Infrared barrier and radiation refrigeration laminated film as well as preparation method and application thereof

Abstract

The invention relates to an infrared barrier and radiation refrigeration laminated film and a preparation method thereof, and the film is composed of a high-molecular polymer A film, a metal oxide B film, a metal C film and a metal oxide B film from bottom to top in sequence. The preparation method comprises the following steps: a) coating a solution A on a planar nano-calcium glass substrate or a nano-calcium glass substrate with a microstructure by adopting a spin-coating method to respectively obtain a planar p-A thin film or a textured t-A thin film; and b) depositing a B / C / B thin film on the p-A thin film or the t-A thin film by adopting magnetron sputtering, and preparing different infrared barrier and radiation refrigeration laminated thin films B / C / B / p-A thin films and B / C / B / t-A thin films by regulating and controlling the thicknesses of the B thin film and the C thin film. According to the infrared blocking and radiation refrigeration laminated film, the temperature of a crystalline silicon solar cell can be reduced, and the generating capacity of a crystalline silicon photovoltaic module can be improved. The process stability is good, and large-scale production is easy.

Description

Technical Field

[0001] This invention belongs to the field of optoelectronic functional materials technology, and relates to an infrared blocking and radiation cooling multilayer thin film, its preparation method and application. Background Technology

[0002] Among renewable energy sources, solar energy is the most ideal alternative. Solar energy can be directly converted into electricity through the photovoltaic effect. However, current solar cells increase the temperature of crystalline silicon photovoltaic modules while generating electricity. As the temperature rises, the output power of crystalline silicon photovoltaic modules decreases. For every 1°C increase in temperature, the power generation of crystalline silicon photovoltaic modules decreases by approximately 0.50%. Therefore, researchers have been searching for low-cost materials and fabrication methods that can effectively reduce the temperature of crystalline silicon photovoltaic modules while increasing their power generation. Currently, many researchers employ methods such as natural wind cooling (Y. Tanagnostopoulos, P. Themelis. AIP Conf. Proc. 2010, 1203: 1013-1018), water cooling (S. Li, ZH Zhou, JW Liu, J. Zhang, HJ Tang, ZF Zhang, YL Na, CX Jiang. Renew. Energ. 2022, 198: 947-959), and phase change materials (A. Hasan, SJ McCormack, MJ Huang, B. Norton. Sol. Energy 2010, 84: 1601-1612) to reduce the temperature of crystalline silicon photovoltaic modules. However, natural wind cooling is ineffective, achieving only a 5°C temperature difference. While water cooling can lower the temperature of crystalline silicon photovoltaic modules by 18°C, it requires continuous water circulation, significantly increasing costs. While phase change materials applied to crystalline silicon photovoltaic (PV) modules can achieve a temperature reduction of 20 °C, their high cost limits their mass application. Currently, researchers have proposed using infrared blocking and radiative cooling tandem thin films to lower the temperature of crystalline silicon PV modules. This is achieved by blocking sunlight in the 1.1–2.5 μm wavelength range or radiating the heat absorbed by the crystalline silicon PV module in the 4.0–16.0 μm wavelength range into outer space (K. Gao, HL Shen, YW Liu, QC Zhao, YF Li, JQ Liu. Sol. Energy 2022, 236: 703-711). Such thin films with infrared blocking and radiative cooling properties are low-cost, easy to prepare, and have a significant effect on crystalline silicon PV modules, thus showing great application potential and significant commercial value.

[0003] However, it is extremely difficult to simultaneously achieve high reflectivity in the 1.1-2.5 μm wavelength band and high emissivity in the 4.0-16.0 μm wavelength band in infrared blocking and radiative cooling laminated films. Currently, international researchers design thin film structures that possess only one infrared blocking or radiative cooling property. Although thin films with a single property can reduce the temperature of crystalline silicon photovoltaic modules, they still do not meet the ideal requirements. Summary of the Invention

[0004] This invention proposes an infrared blocking and radiation cooling multilayer thin film, its preparation method, and its application. The method is low-cost, simple to prepare, and has a short production cycle, making it suitable for large-scale industrial production. The materials used to prepare the ZAZ / PDMS multilayer thin film are non-toxic and pollution-free, which can greatly reduce the temperature of crystalline silicon photovoltaic modules and significantly increase the power generation of crystalline silicon photovoltaic modules, showing good application prospects.

