A display device

Abstract

The present invention provides a display device comprising: a narrowband absorber structure comprising a dielectric layer and a metal layer; and a broadband absorber structure comprising a dielectric layer, a metal layer, and a phase change layer. The metal layer in the broadband absorber structure comprises multiple layers, exhibits loss, and has a K value greater than a preset threshold. The phase change layer is positioned between the multiple metal layers. The broadband absorber structure is positioned above the narrowband absorber structure and coupled with the narrowband absorber structure to produce vivid colors. The present invention has the advantages of a simple structure, being less susceptible to environmental influences, maintaining minimal changes in color reflectivity and saturation with temperature changes, and being angle-insensitive.

Description

Technical Field

[0001] The present invention relates to the technical field of phase change material display, and in particular to a display device. Background Art

[0002] Structural colors produce colors only through the nanostructure of the object itself, and have important scientific and practical value. Compared with traditional dyes and pigments, structural colors have significant advantages in color purity, brightness, clarity, durability and environmental friendliness. Therefore, they have important applications in optical imaging, display, detection equipment, color sensors, anti-counterfeiting technology and surface decoration. To date, a variety of physical mechanisms have been proposed to produce structural colors, such as Guide Mode Resonances (GMR), Surface Plasmon Resonance (SPR) and Mie resonance. However, these structures usually require complex nanoscale patterning, which is difficult to manufacture on a large scale or over a large area, and the cost is relatively high.

[0003] In contrast, planar thin-film structural colors based on photolithography-free technology offer a simple approach to color generation. This design approach is easily adjustable and scalable, and can be deposited and expanded using magnetron sputtering instruments or EBE (Electron Beam Evaporation). The Fabry-Perot (FP) cavity is one of the simplest and most commonly used thin-film configurations for generating structural colors. It consists of a transparent dielectric or absorbing semiconductor material sandwiched between two metal mirrors. Constructive interference occurring in the dielectric layer forms transmission peaks or reflection valleys at specific wavelengths. However, due to the narrow absorption bandwidth caused by the cavity resonance and the fact that the RGB color space is larger than CMY, designing reflective RGB colors with high purity and brightness remains challenging. Although various designs have been proposed to generate RGB colors, it remains challenging to tune reflective full-color structural colors to achieve high brightness and purity using simple thin-film structures and processes due to limitations in preparation technology, the FP structure itself, or the inherent absorption of the material.

[0004] Phase-change materials (PCMs) have attracted considerable attention due to their advantages, such as high temperature stability and favorable optical constants. Consequently, many structures have been developed that combine PCMs with FP cavities to achieve high reflectivity. However, achieving high reflectivity often faces the challenge of high reflectivity in non-target peak regions. Furthermore, at high temperatures, the inherent properties of PCMs can cause color fluctuations, which can be detrimental to their application in certain fields. Summary of the Invention

[0005] The present invention provides a display device to solve the defects of the high reflectivity in non-target peak areas and low color saturation in the high reflectivity structure based on phase change material combined with FP cavity in the prior art, and realizes a structural design that uses phase change material to achieve high color saturation and high reflectivity. Under this structure, its color remains almost unchanged with changes in temperature, while meeting the characteristics of high reflectivity and high color saturation.

[0006] The present invention provides a display device, comprising:

[0007] a narrowband absorber structure comprising a dielectric layer and a metal layer;

[0008] A broadband absorber structure includes a dielectric layer, a metal layer, and a phase change layer. The metal layer in the broadband absorber structure has multiple layers and has loss, and the K value is greater than a preset threshold. The phase change layer is located between the multiple metal layers. The broadband absorber structure is located above the narrowband absorber structure and couples with the narrowband absorber structure to produce bright colors.

[0009] According to a display device provided by the present invention, the broadband absorber structure includes a first reflective layer, a phase change layer, a first metal layer, a first dielectric layer, and a second dielectric layer arranged in sequence from bottom to top.

[0010] According to a display device provided by the present invention, the first reflective layer is Ag;

[0011] The phase change layer is Ge2Sb2Se5, the ratio of each element in Ge2Sb2Se5 is adjustable, or a chalcogenide phase change material doped with elements such as C and N, and the K value and N value before and after the phase change decrease or increase with the movement of the wavelength;

[0012] The first metal layer is made of elements such as W, Ge, and Ta, and its K value is greater than 1;

[0013] The first dielectric layer is Ta2O3.5, TiO2, SiO2, and the K value of the material must be 0;

[0014] The second medium layer is MgF2, which satisfies the K value of 0 and has a refractive index gradient with the first medium layer.

