Preparation method of anti-reflection antifouling coating for photovoltaic cell

Abstract

The invention discloses a preparation method of an anti-reflection anti-fouling coating for a photovoltaic cell, which comprises the following steps: mixing and dissolving zinc acetate, polyethylene glycol and modified silica gel consisting of low-surface-energy substances methyltrimethoxysilane and tetraethyl orthosilicate, coating on the surface of glass, and calcining at high temperature to obtain the anti-reflection anti-fouling coating. The coating provided by the invention has a porous cross-linked network, and can ensure low refractive index and excellent substrate binding force. Moreover, the coating also has high transmittance and excellent organic matter degradation capability, can effectively improve the power conversion efficiency of the solar cell when being applied to the field of solar cells, and can effectively reduce high maintenance cost caused by pollution of organic matters such as dust, bird droppings and the like when the solar cell is applied in various complex environments; and huge application potential is shown.

Description

Technical Field

[0001] The invention belongs to the field of polymer coatings, and in particular relates to a method for preparing an anti-reflection and anti-fouling coating for photovoltaic cells. Background Art

[0002] Photovoltaic power generation has attracted much attention due to its ability to produce clean energy and alleviate the fossil energy crisis, and its importance in the energy field is increasing day by day. During long-term outdoor use, the operating efficiency of photovoltaic cells will be greatly reduced due to the deposition of pollutants. Therefore, the cleaning and maintenance of the surface of photovoltaic cells will cost a lot of money every year, making its application cost high. For this reason, researchers have been working hard to find a solution that can achieve self-cleaning of the surface of photovoltaic cells to solve the problem of surface contamination.

[0003] At the same time, how to achieve surface self-cleaning while maintaining good anti-reflection (improving transmittance) effect remains a challenge. There are two main surface treatment methods currently used: biomimetic films and anti-reflection coatings. Bionic films mainly form uniform nanoarrays on the surface of the substrate to achieve anti-reflection effects, such as high-transmittance surfaces that imitate cicada wings, light-harvesting films inspired by butterfly wings, and anti-reflection functional materials that imitate compound eyes. These biomimetic surfaces improve transmittance by reducing effective reflection over a wide spectral range. However, their scalability is limited due to the complex preparation process, poor mechanical durability, and difficult structure control. In contrast, anti-reflection coatings have attracted much attention due to their simple preparation and low cost. Compared with biomimetic films, anti-reflection coatings have the advantages of simple preparation and easy large-scale production, but there are still problems such as cumbersome processes, harmful to the environment, and poor anti-fouling effects, which greatly limit the application of coatings in outdoor areas. Therefore, it is particularly important to develop hydrophobic, easy-to-process, and environmentally friendly anti-reflection coatings. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing an antireflective and antifouling coating for photovoltaic cells, which is an antireflective coating with excellent antireflective performance and antifouling performance, and can solve the problems of complex operation process, poor bonding with substrate, and low weather resistance of the currently prepared antireflective coating. At the same time, compared with commercial antireflective coatings, the coating has higher power conversion efficiency in the field of solar cells, and thus has great commercial value potential.

[0005] In order to achieve the above object, the present invention adopts the following technical solution: An antireflection and antifouling coating for photovoltaic cells, the preparation method of which comprises the following steps: (1) Methyltrimethoxysilane, tetraethyl orthosilicate and hydrochloric acid are fully stirred in a mixed solvent to obtain a solution A; (2) Stir zinc acetate dihydrate, ethylene glycol methyl ether and ethanolamine to obtain solution B; (3) After stirring and mixing the solution A obtained in step (1) and the solution B obtained in step (2), polyethylene glycol is added and stirring is continued to obtain solution C; (4) The solution C obtained in step (3) is coated on the surface of a clean glass substrate, and then calcined in a muffle furnace to obtain a coating with antireflection and antifouling properties.

[0006] Further, the mixed solvent in step (1) is an ethanol solution with a mass concentration of 90%.

[0007] Further, the mass concentrations of methyltrimethoxysilane, tetraethyl orthosilicate, and hydrochloric acid in the solution A obtained in step (1) are 1-30%, 1-25%, and 0.1-1% respectively.

