target and the substrate was 15 cm, the initial substrate temperature was 90 °C, and the DC power applied to the target was 350 W or the power density was 3.5 W / cm². 2 A 400 nm electrochromic layer film is deposited; wherein the material of the micro-nano fabricated electrochromic layer is WO3; it is composed of a columnar crystal array containing nanoporous structures, the diameter of the nano-columnar crystals is 20 nm, the distance between the columnar crystals is 15 nm, the pore size of the nanoporous structures is 10 nm, and the porosity of the electrochromic layer is 20%; after magnetron sputtering of the electrochromic layer, an annealing heat treatment is performed, the annealing heat treatment process includes: heating from room temperature to 400°C at a heating rate of 10°C / s and holding at that temperature for 5 minutes, and then naturally cooling to room temperature;

[0106] (4) Subsequently, the electrochromic layer film was micro-nano-fabricated according to the designed size using EBL, with a cycle of 1 μm × 1 μm, a processing depth of 400 nm, and an etching steepness angle of 85°. Within a single processing cycle, the diameters of the processed cylindrical pixels were 200, 400, and 600 nm, the side length of the square in the lower right corner was 600 nm, the height of the processed cylindrical pixels was 400 nm, and the number of processed cylindrical pixels was 3, thus obtaining the micro-nano-fabricated electrochromic layer.

[0107] (5) A visible light highly transparent ITO second electrode is deposited on the surface of the micro-nano fabricated electrochromic layer using magnetron sputtering. The sputtering parameters are: ITO as target material, total pressure of 0.3 Pa, pure argon atmosphere, distance between target material and substrate of 15 cm, DC power of 80 W, and surface deposition thickness of 400 nm using medium frequency power supply to obtain the transparent wide color gamut all-solid-state electrochromic display.

[0108] Comparative Example 1

[0109] The method for preparing the electrochromic display provided in this comparative example is the same as in Example 1, with the main difference being:

[0110] In step (2), the diameter of the micro / nano fabrication is 50 nm.

[0111] Comparative Example 2

[0112] The method for preparing the electrochromic display provided in this comparative example is the same as in Example 1, with the main difference being:

[0113] In step (2), the diameter of the micro / nano fabrication is 1000 nm.

[0114] Comparative Example 3

[0115] The method for preparing the electrochromic display provided in this comparative example is the same as in Example 1, with the main difference being:

[0116] In step (2), the etching steepness angle of the micro / nano fabrication is 60°.

[0117] Comparative Example 4

[0118] The method for preparing the electrochromic display provided in this comparative example is the same as in Example 1, with the main difference being:

[0119] In step (2), the micro / nano fabrication cycle is 0.2 μm × 0.2 μm.

[0120] Comparative Example 5

[0121] The method for preparing the electrochromic display provided in this comparative example is the same as in Example 1, with the main difference being:

[0122] In step (3), the thickness of the electron blocking layer is 3 nm.

[0123] Comparative Example 6

[0124] The method for preparing the electrochromic display provided in this comparative example is the same as in Example 1, with the main difference being:

[0125] In step (1), the initial substrate temperature for preparing the electrochromic layer by magnetron sputtering is 30°C;

[0126] In step (2), the etching steepness angle of the micro / nano fabrication is 55°.

[0127] The obtained micro-nano fabricated electrochromic layer was made of WO3; it consisted of an array of columnar crystals containing mesopores, with a diameter of 50 nm, a distance of 3 nm between the columnar crystals, a pore size of 2 nm, and a porosity of 5%.

[0128] Comparative Example 7

[0129] The method for preparing the electrochromic display provided in this comparative example is the same as in Example 1, with the main difference being:

[0130] In step (1), the initial substrate temperature for preparing the electrochromic layer by magnetron sputtering is 200℃;

[0131] In step (2), the etching steepness angle of the micro / nano fabrication is 60°.

[0132] Testing revealed that the material of the micro-nano fabricated electrochromic layer was WO3; the electrochromic layer film underwent crystallization, resulting in the film containing a large number of crystalline particles with a particle size range of 50-150 nm.

[0133] Comparative Example 8

[0134] The method for preparing the electrochromic display provided in this comparative example is the same as in Example 1, with the main difference being:

[0135] In step (1), the DC power applied to the target material during magnetron sputtering to prepare the electrochromic layer is 100W;

[0136] In step (2), the etching steep angle of the micro / nano fabrication is 80°.

