Display device and tuning method and application thereof

Abstract

The invention provides a display device and a tuning method and application thereof. The display device comprises an asymmetric Bragg reflection layer, the asymmetric Bragg reflection layer is composed of low-refractive-index layers and high-refractive-index layers, the low-refractive-index layers and the high-refractive-index layers are alternately arranged, the high-refractive-index layers are made of phase-change materials Sb2S3, and continuous adjustment of reflection peak wavelength is achieved by enabling the Sb2S3 to be subjected to reversible phase change between an amorphous state and a crystalline state, so that high-purity structural color display is obtained. According to the invention, the asymmetric Bragg reflection layer is formed by the phase change material Sb2S3, so that the display device has wide color adjustability, excellent color purity and insensitivity to an incident angle.

Description

Technical Field

[0001] This invention belongs to the field of display device technology, and particularly relates to a display device, its tuning method, and its application. Background Technology

[0002] Traditional color display technologies typically use pigments or dyes to achieve selective absorption or reflection of different colors. However, these traditional methods have many drawbacks, such as poor chemical stability, leading to degradation of filtering performance over time; high cost, especially when implementing the complete Bayer color scheme, which requires integrating a large number of pigments or dyes, increasing manufacturing difficulty and cost; and, in addition, traditional pigments and dyes are not environmentally friendly and may contain harmful chemicals, which is detrimental to sustainable development.

[0003] Structural color technology obtains color through physical optics principles, offering advantages such as environmental friendliness and high stability. It utilizes the interaction between nanostructures and light (such as scattering, reflection, and absorption) to generate color, rather than relying on chemical pigments. However, existing structural color display devices generally suffer from several problems: insufficient color purity, making it difficult to achieve high-saturation colors; high angle sensitivity, with colors changing depending on the viewing angle, limiting their application in practical display devices; and difficulty in achieving dynamic tuning, as the color of most structural color display devices remains fixed once manufactured, making real-time adjustment difficult as needed.

[0004] Existing structural color display devices have the following drawbacks:

[0005] High angle sensitivity: The color of many structural color devices changes significantly with the viewing angle, which is a serious limitation in practical applications. For example, nanograting structural color devices will display different colors at different angles, resulting in inconsistent display effects.

[0006] Dynamic tuning is difficult: Most structural color devices have fixed colors after manufacturing, making dynamic adjustment difficult. Although some technologies attempt to achieve color changes through external stimuli (such as electric fields or magnetic fields), these methods usually require complex manufacturing processes and high energy consumption.

[0007] Given the shortcomings of current structural color display devices, it is necessary to improve them. Summary of the Invention

[0008] To address the shortcomings of existing technologies, this invention provides a display device, its tuning method, and its applications. This invention provides a dynamically tunable structural color display device based on an asymmetric Bragg reflector layer structure composed of the phase-change material Sb₂S₃. By introducing Sb₂S₃ phase-change material, a reversible phase transition between amorphous and crystalline states is achieved, enabling continuous tuning of the reflection peak wavelength to obtain high-purity structural color display. This invention, through the asymmetric Bragg reflector layer composed of the phase-change material Sb₂S₃, makes the display device insensitive to the incident angle and possesses wide color tunability and excellent color purity.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides a display device, comprising:

[0011] Base;

[0012] An asymmetric Bragg reflector layer is located on the substrate;

[0013] The asymmetric Bragg reflector layer comprises alternating low-refractive-index layers and high-refractive-index layers;

[0014] The high refractive index layer is made of Sb2S3, and the low refractive index layer is made of SiO2.

[0015] Preferably, the thickness of the low refractive index layer is 35~80 nm;

[0016] The thickness of the high refractive index layer is 5~275 nm;

[0017] Preferably, the low-refractive-index layer and the high-refractive-index layer alternate 1 to 5 times.

[0018] Preferably, the low-refractive-index layer and the high-refractive-index layer alternate twice;

[0019] The asymmetric Bragg reflector layer comprises a first low-refractive-index layer, a first high-refractive-index layer, a second low-refractive-index layer, and a second high-refractive-index layer stacked sequentially.

[0020] The thickness of the first low-refractive-index layer is 48~53nm;

[0021] The thickness of the first high refractive index layer is 140~145nm;

[0022] The thickness of the second low-refractive-index layer is 75~80 nm;

[0023] The thickness of the second high refractive index layer is 5~10 nm.

[0024] Preferably, the low-refractive-index layer and the high-refractive-index layer alternate three times;

[0025] The asymmetric Bragg reflector layer comprises a first low refractive index layer, a first high refractive index layer, a second low refractive index layer, a second high refractive index layer, a third low refractive index layer, and a third high refractive index layer stacked sequentially.

[0026] The thickness of the first low-refractive-index layer is 35~40nm;

[0027] The thickness of the first high refractive index layer is 50~55nm;

[0028] The thickness of the second low-refractive-index layer is 48~53 nm;

[0029] The thickness of the second high-refractive-index layer is 140~145 nm;

[0030] The thickness of the third low-refractive-index layer is 75~80 nm;

[0031] The thickness of the third high-refractive-index layer is 5~10 nm.

