Application of electrotropic infrared emissivity materials and their prepared devices in visible-infrared multispectral displays

Abstract

The present invention discloses an application of an electrovariable infrared emissivity material and a device prepared therefrom in a visible-infrared multi-spectral display. The electrovariable infrared emissivity material is prepared into a transparent electrovariable infrared emissivity device and then combined with a light-emitting device, and the electrovariable infrared emissivity device is placed above the light-emitting device. The present invention utilizes a transparent electrovariable infrared emissivity device to regulate the infrared band while maintaining visible light transparency without affecting the lower light-emitting device. By combining the two, the upper transparent electrovariable infrared emissivity device realizes infrared display, and the lower light-emitting device displays visible light images, thereby realizing a visible-infrared multi-spectral display.

Description

Technical Field

[0001] The invention belongs to the technical field of stealth materials, and in particular relates to an electrovariable infrared emissivity material and a preparation device thereof and their application in a visible light-infrared multi-spectral display. Background Art

[0002] Current displays, such as screens of televisions and mobile phones, can usually only display visible light bands, and cannot achieve multi-spectral display of visible light and infrared. Chinese invention patent CN107065172A discloses a wide spectrum display covering the visible light to infrared bands, which is composed of an arrayed display unit, which is composed of a second electrode, a hydrophobic insulating layer, a fluid chamber, a barrier layer, a dielectric layer, a first electrode, a substrate, and an illumination layer from top to bottom, and the two ends of the peripheral drive circuit are respectively connected to the first electrode (4) and the second electrode. By utilizing the localized plasmon resonance effect of plasmon nanoparticles, when the spacing between nanoparticles changes, the spectral peak will move, thereby changing the color of the display unit and achieving dynamic tunability of the spectrum. The manufacturing process of the above-mentioned display is relatively complicated.

[0003] Electrochromic infrared emissivity materials refer to materials that can control infrared emissivity through the action of electric fields. The main application of electrochromic infrared emissivity materials is electrochromic emissivity devices, which have the advantages of flexible regulation, simple structure, and excellent performance. They have important application value in the fields of adaptive infrared camouflage and intelligent thermal control of spacecraft. As an electrochromic material, aluminum-doped zinc oxide has not yet been reported in the application of visible-infrared multi-spectral displays. Summary of the invention

[0004] In order to overcome the technical problems in the prior art, the present invention provides an application of an electrotropic infrared emissivity material and a device prepared therefrom in a visible light-infrared multi-spectral display. After the electrotropic infrared emissivity material is prepared into a device and combined with an LED display, the electrotropic infrared emissivity device realizes infrared display, and the lower LED display displays visible light images, thereby jointly realizing a visible light-infrared multi-spectral display.

[0005] In order to solve the above technical problems, the technical solutions proposed by the present invention are as follows:

[0006] A first aspect of the present invention provides an application of an electrotropic infrared emissivity material in a visible light-infrared multi-spectral display.

[0007] As an optional implementation, in the application provided by the present invention, the electrotropic infrared emissivity material is doped with zinc oxide nanocrystals, the doping ions in the doped zinc oxide nanocrystals are trivalent metal ions, and the doping amount of the trivalent metal ions is 0.1-10%.

[0008] As an optional implementation, in the application provided by the present invention, the diameter of the electrotropic infrared emissivity material is 2-30 nm, and its LSPR absorption peak is located at 3-14 μm.

[0009] The doping amount of trivalent metal ions in the doped zinc oxide nanocrystals of the present invention is 0.1-10%, so that the localized surface plasmon resonance (LSPR) absorption peak of the trivalent metal ion-doped zinc oxide nanocrystals is located in the infrared band of 3-14 μm. The regulation of infrared emissivity by doped zinc oxide nanocrystals is achieved by electrochemically injecting and escaping electrons to enhance and weaken the LSPR absorption peak. When negative electricity is applied, electrons are injected into the doped zinc oxide nanocrystal layer, the LSPR absorption peak is enhanced, and the device exhibits high infrared emissivity characteristics. When positive electricity is applied, electrons are escaped from the doped zinc oxide nanocrystal layer, the LSPR absorption peak is weakened, the doped zinc oxide nanocrystal layer exhibits high transmittance, and the device exhibits a low emissivity state, thereby achieving the regulation of infrared emissivity.

