Self-emissive radiation refrigeration-information display device and preparation method thereof

Abstract

The application relates to a self-emission radiation refrigeration-information display device and a preparation method, which comprises, from top to bottom, a working electrode, an electrolyte layer and a counter electrode; the working electrode comprises a substrate and a multilayer film nanocavity electrode, the multilayer film nanocavity electrode is composed of a top metal reflection layer, a dielectric cavity layer and a bottom ultrathin seed layer; the electrolyte layer is used for realizing reversible electrodeposition of the metal reflection layer, and the formed metal reflection layer and the working electrode form a reconfigurable nanoresonant cavity structure. The device structure is simple, display energy consumption is low, color display is rich, and not only can the display function be completed while achieving self-emission radiation refrigeration which cannot be realized in the traditional emission / reflection display technical field, but also can achieve dynamic color change and information display functions which cannot be realized in the current daytime radiation refrigeration technology.

Description

Technical Field

[0001] This invention belongs to the field of daytime radiation cooling technology, and specifically relates to an information display device that can realize spontaneous radiation cooling and its preparation method. Background Technology

[0002] In-day radiation cooling is an emerging passive cooling technology that enables objects to cool themselves spontaneously without additional accessories or energy consumption. However, most sub-environmental in-day radiation coolers typically only exhibit opaque white or silver colors, and this limited color range severely restricts the application scenarios of this technology. Currently, although the coloring problem of in-day radiation cooling materials can be solved through methods such as micro-nano structure design to excite optical resonance modes, multi-scale interference effects, and diffraction effects, almost all current colored in-day radiation cooling materials and devices can only achieve static spectral design and exhibit fixed colors. These limitations restrict the application possibilities of colored radiation cooling technology in the field of outdoor information displays.

[0003] Generally, dynamic color changing requires smart materials that can respond to external stimuli such as temperature, electricity, light, and humidity. Among various smart materials, electrochromic materials driven by external electrical signals have advantages such as low energy consumption, multiple colors, high controllability, and programmability, making them a promising choice for next-generation outdoor energy-saving display technology. Combining electrochromic technology with daytime radiative cooling technology may provide a new application paradigm for outdoor thermal management technology that also features information display. However, the increase in solar absorption rate during the color-changing process of common electrochromic materials is uncontrollable, making direct compatibility with daytime radiative cooling technology difficult. Currently, no electrochromic device or daytime radiative cooling material can integrate both dynamic color changing and daytime radiative cooling functions. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a self-radiative cooling information display device and its preparation method, which overcomes the problem that existing electrochromic technology is difficult to be compatible with passive cooling technologies such as radiative cooling, opens up new application paths for outdoor thermal management technology, and also builds a new paradigm for the development of outdoor display technology.

[0005] This invention provides a self-radiative cooling information display device, comprising, from top to bottom, a working electrode, an electrolyte layer, and a counter electrode. The working electrode includes a substrate and a multilayer nanocavity electrode, which consists of a top metal reflective layer, a dielectric cavity layer, and a bottom ultrathin seed layer. The electrolyte layer is used to achieve reversible electrodeposition of the metal reflective layer, and the formed metal reflective layer and the working electrode constitute a reconfigurable nanoresonant cavity structure. The reconfigurable nanoresonant cavity structure enables dynamic control of the optical resonance excitation / annihilation within the device structure.

[0006] Preferably, the substrate is one or more of the visible light transparent materials such as quartz, glass, PET film, and PDMS film, which provides the device with a high mid-infrared emissivity.

[0007] Preferably, the material of the top metal reflective layer is one or more of Ag, Al, Ag:Au, Al:Ag, and Cu:Ag. To ensure its daytime radiative cooling function, the thickness of the top metal reflective layer is 20-40 nm.

[0008] Preferably, the dielectric cavity layer is made of one or more of ITO, AZO, TiO2, SiO2, HfO2, TeO2, Sb2O3, WO3, and Al2O3, and the thickness of the dielectric cavity layer is 50–200 nm.