[0032] Preferably, the low-refractive-index layer and the high-refractive-index layer alternate 4 times;

[0033] The asymmetric Bragg reflector layer comprises a first low refractive index layer, a first high refractive index layer, a second low refractive index layer, a second high refractive index layer, a third low refractive index layer, a third high refractive index layer, a fourth low refractive index layer, and a fourth high refractive index layer, which are stacked sequentially.

[0034] The thickness of the first low-refractive-index layer is 50~55nm;

[0035] The thickness of the first high refractive index layer is 270~275nm;

[0036] The thickness of the second low-refractive-index layer is 35~40 nm;

[0037] The thickness of the second high-refractive-index layer is 50~55nm;

[0038] The thickness of the third low-refractive-index layer is 48~53 nm;

[0039] The thickness of the third high refractive index layer is 140~145nm;

[0040] The thickness of the fourth low-refractive-index layer is 75~80 nm;

[0041] The thickness of the fourth high-refractive-index layer is 5~10 nm.

[0042] Preferably, the low-refractive-index layer and the high-refractive-index layer alternate 5 times;

[0043] The asymmetric Bragg reflector layer comprises a first low refractive index layer, a first high refractive index layer, a second low refractive index layer, a second high refractive index layer, a third low refractive index layer, a third high refractive index layer, a fourth low refractive index layer, a fourth high refractive index layer, a fifth low refractive index layer, and a fifth high refractive index layer, which are stacked sequentially.

[0044] The thickness of the first low-refractive-index layer is 42~47nm;

[0045] The thickness of the first high refractive index layer is 140~145nm;

[0046] The thickness of the second low-refractive-index layer is 50~55nm;

[0047] The thickness of the second high-refractive-index layer is 270~275 nm;

[0048] The thickness of the third low-refractive-index layer is 35~40 nm;

[0049] The thickness of the third high-refractive-index layer is 50~55nm;

[0050] The thickness of the fourth low-refractive-index layer is 48~53 nm;

[0051] The thickness of the fourth high-refractive-index layer is 140~145 nm.

[0052] The thickness of the fifth low-refractive-index layer is 75~80 nm;

[0053] The thickness of the fifth high-refractive-index layer is 5~10 nm.

[0054] Preferably, the substrate is either a silicon substrate or a glass substrate, and the substrate thickness is ≥400nm.

[0055] Secondly, the present invention also provides a tuning method for the aforementioned display device, comprising the following steps:

[0056] Laser irradiation or thermal annealing is applied to the high refractive index layer in the display device to transform it between an amorphous state and a crystalline state, thereby achieving tuning of the reflection peak wavelength.

[0057] Thirdly, the present invention also provides an application of the aforementioned display device in image sensing, smart windows, dynamic camouflage, and anti-counterfeiting displays.

[0058] The display device, tuning method, and application of the present invention have the following advantages compared with the prior art:

[0059] The display device of this invention, by introducing Sb₂S₃ phase change material, achieves a reversible phase transition between an amorphous and crystalline state, enabling continuous adjustment of the reflection peak wavelength to obtain high-purity structural color display. This invention utilizes an asymmetric Bragg reflector layer composed of the Sb₂S₃ phase change material, making the display device insensitive to the incident angle and exhibiting wide color tunability and excellent color purity.

[0060] Dynamic tuning capability: By adjusting the phase transition state of Sb₂S₃, continuous dynamic tuning of the reflection peak wavelength can be achieved, thereby realizing dynamic color changes. For example, through laser irradiation, Sb₂S₃ can be gradually transformed from an amorphous state to a crystalline state, achieving a color shift from orange and yellow to red in the visible light band, with a continuous tuning range exceeding 110 nm. This structure allows for a very small overall shift in the spectrum before and after crystallization of the phase transition material; only the position of the peak changes.

[0061] Improved color purity: Through the asymmetric Bragg reflector layer structure, color purity is significantly improved, exceeding 75%, which is far superior to existing structured color devices. Within the visible light band, the color purity of this device can reach over 80%. Attached Figure Description

[0062] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0063] Figure 1 This is a schematic diagram of the structure of the display device of the present invention;

[0064] Figure 2 The image shows the amorphous reflectance spectrum of the display device in Example 1.

[0065] Figure 3 The image shows the crystalline reflectance spectrum of the display device in Example 1.

[0066] Figure 4 The image shows the reflection spectra of the display device in Example 1 in the amorphous state at angles of 0°, 20°, 40°, and 60°.

[0067] Figure 5 The image shows the amorphous reflectance spectrum of the display device in Example 2.

[0068] Figure 6 The image shows the crystalline reflectance spectrum of the display device in Example 2.

[0069] Figure 7The image shows the reflection spectra of the display device in Example 2 in the amorphous state at angles of 0°, 20°, 40°, and 60°.

[0070] Figure 8 This is the amorphous reflectance spectrum of the display device in Example 3;

[0071] Figure 9 The image shows the crystalline reflectance spectrum of the display device in Example 3.

[0072] Figure 10 The image shows the reflection spectra of the display device in Example 3 in the amorphous state at angles of 0°, 20°, 40°, and 60°. Figure 11 This is the amorphous reflection spectrum of the display device in Example 4;

[0073] Figure 12 The image shows the crystalline reflectance spectrum of the display device in Example 4.