[0015] According to a display device provided by the present invention, the thickness of the first reflective layer varies in the range of 10 nm to 40 nm;

[0016] The thickness of the phase change layer varies in the range of 1 nm to 20 nm;

[0017] The thickness of the first metal layer varies in the range of 1 nm to 20 nm;

[0018] The thickness of the first dielectric layer varies in the range of 1 nm to 500 nm;

[0019] The thickness of the second dielectric layer ranges from 4 nm to 500 nm.

[0020] According to a display device provided by the present invention, the broadband absorber structure further includes a second metal layer and a third metal layer, the second metal layer is located between the first reflective layer and the phase change layer, and the third metal layer is located between the phase change layer and the first metal layer.

[0021] According to a display device provided by the present invention, the second metal layer and the third metal layer are both made of elements such as Ge, W, Ge, and Ta, and their K values ​​are greater than 1.

[0022] According to a display device provided by the present invention, the thicknesses of the second metal layer and the third metal layer both range from 1 nm to 5 nm.

[0023] According to a display device provided by the present invention, the narrow-band absorber structure includes a second reflective layer, a third dielectric layer, a fourth dielectric layer and the first reflective layer arranged in sequence from bottom to top.

[0024] According to a display device provided by the present invention, the second reflective layer is Ag, the third dielectric layer is Ta2O3.3, the fourth dielectric layer is Ta2O3.5 or Ta oxide with a K value of 0, and the first reflective layer is Ag.

[0025] According to a display device provided by the present invention, the thickness of the second reflective layer is greater than 50 nm, the thickness of the third dielectric layer is 6 nm, the thickness of the fourth dielectric layer varies in the range of 10 nm to 1 micron, and the thickness of the first reflective layer varies in the range of 10 nm to 40 nm.

[0026] The display device provided by the present invention adopts a broadband absorber structure composed of a dielectric layer, a metal material and a phase change material, and a narrowband absorption structure composed of a dielectric and a metal to form a display device. The broadband absorber structure adopts multiple layers of metal with a high K value and low loss, and the phase change material is located in the middle of the metal layer. It has the advantages of simple structure, not being easily affected by the environment, little change in color reflectivity and saturation when the temperature changes, and being insensitive to angles. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 This is a schematic diagram of the structure of a broadband absorber in a display device provided by the present invention;

[0029] Figure 2 The display device provided by the present invention Figure 1 Schematic diagram of the corresponding narrow absorber structure;

[0030] Figure 3 This is one of the structural schematic diagrams of the display device provided by the present invention;

[0031] Figure 4 This is a schematic diagram of the narrow absorber structure in the display device provided by the present invention;

[0032] Figure 5 The display device provided by the present invention Figure 4 Schematic diagram of the corresponding broadband absorber structure;

[0033] Figure 6 This is the second structural schematic diagram of the display device provided by the present invention;

[0034] Figure 7 The display device provided by the present invention Figure 1 Schematic diagram of the spectrum corresponding to the broadband absorber structure shown;

[0035] Figure 8 The display device provided by the present invention Figure 5 Schematic diagram of the spectrum corresponding to the broadband absorber structure shown;

[0036] Figure 9 The display device provided by the present invention Figure 2 and Figure 4 Schematic diagram of the spectrum corresponding to the narrow-band structure in;

[0037] Figure 10 yes Figure 3 Schematic diagram of the spectrum corresponding to the display device in;

[0038] Figure 11 1 is a schematic diagram of spectrum comparison of the display device provided by the present invention;

[0039] Figure 12 yes Figure 3 The angle-insensitive spectrum of the display device in

[0040] Figure 13 It is a schematic diagram of the values ​​of the optical constants N and K in the display device provided by the present invention. DETAILED DESCRIPTION

[0041] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0042] The following combination Figures 1 to 13 A display device of the present invention is described, comprising:

[0043] a narrowband absorber structure comprising a dielectric layer and a metal layer;

[0044] A broadband absorber structure includes a dielectric layer, a metal layer, and a phase change layer. The metal layer in the broadband absorber structure has multiple layers and has loss, and the K value is greater than a preset threshold. The phase change layer is located between the multiple metal layers. The broadband absorber structure is located above the narrowband absorber structure and couples with the narrowband absorber structure to produce bright colors.