[0010] As an optional implementation, in the application provided by the present invention, the diameter of the electrotropic infrared emissivity material is 2-30 nm.

[0011] As an optional embodiment, in the application provided by the present invention, the trivalent metal ion is one of aluminum ion, boron ion, gallium ion or indium ion.

[0012] The n-type semiconductor nanocrystal based on ZnO in the present invention generally has a dopant comprising boron ions (B 3+ ), aluminum ions (Al 3+ ), gallium ions (Ga 3+ ) and indium ions (In 3+ ), LSPR absorption will occur in the 3-14μm band, and the LSPR absorption peak of ZnO-based n-type semiconductor nanocrystals can be further regulated by electrochemical means, thereby achieving regulation of infrared emissivity.

[0013] A second aspect of the present invention provides an application of an electrovariable infrared emissivity device in a visible light-infrared multi-spectral display.

[0014] As an optional embodiment, in the application provided by the present invention, the electrovariable infrared emissivity device includes, from top to bottom, a visible light-infrared transparent substrate layer, a variable infrared emissivity functional layer, an infrared high reflective layer, an electrolyte layer, an ion storage layer and a transparent counter electrode layer, and the electrovariable infrared emissivity functional layer is doped zinc oxide nanocrystals, the doped ions in the doped zinc oxide nanocrystals are trivalent metal ions, and the doping amount of the trivalent metal ions is 0.1 to 10%.

[0015] As an optional embodiment, in the application provided by the present invention, the trivalent metal ion is one of aluminum ion, boron ion, gallium ion or indium ion.

[0016] As an optional embodiment, in the application provided by the present invention, the visible light transmittance of the visible light-infrared transparent substrate layer, the infrared high reflective layer and the transparent counter electrode layer is greater than 80%, and the infrared transmittance of the visible light-infrared transparent substrate layer and the infrared high reflective layer is greater than 80%.

[0017] As an optional implementation, in the application provided by the present invention, the visible light-infrared multi-spectral display is composed of a light-emitting device and a transparent electrotropic infrared emissivity device arrayed on the light-emitting device.

[0018] As an optional implementation, in the application provided by the present invention, the reflectivity of the visible light-infrared multi-spectral display to the infrared band of 3 to 5 μm is 0.1-0.6, and the reflectivity to the infrared band of 8 to 14 μm is 0.1-0.6.

[0019] As an optional embodiment, in the application provided by the present invention, the visible light-infrared transparent substrate layer material is selected from one of BaF2, CaF2, polypropylene, polytetrafluoroethylene, polyethylene or nylon film.

[0020] As an optional implementation, in the application provided by the present invention, the infrared high reflective layer is selected from one of an ITO film, an AZO film or a FTO film.

[0021] As an optional implementation, in the application provided by the present invention, the ion storage layer is selected from one of a Pt nanocrystalline layer, an AZO film, a NiO film, and a V2O5 film.

[0022] In the present invention, an ion storage layer is provided, and the material can be selected from Pt nanocrystalline layer, AZO film, NiO film, V2O5 film, and its function is to balance the charge change in the process of infrared emissivity regulation.

[0023] As an optional embodiment, in the application provided by the present invention, the transparent counter electrode layer is selected from one of ITO glass, AZO glass, ITO flexible film, AZO flexible film, carbon nanotube film, metal mesh glass or metal mesh film.

[0024] As an optional implementation, in the application provided by the present invention, the electrolyte layer does not need to be specifically limited, as long as it is an electrolyte, a lithium-based electrolyte or a sodium-based electrolyte can be selected during specific use.