[0005] To prepare thin films with high reflectivity in the 1.1-2.5 μm wavelength range and high emissivity in the 4.0-16.0 μm wavelength range, this invention first prepares p-PDMS or t-PDMS thin films on a glass substrate using a chemical spin-coating method. Then, using magnetron sputtering, ZnO and Ag films of different thicknesses (ZnO / Ag / ZnO (ZAZ) films) are deposited on the p-PDMS or t-PDMS films to construct ZAZ / t-PDMS and ZAZ / p-PDMS stacked films (collectively referred to as ZAZ / PDMS stacked films). Finally, the stacked films are removed from the glass substrate. The ZAZ / PDMS stacked films prepared by this invention exhibit excellent optical properties. After being applied to crystalline silicon photovoltaic modules, the stacked films can effectively reduce the temperature of the crystalline silicon photovoltaic modules and increase their power generation.

[0006] Specifically, the present invention is achieved through the following technical solutions.

[0007] The infrared blocking and radiation cooling laminated film of the present invention has the following structure: from bottom to top, it consists of a polymer film, a metal oxide film, a metal film, and a metal oxide film.

[0008] The polymers in the polymer film (represented by the letter A) include PDMS, PET, and PEN.

[0009] The metal oxides (represented by the letter B) in the metal oxide thin film include ZnO, AZO, ATO, ITO, and FTO.

[0010] The metals in the aforementioned metal thin film (represented by the letter C) include Ag, Cu, Ti, Ni, Fe, and Co.

[0011] Preferably, the polymer A film is a pA film or a tA film with a thickness of 1 μm-40 μm.

[0012] Preferably, the thickness of the metal oxide B film is 25 nm-200 nm.

[0013] Preferably, the thickness of the metal C film is 6 nm-18 nm.

[0014] The present invention discloses a method for preparing an infrared blocking and radiation cooling multilayer thin film, comprising the following steps.

[0015] (1) Cleaning of glass substrate: The planar glass substrate is ultrasonically cleaned in sequence with soapy water, deionized water, ethanol and deionized water.

[0016] (2) Preparation of solution A: Solution A was prepared by chemical method; A and curing agent were mixed in a weight ratio of 15:1-5:1 and ultrasonically stirred for 10 min.

[0017] (3) Preparation of pA thin film: A solution was dropped onto a flat glass substrate, three layers were spin-coated at 2000 rpm, and cured at 100 ℃ for 75 min to obtain a pA thin film with a thickness of 1 μm-50 μm and then removed from the flat glass.

[0018] (4) Preparation of BCB / pA thin film: Using magnetron sputtering, B target and C target are used at room temperature to deposit B / C / B thin film on pA thin film to form B / C / B / pA film.

[0019] The method for preparing an infrared blocking and radiation cooling multilayer thin film according to the present invention includes the following steps: (1) Cleaning of glass substrate: The planar glass substrate is ultrasonically cleaned in sequence with soapy water, deionized water, ethanol and deionized water.

[0020] (2) Preparation of PDMS solution: PDMS solution was prepared by chemical method; PDMS and curing agent were mixed at a weight ratio of 15:1-5:1 and ultrasonically stirred for 10 min.

[0021] (3) Preparation of t-PDMS thin film: PDMS solution was dropped onto a glass substrate with different microstructures, three layers were spin-coated at 2000 rpm, and cured at 100℃ for 75 min to obtain t-PDMS thin film with microstructure diameter of 1μm-50μm and removed from the microstructure glass.

[0022] (4) Preparation of ZAZ / t-PDMS film: The B / C / B film was deposited on the t-PDMS film by magnetron sputtering at room temperature using B and C targets to form B / C / B / t-PDMS film.

[0023] The polymer in the polymer film A of the present invention includes PDMS, PET, and PEN.

[0024] The metal oxides in the metal oxide thin film B of the present invention include ZnO, AZO, ATO, ITO, and FTO.

[0025] In the B / C / B structure described in this invention, B can be different transparent conductive oxide films.

[0026] The C mentioned in this invention includes Ag, Cu, Ti, Ni, Fe, and Co.

[0027] The microstructure described in this invention can be an upright pyramid, an inverted pyramid, a corn cob shape, or a honeycomb shape, etc.

[0028] This invention relates to the application of an infrared blocking and radiation-cooling multilayer thin film in crystalline silicon photovoltaic modules. The infrared blocking and radiation-cooling multilayer thin film is applied to the crystalline silicon photovoltaic module.

