Display devices based on phase change materials

Abstract

The present invention provides a display device based on phase change material, the device comprising: a broadband absorption cavity structure, comprising a lossy phase change layer and a metal layer, the lossy phase change layer is deposited on the metal layer, the lossy phase change layer is a lossy phase change material, and the metal layer is composed of multiple layers of metals with a K value greater than 1; a narrowband absorption cavity structure, located below the broadband absorption cavity structure, the narrowband absorption cavity structure comprising a first narrowband absorption cavity structure and a second narrowband absorption cavity structure, the first narrowband absorption cavity structure being located above the second narrowband absorption cavity structure; the first narrowband absorption cavity structure comprising a lossless phase change layer and a metal layer located on both sides of the lossless phase change layer; the second narrowband absorption cavity structure comprising a dielectric layer and a metal layer located on both sides of the dielectric layer, the lossless phase change layer is a lossless phase change material. The present invention realizes the characteristics of the same transmission and reflection colors, weak rainbow color phenomenon, adjustable colors, and angle insensitivity.

Description

Technical Field

[0001] The present invention relates to the technical field of display devices, and particularly to a display device based on phase change materials. Background Art

[0002] In the existing phase change material display technology, most display structures adopt a metal / phase change material / metal structure. There is a top metal layer in it, which is easily scratched and oxidized, and this will quickly damage the formed color. Most metal / phase change material / metal structures are rainbow-colored, that is to say, their colors change with the polarization and the angle of incidence. If the problem of rainbow color needs to be solved, an anti-reflection layer often needs to be introduced, and the structure is complex. The structure cavity of metal / phase change material / metal provides different colors in the reflection and transmission modes, which limits its application prospects. Or an FP cavity composed of dielectric materials, metals and phase change materials is used to display different colors, but the consistency of transmission and reflection colors cannot be achieved. Currently, generating the same color in reflection and transmission in the same structure has a broad market and can be used in scenarios such as vehicle-mounted glass, AR, and VR. Therefore, there is an urgent need for a structure to solve the above problems.

[0003] Therefore, the traditional metal / phase change material / metal structure based on phase change materials has the problem of rainbow color, and it is difficult to achieve the same color in transmission and reflection. Summary of the Invention

[0004] The present invention provides a display device based on phase change materials, which is used to solve the defects that the display device based on phase change materials in the prior art has rainbow color and provides different colors in the reflection and transmission modes, and realizes providing the same color and adjustable color in the reflection and transmission modes, and is insensitive to the angle.

[0005] The present invention provides a display device based on phase change materials, including:

[0006] A broadband absorption cavity structure, including a lossy phase change layer and a metal layer, the lossy phase change layer is deposited on the metal layer, the lossy phase change layer is a lossy phase change material with a K value greater than 1 in the visible light region, the metal layer is composed of multiple metals, the K value of the metal is greater than 1 in the visible light region, the thickness of the metal layer is less than 30 nm, and together with the lossy phase change material in the visible light region, it forms a broadband absorber with an absorption rate greater than a preset threshold;

[0007] A narrowband absorption cavity structure, located under the broadband absorption cavity structure, the narrowband absorption cavity structure includes a first narrowband absorption cavity structure and a second narrowband absorption cavity structure, and the first narrowband absorption cavity structure is located above the second narrowband absorption cavity structure;

[0008] The first narrowband absorption cavity structure includes a lossless phase change layer with a K value less than 1 in the visible light region and metal layers on both sides of the lossless phase change layer;

[0009] The second narrowband absorption cavity structure includes a dielectric layer and metal layers on both sides of the dielectric layer, and the lossless phase change layer is a lossless phase change material.

[0010] For a display device based on a phase change material according to the present invention, when a voltage is applied to the metal layer in the broadband absorption cavity structure, the crystal structure and gray scale of the lossy phase change material change to adjust the absorption of the broadband absorption cavity structure;

[0011] When a voltage is applied to the metal layers on both sides of the lossless phase change layer, the crystal structure and gray scale of the lossless phase change material change to adjust the absorption of the narrowband absorption cavity structure.