[0025] As an optional implementation, in the application provided by the present invention, the refresh frequency of the visible light-infrared multi-spectral display is 2 Hz.

[0026] In the present invention, doped zinc oxide nanocrystals are used as electro-variable infrared emissivity materials, and the doped ions are trivalent metal ions. The doping amount of trivalent metal ions is 0.1-10%, so that the localized surface plasma resonance (LSPR) absorption peak of aluminum-doped zinc oxide nanocrystals is located in the infrared band of 3-14 μm. After it is used as the variable infrared emission functional layer in the electro-variable infrared emissivity device, each film layer in the prepared device is a visible light transparent material. Through the variable infrared emissivity functional layer, the LSPR absorption peak is enhanced and weakened by electrochemical injection and extraction of electrons, thereby realizing the regulation of infrared emissivity by doped zinc oxide nanocrystals. When negative electricity is applied, electrons are injected into the doped zinc oxide nanocrystal layer, the LSPR absorption peak is enhanced, and the device exhibits high infrared emissivity characteristics. When positive electricity is applied, electrons are extracted from the doped zinc oxide nanocrystals, the LSPR absorption peak is weakened, the doped zinc oxide nanocrystal layer exhibits high transmittance, and the device exhibits the high reflection characteristics of the infrared high reflection layer, that is, the low emissivity state, thereby realizing the regulation of infrared emissivity.

[0027] The present invention uses a transparent electrovariable infrared emissivity device in combination with a light-emitting device, and places the transparent electrovariable infrared emissivity device above the light-emitting device. The transparent electrovariable infrared emissivity device regulates the infrared band while maintaining visible light transparency, without affecting the lower light-emitting device. Through the combination of these two devices, the upper transparent electrovariable infrared emissivity device realizes infrared display, and the lower light-emitting device displays visible light images, thereby realizing visible light-infrared multi-spectrum display.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] In the present invention, the electrovariable infrared emissivity material is prepared into a transparent electrovariable infrared emissivity device and then combined with a light-emitting device, and the transparent electrovariable infrared emissivity device is placed above the light-emitting device. The transparent electrovariable infrared emissivity device regulates the infrared band while maintaining visible light transparency, and does not affect the lower light-emitting device. By combining the two, the upper transparent electrovariable infrared emissivity device realizes infrared display, and the lower light-emitting device displays visible light images, realizing a multi-spectral display of visible light infrared. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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.

[0031] Figure 1 is the LSPR absorption peak of the aluminum-doped zinc oxide nanocrystals prepared in Example 1;

[0032] Figure 2 is the LSPR absorption peak of the aluminum-doped zinc oxide nanocrystals prepared in Example 2;

[0033] Figure 3 The morphology and diameter distribution results of the aluminum-doped zinc oxide nanocrystals prepared in Example 1;

[0034] Figure 4 is an infrared reflectivity curve diagram of the visible light-infrared multi-spectral display in Example 3;

[0035] Figure 5 is a visible light transmittance curve of the electrovariable infrared emissivity device in Example 3;

[0036] Figure 6 This is a multi-spectral display demonstration diagram of the visible light-infrared multi-spectral display in Example 3;

[0037] Figure 7 Schematic diagram of the structure of the visible light-infrared multi-spectral display in Example 4.

[0038] Reference numerals:

[0039] 1. Electro-variable infrared emissivity device; 2. LED display;

[0040] 11. Visible light-infrared transparent substrate layer; 12. Variable infrared emissivity functional layer; 13. Infrared high reflection layer; 14. Electrolyte layer; 15. Ion storage layer; 16. Transparent counter electrode layer. DETAILED DESCRIPTION

[0041] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively and meticulously below in conjunction with the accompanying drawings and preferred embodiments of the present invention, but the protection scope of the present invention is not limited to the following specific embodiments.