[0045] This embodiment employs a novel technical strategy, employing a broadband absorber structure composed of a dielectric layer, a metal material, and a phase-change material, along with a narrowband absorber structure composed of a dielectric layer and a metal layer, to form a display device. The display device comprises two main components: a broadband visible light absorber structure and a narrowband absorber structure. When these two components are combined, they form the broadband absorber structure and the narrowband absorber structure, respectively, from top to bottom.

[0046] The broadband absorber structure is constructed using multiple layers of high-K metal, phase-change material, and dielectric. The metal layer consists of two or more layers, each no thicker than 30nm. The metal is lossy, meaning its extinction coefficient is not zero. The phase-change material is located in the middle of the metal layer.

[0047] The broadband absorber formed by this design can achieve an absorption effect of more than 90% in the visible light band. It is mainly coupled with a narrow-band absorber to form bright colors, which can improve the color saturation and color purity. Moreover, it has a stable structure, is not easily oxidized, is not easily affected by temperature, and is insensitive to temperature changes, so as to meet the demand for high color purity based on the reflective display market.

[0048] Compared with the phase change display composed of traditional broadband absorber structure and narrowband absorber structure, this design can better improve its color purity and reflectivity.

[0049] In summary, this embodiment adopts a completely new display structure design approach, successfully developing a display structure that is insensitive to temperature changes. This technical strategy overcomes the inherent limitations of existing structures, has significant technological advancement significance, and opens up new possibilities for the further development of display technology.

[0050] This embodiment adopts a broadband absorber structure composed of a dielectric layer, a metal material and a phase change material, and a narrow-band absorption structure composed of a dielectric and a metal to form a display device. The broadband absorber structure adopts multiple layers of metal with a high K value and loss, and the phase change material is located in the middle of the metal layer. It has the advantages of simple structure, not being easily affected by the environment, little change in color reflectivity and saturation when the temperature changes, and being insensitive to angles.

[0051] Based on the above embodiments, Figure 5 As shown, the broadband absorber structure in this embodiment includes a first reflective layer 501, a phase change layer 502, a first metal layer 503, a first dielectric layer 504 and a second dielectric layer 505 arranged in sequence from bottom to top.

[0052] The first reflective layer 501 is made of metal material. The phase change layer 502 in this embodiment is located between two metal layers, that is, between the first reflective layer 501 and the first metal layer 503 .

[0053] The first dielectric layer 504 is mainly used to improve the saturation of the color, and the second dielectric layer 505 is mainly used to improve the saturation of the color display.

[0054] Based on the above embodiment, in this embodiment, the first reflective layer 501 is Ag;

[0055] The phase change layer 502 is a phase change layer made of Ge2Sb2Se5, wherein the ratio of each element in Ge2Sb2Se5 is adjustable, or a chalcogenide phase change material doped with elements such as C and N, wherein the K value and N value before and after the phase change decrease or increase with the shift of the wavelength;

[0056] The first metal 503 layer is a metal element with a relatively high K value, such as W, Ge, or Ta;

[0057] The first dielectric layer 504 is Ta2O3.5 or Ta oxide with a K value of 0;

[0058] The second dielectric layer 505 is made of MgF2.

[0059] Based on the above embodiment, in this embodiment, the thickness of the first reflective layer 501 varies in the range of 10 nm to 40 nm;

[0060] The thickness of the phase change layer 502 varies in the range of 1 nm to 20 nm;

[0061] The thickness of the first metal layer 503 varies in the range of 1 nm to 20 nm;

[0062] The thickness of the first dielectric layer 504 varies in the range of 1 nm to 500 nm;

[0063] The thickness of the second dielectric layer 505 ranges from 4 nm to 500 nm.

[0064] When the broadband absorber structure is Ag (150nm) + GSSE (7nm) + W (6nm) + Ta2O3.5 (39nm) + MgF2 (90nm) from bottom to top, the spectrum corresponding to the broadband absorber structure is as follows: Figure 8 shown.

[0065] Based on the above embodiments, Figure 1 As shown, the broadband absorber structure in this embodiment further includes a second metal layer 102 and a third metal layer 104, the second metal layer 102 is located between the first reflective layer 101 and the phase change layer 103, and the third metal layer 104 is located between the phase change layer 103 and the first metal layer 105.