[0008] Further, the mass concentrations of zinc acetate dihydrate, ethylene glycol methyl ether, and ethanolamine in the solution B obtained in step (2) are 1-40 wt%, 1-80 wt%, and 1-20 wt% respectively, and the sum of the three is 100%.

[0009] Further, the molecular weight of the polyethylene glycol used in step (3) is 600.

[0010] Further, the dosages of the solution B and the polyethylene glycol in step (3) are 1-25% and 1-30% of the mass of the solution A used respectively.

[0011] Further, the glass substrate used in step (4) is rinsed with absolute ethanol, deionized water, and acetone before use, and then pretreated with oxygen plasma.

[0012] Further, the solution C is coated on the surface of the glass substrate by double-sided spin coating in step (4), the spin coating speed is 1000-5000 r / min, the spin coating time is 10-40 s, and the single-sided coating amount is 0.02 mL / cm 2 .

[0013] Further, the time for pretreatment with oxygen plasma is 5 min.

[0014] Further, the pre-curing temperature in step (4) is 60-70 °C and the time is 10 min.

[0015] Further, the calcination temperature in step (4) is 250-550 °C and the time is 60-360 min.

[0016] The advantages of the present invention are: (1) The preparation process of the present invention adopts a spin-coating process. The prepolymer solution is coated on the glass surface, and the antireflective and antifouling coating can be obtained by calcination. The preparation process is simple in operation, and the materials are green and friendly, overcoming the problems of complex preparation procedures, long time consumption, and environmental harm of traditional processes.

[0017] (2) The coating prepared by the present invention has excellent transmittance and power conversion efficiency. In the range of 380 - 1100 nm, the average transmittance of the coating is significantly higher than that of untreated glass and commercial coatings, showing excellent optical transparency. In addition, when the coating is applied to the surface of a solar cell, its power conversion efficiency is significantly improved compared with commercial coatings and untreated glass, further highlighting its great application potential in the field of solar cells.

[0018] (3) The coating prepared by the present invention has self-cleaning function and wear resistance. The coating can effectively promote the degradation of organic substances, and at the same time has excellent liquid repellency, which can effectively improve the antifouling effect of the coating under dry conditions. And in the sand-drop experiment, the contact angle of the coating hardly changes, further proving its excellent durability.

[0019] (4) The coating of the present invention uses a combination of ZnO and polyethylene glycol (Mn = 600) to adjust the porosity of the coating. The organosilicon formed by the sol-gel method usually has relatively large pores, resulting in a decrease in the hardness of the coating. The addition of zinc oxide can fill the pores to make its structure dense, and the use of low-molecular-weight polyethylene glycol can successfully prepare a coating with a microporous structure, further reducing the influence of pores on the coating. In addition, the addition of ZnO can also change the peak position of the transmittance of the coating, playing a great role in enhancing the transmittance of the coating. Brief Description of the Drawings

[0020] Figure 1 SEM images of the coatings prepared in Comparative Example 1 (a), Comparative Example 2 (b), and Example 1 (c).

[0021] Figure 2 Comparative diagram of the transmittance of the coatings prepared in Comparative Example 1 and Comparative Example 2.

[0022] Figure 3 Antireflection effect diagram of the antireflective coating prepared in Example 1.

[0023] Figure 4 Comparative diagram of the transmittance of the antireflective coating prepared in Example 1 with commercial coatings and untreated bare glass (a) and power-voltage diagram when it is applied to a solar cell (b).

[0024] Figure 5Experimental diagram (a) of using the antireflection coating prepared in Example 1 to degrade the organic matter methylene blue, and the ultraviolet-visible transmission spectrum comparison diagram (b) and degradation rate comparison diagram (c) of its degradation of organic matter compared with untreated bare glass.

[0025] Figure 6 Comparison diagram of the liquid repellency performance (a) and dust removal effect (b) of the antireflection coating prepared in Example 1 and the surface of untreated bare glass.

[0026] Figure 7 Comparison diagram of the effect of the antireflection coating prepared in Example 1 and untreated bare glass on preventing bird droppings pollution.