[0042] Unless otherwise defined, all professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0043] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0044] Example 1

[0045] Preparation of electrovariable infrared emissivity material, namely, preparation of aluminum-doped zinc oxide nanocrystalline dispersion.

[0046] Dissolve zinc acetate (14.4mmol) and aluminum acetylacetonate (0.16mmol) in 32mL oleic acid (aluminum doping amount is 1%). Degas at 110°C for 1 hour, then add 16ml oleylamine, and further degas at this temperature for 15 minutes to obtain a metal precursor. Add excess oleyl alcohol (160mL) to a 250mL three-necked round-bottom flask, heat to 280°C under strong stirring, and fill with nitrogen at a nitrogen flow rate of 20 liters / hour. In a nitrogen atmosphere, use a syringe pump to slowly add 45ml (15mmol) of the metal precursor at an injection rate of 3ml / minute. React for 1h to obtain nanocrystals. After washing the nanocrystals with a toluene / ethanol solution, disperse the nanocrystals in a toluene solvent to obtain an aluminum-doped zinc oxide nanocrystal dispersion.

[0047] The content of Al element in the prepared aluminum-doped zinc oxide nanocrystals was detected by inductively coupled plasma optical emission spectrometer (ICP-OES, Agilent 720ES), and the actual measurement showed that the doping amount of aluminum was 0.97%.

[0048] Example 2

[0049] Preparation of electrovariable infrared emissivity material, namely, preparation of aluminum-doped zinc oxide nanocrystalline dispersion.

[0050] Dissolve zinc acetate (14.4mmol) and aluminum acetylacetonate (1.6mmol) in 32mL oleic acid (aluminum doping amount is 10%). Degas at 110°C for 1 hour, then add 16ml oleylamine, and further degas at this temperature for 15 minutes to obtain a metal precursor. Add excess oleyl alcohol (160mL) to a 250mL three-necked round-bottom flask, heat to 280°C under strong stirring, and fill with nitrogen at a nitrogen flow rate of 20 liters / hour. In a nitrogen atmosphere, use a syringe pump to slowly add 45ml (15mmol) of the metal precursor at an injection rate of 3ml / minute. React for 1h to obtain nanocrystals. After washing the nanocrystals with a toluene / ethanol solution, disperse the nanocrystals in a toluene solvent to obtain an aluminum-doped zinc oxide nanocrystal dispersion.

[0051] The content of Al element in the prepared aluminum-doped zinc oxide nanocrystals was detected by inductively coupled plasma optical emission spectrometer (ICP-OES, Agilent 720ES), and the actual measurement showed that the doping amount of aluminum was 5.79%.

[0052] Example 3

[0053] Fabrication of visible-infrared multispectral displays using aluminum-doped zinc oxide nanocrystals.

[0054] (1) Preparation of the upper half of the transparent electro-variable infrared emissivity device

[0055] Select a BaF2 transparent substrate material with a thickness of 1mm, and spin-coat the aluminum-doped zinc oxide nanocrystal dispersion prepared in Example 1 on the BaF2 substrate. The spin-coating speed is 1000rpm for 60s, followed by 4000rpm for 20s and repeating the above spin-coating process until the film thickness is 1.1μm. BaF2 / AZO nanocrystals are heated in an argon environment at 250°C for 30 minutes. An ITO film of about 330nm is evaporated onto the sample at a deposition rate of 1A / s using an electron beam evaporation coating machine as an infrared high reflection layer, i.e., a working electrode. The substrate temperature is set to 300°C and the oxygen flow rate is 20sccm. Use a transparent double-sided tape to stick a 0.1mm silver wire to one side of the semi-device and compact it so that the silver wire is in full contact with the ITO film to ensure good conductivity.

[0056] (2) Preparation of the lower half device in the transparent electro-variable infrared emissivity device

[0057] ITO glass was selected as the transparent counter electrode material, and a 700nm AZO nanocrystal dispersion was spin-coated on the counter electrode ITO glass as an ion storage layer. One side of the ion storage layer was wiped off to expose the ITO glass substrate. A 0.1mm silver wire was tightly attached to the ITO glass substrate with a transparent double-sided tape, so that the silver wire was in full contact with the ITO glass substrate to ensure good conductivity.