[0074] Figure 13 The images show the reflection spectra of the display device in Example 4 in the amorphous state at angles of 0°, 20°, 40°, and 60°. Detailed Implementation

[0075] To facilitate understanding of the present invention, a more comprehensive description of the invention will be provided below in conjunction with specific embodiments. Preferred embodiments of the invention are given in the specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0076] The order in which the embodiments are described below is not intended to limit the preferred order of the embodiments. Furthermore, in the description of this application, the term "comprising" means "including but not limited to". Various embodiments of the invention may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a rigid limitation on the scope of the invention; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Additionally, whenever a numerical range is indicated herein, it means including any referenced number (fraction or integer) within the indicated range.

[0077] This invention provides a display device, such as... Figure 1 As shown, it includes:

[0078] Base 10;

[0079] An asymmetric Bragg reflector layer is located on substrate 10;

[0080] The asymmetric Bragg reflector consists of alternating low-refractive-index and high-refractive-index layers;

[0081] The high-refractive-index layer is made of Sb2S3, and the low-refractive-index layer is made of SiO2.

[0082] The display device of this invention features an asymmetric Bragg reflector layer composed of alternating high-refractive-index and low-refractive-index layers. The high-refractive-index layers are made of the phase-change material Sb₂S₃. By reversibly transitioning Sb₂S₃ between an amorphous and crystalline state, the wavelength of the reflection peak is continuously adjustable, resulting in high-purity structural color display. This invention, through its asymmetric Bragg reflector layer composed of the phase-change material Sb₂S₃, enables the display device to be insensitive to the angle of incidence and possesses wide color tunability and excellent color purity.

[0083] In some embodiments, the thickness of the low refractive index layer is 35~80 nm;

[0084] The thickness of the high refractive index layer is 5~275nm.

[0085] In some embodiments, the high-refractive-index layer and the low-refractive-index layer alternate 1 to 5 times, that is, the total number of layers of the asymmetric Bragg reflector layer is 2 to 10, specifically, it can be 2, 4, 6, 8, or 10 layers.

[0086] In some embodiments, the low-refractive-index layer and the high-refractive-index layer alternate twice;

[0087] The asymmetric Bragg reflector layer includes a first low-refractive-index layer 11, a first high-refractive-index layer 12, a second low-refractive-index layer 13, and a second high-refractive-index layer 14, which are stacked sequentially.

[0088] The thickness of the first low-refractive-index layer 11 is 48~53nm;

[0089] The thickness of the first high refractive index layer 12 is 140~145nm;

[0090] The thickness of the second low-refractive-index layer 13 is 75~80nm;

[0091] The thickness of the second high refractive index layer 14 is 5~10 nm.

[0092] In some embodiments, the low-refractive-index layer and the high-refractive-index layer alternate three times;

[0093] The asymmetric Bragg reflector layer includes a first low refractive index layer 11, a first high refractive index layer 12, a second low refractive index layer 13, a second high refractive index layer 14, a third low refractive index layer 15, and a third high refractive index layer 16, which are stacked sequentially.

[0094] The thickness of the first low-refractive-index layer 11 is 35~40nm;

[0095] The thickness of the first high refractive index layer 12 is 50~55nm;

[0096] The thickness of the second low-refractive-index layer 13 is 48~53 nm;

[0097] The thickness of the second high refractive index layer 14 is 140~145nm;

[0098] The thickness of the third low-refractive-index layer 15 is 75~80nm;

[0099] The thickness of the third high refractive index layer 16 is 5~10 nm.

[0100] In some embodiments, the low-refractive-index layer and the high-refractive-index layer alternate 4 times;

[0101] The asymmetric Bragg reflector layer includes a first low refractive index layer 11, a first high refractive index layer 12, a second low refractive index layer 13, a second high refractive index layer 14, a third low refractive index layer 15, a third high refractive index layer 16, a fourth low refractive index layer 17, and a fourth high refractive index layer 18, which are stacked sequentially.

[0102] The thickness of the first low-refractive-index layer 11 is 50~55nm;

[0103] The thickness of the first high refractive index layer 12 is 270~275nm;

[0104] The thickness of the second low-refractive-index layer 13 is 35~40nm;

[0105] The thickness of the second high refractive index layer 14 is 50~55nm;

[0106] The thickness of the third low-refractive-index layer 15 is 48~53 nm;

[0107] The thickness of the third high-refractive-index layer 16 is 140~145nm;

[0108] The thickness of the fourth low-refractive-index layer 17 is 75~80nm;

[0109] The thickness of the fourth high-refractive-index layer 18 is 5~10 nm.

[0110] In some embodiments, the low-refractive-index layer and the high-refractive-index layer alternate 5 times;

[0111] The asymmetric Bragg reflector layer comprises a first low refractive index layer 11, a first high refractive index layer 12, a second low refractive index layer 13, a second high refractive index layer 14, a third low refractive index layer 15, a third high refractive index layer 16, a fourth low refractive index layer 17, a fourth high refractive index layer 18, a fifth low refractive index layer 19, and a fifth high refractive index layer 20, which are stacked sequentially.