[0009] Preferably, the material of the bottom ultrathin seed layer is one or more of Pt, Au, Ti, MPTMS monolayer, and APTMS monolayer, and the thickness of the bottom ultrathin seed layer is 0.5-10 nm, which serves to improve the growth quality of the reversible electrodeposited metal reflective layer.

[0010] Preferably, the electrolyte layer comprises a gel electrolyte and an encapsulation material; wherein the gel electrolyte is composed of ionic reactants, an organic matrix, and a solvent.

[0011] Preferably, the ionic reactant is silver ions (Ag). + ), divalent copper ions (Cu) 2+ ), bromide ions (Br) - One or more of the following: the organic matrix is ​​one or more of polyvinyl alcohol, polyvinyl butyral, and polyethylene oxide; the solvent is one or more of dimethyl sulfoxide, N,N-dimethylformamide, and water.

[0012] Preferably, the encapsulation material is one or more of silicone, rubber, and acrylic hollow gaskets.

[0013] Preferably, the counter electrode comprises one or more of the following: transparent oxide electrode (ITO glass, FTO glass, etc.), metal electrode (platinum electrode, platinum wire mesh, etc.), and electrochromic material electrode (WO3 / glass electrode, Prussian blue / glass electrode, etc.). Multi-pixelation of the counter electrode is achieved by designing and controlling the conductive area on the counter electrode.

[0014] This invention also provides a method for fabricating a self-radiative cooling information display device, comprising the following steps:

[0015] S1. Select a substrate for multilayer film nanocavity electrode deposition;

[0016] S2. A multilayer nanocavity electrode is deposited on one side of the substrate using multi-target magnetron sputtering, electron beam evaporation, atomic layer deposition, and inductively coupled plasma chemical vapor deposition to obtain the working electrode.

[0017] S3. Prepare a gel electrolyte for achieving reversible metal reflective layer electrodeposition;

[0018] S4. Select a substrate and deposit a conductive layer in the designed area to obtain the counter electrode;

[0019] S5. Connect the working electrode obtained in S2 and the counter electrode obtained in S4 through the encapsulation material, and then inject the gel electrolyte prepared in S3 into the space constructed by the encapsulation material between the working electrode and the counter electrode. Finally, seal the edge of the space to obtain a self-radiative cooling-information display device.

[0020] The device of the present invention can achieve daytime radiative cooling under direct sunlight, and can reduce the temperature by 6 to 12.7°C compared with traditional LED digital tubes and commercial electrochromic devices.

[0021] The device of this invention, when used in conjunction with a control circuit based on a 74HC5958 shift register, can achieve multi-pixel display of 5×5 or more, and the displayed letter patterns have high visibility and readability under strong sunlight.

[0022] When the device of the present invention uses a flexible transparent material as the substrate for both the working and counter electrodes, it can achieve flexible wearability and patterned multi-color dynamic information display functions. Simultaneously, under sunlight conditions, this flexible device can achieve a temperature reduction of ~5.8°C compared to commercial automotive films with similar colors.

[0023] When the device of this invention uses a flexible transparent material as the substrate for both the working and counter electrodes, it can achieve large-area dynamic color switching. The flexible device can achieve an area of ​​up to 100 cm². 2 Achieve uniform coloring / bleaching at the same time.

[0024] Beneficial effects

[0025] (1) Compared with traditional daytime radiation cooling materials, the present invention can achieve dynamic multi-color switching with a wide color gamut while maintaining continuous radiation cooling function.

[0026] (2) Compared with traditional daytime radiation cooling materials, the present invention can achieve highly controllable and programmable dynamic color information display and patterned display while maintaining continuous radiation cooling function. These functions are currently unattainable in the field of daytime radiation cooling.