[0012] For a display device based on a phase change material according to the present invention, the lossy phase change material includes one or more alloys of GeTe, SbTe, SnSb, AgSbTe, InSbTe, and GeSb with a K value greater than 0.5 in the visible light part, and the percentage of each atom is adjustable.

[0013] For a display device based on a phase change material according to the present invention, the metal layer in the broadband absorption cavity structure includes one or more of metal materials such as ITO, Ag, Au, W, and Cr with a K value greater than 1 in the visible light part;

[0014] The metal layer in the narrowband absorption cavity structure includes one or more of metal materials such as ITO, Ag, Au, and W with a K value greater than 1 in the visible light part.

[0015] For a display device based on a phase change material according to the present invention, the thickness of the lossy phase change layer is less than 100 nm, and the thickness of the metal layer in the broadband absorption cavity structure is less than 30 nm.

[0016] For a display device based on a phase change material according to the present invention, the lossless phase change material includes one or more of alloys such as SbS and SbSe, the percentage of each atom is adjustable, and the K value of the phase change material is small, with a K value less than 1 in the visible light part.

[0017] For a display device based on a phase change material according to the present invention, the dielectric layer includes one or more of transparent dielectric materials such as SIO2, TIO2, and Ta 2 O 5 with a K value less than 1.

[0018] A display device based on phase change materials provided by the present invention, wherein the thickness of the lossless phase change layer is less than 200 nm, and the thickness of the dielectric layer is less than 1 micron.

[0019] A display device based on phase change materials provided by the present invention, wherein the lossy phase change material is GSST, and the metal layers in the broadband absorption cavity structure are Ag and Cr. The double-layer metal is beneficial to reducing other peaks except the target peak of transmission and reflection, and increasing the color saturation.

[0020] A display device based on phase change materials provided by the present invention, wherein the metal layer in the narrowband absorption cavity structure is Ag, and the dielectric layer is TIO 2 , and the lossless phase change material is Sb 2 Se 3 .

[0021] The display device based on phase change materials provided by the present invention combines a broadband absorber cavity and a narrowband absorber cavity. The broadband absorber cavity structure includes a lossy phase change material with high and low refractive indices and multiple metal materials. The narrowband light absorber cavity includes a metal-dielectric / phase change material-metal cavity. When the broadband light absorber cavity and the narrowband light absorber cavity are weakly coupled, resonant destructive interference occurs in the spectral overlap region, generating asymmetric Fano resonance absorption and reflection spectra, thereby achieving the same transmission and reflection colors and a weak rainbow color phenomenon. In addition, a phase change material is introduced to achieve tunable color generation in reflection and transmission modes and is insensitive to angles. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0023] Figure 1 is a schematic diagram of a broadband absorption cavity structure with a single-layer metal in the display device based on phase change materials provided by the present invention;

[0024] Figure 2 is a schematic diagram of the narrowband absorption cavity structure in the display device based on phase change materials provided by the present invention;

[0025] Figure 3 is a schematic diagram of the structure of the display device based on phase change materials provided by the present invention (with a single-layer metal in the metal layer of the broadband absorption cavity structure);

[0026] Figure 4It is the spectral schematic diagram of the broadband absorption cavity structure in the display device based on phase change materials provided by the present invention;

[0027] Figure 5 It is the spectral schematic diagram of the narrowband absorption cavity structure in the display device based on phase change materials provided by the present invention;

[0028] Figure 6 It is the blue spectral schematic diagram of the display device based on phase change materials provided by the present invention;

[0029] Figure 7 It is the green spectral schematic diagram of the display device based on phase change materials provided by the present invention;

[0030] Figure 8 It is the red spectral schematic diagram of the display device based on phase change materials provided by the present invention;

[0031] Figure 9 Schematic diagram of the structure of the display device based on phase change materials provided by the present invention (there are two metal layers in the broadband absorption cavity structure);