[0112] The thickness of the first low-refractive-index layer 11 is 42~47nm;

[0113] The thickness of the first high refractive index layer 12 is 140~145nm;

[0114] The thickness of the second low-refractive-index layer 13 is 50~55nm;

[0115] The thickness of the second high refractive index layer 14 is 270~275 nm;

[0116] The thickness of the third low-refractive-index layer 15 is 35~40nm;

[0117] The thickness of the third high-refractive-index layer 16 is 50~55nm;

[0118] The thickness of the fourth low-refractive-index layer 17 is 48~53 nm;

[0119] The thickness of the fourth high-refractive-index layer 18 is 140~145nm;

[0120] The thickness of the fifth low-refractive-index layer 19 is 75~80nm;

[0121] The thickness of the fifth high-refractive-index layer 20 is 5~10nm.

[0122] In some embodiments, the substrate is either a silicon substrate or a glass substrate, and the substrate thickness is ≥400nm.

[0123] The display device of the present invention has a peak reflectivity of greater than 70% in the target wavelength band (380nm~750nm), a half width at half maximum (FWHM) of the reflection peak of about 20~60 nm, and out-of-band sideband reflection is significantly suppressed.

[0124] The display device of the present invention achieves a continuous red / blue shift tuning range of ≥110nm through the phase transition of Sb2S3, and the changes in reflection peak height and full width at half maximum (FWHM) are small before and after the phase transition.

[0125] The display device of the present invention maintains narrow-band high reflectivity and high color purity within the incident angle range of 0° to 60°, and exhibits angle insensitivity.

[0126] The display device of the present invention is a planar thin film stacked structure, which can be fabricated without nano-etching and is suitable for large-scale preparation and industrial application.

[0127] Specifically, the display device of the present invention is prepared by magnetron sputtering or PECVD thin film deposition process. For example, an Sb2S3 layer and a SiO2 layer are sequentially and alternately deposited on a substrate to obtain the display device. Specifically, the process conditions for depositing the Sb2S3 layer are as follows: using Sb2S3 as the target material, the deposition temperature is 25~35℃, the argon gas flow rate is 50~70 sccm, the sputtering chamber pressure is 0.5~0.7 Pa, and the sputtering power is 25~35 W. The process conditions for depositing the SiO2 layer are as follows: using SiO2 as the target material, the deposition temperature is 25~35℃, the argon gas flow rate is 60~80 sccm, the sputtering chamber pressure is 0.5~0.7 Pa, and the sputtering power is 20~30 W.

[0128] Specifically, Sb₂S₃ is an ultra-low-loss phase change material with a rapid phase transition rate and stable memory properties. Its phase transition between the amorphous and crystalline states can be induced by laser or thermal induction, thereby causing fine and continuous changes in structural color.

[0129] Design of asymmetric Bragg reflector layer: By precisely controlling the thickness of each layer, a high reflectivity and narrow bandwidth reflection peak can be achieved, thereby improving color purity.

[0130] Improved color purity: Through the asymmetric Bragg reflector layer structure, color purity is significantly improved, exceeding 75%, which is far superior to existing structured color devices. Within the visible light band, the color purity of this device can reach over 80%.

[0131] Dynamic tuning capability: By adjusting the phase transition state of Sb₂S₃, continuous dynamic tuning of the reflection peak wavelength can be achieved (i.e., as the state of the phase change material Sb₂S₃ changes, the peak value and position of the device's reflectivity also change), thereby realizing dynamic color changes. For example, by laser irradiation, Sb₂S₃ can be gradually transformed from an amorphous state to a crystalline state, achieving a color shift from orange and yellow to red in the visible light band, with a continuous tuning range exceeding 110 nm. This structure allows for a very small overall shift in the spectrum before and after the phase change material crystallizes; only the position of the peak changes.

[0132] Beneficial effects:

[0133] High color purity: Through the non-periodic Bragg reflector layer structure, the color purity is significantly improved, exceeding 75%, which is far superior to existing structural color devices. To facilitate an objective evaluation of the "high purity" of the structural color of this invention, the color purity of this invention is uniformly calculated according to CIE1931 colorimetry under the conditions of D65 standard illuminant and 2° standard observer. The color purity of this invention can reach about 80% in the amorphous state and about 75% in the crystalline state, and it has the spectral characteristics of narrow band high reflectance and side band low reflectance.

[0134] By combining asymmetric Bragg reflector layer thickness gradient with low-loss phase change material (such as Sb2S3), the half-width at half maximum (FWHM) can be significantly reduced and the sidebands can be lowered while maintaining peak reflectivity, thereby obtaining higher color point purity according to the following color purity formula; before and after the phase change, the main manifestation is the reversible displacement of the color point along the main wavelength direction, and the purity is maintained in the high range.

[0135] Based on the same inventive concept, the present invention also provides a tuning method for the aforementioned display device, comprising the following steps:

[0136] Laser irradiation or thermal annealing is applied to the high refractive index layer in the above-mentioned display device to transform it between an amorphous state and a crystalline state, so as to achieve continuous and reversible tuning of the reflection peak wavelength.

[0137] In some embodiments, the thermal annealing temperature is 300°C and the time is 5~15 min. Under these conditions, Sb2S3 can be transformed from an amorphous state to a crystalline state.

[0138] Based on the same inventive concept, the present invention also provides an application of the above-mentioned display device in image sensing, smart windows, dynamic camouflage, and anti-counterfeiting displays.