[0029] The principle of this invention is as follows: A ZAZ / PDMS film is laminated with a ZAZ / PDMS film. The laminated film has high transmittance in the 0.4-1.1 μm wavelength range, which meets the light absorption requirements for crystalline silicon solar cells to generate electricity. Secondly, the high reflectivity of the laminated film in the 1.1-2.5 μm wavelength range reflects sunlight in this range, thereby reducing the temperature of the crystalline silicon photovoltaic module. Furthermore, the high emissivity of the laminated film in the 4.0-16.0 μm wavelength range increases the rate at which the crystalline silicon photovoltaic module radiates heat into outer space, further reducing the module's temperature. Therefore, the ZAZ / PDMS film, while meeting the power generation requirements of crystalline silicon photovoltaic modules, can minimize the module's temperature and maximize its power output.

[0030] The raw materials used in this invention are all environmentally compatible and will not cause damage to the environment, avoiding the use of chemicals or reagents that are difficult to degrade or pollute the environment.

[0031] This invention enables infrared blocking and radiation cooling laminated films to simultaneously possess high transmittance in the 0.4-1.1 μm band, high reflectivity in the 1.1-2.5 μm band, and high emissivity in the 4.0-16.0 μm band, thus enabling the fabrication of ZAZ / PDMS films with controllable optical properties within a certain range.

[0032] The ZAZ / PDMS film prepared by this invention, which has infrared blocking and radiation cooling properties, can effectively reduce the temperature rise of crystalline silicon photovoltaic modules during power generation.

[0033] The ZAZ / PDMS film prepared by this invention, which has infrared blocking and radiation cooling properties, can significantly improve the power generation of crystalline silicon photovoltaic modules and has broad application prospects. Attached Figure Description

[0034] Figure 1 The schematic diagram of the ZAZ / PDMS thin film structure prepared in Example 12 is as follows: from bottom to top, they are PDMS thin film 1, ZnO thin film 2, Ag thin film 3, and ZnO thin film 4.

[0035] Figure 2 X-ray diffraction (XRD) patterns of ZAZ films prepared at Ag film thicknesses of 6 nm, 9 nm, 12 nm, 15 nm, and 18 nm.

[0036] Figure 3 The Ag films are shown in the scanning electron microscope (SEM) morphology of ZAZ films prepared at different thicknesses. The grain sizes are: (a) 6 nm; (b) 9 nm; (c) 12 nm; (d) 15 nm; (e) 18 nm; and (f) is the average grain size.

[0037] Figure 4 Atomic force microscopy (AFM) morphology of ZAZ films with different Ag film thicknesses. The grain size is shown in (a) as 6 nm; (b) as 9 nm; (c) as 12 nm; (d) as 15 nm; (e) as 18 nm; and (f) as roughness.

[0038] Figure 5 Optical performance spectra of ZAZ films prepared with Ag films at 6 nm, 9 nm, 12 nm, 15 nm, and 18 nm are shown. Among them, (a) is the transmittance spectrum; (b) is the reflectance spectrum; (c) is the optical performance statistics; and (d) is the emissivity spectrum.

[0039] Figure 6 Temperature rise and power generation curves of the crystalline silicon photovoltaic module with ZA9Z thin film prepared in Example 2 and the comparative example (blank sample) are shown. Among them, (a) is the time-temperature rise curve; (b) is the time-power generation curve.

[0040] Figure 7 The image shows the SEM microstructure of the t-PDMS film prepared in Example 9.

[0041] Figure 8The optical properties of the t-PDMS films prepared in Examples 5, 6, 7, 8, 9, 10 and 11 are statistically analyzed (the relationship between the average transmittance and average emissivity of the t-PDMS film and the surface microstructure size; a microstructure size of zero indicates a p-PDMS sample). Wherein, (a) is the average transmittance; (b) is the average emissivity.

[0042] Figure 9 The optical properties of the thin films prepared in Examples 1, 3, 4, 9, and 12 are shown. Among them, (a) is the transmittance spectrum; (b) is the reflectance spectrum; (c) is the emissivity spectrum; and (d) is the optical performance statistics.

[0043] Figure 10 The temperature rise curves and real-time power generation curves of the thin films and blank crystalline silicon photovoltaic modules prepared in Examples 1, 4, and 12, and the comparative example (blank sample) are shown. Among them, (a) is the time-temperature rise curve; (b) is the temperature after 1 hour; (c) is the time-power generation curve; and (d) is the power generation per unit time (cs refers to the blank sample). Detailed Implementation

[0044] The present invention will be further described below with reference to embodiments, but these should not be construed as limiting the scope of protection of the present invention.