[0032] Figure 10 It is the blue spectral schematic diagram of the display device based on phase change materials provided by the present invention (there are two metal layers in the broadband absorption cavity structure);

[0033] Figure 11 It is the green spectral schematic diagram of the display device based on phase change materials provided by the present invention (there are two metal layers in the broadband absorption cavity structure);

[0034] Figure 12 It is the red spectral schematic diagram of the display device based on phase change materials provided by the present invention (there are two metal layers in the broadband absorption cavity structure);

[0035] Figure 13 It is the blue spectral schematic diagram of the display device based on phase change materials provided by the present invention (there are two metal layers in the broadband absorption cavity structure);

[0036] Figure 14 It is the green angle-insensitive schematic diagram of the display device based on phase change materials provided by the present invention (there are two metal layers in the broadband absorption cavity structure);

[0037] Figure 15 It is the red angle-insensitive schematic diagram of the display device based on phase change materials provided by the present invention (there are two metal layers in the broadband absorption cavity structure);

[0038] Figure 16 It is the schematic diagram of the experimental results of the red, blue and green primary colors of the display device based on phase change materials provided by the present invention.

[0039] Reference numerals:

[0040] 101. Metal layer of the broadband absorption cavity structure; 102. Lossy phase change layer of the broadband absorption cavity structure; 201. Substrate; 202. Metal layer of the narrowband absorption cavity structure; 203. Dielectric layer of the narrowband absorption cavity structure; 204. Metal layer of the narrowband absorption cavity structure; 205. Non-lossy phase change layer of the narrowband absorption cavity structure; 206. Metal layer of the narrowband absorption cavity structure. 301. Substrate when the two structures are combined; 302. Metal layer of the narrowband absorption cavity structure when the two structures are combined; 303. Dielectric layer of the narrowband absorption cavity structure when the two structures are combined (the metal layer in the broadband absorption cavity structure has a single layer of metal); 304. Metal layer of the narrowband absorption cavity structure when the two structures are combined (the metal layer in the broadband absorption cavity structure has a single layer of metal); 305. Non-lossy phase change layer of the narrowband absorption cavity structure when the two structures are combined (the metal layer in the broadband absorption cavity structure has a single layer of metal); 306. Metal layer of the narrowband absorption cavity structure when the two structures are combined (the metal layer in the broadband absorption cavity structure has a single layer of metal); 307. Lossy phase change layer of the broadband absorption cavity structure when the two structures are combined (the metal layer in the broadband absorption cavity structure has a single layer of metal); 901. Substrate when the two structures are combined (the metal layer in the broadband absorption cavity structure has two layers of metal); 902. Metal layer of the narrowband absorption cavity structure when the two structures are combined (the metal layer in the broadband absorption cavity structure has two layers of metal); 903. Dielectric layer of the narrowband absorption cavity structure when the two structures are combined (the metal layer in the broadband absorption cavity structure has two layers of metal); 904. Metal layer of the narrowband absorption cavity structure when the two structures are combined (the metal layer in the broadband absorption cavity structure has two layers of metal); 905. Non-lossy phase change layer of the narrowband absorption cavity structure when the two structures are combined (the metal layer in the broadband absorption cavity structure has two layers of metal); 906. Metal layer of the narrowband absorption cavity structure when the two structures are combined (the metal layer in the broadband absorption cavity structure has two layers of metal); 907. Metal layer of the broadband absorption cavity structure when the two structures are combined (the metal layer in the broadband absorption cavity structure has two layers of metal); 908. Lossy phase change layer of the broadband absorption cavity structure when the two structures are combined (the metal layer in the broadband absorption cavity structure has two layers of metal). Detailed implementation manners

[0041] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art without making creative efforts based on the embodiments in the present invention fall within the protection scope of the present invention.