[0066] The broadband absorber structure comprises, from bottom to top, a first reflective layer 101, a second metal layer 102, a phase change layer 103, a third metal layer 104, a first metal layer 105, a first dielectric layer 106, and a second dielectric layer 107. In this embodiment, the phase change layer 103 is located in the middle of the four metal layers.

[0067] Based on the above embodiment, in this embodiment, the second metal layer and the third metal layer are both Ge.

[0068] On the basis of the above embodiment, in this embodiment, the thickness of the second metal layer and the third metal layer both vary in the range of 1 nm to 5 nm.

[0069] When the broadband absorber structure is Ag (150nm) + Ge (2nm) + GSSE (7nm) + Ge (2nm) + W (6nm) + Ta2O3.5 (39nm) + MgF2 (90nm) from bottom to top, the spectrum corresponding to the broadband absorber structure is as follows: Figure 7 shown.

[0070] from Figure 7 It can be seen that the broadband absorption reaches more than 90%. Figure 8It can be found that when the multilayer phase change material GSSE is in the middle of four layers of metal, the absorption effect is much better than that in the middle of two layers of metal. This shows that the absorption effect of multilayer metal can be improved through optimization due to the different values ​​of its optical constants N and K.

[0071] Based on the above embodiment, in this embodiment, Figure 2 As shown, the narrowband absorber structure includes a second reflective layer 201, a third dielectric layer 202, a fourth dielectric layer 203 and the first reflective layer 204 arranged in sequence from bottom to top.

[0072] like Figure 4 As shown, the narrow-band absorber structure includes a second reflective layer 401 , a third dielectric layer 402 , a fourth dielectric layer 403 and the first reflective layer 404 arranged in sequence from bottom to top.

[0073] Figure 5 Broadband absorber structure and Figure 4 By combining the narrowband absorber structure in Figure 6 The display device shown. Figure 6 The display device in the embodiment includes, from bottom to top, a second reflective layer 601, a first dielectric layer 602, a second dielectric layer 603, a first reflective layer 604, a phase change layer 605, a first metal layer 606, a third dielectric layer 607 and a fourth dielectric layer 608.

[0074] Figure 1 Broadband absorber structure and Figure 2 By combining the narrowband absorber structure in Figure 3 The display device shown. Figure 3 The display device includes, from bottom to top, a second reflective layer 301, a first dielectric layer 302, a second dielectric layer 303, a first reflective layer 304, a second metal layer 305, a phase change layer 306, a third metal layer 307, a first metal layer 308, a third dielectric layer 309 and a fourth dielectric layer 310.

[0075] On the basis of the above embodiment, in this embodiment, the second reflective layer is Ag, the third dielectric layer is Ta2O3.3, the fourth dielectric layer is Ta2O3.5, and the first reflective layer is Ag.

[0076] Based on the above embodiment, in this embodiment, the thickness of the second reflective layer is greater than 50 nm, the thickness of the third dielectric layer is 6 nm, the thickness of the fourth dielectric layer varies in the range of 10 nm to 1 micron, and the thickness of the first reflective layer varies in the range of 10 nm to 40 nm.

[0077] Figure 1The broadband absorber structure in the figure can be Ag (150nm) + Ge (2nm) + gsse (7nm) + Ge (2nm) + W (6nm) + Ta2O3.5 (39nm) + MgF2 (90nm) from bottom to top.

[0078] Figure 2 and Figure 4 The narrow absorber structure in the graph can be Ag (150nm) + Ta2O3.3 (6nm) + Ta2O3.5 (84nm) + Ag (13nm) from bottom to top, and the distribution spectrum is as follows Figure 9 shown.

[0079] Figure 3 The display device from bottom to top can be Ag (150nm) + Ta2O3.3 (6nm) + Ta2O3.5 (84nm) + Ag (13nm) + Ge (2nm) + GSS E (7nm) + Ge (2nm) + W (6nm) + Ta2O3.5 (39nm) + MgF2 (90nm), and the distribution spectrum is as follows Figure 10 shown.

[0080] Figure 6 The display device from bottom to top can be Ag (150nm) + Ta2O3.3 (6nm) + Ta2O3.5 (84nm) + Ag (13nm) + GSSE (7nm) + W (6nm) + Ta2O3.5 (39nm) + MgF2 (90nm).