[0045] Comparative Example The comparative example is a conventional crystalline silicon photovoltaic module without infrared blocking and radiation cooling tandem thin film, which consists of a backsheet, EVA film, TOPCon solar cells, EVA film and photovoltaic glass. Example 1

[0046] Preparation of ZnO / Ag / ZnO thin film: A ZnO thin film with a thickness of 25 nm was deposited on a soda-lime glass substrate by magnetron sputtering, followed by a 9 nm Ag thin film, and finally a 25 nm ZnO thin film, referred to as ZA9Z thin film.

[0047] The XRD pattern of the prepared ZAZ thin film is as follows: Figure 2 As shown, the prepared film has obvious diffraction peaks and good crystallinity.

[0048] The SEM morphology of the prepared ZAZ film is as follows: Figure 3 As shown, the ZnO grain size is uniformly distributed.

[0049] The AFM morphology of the prepared ZAZ film is as follows: Figure 4 As shown, the ZAZ film has a low roughness.

[0050] The optical properties of the prepared ZAZ thin film are shown in the following graph. Figure 5 As shown, when the Ag film thickness is 9 nm, the ZAZ film has the best optical performance, that is, the ZAZ film has an average transmittance of 78.8% in the 0.4-1.1 μm band, an average reflectance of 81.8% in the 1.1-2.5 μm band, and an average emissivity of 48.9% in the 4.0-16.0 μm band.

[0051] The temperature rise and real-time power generation curves of the ZA9Z thin-film crystalline silicon photovoltaic module and the comparative model are shown below. Figure 6 As shown, the crystalline silicon photovoltaic module covered with the ZA9Z thin film reached a final temperature of 56.6 °C after 1 hour, generating 2.996 W·h per unit time. The comparative example reached a final temperature of 69.3 °C after 1 hour, generating 2.851 W·h per unit time. The crystalline silicon photovoltaic module covered with the ZA9Z thin film generated 5.09% more power per unit time than the comparative example. Example 2

[0052] Preparation of ZnO / Ag / ZnO thin film: A ZnO thin film with a thickness of 100 nm was deposited on a soda-lime glass substrate by magnetron sputtering, followed by a 6 nm thick Ag thin film, and finally a 100 nm thick ZnO thin film, referred to as ZA6Z thin film. Example 3

[0053] PDMS and curing agent were mixed at a weight ratio of 5:1. After stirring and sonicating for 10 min, three layers were spin-coated onto a glass substrate at 2000 rpm and cured at 100 °C for 75 min to obtain a p-PDMS film with a thickness of 2 μm. Example 4

[0054] ZA9Z / p-PDMS film was prepared by sequentially depositing a 25 nm thick ZnO film, a 9 nm thick Ag film, and a 25 nm thick ZnO film on the surface of the p-PDMS film prepared in Example 3 using magnetron sputtering. Example 5

[0055] PDMS and curing agent were mixed at a weight ratio of 5:1. After stirring and sonicating for 10 min, three layers were spin-coated on a glass substrate with a microstructure of 1 μm diameter at 2000 rpm and cured at 100 °C for 75 min to obtain a t-PDMS-1 film with a thickness of 2 μm and a microstructure size of 1 μm diameter. Example 6

[0056] PDMS and curing agent were mixed at a weight ratio of 10:1. After stirring and sonicating for 10 min, three layers were spin-coated on a glass substrate with a microstructure of 2 μm diameter at 2000 rpm and cured at 100 °C for 75 min to obtain a t-PDMS-2 film with a thickness of 4 μm and a microstructure size of 2 μm diameter. Example 7

[0057] PDMS and curing agent were mixed at a weight ratio of 15:1. After stirring and sonicating for 10 min, three layers were spin-coated on a glass substrate with a microstructure of 3 μm diameter at 2000 rpm and cured at 100 °C for 75 min to obtain a t-PDMS-3 film with a thickness of about 6 μm and a microstructure size of 3 μm diameter. Example 8

[0058] PDMS and curing agent were mixed at a weight ratio of 10:1. After stirring and sonicating for 10 min, 6 layers were spin-coated on a glass substrate with a microstructure of 4 μm diameter at 2000 rpm and cured at 100 °C for 75 min to obtain a t-PDMS-4 film with a thickness of 8 μm and a microstructure size of 4 μm diameter. Example 9

[0059] PDMS and curing agent were mixed at a weight ratio of 10:1. After stirring and sonicating for 10 min, 12 layers were spin-coated on a glass substrate with a microstructure of 5 μm diameter at 2000 rpm and cured at 100 °C for 75 min to obtain a t-PDMS film with a thickness of 16 μm and a microstructure size of 5 μm diameter.