[0042] The following combinesFigures 1 to 3 A display device based on phase change materials according to the present invention includes:

[0043] A broadband absorption cavity structure, including a lossy phase change layer 307 and a metal layer 306. The lossy phase change layer 307 is deposited on the metal layer 306. The lossy phase change layer 307 is a lossy phase change material with a K value greater than 1 in the visible light region. The metal layer is composed of multiple metals, and the K value of the metal is greater than 1 in the visible light region. The thickness of the metal layer is less than 30 nm, and together with the lossy phase change material in the visible light region, it forms a broadband absorber with an absorption rate greater than a preset threshold;

[0044] A narrowband absorption cavity structure, located below the broadband absorption cavity structure. The narrowband absorption cavity structure includes a first narrowband absorption cavity structure and a second narrowband absorption cavity structure, and the first narrowband absorption cavity structure is located above the second narrowband absorption cavity structure;

[0045] The first narrowband absorption cavity structure includes a lossless phase change layer 305 and metal layers 304 and 306 located on both sides of the lossless phase change layer;

[0046] The second narrowband absorption cavity structure includes a dielectric layer 303 and metal layers 302 and 304 located on both sides of the dielectric layer. The lossless phase change layer is a lossless phase change material with a K value less than 1 in the visible light region.

[0047] The second narrowband absorption cavity structure may further include a substrate 301.

[0048] The broadband absorption cavity structure is formed by depositing an ultra-thin dielectric film phase change material (Phase Change Material, PCM) with low refractive index and strong optical loss on a high-reflection metal substrate or other high-refractive-index dielectric materials, which is used to improve the angular insensitivity of the display structure and solve the rainbow color problem caused by angle sensitivity in phase change displays based on the MDM structure. At the same time, it provides a broadband absorber.

[0049] As Figure 1 shown, the lossy phase change layer 102 is deposited on the metal layer 101 to form a broadband absorption cavity structure. The broadband absorption cavity structure is designed to form a broadband absorber and constitute an antireflection layer to suppress reflection.

[0050] The narrowband light absorber cavity structure is composed of a metal-dielectric / lossless phase change material-metal cavity or multiple cavities of the same type. Among them, the lossless phase change material must have the characteristics of low loss and high refractive index, including but not limited to SbS and materials doped to have this characteristic.

[0051] The narrowband optical absorber cavity structure includes a first narrowband absorption cavity structure and a second narrowband absorption cavity structure. The first narrowband absorption cavity structure can be multiple, and each first narrowband absorption cavity structure is composed of a phase change material layer and electrode layers located on both sides of the phase change material layer. Optionally, the electrode layers between adjacent phase change material layers can be shared.

[0052] As Figure 2 shown, the first narrowband absorption cavity structure is an FP (Fabry - Perot Cavity) cavity structure formed by sandwiching a phase change material with metals, including a non - loss phase change layer 205 and metal layers 204 and 206 on both sides of it. The metal layers 204 and 206 not only play the role of forming an FP cavity with the non - loss phase change material but also play the role of controlling the phase change of the non - loss phase change material.

[0053] The first narrowband absorption cavity structure is an MDM (Metal - Dielectric - Metal) cavity structure formed by sandwiching a dielectric with metals, including a dielectric layer 203 and metal layers 202 and 204 on both sides of it, and also includes a substrate 201.

[0054] When the broadband optical absorber cavity structure and the narrowband optical absorber cavity structure are combined, the broadband optical absorber cavity structure is located above the narrowband optical absorber cavity structure, and resonant destructive interference occurs in the spectral overlap region between the two, generating asymmetric Fano resonance absorption and reflection spectra at the resonance of the narrowband absorption layer, so that the reflection and transmission colors of the entire structure are consistent. By applying voltage or heat to control the broadband phase change state, the gray scale of the display structure can be adjusted.

[0055] Through this design, not only can the transmission and reflection colors of the display device be the same, but also it can be insensitive to the angle, to meet the requirements of different VR (Virtual Reality), smart glasses, etc. for the same - color transmission and reflection.