[0058] (3) Preparation of transparent electro-variable infrared emissivity devices

[0059] The upper half device and the lower half device are bonded together by transparent silicone rubber, and a 1 mol tetraethylene glycol dimethyl ether solution of lithium bis(trifluoromethanesulfonyl)imide is injected into the middle by using a syringe to obtain a transparent electrovariable infrared emissivity device.

[0060] (4) Select a commercial LED display. In this embodiment, an iPad mini 5 LED display is used. The transparent electrotropic infrared emissivity device array prepared above is arranged on the LED display to prepare a visible light-infrared multi-spectral display.

[0061] Example 4

[0062] In this embodiment, the light-emitting device is an LED display, and the visible light-infrared multi-spectrum display is composed of an LED display 2 and an electro-variable infrared emissivity device 1 arranged in an array on the LED display 2. The structural diagram is shown in FIG. Figure 7As shown, the electro-variable infrared emissivity device includes, from top to bottom, a visible light-infrared transparent substrate layer 11, a variable infrared emissivity functional layer 12, an infrared high reflective layer 13, an electrolyte layer 14, an ion storage layer 15 and a transparent counter electrode layer 16. Specifically, the visible light-infrared transparent substrate layer is selected from one of BaF2, CaF2, polypropylene, polytetrafluoroethylene, polyethylene or nylon film, and its visible light transmittance is greater than 80%, and its infrared transmittance is greater than 80%.

[0063] The infrared high reflection layer is selected from one of ITO film, AZO film or FTO film, and its visible light transmittance is greater than 80%, and its infrared transmittance is greater than 80%.

[0064] The ion storage layer is used to balance the charge change in the process of infrared emissivity regulation, and the material is selected from one of Pt nanocrystalline layer, AZO film, NiO film, and V2O5 film.

[0065] The transparent counter electrode layer is selected from one of ITO glass, AZO glass, ITO flexible film, AZO flexible film, carbon nanotube film, metal mesh glass or metal mesh film, and its visible light transmittance is greater than 80%.

[0066] The electrolyte layer does not require specific restrictions, as long as it is an electrolyte, it can be realized. Lithium-based electrolytes and sodium-based electrolytes can be selected during specific use.

[0067] There is no need to specifically limit the LED display, and any common commercial LED display can be used.

[0068] Performance Testing

[0069] (1) LSPR absorption peak detection of aluminum-doped zinc oxide nanocrystal dispersion

[0070] The LSPR absorption peak of the aluminum-doped zinc oxide nanocrystal dispersion prepared in Example 1-2 was detected. Specifically, a trace amount of the aluminum-doped zinc oxide nanocrystal dispersion was dropped into the slits of two BaF2 substrates, and the absorption peak of the aluminum-doped zinc oxide nanocrystal was tested in an infrared spectrometer. The detection results are as follows: Figure 1 and Figure 2 As shown. Figure 1 It can be seen that the LSPR absorption peak of the aluminum-doped zinc oxide nanocrystal dispersion prepared in Example 1 is located at 7.78 μm. Figure 2 It can be seen that the LSPR absorption peak of the aluminum-doped zinc oxide nanocrystal dispersion prepared in Example 2 is located at 3.15 μm.

[0071] (2) Diameter detection of aluminum-doped zinc oxide nanocrystals

[0072] Scanning electron microscopy (FE-SEM; TESCANMIRA) was used to detect the surface morphology of the AZONCs ​​membrane and measure its diameter. The test results are as follows: Figure 3 As shown, Figure 3 a is the transmission electron microscope morphology of AZO nanocrystals. Figure 3 b is the diameter distribution diagram of AZO nanocrystals. It can be seen from the figure that the diameter of AZO nanocrystals is in the range of 2-16nm, among which the majority are in the range of 10-12nm.