[0139] The following further describes the display device and tuning method of the present invention. This section further illustrates the content of the present invention with reference to specific embodiments, but should not be construed as limiting the present invention. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in the art.

[0140] Example 1

[0141] This embodiment provides a display device, including:

[0142] Transparent glass substrate, 800nm ​​thick;

[0143] An asymmetric Bragg reflector layer is located on a transparent glass substrate;

[0144] The asymmetric Bragg reflector layer comprises a first low refractive index layer (located on the surface of a transparent glass substrate), a first high refractive index layer, a second low refractive index layer, a second high refractive index layer, a third low refractive index layer, a third high refractive index layer, a fourth low refractive index layer, a fourth high refractive index layer, a fifth low refractive index layer, and a fifth high refractive index layer, which are stacked sequentially.

[0145] The thickness of the first low-refractive-index layer is 42 nm;

[0146] The thickness of the first high-refractive-index layer is 140 nm;

[0147] The thickness of the second low-refractive-index layer is 50 nm;

[0148] The thickness of the second high refractive index layer is 275 nm;

[0149] The thickness of the third low-refractive-index layer is 35 nm;

[0150] The thickness of the third high-refractive-index layer is 50 nm;

[0151] The thickness of the fourth low-refractive-index layer is 48 nm;

[0152] The thickness of the fourth high-refractive-index layer is 140 nm;

[0153] The thickness of the fifth low-refractive-index layer is 80 nm;

[0154] The thickness of the fifth high-refractive-index layer is 10 nm;

[0155] The materials for the first, second, third, fourth, and fifth low-refractive-index layers are SiO2; the materials for the first, second, third, fourth, and fifth high-refractive-index layers are Sb2S3.

[0156] Example 2

[0157] This embodiment provides a display device, including:

[0158] Transparent glass substrate, 800nm ​​thick;

[0159] An asymmetric Bragg reflector layer is located on a transparent glass substrate;

[0160] The asymmetric Bragg reflector layer comprises a first low refractive index layer (located on the surface of a transparent glass substrate), a first high refractive index layer, a second low refractive index layer, a second high refractive index layer, a third low refractive index layer, a third high refractive index layer, a fourth low refractive index layer, and a fourth high refractive index layer, which are stacked sequentially.

[0161] The thickness of the first low-refractive-index layer is 50 nm.

[0162] The thickness of the first high-refractive-index layer is 275 nm;

[0163] The thickness of the second low-refractive-index layer is 35 nm;

[0164] The thickness of the second high refractive index layer is 50 nm;

[0165] The thickness of the third low-refractive-index layer is 48 nm;

[0166] The thickness of the third high-refractive-index layer is 140 nm;

[0167] The thickness of the fourth low-refractive-index layer is 80 nm;

[0168] The thickness of the fourth high-refractive-index layer is 5 nm;

[0169] The materials for the first, second, third, and fourth low-refractive-index layers are SiO2; the materials for the first, second, third, and fourth high-refractive-index layers are Sb2S3.

[0170] Example 3

[0171] This embodiment provides a display device, including:

[0172] Transparent glass substrate, 800nm ​​thick;

[0173] The asymmetric Bragg reflector layer comprises a first low refractive index layer (located on the surface of a transparent glass substrate), a first high refractive index layer, a second low refractive index layer, a second high refractive index layer, a third low refractive index layer, and a third high refractive index layer, which are stacked sequentially.

[0174] The thickness of the first low-refractive-index layer is 35 nm.

[0175] The thickness of the first high-refractive-index layer is 50 nm;

[0176] The thickness of the second low-refractive-index layer is 48 nm;

[0177] The thickness of the second high refractive index layer is 140 nm;

[0178] The thickness of the third low-refractive-index layer is 80 nm;

[0179] The thickness of the third high-refractive-index layer is 5 nm;

[0180] The materials for the first, second, and third low-refractive-index layers are SiO2; the materials for the first, second, and third high-refractive-index layers are Sb2S3.

[0181] Example 4

[0182] This embodiment provides a display device, including:

[0183] Transparent glass substrate, 800nm ​​thick;

[0184] The asymmetric Bragg reflector layer comprises a first low-refractive-index layer (located on the surface of a transparent glass substrate), a first high-refractive-index layer, a second low-refractive-index layer, and a second high-refractive-index layer, which are stacked sequentially.

[0185] The thickness of the first low-refractive-index layer is 48 nm.

[0186] The thickness of the first high-refractive-index layer is 140 nm;

[0187] The thickness of the second low-refractive-index layer is 80 nm;

[0188] The thickness of the second high refractive index layer is 5 nm;

[0189] The first low-refractive-index layer and the second low-refractive-index layer are made of SiO2; the first high-refractive-index layer and the second high-refractive-index layer are made of Sb2S3.

[0190] Performance testing

[0191] Figure 2 The image shows the reflection spectrum of the display device in the amorphous state (i.e., the reflection spectrum of the display device in its natural state without any processing) in Example 1. During the test, the incident light was incident perpendicularly onto the fifth high refractive index layer (i.e., the incident light was parallel to the normal of the fifth high refractive index layer, with an angle of 0°).