[0027] (3) Compared with traditional electrochromic materials and corresponding display technologies, the present invention utilizes micro-nano structure changes to achieve dynamic characteristics, and can realize functions based on conventional material systems without relying on specific dynamic smart materials.

[0028] (4) Compared with traditional electrochromic materials and corresponding display technologies, this invention achieves dynamic coloring by controlling the excitation / annihilation of optical resonance, which has higher designability and controllability. This control method can simultaneously and flexibly design the coverage band, peak bandwidth, and angular characteristics of the optical absorption on which the coloring is based, and is no longer limited by the changes in the refractive index / absorption coefficient of the dynamic smart material itself.

[0029] (5) The present invention can be processed based on conventional coating technology. The overall structure can be processed by large-scale vacuum coating technology such as multi-target magnetron sputtering and electron beam evaporation, which reduces the difficulty and cost of preparation and processing, and is expected to achieve large-scale preparation. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of the self-radiative cooling-information display device described in this invention; wherein, 1-working electrode, 2-electrolyte layer, 3-counter electrode, 11-substrate, 12-multilayer film nanocavity electrode.

[0031] Figure 2 This is a graph showing the cooling effect of the self-radiative cooling information display device prepared in Example 1 under direct sunlight, compared to commercial electrochromic display devices and white LED devices.

[0032] Figure 3 This is an infrared camera test image showing the cooling effect of the self-radiative cooling information display device prepared in Example 1 under outdoor conditions compared to the cooling effect of film applied to commercial vehicles.

[0033] Figure 4 This is an image showing the flexible and large-scale uniform color-changing effect of the self-radiative cooling information display device prepared in Example 1.

[0034] Figure 5 This is a flowchart illustrating the fabrication process of the self-radiative cooling-pixelated information display device described in this invention.

[0035] Figure 6 This is the reflection spectrum of each pixel of the self-radiative cooling-pixelated information display device prepared in Example 1, and its multi-pixelated display effect under indoor and outdoor conditions.

[0036] Figure 7This is an infrared camera test image showing the cooling effect of the self-radiative cooling-pixelated information display device prepared in Example 1 compared to the LED digital tube display device under outdoor conditions.

[0037] Figure 8 This is a schematic diagram illustrating the working principle of the self-radiative cooling-patterned information display device prepared in Example 1.

[0038] Figure 9 These are dynamic patterned display effect diagrams and wearable effect diagrams of the self-radiative cooling-patterned information display device prepared in Example 1. Detailed Implementation

[0039] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0040] This invention proposes a self-radiative cooling information display device, such as... Figure 1 As shown, the device comprises, from top to bottom, a working electrode 1, an electrolyte layer 2, and a counter electrode 3; the working electrode comprises a substrate 11 and a multilayer nanocavity electrode 12, which consists of a top metal reflective layer, a dielectric cavity layer, and a bottom ultrathin seed layer; the electrolyte layer 2 is used to realize the electrodeposition of a reversible metal reflective layer, and the formed reversible metal reflective layer and the working electrode 1 form a reconfigurable nanoresonant cavity structure.

[0041] Preferably, the substrate 11 is one or more of visible light transparent materials such as quartz, glass, PET film, and PDMS film, providing the device with a high mid-infrared emissivity.

[0042] Preferably, the multilayer nanocavity electrode 12 is used to excite dynamic Fabry-Pérot resonance to control color in the visible light band. When it forms a nanoresonant cavity together with the metal reflective layer, the resonant frequency satisfies the phase-matching equation: The top metallic reflective layer is made of one of the following metals or alloys: Ag, Al, Ag:Au, Al:Ag, Cu:Ag, etc., with a thickness of 20–40 nm. The dielectric cavity layer is made of one or more of the following dielectric materials: ITO, AZO, TiO2, SiO2, HfO2, TeO2, Sb2O3, WO3, Al2O3, etc., with a thickness of 50–200 nm. The bottom ultrathin seed layer is made of one of the following: Pt, Au, Ti, MPTMS monolayer, APTMS monolayer, with a thickness of 0.5–10 nm. Its function is to improve the growth quality of the electrodeposited metallic reflective layer.