[0027] Figure 8 Diagram of the change in contact angle during the sandblasting experiment of the antireflection coating prepared in Example 1.

[0028] Figure 9 Comparison diagram of the average transmittance of the antireflection coatings prepared in Examples 1-5.

[0029] Figure 10 Comparison diagram of the transmittance of the antireflection coating prepared in Example 1 and the coatings obtained in Comparative Examples 3-5.

[0030] Figure 11 Schematic diagram of the transmittance of the antireflection coating prepared in Example 1 and the coating obtained in Comparative Example 6. Detailed implementation manners

[0031] An antireflection and antifouling coating for photovoltaic cells, and its preparation method includes the following steps: (1) Stir methyltrimethoxysilane, tetraethyl orthosilicate, and hydrochloric acid in an ethanol solution with a mass concentration of 90% to obtain solution A, where the mass concentrations of methyltrimethoxysilane, tetraethyl orthosilicate, and hydrochloric acid are 1-30%, 1-25%, and 0.1-1% respectively; (2) Stir zinc acetate dihydrate, ethylene glycol methyl ether, and ethanolamine evenly according to mass percentages of 1-40 wt%, 1-80 wt%, and 1-20 wt% respectively to obtain solution B; (3) Stir and mix solution A, 1-25% of solution B by its mass, and 1-30% of polyethylene glycol (Mn = 600) to obtain solution C; (4) First rinse the glass substrate with absolute ethanol, deionized water, and acetone, and then pretreat it with oxygen plasma for 5 min; (5) Coating solution C obtained in step (3) on the surface of the treated glass substrate by double-sided spin coating, with a spin coating speed of 1000-5000 r / min, a spin coating time of 10-40 s, and a single-sided coating amount of 0.02 mL / cm 2, after each side is coated, it needs to be pre-cured at 60-70 °C for 10 min. Finally, it is placed in a muffle furnace and calcined at 250-550 °C for 60-360 min to obtain a coating with anti-reflection and anti-fouling properties.

[0032] To make the content of the present invention easier to understand, the technical solutions of the present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited thereto.

[0033] Unless otherwise specifically stated, various raw materials, reagents, instruments, and equipment used in the present invention can be obtained through market purchases or can be prepared by existing methods.

[0034] Example 1 1) Weigh 43.4 g of absolute ethanol and 4.85 g of deionized water as a mixed solvent, and add 19% by weight of methyltrimethoxysilane, 19% by weight of tetraethyl orthosilicate, and 0.7% by weight of hydrochloric acid thereto respectively. After stirring evenly, it is denoted as reaction solution A.

[0035] 2) Weigh 20 wt% of zinc acetate dihydrate, 70 wt% of ethylene glycol methyl ether, and 10 wt% of ethanolamine, stir at 65 °C at a speed of 400 r / min for 30 min, and then transfer it to a dark environment for storage, denoted as reaction solution B.

[0036] 3) Weigh 4 g of reaction solution A, and add 12% by weight of reaction solution B and 16% by weight of polyethylene glycol (Mn = 600) thereto respectively. After stirring evenly, it is denoted as reaction solution C.

[0037] 4) Place the glass slide in a beaker, wash it successively with acetone, absolute ethanol, and deionized water, then wipe it with lens paper, and then treat it with oxygen plasma for 5 min. Then, spin-coat reaction solution C on the treated glass surface at a coating amount of 0.02 mL / cm 2 (the spin-coating speed is 2000 r / min and the time is 20 s). After pre-curing in an oven at 65 °C for 10 min, spin-coat reaction solution C on the other surface of the glass in the same manner. After pre-curing in an oven at 65 °C for 10 min, place it in a muffle furnace at 450 °C and calcine for 120 min.

[0038] Example 2 1) Weigh 43.4 g of absolute ethanol and 4.85 g of deionized water as a mixed solvent, and add 19% by weight of methyltrimethoxysilane, 19% by weight of tetraethyl orthosilicate, and 0.7% by weight of hydrochloric acid thereto respectively. After stirring evenly, it is denoted as reaction solution A.