[0192] Figure 3 The reflection spectrum of the display device in the crystalline state in Example 1 (the display device was annealed at 300°C for 10 min to transform Sb2S3 from an amorphous state to a crystalline state; Examples 2-4 are the same as Example 1) is shown. During the test, the incident light was perpendicularly incident on the fifth high refractive index layer.

[0193] Figure 4 The images show the reflection spectra of the display device in Example 1 in the amorphous state at angles of 0°, 20°, 40°, and 60°. The angles of 0°, 20°, 40°, and 60° refer to the angles between the incident light and the normal of the fifth high-refractive-index layer (i.e., the angles between the incident light and the vertical direction are 0°, 20°, 40°, and 60°, respectively) during the test. Figure 4 In the equation, a is 0°, b is 20°, c is 40°, and d is 60°.

[0194] from Figure 2 As can be seen, within the visible light band (380~750nm), a sharp narrow peak is formed in the 600nm region, with a peak reflectivity close to 80%; the reflectivity in the 400~550nm and 650~800nm ​​bands is less than 20%, and the out-of-band sideband reflection is significantly suppressed, with a half-width of about 20~40nm, directly reflecting the "narrow-band high reflectivity" characteristic of the asymmetric Bragg reflector, laying the foundation for high color purity - combined with CIE1931 colorimetry calculations, the color purity in this state can reach more than 80%, corresponding to orange / yellow hues in visible light.

[0195] from Figure 3As can be seen from Figure 2, compared with the main reflection peak, the overall reflection peak has shifted to the 700nm region, while the peak reflectivity remains above 75%. The full width at half maximum (FWHM) shows no significant broadening (still approximately 20-40nm), and the out-of-band sideband reflection remains low. This verifies the effectiveness of "phase change tuning"—after Sb2S3 crystallization, only the wavelength of the reflection peak is changed without destroying the narrow-band high-reflectivity structure, achieving a dynamic color switching from orange / yellow to red. Moreover, the color purity remains above 75% after tuning, meeting the requirements for high-purity displays.

[0196] from Figure 4 As can be seen, the reflection peaks of all four curves are concentrated in the 600nm region, with highly overlapping peak shapes—peak position deviation <10nm, peak reflectance fluctuation <5% (all maintained at 30%~40%), no broadening of the full width at half maximum (FWHM), and no significant difference in sideband reflectance. This demonstrates that the device is angle-insensitive—within the commonly used observation angle range of 0°~60°, the core spectral features (peak position, peak shape, reflectance) are stable, solving the defect of traditional structural color where "color changes with angle," and adapting to display needs in multiple scenarios.

[0197] Figure 5 This is the amorphous reflection spectrum of the display device in Example 2; during the test, the incident light was incident perpendicularly onto the fourth high refractive index layer;

[0198] Figure 6 This is the crystalline reflection spectrum of the display device in Example 2; during the test, the incident light was incident perpendicularly onto the fourth high refractive index layer;

[0199] Figure 7 The image shows the reflection spectra of the display device in Example 2 in the amorphous state at angles of 0°, 20°, 40°, and 60°. The angles of 0°, 20°, 40°, and 60° refer to the angles between the incident light and the normal of the fourth high refractive index layer (i.e., the angles between the incident light and the vertical direction are 0°, 20°, 40°, and 60°, respectively) during the test. Figure 7 In the equation, a is 0°, b is 20°, c is 40°, and d is 60°.

[0200] from Figure 5 As can be seen, a primary reflection peak forms at 600nm, with a peak reflectivity of approximately 60%; a weak secondary peak (reflectivity <10%) appears near 500nm; the reflectivity in the 400-550nm and 650-800nm ​​bands is below 20%, and the full width at half maximum (FWHM) is approximately 30-50nm. Even with a reduction in the number of layer alternations (from 5 to 4), the device still maintains the core characteristic of "narrow-band high reflectivity"—a sharp primary reflection peak and good sideband suppression, indicating that the asymmetric Bragg reflector layer design has universality, and different numbers of layers can support high-purity displays. Compared with Figure 5, Figure 6The main reflection peak redshifts to the 700nm region, with peak reflectivity remaining above 55%. Secondary peaks redshift synchronously with the main peak but their intensity does not increase, and the full width at half maximum (FWHM) remains at 30-50nm. Out-of-band reflectivity shows no significant increase. This further verifies the stability of phase transition tuning—regardless of whether the layer alternation occurs 4 or 5 times, the Sb₂S₃ phase transition can drive a continuous redshift of the reflection peak wavelength without disrupting the narrowband structure, proving that this tuning mechanism is applicable to different layer structures.

[0201] from Figure 7 As can be seen, the main reflection peaks of the four curves almost completely overlap, with the peak position concentrated at 600nm. The peak reflectance fluctuation is <3%, and there is no difference in the full width at half maximum (FWHM). The secondary peak at 500nm also does not shift or intensify with changes in angle. The 4-layer alternation structure is consistent with the 5-layer structure, maintaining spectral stability within the incident angle range of 0° to 60°. This indicates that the number of layer alternations does not affect angular stability, making the device suitable for multi-view applications.

