Display device

Abstract

The invention provides a display device, and the display device comprises a narrow-band absorber structure which comprises a dielectric layer and a metal layer; the broadband absorber structure comprises a dielectric layer, metal layers and phase change layers, the number of the metal layers in the broadband absorber structure is multiple, the metal layers have loss, the K value is larger than a preset threshold value, the phase change layers are located among the multiple metal layers, and the broadband absorber structure is located on the narrow-band absorber structure and coupled with the narrow-band absorber structure. And bright color is generated. The device has the advantages that the structure is simple, the device is not easily influenced by the environment, when the temperature changes, the color reflectivity and saturation change is not large, and the angle is not sensitive.

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 protection. Therefore, they have important applications in optical imaging, display, detection equipment, color sensors, anti-counterfeiting technology and surface decoration. So far, 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 lithography-free technology provide a simple method for color generation. This design method is easy to adjust and expand, and can be deposited and expanded by magnetron sputtering instruments or EBE (Electron Beam Evaporation). One of the simplest and most commonly used thin-film configurations for generating structural colors is the Fabry-Perot (FP) cavity, which consists of a transparent dielectric or absorbing semiconductor material sandwiched between two metal mirrors. The constructive interference occurring in the dielectric layer forms a transmission peak or reflection valley at a specific wavelength. However, due to the narrow absorption bandwidth caused by the cavity resonance and the larger RGB color space than CMY, it is still challenging to design reflective RGB colors with high purity and brightness. Although a variety of designs have been proposed to produce RGB colors, it is still challenging to adjust the reflective full-color structural color to achieve high brightness and purity through 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 have attracted much attention due to their advantages such as high temperature stability and good optical constants. Therefore, many structures based on phase change materials combined with FP cavities have achieved high reflectivity. However, achieving high reflectivity often faces the problem of high reflectivity in non-target peak areas. Moreover, under high temperature conditions, the color of the phase change material fluctuates due to its own properties, which is very unfavorable for its application in certain fields. Summary of the invention

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

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

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

[0008] A broadband absorber structure comprises 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. 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 is coupled 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 sulfur-based phase change material doped with elements such as C and N, and the changes in 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 an element such as W, Ge, Ta, etc., 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 is 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, Ta, etc., 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 vary within a range of 1 nm to 5 nm.

[0023] According to a display device provided by the present invention, the narrow-band absorber structure comprises 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 50nm, the thickness of the third dielectric layer is 6nm, the thickness of the fourth dielectric layer varies in the range of 10nm to 1 micron, and the thickness of the first reflective layer varies in the range of 10nm to 40nm.

[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 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces 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 creative work.

[0028] Figure 1 It 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 It is a schematic diagram of the structure of a narrow absorber in a 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] Fig. 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] Fig.10 yes Figure 3 Schematic diagram of the spectrum corresponding to the display device in;

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

[0039] Fig.12 yes Figure 3 Spectrum diagram of angle-insensitive display device in;

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

[0041] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

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

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

[0044] A broadband absorber structure comprises 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. 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 is coupled with the narrowband absorber structure to produce bright colors.

[0045] This embodiment adopts a new technical strategy, that is, a broadband absorber structure composed of a dielectric layer, a metal material and a phase change material, and a narrow-band absorber structure composed of a dielectric and a metal are used to form a display device. The display device includes two main components, namely, a visible light broadband absorber structure and a narrow-band absorber structure. When the two are combined, they are a broadband absorber structure and a narrow-band absorber structure from top to bottom.

[0046] The broadband absorber structure is composed of multiple layers of metal with high K value, phase change material and dielectric. The metal in this structure is two or more layers, each layer is no thicker than 30nm, and is a lossy metal material, that is, the extinction coefficient is not 0. And 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 general, this embodiment adopts a new display structure design idea and successfully develops 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 forms a display device by using 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. The broadband absorber structure uses 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 a simple structure, not being easily affected by the environment, and having 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 color, and the second dielectric layer 505 is mainly used to improve the saturation of 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, in which the ratio of each element 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 are reduced or increased with the movement of the wavelength;

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

[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 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 includes, 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. The phase change layer 103 in this embodiment is located in the middle of the four metal layers.

[0067] On the basis of 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, which shows that the absorption effect of multilayer metal can be improved by optimization due to the different values ​​of its optical constants N and K.

[0071] Based on the above embodiments, in this embodiment, Figure 2 As shown, the narrow-band 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 The 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 The broadband absorber structure and Figure 2 By combining the narrowband absorber structure in Figure 3 The display device shown. Figure 3 The display device in the embodiment 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 50nm, the thickness of the third dielectric layer is 6nm, the thickness of the fourth dielectric layer varies in the range of 10nm to 1 micron, and the thickness of the first reflective layer varies in the range of 10nm to 40nm.

[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 Fig. 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 Fig.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] Fig.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] Fig.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] Fig.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 Fig.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, the color saturation will be higher and the peak bandwidth will be narrower.

[0088] Fig.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). Fig.12 It can be seen that when the phase change material GSSE is in the crystalline state and the amorphous state, its reflectivity curve is almost unchanged, and the color changes with temperature are robust. Fig.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 embodiments of the present invention.

Claims

1. A display device, characterized in that: include: A narrowband absorber structure including a dielectric layer and a metal layer; A broadband absorber structure comprises 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. 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 is coupled with the narrowband absorber structure to produce bright colors.

2. The display device according to claim 1, characterized in that 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 which are arranged in sequence from bottom to top.

3. The display device according to claim 2, characterized in that The first reflective layer is Ag; The phase change layer is Ge2Sb2Se5 or a chalcogenide phase change material doped with C and N elements. The proportion of each element in the phase change material of the phase change layer is adjustable, and the changes in the K value and the 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 first dielectric layer is Ta2O3.5, TiO2 or SiO2, and its K value is 0; The second medium layer is MgF2, the K value is 0, and has a refractive index gradient with the first medium layer.

4. The display device according to claim 3, characterized in that 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.

5. The display device according to claim 2, characterized in that: The broadband absorber structure further includes a second metal layer and a third metal layer, wherein 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.

6. The display device according to claim 5, characterized in that The second metal layer and the third metal layer are made of the same material, which is Ge, W, Ge or Ta, and the K value thereof is greater than 1.

7. The display device according to claim 6, characterized in that The thickness of the second metal layer and the third metal layer both range from 1 nm to 5 nm.

8. The display device according to claim 2, characterized in that: The narrow-band absorber structure includes a second reflective layer, a third dielectric layer, a fourth dielectric layer and the first reflective layer which are arranged in sequence from bottom to top.

9. The display device according to claim 8, characterized in that: 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.

10. The display device according to claim 9, characterized in that 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.

Images