[0039] 2) Weigh 20 wt% of zinc acetate dihydrate, 70 wt% of ethylene glycol methyl ether, and 10 wt% of ethanolamine respectively, stir at a speed of 400 r / min at 65 °C for 30 min, and then transfer it to a dark environment for storage, denoted as reaction solution B.

[0040] 3) Weigh 4 g of reaction solution A, add 4% of reaction solution B and 16% of polyethylene glycol (Mn = 600) by weight respectively, and stir evenly, denoted as reaction solution C.

[0041] 4) Place the glass slide in a beaker, wash it successively with acetone, absolute ethanol, and deionized water, then wipe it with lens paper, and then treat it with oxygen plasma for 5 min. Then, spin-coat reaction solution C on the treated glass surface at a coating amount of 0.02 mL / cm 2 (the spin-coating speed is 2000 r / min and the time is 20 s). After pre-curing in an oven at 65 °C for 10 min, spin-coat reaction solution C on the other surface of the glass in the same way, pre-cure it in an oven at 65 °C for 10 min, and then place it in a muffle furnace at 450 °C and calcine for 120 min.

[0042] Example 3 1) Weigh 43.4 g of absolute ethanol and 4.85 g of deionized water as a mixed solvent respectively, add 19% of methyltrimethoxysilane, 19% of tetraethyl orthosilicate, and 0.7% of hydrochloric acid by weight respectively, stir evenly, and denote it as reaction solution A.

[0043] 2) Weigh 20 wt% of zinc acetate dihydrate, 70 wt% of ethylene glycol methyl ether, and 10 wt% of ethanolamine respectively, stir at a speed of 400 r / min at 65 °C for 30 min, and then transfer it to a dark environment for storage, denoted as reaction solution B.

[0044] 3) Weigh 4 g of reaction solution A, add 8% of reaction solution B and 16% of polyethylene glycol (Mn = 600) by weight respectively, and stir evenly, denoted as reaction solution C.

[0045] 4) Place the glass slide in a beaker, wash it successively with acetone, absolute ethanol, and deionized water, then wipe it with lens paper, and then treat it with oxygen plasma for 5 min. Then, spin-coat reaction solution C on the treated glass surface at a coating amount of 0.02 mL / cm 2 (the spin-coating speed is 2000 r / min and the time is 20 s). After pre-curing in an oven at 65 °C for 10 min, spin-coat reaction solution C on the other surface of the glass in the same way, pre-cure it in an oven at 65 °C for 10 min, and then place it in a muffle furnace at 450 °C and calcine for 120 min.

[0046] Example 4 1) Weigh 43.4 g of absolute ethanol and 4.85 g of deionized water respectively as a mixed solvent. Add 19% of methyltrimethoxysilane, 19% of tetraethyl orthosilicate, and 0.7% of hydrochloric acid by weight to it respectively. After stirring evenly, it is denoted as reaction solution A.

[0047] 2) Weigh 20 wt% of zinc acetate dihydrate, 70 wt% of ethylene glycol methyl ether, and 10 wt% of ethanolamine respectively. Stir at a speed of 400 r / min at 65 °C for 30 min, and then transfer it to a dark environment for storage, denoted as reaction solution B.

[0048] 3) Weigh 4 g of reaction solution A, and add 16% of reaction solution B and 16% of polyethylene glycol (Mn = 600) by weight to it respectively. Stir evenly, denoted as reaction solution C.

[0049] 4) Place the glass slide in a beaker, clean it successively with acetone, absolute ethanol, and deionized water, then wipe it with lens paper, and then treat it with oxygen plasma for 5 min. Then, spin-coat reaction solution C on the treated glass surface at a coating amount of 0.02 mL / cm 2 (the spin-coating speed is 2000 r / min and the time is 20 s). After pre-curing in an oven at 65 °C for 10 min, spin-coat reaction solution C on the other surface of the glass in the same manner. After pre-curing in an oven at 65 °C for 10 min, place it in a muffle furnace at 450 °C and calcine for 120 min.

[0050] Example 5 1) Weigh 43.4 g of absolute ethanol and 4.85 g of deionized water respectively as a mixed solvent. Add 19% of methyltrimethoxysilane, 19% of tetraethyl orthosilicate, and 0.7% of hydrochloric acid by weight to it respectively. After stirring evenly, it is denoted as reaction solution A.