[0202] Figure 8 This is the amorphous spectrum of the display device in Example 3; during the test, the incident light was incident perpendicularly onto the third high refractive index layer;

[0203] Figure 9 This is the crystalline spectrum of the display device in Example 3; during the test, the incident light was incident perpendicularly onto the third high refractive index layer;

[0204] Figure 10 The image shows the reflection spectra of the display device in Example 3 in the amorphous state at angles of 0°, 20°, 40°, and 60°. The angles of 0°, 20°, 40°, and 60° refer to the angles between the incident light and the normal of the third high refractive index layer (i.e., the angles between the incident light and the vertical direction are 0°, 20°, 40°, and 60°, respectively) during the test. Figure 10 In the equation, a is 0°, b is 20°, c is 40°, and d is 60°.

[0205] from Figure 8 As can be seen, the reflection peak rises from the 500nm band, reaching its peak at 600nm (reflectivity nearly 80%). The reflectivity in the 400-500nm and 650-800nm ​​bands is less than 15%, with a full width at half maximum (FWHM) of approximately 25-45nm and no obvious secondary peaks. Even with the layer alternation count further reduced to three, the device still achieves "high reflectivity + narrow bandwidth"—the peak reflectivity is comparable to that of the five-layer structure (nearly 80%), and the sideband suppression effect is even better (no secondary peaks). This indicates that the three-layer structure exhibits outstanding performance in reflection efficiency and spectral purity, providing a possibility for low-cost fabrication.

[0206] from Figure 9As can be seen from Figure 8, the main reflection peak has significantly redshifted to the 710nm region, and the peak reflectivity has decreased to over 70% (still within the high reflectivity range). The full width at half maximum (FWHM) has not changed significantly (25~45nm), and the out-of-band reflectivity remains below 15%. The redshift amplitude of the reflection peak of the tertiary alternating layer structure (approximately 110nm) is consistent with that of the quintiary and quaternary structures, and the reflectivity reduction after tuning is less than 10%, proving that this technology can reduce the fabrication difficulty by reducing the number of layers while retaining the core performance.

[0207] from Figure 10 As can be seen, the main reflection peaks of the four curves completely overlap at 600nm, the peak reflectance fluctuation is <4%, the full width at half maximum (FWHM) is consistent, and the reflectance distribution in the 400~800nm ​​band shows no angular difference, peak position shift, or peak shape distortion. This further demonstrates that the "angle insensitivity" still holds true in low-layer structures—the angular stability of the 3-layer alternating structure is consistent with that of the high-layer structures (4-layer and 5-layer), indicating that the angle insensitivity of the asymmetric Bragg reflector layer originates from the structural design rather than the number of layers, providing a basis for simplifying the device structure.

[0208] Figure 11 This is the amorphous spectrum of the display device in Example 4; during the test, the incident light was incident perpendicularly onto the second high refractive index layer;

[0209] Figure 12 The image shows the crystalline spectrum of the display device in Example 4; during the test, the incident light was incident perpendicularly onto the second high refractive index layer.

[0210] Figure 13 The image shows the reflection spectra of the display device in Example 4 in the amorphous state at angles of 0°, 20°, 40°, and 60°. The angles of 0°, 20°, 40°, and 60° refer to the angles between the incident light and the normal of the second high refractive index layer (i.e., the angles between the incident light and the vertical direction are 0°, 20°, 40°, and 60°, respectively) during the test. Figure 13 In the equation, a is 0°, b is 20°, c is 40°, and d is 60°.

[0211] from Figure 12As can be seen, a main reflection peak is formed at 600nm, with a peak reflectivity of approximately 40%; there is a slight fluctuation around 500nm (reflectivity <10%), and the reflectivity in the 400-550nm and 650-800nm ​​bands is less than 15%, with a full width at half maximum (FWHM) of approximately 40-60nm. Even with the layer alternation count reduced to a minimum (2 times), the device still maintains the "narrowband high reflectivity" characteristic—although the peak reflectivity is lower than that of higher layer count structures, the FWHM is still controlled within 60nm, the sideband suppression effect is good, and the color purity is still >75%, proving that the lowest layer count structure of this technology still meets the requirements for high-purity display and significantly reduces the fabrication complexity.

[0212] Compared with Figure 11, Figure 12 The main reflection peak redshifts to the 700nm region, with peak reflectivity remaining above 35%. Fluctuations at 500nm redshift synchronously with the main peak but without increased intensity. The full width at half maximum (FWHM) remains 40-60nm, and out-of-band reflectivity shows no increase. This further verifies that "the alternating layer structure still possesses dynamic tuning capability"—although the reflectivity is lower than that of higher-layer structures, the phase-change-driven redshift amplitude (approximately 100nm) is close to that of higher-layer structures, and the narrowband characteristics remain unchanged after tuning. This indicates that the technology can select the lowest layer structure based on the application scenario (such as anti-counterfeiting displays with lower reflectivity requirements), balancing performance and cost.

[0213] from Figure 13 As can be seen, the main reflection peaks of the four curves are concentrated at 600nm, with a peak position deviation of <8nm, peak reflectance fluctuation of <5% (all maintained at 30%~40%), no difference in half-width at half-maximum, and fluctuations at 500nm showing no angle dependence. This indicates "angle insensitivity" across the entire structure—from 2 to 5 layers of alternation, all structures maintain spectral stability within the 0°~60° incident angle range, completely solving the angle dependence problem of traditional structural colors and providing key support for multi-scenario applications of the device (such as large-area smart windows and multi-angle dynamic camouflage). This invention uniformly calculates color purity according to CIE1931 colorimetry under D65 standard illuminant and 2° standard observer conditions. Examples 1-4 show that the device's color purity is greater than 75% in the amorphous state and greater than 70% in the crystalline state, exhibiting narrow-band high reflectance and side-band low reflectance spectral characteristics.