[0056] Generally speaking, this embodiment adopts a brand - new design idea for the display structure, and successfully develops a display structure with full - color access, high color purity, high brightness, controllable rainbow effect, and consistent colors in reflection and transmission modes. This technical strategy overcomes the inherent limitations of the existing structure, has great significance in technological progress, and opens up new possibilities for the further development of phase - change display technology.

[0057] This embodiment combines a broadband absorber cavity with a narrowband absorber cavity. The broadband absorber cavity structure includes lossy phase change materials and metal materials with high and low refractive indices. The narrowband light absorber cavity includes a metal-medium / phase change material-metal cavity. When the broadband light absorber cavity is weakly coupled with the narrowband light absorber cavity, resonant destructive interference occurs in the spectral overlap region, generating asymmetric Fano resonant absorption and reflection spectra, thereby achieving the same transmission and reflection colors and weak rainbow color phenomenon. In addition, phase change materials are introduced to achieve adjustable color generation in reflection and transmission modes.

[0058] Based on the above embodiment, in this embodiment, when a voltage is applied to the metal layer in the broadband absorption cavity structure, the crystal structure and grayscale of the lossy phase change material change to adjust the absorption of the broadband absorption cavity structure;

[0059] When voltage is applied to the metal layers on both sides of the lossless phase change layer, the crystal structure and grayscale of the lossless phase change material change to adjust the absorption of the narrow-band absorption cavity structure.

[0060] For example, the phase change materials in the lossy phase change layer 307 and the lossless phase change layer 305 can be converted between a crystalline state and an amorphous state under electrical stimulation or laser stimulation, thereby changing the transmittance and reflectivity of the phase change layer.

[0061] A metal layer is deposited under the top lossy phase change layer 307, and the crystallization state of the lossy phase change material can be controlled by applying a voltage on the metal layer 306. The crystallization state of the lossless phase change layer 305 can be controlled by applying a voltage on the metal layers 306 and 304.

[0062] Specifically, a pulse voltage or laser pulse of medium intensity can be applied to the lossy phase change layer 307 and / or the lossless phase change layer 305. Under the action of the current or laser pulse, the temperature of the phase change material rises to a temperature range above the crystallization temperature and below the melting temperature, and is maintained for a certain period of time. At this time, the lattice is orderly arranged to form a crystalline state, realizing the transition from the amorphous state to the crystalline state.

[0063] A short and strong voltage or laser pulse is applied to the lossy phase change layer 307 and / or the lossless phase change layer 305 to raise the temperature of the phase change material above the melting temperature, destroying the long-range order of the crystalline state. The pulse falling edge is very short, causing the phase change material to be quickly cooled to below the crystallization temperature, so that the phase change material is fixed in the amorphous state, realizing the transition from the crystalline state to the amorphous state.

[0064] The gray scale of the phase change material is regulated by the changes in transmittance and reflectance when the phase change material in the lossy phase change layer 307 and / or the non-lossy phase change layer 305 transforms between the amorphous state and the crystalline state, thereby adjusting the absorption peaks and positions of the broadband light absorber cavity structure and the narrowband light absorber cavity structure, and realizing adjustable color generation in the reflection and transmission modes.

[0065] The transmittance of the non-lossy phase change layer 305 varies greatly in different states. The phase change material is stable in the crystalline and amorphous states. Therefore, the voltage or laser can be removed when the phase change material is in the stable state, so the power consumption of the entire display device during the display process is very low.

[0066] Based on the above embodiments, in this embodiment, the lossy phase change material includes one or more of GeTe, SbTe, SnSb, AgSbTe, InSbTe, and GeSb, wherein the percentage of each atom is adjustable, and the k value of the lossy phase change material is greater than 1 in the visible light part.

[0067] The lossy phase change material may further include the following chalcogenide compounds and their alloys, including but not limited to: phase change materials with high-loss and low-refractive-index characteristics such as GST, GSST, IST, GeTe, SbTe, BiTe, InSb, InSe, GeSb, GaSb, GaSb, GeSbTe, AgInSbTe, InSbTe, AgSbTe, and Ag2In4Sb76Te17 (AIST).