[0043] Preferably, the electrolyte layer 2 includes a gel electrolyte and an encapsulation material; the gel electrolyte is composed of ionic reactants, an organic matrix, and a solvent required for realizing the reversible metal reflective layer electrodeposition technology.

[0044] Preferably, the electrolyte layer 2 has a thickness of 0.1–0.5 mm, and uses one of silicone, rubber, or acrylic hollow gaskets as the encapsulation material, while simultaneously providing space for the electrolyte gel. Furthermore, the aforementioned encapsulation material has patterning capabilities, enabling it to coordinate with the working electrode to achieve complex dynamic pattern displays.

[0045] Preferably, the ionic reactant comprises a main metal ion enabling reversible electroplating / dissolution of a layered metal mirror structure, an auxiliary metal ion regulator (with a reduction potential lower than that of the main metal ion) to accelerate the reversible reaction process, and a halide anion acting as a reactant in the electrochemistry of the counter electrode and complexing with the main metal ion to control the reaction rate of the working electrode. All ions in the electrolyte are provided by salt compounds containing these ions. Specifically, the ionic reactant is silver ions (Ag). + ), divalent copper ions (Cu) 2+ ), bromide ions (Br) - One or more of them.

[0046] Preferably, the organic matrix is ​​one of polyvinyl alcohol (PVA), polyvinyl butyral (PVB), and polyethylene oxide (PEO); the solvent is one of dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), and water (H2O).

[0047] Preferably, the counter electrode 3 is one of the following: a transparent oxide electrode material (ITO glass, FTO glass, etc.), a metal electrode (platinum electrode, platinum wire mesh, etc.), or an electrochromic material electrode (WO3 / glass electrode, Prussian blue / glass electrode, etc.). Furthermore, by designing and controlling the conductive area on the counter electrode, multi-pixelation of the counter electrode can be achieved, and in conjunction with the working electrode, dynamic pixelated information display can be realized.

[0048] The present invention also proposes a method for fabricating a self-radiative cooling-information display device, comprising the following fabrication steps: S1, selecting a substrate for multilayer film nanocavity electrode deposition;

[0049] S2. A multilayer nanocavity electrode is deposited on one side of the substrate using multi-target magnetron sputtering, electron beam evaporation, atomic layer deposition, and inductively coupled plasma chemical vapor deposition to obtain the working electrode.

[0050] S3. Prepare a gel electrolyte for achieving reversible metal reflective layer electrodeposition;

[0051] S4. Select a substrate and deposit a conductive layer in the designed area to obtain the counter electrode;

[0052] S5. Connect the working electrode obtained in S2 and the counter electrode obtained in S4 through the encapsulation material, and then inject the gel electrolyte prepared in S3 into the space constructed by the encapsulation material between the working electrode and the counter electrode. Finally, seal the edge of the space to obtain a self-radiative cooling-information display device.

[0053] Example 1

[0054] This embodiment provides a self-radiative cooling information display device. The device is developed based on the above-mentioned design and material selection principles and processing methods, and the device function is verified by performance testing.

[0055] Specifically, the device comprises, from top to bottom, a working electrode 1, an electrolyte layer 2, and a counter electrode 3. The working electrode includes a substrate 11 and a multilayer nanocavity electrode 12. The substrate 11 is one of a quartz substrate, a PDMS film, and a PET film. The multilayer nanocavity electrode 12 consists of a top semi-transparent Ag metal reflective layer, a middle dielectric cavity layer structure (one or two of ITO, TiO2, and SiO2), and a bottom ultrathin Pt seed layer. The electrolyte layer is used to achieve reversible electrodeposition of the metal reflective layer, and the formed metal reflective layer and the working electrode form a reconfigurable nanocavity structure. The electrolyte layer 2 includes a gel electrolyte and an encapsulation material; the gel electrolyte is composed of silver nitrate (AgNO3), copper chloride (CuCl2), tetrabutylammonium bromide (TBABr), dimethyl sulfoxide (DMSO), and polyvinyl butyral (PVB) required for realizing the reversible metal reflective layer electrodeposition technology. The molar concentration of AgNO3 is 0.1 mol / L, the ratio of AgNO3:CuCl2:TBABr is 5:1:25, and the mass fraction of PVB is 10 wt%.