[0137] Due to the low sputtering power, columnar crystal structures could not be formed, and amorphous structures were mainly formed. There were no obvious nanopillars, and the stacking was dense with small gaps.

[0138] Comparative Example 9

[0139] The method for preparing the electrochromic display provided in this comparative example is the same as in Example 1, with the main difference being:

[0140] In step (1), the DC power applied to the target material is 600 W;

[0141] In step (2), the etching steepness angle of the micro / nano fabrication is 55°.

[0142] Testing revealed that the material of the obtained micro-nano-fabricated electrochromic layer was WO3; it consisted of an array of columnar crystals containing mesopores, with a diameter of 80 nm for the nano-columnar crystals, a distance of 10 nm between the columnar crystals, a pore size of 10 nm for the mesopores, and a porosity of 5% for the electrochromic layer; the film was too dense, which also affected the film's processing capability.

[0143] Table 1 below shows the relevant parameters of the electrochromic devices prepared in Examples 1-12 and Comparative Examples 1-9:

[0144] .

[0145] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A transmissive wide color gamut all-solid-state electrochromic display, characterized in that, The structure of the transmissive wide color gamut all-solid-state electrochromic display includes: a substrate, a bottom electrode, a micro-nano fabricated electrochromic layer, an electron blocking layer, an ion conducting layer, an ion storage layer, and a second electrode. The micro / nano-fabricated electrochromic layer is composed of an array of nano-columnar crystals containing nanopores; the diameter of the nano-columnar crystals is 10-30 nm, the distance between the nano-columnar crystals is 5-20 nm, the pore size of the nano-columnar crystals is 2-15 nm, and the porosity of the electrochromic layer is 10-30%.

2. The transmissive wide color gamut all-solid-state electrochromic display according to claim 1, characterized in that, The material of the micro / nano-fabricated electrochromic layer includes WO3. 3-x1 MoO 3-x2 TiO 2-x3 It contains at least one of V2O5, with 0≤x1≤0.3, 0≤x2≤0.3, 0≤x3≤0.2, and a thickness of 200~600nm.

3. The transmissive wide color gamut all-solid-state electrochromic display according to claim 1, characterized in that, The processing cycle of the electrochromic layer in the micro-nano fabrication is 0.5-10 μm × 0.5-10 μm, the processing depth is the thickness of the electrochromic layer, and the etching steepness angle is ≥70°; within a single processing cycle, the diameter of the processed columnar pixels is 100-800 nm, the height of the processed columnar pixels is the thickness of the electrochromic layer, and the number of processed columnar pixels is 1-10.

4. The transmissive wide color gamut all-solid-state electrochromic display according to claim 1, characterized in that, The electron blocking layer material includes a wide bandgap material with a bandgap width ≥ 3.5 eV and a thickness of 5-20 nm.

5. The transmissive wide color gamut all-solid-state electrochromic display according to claim 4, characterized in that, The electron blocking layer material is SiO2, Al2O3, or SnO2.

6. A method for manufacturing a transmissive wide color gamut all-solid-state electrochromic display as described in claim 1, characterized in that, The preparation method includes the following steps: preparing an electrochromic layer by magnetron sputtering, and then micro- and nano-fabricating the electrochromic layer according to the designed dimensions using an electron beam etching process.

7. The preparation method according to claim 6, characterized in that, The process parameters for preparing the electrochromic layer by magnetron sputtering include: using tungsten, molybdenum, titanium, or vanadium as the target material; using argon and oxygen as the sputtering gas; a total pressure of 0.3-2.0 Pa; an oxygen partial pressure of 0-50%; a target-to-substrate distance of 10-20 cm; an initial substrate temperature of 50-150 °C; and applying a DC power supply of 200-450 W or a power density of 3.5-9.0 W / cm² to the target. 2 .

8. The preparation method according to claim 6, characterized in that, The preparation method further includes annealing heat treatment after magnetron sputtering of the electrochromic layer; wherein the annealing heat treatment process includes: heating from room temperature to 375-500℃ at a heating rate of 5-50℃ / s and holding at that temperature for 2-60 minutes, and then naturally cooling to room temperature.

9. The preparation method according to claim 6, characterized in that, The parameters of the electron beam etching process include: accelerating voltage 30-100 keV, beam current 50-100 pA, and working distance 5-10 mm.

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