[0051] 2) Weigh 20 wt% of zinc acetate dihydrate, 70 wt% of ethylene glycol methyl ether, and 10 wt% of ethanolamine respectively. Stir at a speed of 400 r / min at 65 °C for 30 min, and then transfer it to a dark environment for storage, denoted as reaction solution B.

[0052] 3) Weigh 4 g of reaction solution A, and add 20% of reaction solution B and 16% of polyethylene glycol (Mn = 600) by weight to it respectively. Stir evenly, denoted as reaction solution C.

[0053] 4) Place the glass slide in a beaker, clean it successively with acetone, absolute ethanol, and deionized water, then wipe it with lens paper, and then treat it with oxygen plasma for 5 min. Then, spin-coat reaction solution C on the treated glass surface at a coating amount of 0.02 mL / cm 2The coating amount of the reaction solution C was spin-coated (spin coating speed: 2000 r / min, time: 20 s) on the treated glass surface. After pre-curing in an oven at 65 °C for 10 min, the other surface of the glass was spin-coated with the reaction solution C in the same manner. After pre-curing in an oven at 65 °C for 10 min, it was placed in a muffle furnace at 450 °C and calcined for 120 min.

[0054] Comparative Example 1 1) Weigh 43.4 g of absolute ethanol and 4.85 g of deionized water as a mixed solvent respectively. Add 19% of methyltrimethoxysilane, 19% of tetraethyl orthosilicate, and 0.7% of hydrochloric acid by weight of the mixed solvent respectively. After stirring evenly, it was denoted as reaction solution A.

[0055] 2) Place the glass slide in a beaker and clean it successively with acetone, absolute ethanol, and deionized water. Then wipe it with lens paper. After oxygen plasma treatment for 5 min, the reaction solution A was spin-coated (spin coating speed: 2000 r / min, time: 20 s) on the treated glass surface at a coating amount of 0.02 mL / cm 2 After pre-curing in an oven at 65 °C for 10 min, the other surface of the glass was spin-coated with the reaction solution A in the same manner. After pre-curing in an oven at 65 °C for 10 min, it was placed in a muffle furnace at 450 °C and calcined for 120 min.

[0056] Comparative Example 2 1) Weigh 43.4 g of absolute ethanol and 4.85 g of deionized water as a mixed solvent respectively. Add 19% of methyltrimethoxysilane, 19% of tetraethyl orthosilicate, and 0.7% of hydrochloric acid by weight of the mixed solvent respectively. After stirring evenly, it was denoted as reaction solution A.

[0057] 2) Weigh 20 wt% of zinc acetate dihydrate, 70 wt% of ethylene glycol monomethyl ether, and 10 wt% of ethanolamine respectively. Stir at a speed of 400 r / min at 65 °C for 30 min, and then transfer it to a dark environment for storage. It was denoted as reaction solution B.

[0058] 3) Weigh 4 g of reaction solution A and add 12% of reaction solution B by weight of reaction solution A. Stir evenly and denote it as reaction solution C.

[0059] 4) Place the glass slide in a beaker and clean it successively with acetone, absolute ethanol, and deionized water. Then wipe it with lens paper. After oxygen plasma treatment for 5 min, the reaction solution was spin-coated at a coating amount of 0.02 mL / cm 2The coating amount of C was spin-coated (spin-coating speed: 2000 r / min, time: 20 s) on the treated glass surface. After pre-curing in an oven at 65°C for 10 min, the other surface of the glass was spin-coated with reaction solution C again in the same manner. After pre-curing in an oven at 65°C for 10 min, it was placed in a muffle furnace at 250°C and calcined for 120 min.

[0060] Comparative Example 3 1) Weigh 43.4 g of absolute ethanol and 4.85 g of deionized water as a mixed solvent, and add 19% of methyltrimethoxysilane, 19% of tetraethyl orthosilicate, and 0.7% of hydrochloric acid by weight respectively. After stirring evenly, it is denoted as reaction solution A.

[0061] 2) Weigh 4 g of reaction solution A, and add 16% of polyethylene glycol (Mn = 600) by weight. After stirring evenly, it is denoted as reaction solution B.