[0068] At least one dopant, such as C and N, may be further included in the lossy phase change material.

[0069] Based on the above embodiments, in this embodiment, the metal layer in the broadband absorption cavity structure includes one or more of metal materials such as ITO, Ag, Au, W, and Cr with a k value greater than 1 in the visible light part;

[0070] The metal layer in the narrowband absorption cavity structure includes one or more of metal materials such as ITO, Ag, Au, W, and Cr with a k value greater than 1 in the visible light part. Based on the above embodiments, in this embodiment, the thickness of the lossy phase change layer is less than 100 nm, and the thickness of the metal layer in the broadband absorption cavity structure is less than 100 nm.

[0071] The thickness of the lossy phase change layer 307 is less than 100 nm. Since the increase in the thickness of the phase change material layer will reduce the transmittance of visible light and the temperature required for the crystallization of the phase change material is also higher, a more appropriate thickness is within 40 nm. The phase change material in the phase change material layer can be driven by laser or voltage. When driven by voltage, a voltage is applied to the transparent electrodes on both sides of the phase change layer to cause the phase change of the phase change material.

[0072] Based on the above embodiments, in this embodiment, the lossless phase change material includes SbS and SbSe, where the percentage of each atom is adjustable, and the k value of the lossless phase change material is less than 1 in the visible light part.

[0073] The lossless phase change material may further include at least one dopant, such as C, N.

[0074] Based on the above embodiments, in this embodiment, the dielectric layer includes SIO 2 , TIO 2 and Ta 2 O 5 and one or more of the transparent dielectric materials with a K value less than 1, such as these.

[0075] Based on the above embodiments, in this embodiment, the thickness of the lossless phase change layer is less than 200 nm, and the thickness of the dielectric layer is less than 1 micron.

[0076] Based on the above embodiments, in this embodiment, the lossy phase change material is GSST, and the metal layer in the broadband absorption cavity structure is Ag.

[0077] GSST is an ultrathin phase change material with strong optical loss. It has high loss, low refractive index, and good thermal stability in the visible light range. Ag is a metal with high reflectivity.

[0078] Based on the above embodiments, in this embodiment, the metal layer in the narrowband absorption cavity structure is Ag, the dielectric layer is TIO2, and the lossless phase change material is Sb2Se3.

[0079] The lossless phase change material Sb2Se3 has low loss and high refractive index in the visible light range.

[0080] Figure 4 and Figure 5 are respectively Figure 1 and Figure 2 the schematic diagrams of the reflection and absorption spectra corresponding to each structure in. Among them, Figure 2 the thickness of the metal layer 101Ag in is 12 nm, and the thickness of the lossy phase change layer 102GSST is 10 nm. Figure 3 The respective parameters in are as follows: the metal layer 202Ag is 40 nm, the dielectric layer 203TIO2 is 50 nm, 60 nm, 220 nm, the metal layer 204Ag is 15 nm, the lossless phase change layer 205Sb2Se3 is 8 nm, and the metal layer 206Ag is 12 nm. Figure 1The parameters are: metal layer 302Ag is 40nm, dielectric layer 303TIO2 is 50nm, 60nm, 220nm, metal layer 304Ag is 15nm, lossless phase change layer 305Sb2Se3 is 8nm, metal layer 306Ag is 12nm, lossy phase change layer 307GSST is 10nm.

[0081] Figure 6 、 Figure 7 and Figure 8 The reflection and transmission spectra of the three structures of blue, red and green are shown. The blue corresponds to the dielectric layer 303TIO2 with a thickness of 50nm, the green corresponds to the dielectric layer 303TIO2 with a thickness of 60nm, and the red corresponds to the dielectric layer 303TIO2 with a thickness of 220nm. By applying different voltages or adjusting the laser power, the phase change material layer changes from amorphous to partially crystallized to completely crystallized, thereby adjusting the ratio of transmitted and reflected light to adjust the grayscale of the display device.