[0060] The SEM microstructure of the prepared t-PDMS film is as follows: Figure 7 As shown, the microstructures are uniformly arranged and of uniform size. Example 10

[0061] PDMS and curing agent were mixed at a weight ratio of 15:1. After stirring and sonicating for 10 min, 12 layers were spin-coated on a glass substrate with a microstructure of 6 μm diameter at 2000 rpm and cured at 100 °C for 75 min to obtain a t-PDMS-6 film with a thickness of 24 μm and a microstructure size of 6 μm diameter. Example 11

[0062] PDMS and curing agent were mixed at a weight ratio of 20:1. After stirring and sonicating for 10 min, 12 layers were spin-coated on a glass substrate with a microstructure of 7 μm diameter at 2000 rpm and cured at 100 °C for 75 min to obtain a t-PDMS-7 film with a thickness of 32 μm and a microstructure size of 7 μm diameter.

[0063] Figure 8 The optical properties of the t-PDMS films prepared in Examples 5, 6, 7, 8, 9, 10, and 11 are statistically analyzed. It was found that the t-PDMS film prepared in Example 9 exhibits the best optical properties, with an average transmittance of 98.5% in the 0.4-1.1 μm band and an average emissivity of 95.3% in the 4.0-16.0 μm band. Example 12

[0064] ZA9Z / t-PDMS stacked films were prepared by depositing ZnO films with a thickness of 25 nm, Ag films with a thickness of 9 nm, and ZnO films with a thickness of 25 nm on the surface of the t-PDMS film prepared in Example 9 using magnetron sputtering. Example 13

[0065] Preparation of AZO / Cu / AZO / PET stacked thin films: AZO thin films with a thickness of 200 nm were deposited on PET substrates by magnetron sputtering, followed by Cu thin films with a thickness of 6 nm, and finally AZO thin films with a thickness of 200 nm. Example 14

[0066] Preparation of ATO / Ti / ATO / PEN stacked thin films: ATO thin films with a thickness of 100 nm were deposited on PEN substrates by magnetron sputtering, followed by Ti thin films with a thickness of 10 nm, and finally ATO thin films with a thickness of 100 nm. Example 15

[0067] Preparation of ITO / Ni / ITO / PET stacked thin films: ITO thin films with a thickness of 100 nm were deposited on PET substrates by magnetron sputtering, followed by Ni thin films with a thickness of 18 nm, and finally ITO thin films with a thickness of 100 nm. Example 16

[0068] Preparation of FTO / Fe / FTO / PEN stacked thin films: FTO thin films with a thickness of 100 nm were deposited on PEN substrates by magnetron sputtering, followed by Fe thin films with a thickness of 6 nm, and finally FTO thin films with a thickness of 100 nm. Example 17

[0069] Preparation of AZO / Co / AZO / t-PDMS stacked thin films: AZO films with a thickness of 100 nm were deposited on the surface of t-PDMS films by magnetron sputtering, followed by Co films with a thickness of 6 nm, and finally AZO films with a thickness of 100 nm. Example 18

[0070] Preparation of ATO / Ni / ZnO / PET stacked thin films: A ZnO film with a thickness of 150 nm was deposited on a PET substrate by magnetron sputtering, followed by a Ni film with a thickness of 18 nm, and finally an ATO film with a thickness of 150 nm. Example 19

[0071] Preparation of ITO / Fe / FTO / PEN stacked thin films: A 100 nm thick FTO film was deposited on a PEN substrate by magnetron sputtering, followed by a 10 nm thick Fe film, and finally a 100 nm thick ITO film. Example 20

[0072] The performance of thin films with infrared blocking and radiative cooling properties was characterized by testing. Figure 9 The optical properties of the thin films prepared in Examples 1, 3, 4, 9, and 12 were examined. It was found that the ZA9Z / t-PDMS thin film has the best infrared blocking performance and radiative cooling performance. Specifically, the ZA9Z / t-PDMS thin film has an average transmittance of 78.3% in the 0.4-1.1 μm band, an average reflectance of 83.7% in the 1.1-2.5 μm band, and an average emissivity of 90.6% in the 4.0-16.0 μm band.