[0081] Figure 11 The display devices corresponding to curve 1 in the figure are as follows from bottom to top:

[0082] Ag(150nm)+Ta2O3.3(6nm)+Ta2O3.5(114nm)+Ag(13nm)+Ge(2nm)+GSSE(7nm)+Ge(2nm)+W(6nm)+Ta2O3.5(39nm)+MgF2(90nm).

[0083] Figure 11 The display devices corresponding to curve 2 in the figure are as follows from bottom to top:

[0084] Ag(150nm)+Ta2O3.3(6nm)+Ta2O3.5(84nm)+Ag(13nm)+GSSE(7nm)+W(6nm)+Ta2O3.5(39nm)+MgF2(90nm).

[0085] Figure 11 The display devices corresponding to curve 3 in the figure are as follows from bottom to top:

[0086] Ag(150nm)+Ta2O3.3(6nm)+Ta2O3.5(84nm)+Ag(13nm)+W(6nm)+GSSE(7nm)+Ta2O3.5(39nm)+MgF2(90nm).

[0087] like Figure 11 As shown, by comparing curve 1, curve 2 and curve 3, it can be found that when the phase change material is in the middle layer of the multi-layer thin film metal, its color saturation will be higher and the peak bandwidth will be narrower.

[0088] Figure 12 The display devices from bottom to top are Ag (150nm) + Ta2O3.3 (6nm) + Ta2O3.5 (84nm) + Ag (13nm) + Ge (2nm) + GSS E (7nm) + Ge (2nm) + W (6nm) + Ta2O3.5 (39nm) + MgF2 (90nm). Figure 12 It can be seen that when the phase change material GSSE is in the crystalline and amorphous states, its reflectivity curve is almost unchanged, and the color changes with temperature are robust. Figure 13 It can be seen that its color is not sensitive to changes in angle.

[0089] 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 it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A display device, characterized in that: include: a narrowband absorber structure comprising a dielectric layer and a metal layer; A broadband absorber structure includes a dielectric layer, a metal layer, and a phase change layer. The metal layer in the broadband absorber structure has multiple layers and is lossy. The K value is greater than a preset threshold. The phase change layer is located between the multiple metal layers. The broadband absorber structure is located above the narrowband absorber structure and couples with the narrowband absorber structure to produce bright colors. The broadband absorber structure comprises a first reflective layer, a phase change layer, a first metal layer, a first dielectric layer and a second dielectric layer arranged in sequence from bottom to top; The broadband absorber structure further includes a second metal layer and a third metal layer, the second metal layer is located between the first reflective layer and the phase change layer, and the third metal layer is located between the phase change layer and the first metal layer; The second metal layer and the third metal layer are made of the same material, namely Ge, We or Ta, and their K value is greater than 1; The phase change layer is Ge2Sb2Se5 or a chalcogenide phase change material doped with C and N elements. The ratio of each element in the phase change material of the phase change layer is adjustable, and the changes in the K value and N value before and after the phase change decrease or increase with the movement of the wavelength. The first metal layer is W, Ge or Ta, and its K value is greater than 1; The narrowband absorber structure includes a second reflective layer, a third dielectric layer, a fourth dielectric layer and the first reflective layer arranged in sequence from bottom to top.

2. The display device according to claim 1, wherein The first reflective layer is Ag; The first dielectric layer is Ta2O3.5, TiO2 or SiO2, and its K value is 0; The second medium layer is MgF2, has a K value of 0, and has a refractive index gradient with the first medium layer.

3. The display device according to claim 2, wherein The thickness of the first reflective layer varies in the range of 10 nm to 40 nm; The thickness of the phase change layer varies in the range of 1 nm to 20 nm; The thickness of the first metal layer varies in the range of 1 nm to 20 nm; The thickness of the first dielectric layer varies in the range of 1 nm to 500 nm; The thickness of the second dielectric layer ranges from 4 nm to 500 nm.

4. The display device according to claim 1, wherein The thickness of the second metal layer and the third metal layer ranges from 1 nm to 5 nm.

5. The display device according to claim 1, wherein The second reflective layer is Ag, the third dielectric layer is Ta2O3.3, the fourth dielectric layer is Ta2O3.5 or Ta oxide, whose K value is 0, and the first reflective layer is Ag.

6. The display device according to claim 5, wherein The thickness of the second reflective layer is greater than 50 nm, the thickness of the third dielectric layer is 6 nm, the thickness of the fourth dielectric layer ranges from 10 nm to 1 micron, and the thickness of the first reflective layer ranges from 10 nm to 40 nm.

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