[0082] Figure 9 It is a display device structure composed of a broadband absorber structure and a narrowband absorber structure composed of a double-layer metal, including a substrate 901, a metal layer 902 of a narrowband absorption cavity structure, a dielectric layer 903 of a narrowband absorption cavity structure, a metal layer 904 of a narrowband absorption cavity structure, a lossless phase change layer 905 of a narrowband absorption cavity structure, a metal layer 906 of a narrowband absorption cavity structure, a metal layer 907 of a broadband absorption cavity structure, and a lossy phase change layer 908 of a broadband absorption cavity structure.

[0083] Compared to Figure 3 , Figure 9 The broadband absorber in has an additional layer of metal, which greatly reduces the peak value of the red, blue and green structural colors in the non-target wavelength range and improves the color saturation. Compared with Figure 6 、 Figure 7 and Figure 8 , from Figure 10 、 Figure 11 and Figure 12 You can see it. Figure 13 、 Figure 14 and Figure 15 It can be seen that the angle insensitivity of the three primary colors of red, blue and green can reach 50°, and the structure is simple. The experimental results are as follows Figure 16 As shown.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A display device based on phase change material, characterized in that: include: A broadband absorption cavity structure, comprising a lossy phase change layer and a metal layer, wherein the lossy phase change layer is deposited on the metal layer, the lossy phase change layer is a lossy phase change material with a K value greater than 1 in the visible light region, the metal layer is a double-layer structure of Ag and Cr, the K value of the metal layer is greater than 1 in the visible light region, the thickness of the metal layer is less than 30 nm, and the metal layer and the lossy phase change material together form a broadband absorber with an absorption rate greater than a preset threshold in the visible light region; A narrowband absorption cavity structure, located below the broadband absorption cavity structure, the narrowband absorption cavity structure comprising a first narrowband absorption cavity structure and a second narrowband absorption cavity structure, the first narrowband absorption cavity structure being located above the second narrowband absorption cavity structure; The first narrow-band absorption cavity structure comprises a lossless phase change layer whose K value is less than 1 in the visible light region and metal layers located on both sides of the lossless phase change layer; The second narrowband absorption cavity structure comprises a dielectric layer and metal layers located on both sides of the dielectric layer, and the lossless phase change layer is a lossless phase change material; The metal layer in the narrow-band absorption cavity structure includes one or more metal materials of ITO, Ag, Au, Cr and W, whose K value is greater than 1 in the visible light part; The lossless phase change material includes SbS and / or SbSe alloy, wherein the percentage of each atom is adjustable.

2. The display device based on phase change material according to claim 1, characterized in that: When a voltage is applied to the metal layer in the broadband absorption cavity structure, the crystal structure and grayscale of the lossy phase change material change to adjust the absorption of the broadband absorption cavity structure; When a voltage is applied to the metal layers on both sides of the lossless phase change layer, the crystal structure and grayscale of the lossless phase change material change to adjust the absorption of the narrow-band absorption cavity structure.

3. The display device based on phase change material according to claim 1, characterized in that: The lossy phase change material includes one or more alloys of GeTe, SbTe, SnSb, AgSbTe, InSbTe and GeSb, wherein the K value in the visible light part is greater than 0.5, and the percentage of each atom is adjustable.

4. The display device based on phase change material according to claim 1, characterized in that: The metal layer in the broadband absorption cavity structure includes one or more metal materials of ITO, Ag, Au, Cr and W, whose K value is greater than 1 in the visible light part.

5. The display device based on phase change material according to claim 1, characterized in that: The thickness of the lossy phase change layer is less than 100 nm.

6. The display device based on phase change material according to claim 1, characterized in that: The dielectric layer includes one or more transparent dielectric materials with a K value less than 1 among SIO2, TIO2 and Ta2O5.

7. The display device based on phase change material according to claim 1, characterized in that: The thickness of the lossless phase change layer is less than 200 nm, and the thickness of the dielectric layer is less than 1 micron.

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