[0056] Figure 2 This image shows the cooling effect of the self-radiative cooling information display device prepared in Example 1 under direct sunlight, compared to commercial electrochromic display devices and white LED devices. The switching between the excitation / annihilation states of the optical resonant modes of the device's working electrode before and after the reversible electrodeposition process enables dynamic color changing while maintaining a high average solar reflectivity (color state: R). sol =0.88, original state: R sol =0.86, solar reflectivity R sol Through the formula: (Calculations are performed), the above functions enable the device to operate at ~800W / m 2Under direct sunlight, compared to commercial PEDOT:PSS electrochromic display devices (KV-ECD-4050, Zhuhai Kaiwei Optoelectronics Technology Co., Ltd.) and white LED light-emitting devices (white LED, Suzhou Qipu Microelectronics Co., Ltd.), it can achieve an average temperature drop of ~12.7℃ and ~1.1℃.

[0057] Figure 3 This is an infrared camera test image showing the cooling effect of the self-radiative cooling information display device prepared in Example 1 under outdoor conditions compared to commercial vehicle wrapping film. Since the device's high solar reflectivity remains almost unchanged before and after dynamic coloring, it exhibits a significant cooling effect compared to commercial vehicle wrapping film (purple-red car wrapping film, Beijing Lifangcai Automotive Supplies Co., Ltd.) with a similar color. The infrared thermography camera shows that the self-radiative cooling information display device achieves a temperature reduction of ~5.8℃ compared to commercial vehicle wrapping film with a similar color.

[0058] Figure 4 This image shows the flexible and large-scale uniform color-changing effect of the self-radiative cooling-information display device prepared in Example 1. The self-radiative cooling-information display device proposed in this invention has multi-substrate compatibility and can be integrated with large-area flexible PET substrates. Sheet resistance testing of the multilayer film nanocavity electrode was performed using the four-point probe method. The test results show that the sheet resistance of the working electrode in this example is ~1.059 Ω / sq, exhibiting excellent conductivity. These properties can promote uniform reaction of the reversible metal electrodeposition electrochemical process at various points on the working electrode. Flexible devices can be developed with an area of ​​up to 100 cm². 2 Achieve uniform coloring / bleaching at the same time.

[0059] Figure 5 This is a flowchart illustrating the fabrication process of the self-radiative cooling-pixelated information display device. By pixelating the counter electrode (a PCB board containing Au conductive areas) and the silicone pad, and integrating them with the working electrode, multi-channel pixelated information display with independent control of each channel can be achieved.

[0060] Figure 6 This invention presents the reflectance spectra of each pixel in the self-radiative cooling-pixelated information display device prepared in Example 1, and its multi-pixelated display effect under indoor and outdoor conditions. The device proposed in this invention can realize pixels with additive and subtractive primary colors, and achieves the display of letter information "S", "I", "M", "I", and "T" under indoor lighting and sunlight.

[0061] Figure 7This is an infrared camera test image showing the cooling effect of the self-radiative cooling-pixelated information display device prepared in Example 1 compared to an LED digital tube display device under outdoor conditions. Since the device's high solar reflectivity remains almost unchanged before and after dynamic coloring, it exhibits a significant cooling effect compared to a traditional LED digital tube display. The infrared thermography camera shows that the self-radiative cooling-information display device proposed in this invention can achieve a temperature reduction of ~6°C compared to a traditional LED digital tube display (TM1637, blue display, Shenzhen Rongbo Jiachuang Technology Co., Ltd.).