[0073] The thin films prepared in Examples 1, 3, 4, 9, and 12 were respectively coated onto the surface of crystalline silicon photovoltaic modules. The temperature rise curves and real-time power generation curves of the crystalline silicon photovoltaic modules coated with films possessing infrared blocking and radiative cooling properties were tested, comparing them with those of the comparative examples. Figure 10 As shown in Table 1, the final temperature, power generation, and improvement rate of the crystalline silicon photovoltaic modules covered with various thin films after 1 hour are statistically analyzed. It was found that the crystalline silicon photovoltaic module covered with the ZA9Z / t-PDMS tandem thin film prepared in Example 12 had the lowest temperature (46.2 °C) and the highest power generation (3.137 W·h) per unit time after 1 hour. Compared with the comparative example, the power generation of the crystalline silicon photovoltaic module covered with the ZA9Z / t-PDMS tandem thin film increased by 10.03% per unit time.

[0074] Table 1 Performance parameters of crystalline silicon photovoltaic modules covered with ZAZ / PDMS multilayer thin films sample Final temperature (°C) after 1 hour Electricity generated in 1 hour (W·h) Electricity generation increase rate Comparative Example 69.3 2.851 --- ZA9Z 56.6 2.996 5.09% Example 9 50.9 3.063 7.44% Example 12 46.2 3.137 10.03% .

Claims

1. An infrared blocking and radiation cooling laminated thin film, characterized in that: The structure is as follows: from bottom to top, it consists of polymer A film, metal oxide B film, metal C film, and metal oxide B film. The polymer A includes PDMS, PET, and PEN; The metal oxide B includes ZnO, AZO, ATO, ITO, and FTO; The metal C mentioned includes Ag, Cu, Ti, Ni, Fe, and Co.

2. The infrared blocking and radiation cooling laminated thin film according to claim 1, characterized in that: In the B / C / B structure described above, B represents different oxides.

3. The infrared blocking and radiation cooling laminated thin film according to claim 1, characterized in that: The polymer A film is a pA film or a tA film with a thickness of 1 μm-40 μm.

4. The infrared blocking and radiation cooling laminated thin film according to claim 1, characterized in that: The thickness of the metal oxide B film is 25 nm-200 nm.

5. The infrared blocking and radiation cooling laminated thin film according to claim 1, characterized in that: The thickness of the metal C film is 6 nm-18 nm.

6. The method for preparing an infrared blocking and radiation cooling laminated thin film according to claim 1, characterized in that: Includes the following steps: (1) Cleaning of glass substrate: The planar glass substrate was ultrasonically cleaned in sequence with soapy water, deionized water, ethanol and deionized water. (2) Preparation of solution A: Solution A was prepared by chemical method; A and curing agent were mixed at a weight ratio of 15:1-5:1 and ultrasonically stirred for 10 min. (3) Preparation of pA thin film: A solution was dropped onto a planar glass substrate, three layers were spin-coated at 2000 rpm, and cured at 100℃ for 75 min to obtain a pA thin film with a thickness of 1 μm-50 μm and then removed from the planar glass. (4) Preparation of BCB / pA thin film: Using magnetron sputtering, B target and C target are used at room temperature to deposit B / C / B thin film on pA thin film to form B / C / B / pA film.

7. The method for preparing an infrared blocking and radiation cooling laminated thin film according to claim 1, characterized in that: Includes the following steps: (1) Cleaning of glass substrate: The planar glass substrate was ultrasonically cleaned in sequence with soapy water, deionized water, ethanol and deionized water. (2) Preparation of PDMS solution: PDMS solution was prepared by chemical method; PDMS and curing agent were mixed at a weight ratio of 15:1-5:1 and ultrasonically stirred for 10 min; (3) Preparation of t-PDMS thin film: PDMS solution was dropped onto a glass substrate with different microstructures, three layers were spin-coated at 2000 rpm, and cured at 100℃ for 75 min to obtain t-PDMS thin film with microstructure diameter of 1μm-50μm and removed from the microstructure glass. (4) Preparation of ZAZ / t-PDMS film: BCB film was deposited on t-PDMS film by magnetron sputtering at room temperature using B target and C target to form BCB / t-PDMS film.

8. A method for preparing an infrared blocking and radiation-cooling multilayer thin film according to claims 1-6, characterized in that: The microstructure described is a regular pyramid, an inverted pyramid, a corn cob shape, or a honeycomb shape.

9. The application of the infrared blocking and radiation cooling multilayer thin film as described in any one of claims 1 to 5 in crystalline silicon photovoltaic modules.

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