[0073] (3) Infrared emissivity control and detection of visible light-infrared multispectral displays

[0074] The transparent electrotropic infrared emissivity device array is arranged on the LED display, and its infrared animation demonstration is realized by connecting to a single-chip microcomputer and reading a program, which belongs to the prior art and will not be described in detail here.

[0075] The visible light-infrared multi-spectral display in Example 3 was tested by using an infrared spectrometer in integrating sphere mode. The test results are as follows: Figure 4 As shown, the upper curve is the infrared regulation curve under -2.5V condition, and the lower curve is the curve under 2.5V condition. Figure 4 It can be seen that the prepared visible light-infrared multispectral display has infrared emissivity control values ​​of 0.51 and 0.42 in the 3-5μm band and 8-14μm band, respectively.

[0076] (4) Spectral detection of visible light of transparent electro-variable infrared emissivity devices

[0077] The spectral changes of visible light of the electro-variable infrared emissivity device were tested using an ultraviolet-visible-near-infrared (UV-Vis-NIR) spectrophotometer. The test results are as follows: Figure 5 As shown, the transmittance of visible light was 84.7%.

[0078] (5) Multispectral display demonstration of visible light-infrared multispectral display

[0079] Specific experimental process: For the visible light-infrared multi-spectral display prepared in Example 3, a visible light image is played on the LED display, and an infrared animation is played on the electro-variable infrared emissivity device array. The results are as follows: Figure 6 As shown, from Figure 6 It can be seen that during the infrared animation playing on the electrovariable infrared emissivity device array, it maintains a high visible light transmittance and does not affect the visible light image playing on the LED display below. Therefore, the visible light-infrared multi-spectral display can display visible light and infrared images at the same time, realizing the multi-spectral information display of visible light and infrared.

[0080] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the scope of protection of the present invention.

Claims

1. Application of an electrovariable infrared emissivity device in a visible light-infrared multi-spectral display, characterized in that: The electro-variable infrared emissivity device comprises, from top to bottom, a visible light-infrared transparent substrate layer, a variable infrared emissivity functional layer, an infrared high reflective layer, an electrolyte layer, an ion storage layer and a transparent counter electrode layer, wherein the variable infrared emissivity functional layer is doped zinc oxide nanocrystals, the doped ions in the doped zinc oxide nanocrystals are trivalent metal ions, the doping amount of the trivalent metal ions is 0.1-10%, and the infrared high reflective layer is selected from one of an ITO film, an AZO film or a FTO film; The localized surface plasmon resonance absorption peak of the doped zinc oxide nanocrystal is located in the 3-14 μm infrared band. The localized surface plasmon resonance absorption peak is enhanced and weakened by electrochemical injection and extraction of electrons, thereby achieving regulation of the infrared emissivity of the doped zinc oxide nanocrystal.

2. The use of the electrotropic infrared emissivity device according to claim 1 in a visible light-infrared multi-spectral display, characterized in that: The trivalent metal ion is one of aluminum ion, boron ion, gallium ion or indium ion.

3. The use of the electrotropic infrared emissivity device according to claim 1 in a visible light-infrared multi-spectral display, characterized in that: The visible light transmittance of the visible light-infrared transparent substrate layer, the infrared high reflection layer and the transparent counter electrode layer is greater than 80%, and the infrared transmittance of the visible light-infrared transparent substrate layer and the infrared high reflection layer is greater than 80%.

4. The use of the electrotropic infrared emissivity material according to claim 1 in a visible light-infrared multi-spectral display, characterized in that: The visible light-infrared multi-spectrum display is composed of a light-emitting device and a transparent electrovariable infrared emissivity device arrayed on the light-emitting device.

5. The use of the electrotropic infrared emissivity material according to claim 1 in a visible light-infrared multi-spectral display, characterized in that: The refresh rate of the visible light-infrared multi-spectral display is 2 Hz.

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