[0062] Figure 8 This is a schematic diagram illustrating the working principle of the self-radiative cooling-patterned information display device. By integrating the working electrode, counter electrode, and patterned pad, dynamic patterned information display functionality can be achieved before and after the reversible metal electrodeposition process.

[0063] Figure 9 These are dynamic patterned display effect diagrams and wearable effect diagrams of the self-radiative cooling-patterned information display device prepared in Example 1. The self-radiative cooling-patterned information display device proposed in this invention can not only present complex dynamic pattern information, but also achieve wearability.

Claims

1. A self-radiative cooling information display device, characterized in that: The device comprises, from top to bottom, a working electrode, an electrolyte layer, and a counter electrode; the working electrode comprises a substrate and a multilayer nanocavity electrode, which consists of a top metal reflective layer, a dielectric cavity layer, and a bottom ultrathin seed layer; the electrolyte layer is used to realize the reversible electrodeposition of the metal reflective layer, and the formed metal reflective layer and the working electrode form a reconfigurable nanocavity structure; the thickness of the bottom ultrathin seed layer is 0.5~10 nm.

2. The self-radiative cooling-information display device according to claim 1, characterized in that: The substrate is one or more of quartz, glass, PET film, and PDMS film.

3. The self-radiative cooling-information display device according to claim 1, characterized in that: The material of the top metal reflective layer is one or more of Ag, Al, Ag:Au, Al:Ag, and Cu:Ag, and the thickness of the top metal reflective layer is 20~40 nm.

4. The self-radiative cooling-information display device according to claim 1, characterized in that: The dielectric cavity layer is made of one or more of ITO, AZO, TiO2, SiO2, HfO2, TeO2, Sb2O3, WO3, and Al2O3, and the thickness of the dielectric cavity layer is 50~200 nm.

5. The self-radiative cooling-information display device according to claim 1, characterized in that: The material of the bottom ultrathin seed layer is one or more of Pt, Au, Ti, MPTMS monolayer, and APTMS monolayer.

6. The self-radiative cooling-information display device according to claim 1, characterized in that: The electrolyte layer includes a gel electrolyte and an encapsulation material; wherein the gel electrolyte is composed of ionic reactants, an organic matrix, and a solvent.

7. The self-radiative cooling-information display device according to claim 6, characterized in that: The ionic reactants are one or more of silver ions, divalent copper ions, and bromide ions; the organic matrix is ​​one or more of polyvinyl alcohol, polyvinyl butyral, and polyethylene oxide; and the solvent is one or more of dimethyl sulfoxide, N,N-dimethylformamide, and water.

8. The self-radiative cooling-information display device according to claim 6, characterized in that: The encapsulation material is one or more of silicone, rubber, and acrylic hollow gaskets.

9. The self-radiative cooling-information display device according to claim 1, characterized in that: The counter electrode includes one or more of the following: transparent oxide electrode, metal electrode, and electrochromic material electrode.

10. A method for fabricating a self-radiating cooling information display device as described in any one of claims 1-9, comprising the following steps: S1. Select a substrate for multilayer film nanocavity electrode deposition; S2. A multilayer nanocavity electrode is deposited on one side of the substrate using iontophoresis chemical vapor deposition to obtain the working electrode; S3. Prepare a gel electrolyte for achieving reversible metal reflective layer electrodeposition; S4. Select a substrate and deposit a conductive layer in the designed area to obtain the counter electrode; S5. Connect the working electrode obtained in S2 and the counter electrode obtained in S4 through the encapsulation material, and then inject the gel electrolyte prepared in S3 into the space constructed by the encapsulation material between the working electrode and the counter electrode. Finally, seal the edge of the space to obtain a self-radiative cooling-information display device.

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