[0214] It is understood that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0215] The above are merely preferred embodiments of this application, and only specifically describe the technical principles of this application. These descriptions are only for explaining the principles of this application and should not be construed as limiting the scope of protection of this application in any way. Based on this explanation, any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application, as well as other specific embodiments of this application that can be conceived by those skilled in the art without creative effort, should be included within the scope of protection of this application.

Claims

1. A display device, characterized in that, include: Base; An asymmetric Bragg reflector layer is located on the substrate; The asymmetric Bragg reflector layer comprises alternating low-refractive-index layers and high-refractive-index layers; The high refractive index layer is made of Sb2S3, and the low refractive index layer is made of SiO2.

2. The display device as claimed in claim 1, characterized in that, The thickness of the low-refractive-index layer is 35~80nm; The thickness of the high refractive index layer is 5~275nm.

3. The display device as described in claim 1, characterized in that, The low-refractive-index layer and the high-refractive-index layer alternate 1 to 5 times.

4. The display device as described in claim 3, characterized in that, The low-refractive-index layer and the high-refractive-index layer alternate twice; The asymmetric Bragg reflector layer comprises a first low-refractive-index layer, a first high-refractive-index layer, a second low-refractive-index layer, and a second high-refractive-index layer stacked sequentially. The thickness of the first low-refractive-index layer is 48~53nm; The thickness of the first high refractive index layer is 140~145nm; The thickness of the second low-refractive-index layer is 75~80 nm; The thickness of the second high refractive index layer is 5~10 nm.

5. The display device as described in claim 3, characterized in that, The low-refractive-index layer and the high-refractive-index layer alternate three times; The asymmetric Bragg reflector layer comprises a first low refractive index layer, a first high refractive index layer, a second low refractive index layer, a second high refractive index layer, a third low refractive index layer, and a third high refractive index layer stacked sequentially. The thickness of the first low-refractive-index layer is 35~40nm; The thickness of the first high refractive index layer is 50~55nm; The thickness of the second low-refractive-index layer is 48~53 nm; The thickness of the second high-refractive-index layer is 140~145 nm; The thickness of the third low-refractive-index layer is 75~80 nm; The thickness of the third high-refractive-index layer is 5~10 nm.

6. The display device as claimed in claim 3, characterized in that, The low-refractive-index layer and the high-refractive-index layer alternate 4 times; The asymmetric Bragg reflector layer comprises a first low refractive index layer, a first high refractive index layer, a second low refractive index layer, a second high refractive index layer, a third low refractive index layer, a third high refractive index layer, a fourth low refractive index layer, and a fourth high refractive index layer, which are stacked sequentially. The thickness of the first low-refractive-index layer is 50~55nm; The thickness of the first high refractive index layer is 270~275nm; The thickness of the second low-refractive-index layer is 35~40 nm; The thickness of the second high-refractive-index layer is 50~55nm; The thickness of the third low-refractive-index layer is 48~53 nm; The thickness of the third high refractive index layer is 140~145nm; The thickness of the fourth low-refractive-index layer is 75~80 nm; The thickness of the fourth high-refractive-index layer is 5~10 nm.

7. The display device as claimed in claim 3, characterized in that, The low-refractive-index layer and the high-refractive-index layer alternate 5 times; The asymmetric Bragg reflector layer comprises a first low refractive index layer, a first high refractive index layer, a second low refractive index layer, a second high refractive index layer, a third low refractive index layer, a third high refractive index layer, a fourth low refractive index layer, a fourth high refractive index layer, a fifth low refractive index layer, and a fifth high refractive index layer, which are stacked sequentially. The thickness of the first low-refractive-index layer is 42~47nm; The thickness of the first high refractive index layer is 140~145nm; The thickness of the second low-refractive-index layer is 50~55nm; The thickness of the second high-refractive-index layer is 270~275 nm; The thickness of the third low-refractive-index layer is 35~40 nm; The thickness of the third high-refractive-index layer is 50~55nm; The thickness of the fourth low-refractive-index layer is 48~53 nm; The thickness of the fourth high-refractive-index layer is 140~145 nm. The thickness of the fifth low-refractive-index layer is 75~80 nm; The thickness of the fifth high-refractive-index layer is 5~10 nm.

8. The display device as claimed in claim 1, characterized in that, The substrate is either a silicon substrate or a glass substrate, and the substrate thickness is ≥400nm.

9. A tuning method for a display device as described in any one of claims 1 to 8, characterized in that, Includes the following steps: Laser irradiation or thermal annealing is applied to the high refractive index layer in the display device to transform it between an amorphous state and a crystalline state, thereby achieving tuning of the reflection peak wavelength.

10. The application of a display device as described in any one of claims 1 to 8 in image sensing, smart windows, dynamic camouflage, and anti-counterfeiting displays.

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