[0062] 3) Place the glass slide in a beaker, wash it successively with acetone, absolute ethanol, and deionized water, then wipe it with lens paper, and then treat it with oxygen plasma for 5 min. Then, spin-coat reaction solution B on the treated glass surface at a coating amount of 0.02 mL / cm 2 The coating amount of C was spin-coated (spin-coating speed: 2000 r / min, time: 20 s) on the treated glass surface. After pre-curing in an oven at 65°C for 10 min, the other surface of the glass was spin-coated with reaction solution C again in the same manner. After pre-curing in an oven at 65°C for 10 min, it was placed in a muffle furnace at 250°C and calcined for 120 min.

[0063] Comparative Example 4 1) Weigh 20 wt% of zinc acetate dihydrate, 70 wt% of ethylene glycol methyl ether, and 10 wt% of ethanolamine respectively, stir at a speed of 400 r / min at 65°C for 30 min, and then transfer it to a dark environment for storage, denoted as reaction solution A.

[0064] 2) Place the glass slide in a beaker, wash it successively with acetone, absolute ethanol, and deionized water, then wipe it with lens paper, and then treat it with oxygen plasma for 5 min. Then, spin-coat reaction solution A on the treated glass surface at a coating amount of 0.02 mL / cm 2 The coating amount of C was spin-coated (spin-coating speed: 2000 r / min, time: 20 s) on the treated glass surface. After pre-curing in an oven at 65°C for 10 min, the other surface of the glass was spin-coated with reaction solution C again in the same manner. After pre-curing in an oven at 65°C for 10 min, it was placed in a muffle furnace at 450°C and calcined for 120 min.

[0065] Comparative Example 5 1) Weigh 43.4 g of absolute ethanol and 4.85 g of deionized water respectively as a mixed solvent, and add 19% of methyltrimethoxysilane, 19% of tetraethyl orthosilicate, and 0.7% of hydrochloric acid by weight of the solvent respectively. After stirring evenly, it is denoted as reaction solution A.

[0066] 2) Weigh 20 wt% of zinc acetate dihydrate, 70 wt% of ethylene glycol methyl ether, and 10 wt% of ethanolamine respectively. Stir at a speed of 400 r / min at 65 °C for 30 min, and then transfer it to a dark environment for storage, denoted as reaction solution B.

[0067] 3) Weigh 4 g of reaction solution A, and add 50% of reaction solution B and 16% of polyethylene glycol (Mn = 600) by weight of reaction solution A respectively. Stir evenly, denoted as reaction solution C.

[0068] 4) Place the glass slide in a beaker, clean it successively with acetone, absolute ethanol and deionized water, then wipe it with lens paper, and then treat it with oxygen plasma for 5 min. Then, spin-coat reaction solution C on the treated glass surface at a coating amount of 0.02 mL / cm 2 (the spin-coating speed is 2000 r / min and the time is 20 s). After pre-curing in an oven at 65 °C for 10 min, spin-coat reaction solution C on the other surface of the glass in the same way. After pre-curing in an oven at 65 °C for 10 min, place it in a muffle furnace at 450 °C and calcine for 120 min.

[0069] Comparative Example 6 1) Weigh 43.4 g of absolute ethanol and 4.85 g of deionized water respectively as a mixed solvent, and add 19% of methyltrimethoxysilane, 19% of tetraethyl orthosilicate, and 0.7% of hydrochloric acid by weight of the solvent respectively. After stirring evenly, it is denoted as reaction solution A.

[0070] 2) Weigh 23 wt% of tetrabutyl titanate, 71 wt% of absolute ethanol, 4.8 wt% of concentrated hydrochloric acid and 1.2 wt% of deionized water respectively. Stir at a speed of 400 r / min at 40 °C for 2 h, denoted as reaction solution B.

[0071] 3) Weigh 4 g of reaction solution A, and add 12% of reaction solution B and 16% of polyethylene glycol (Mn = 600) by weight of reaction solution A respectively. Stir evenly, denoted as reaction solution C.

[0072] 4) Place the glass slide in a beaker, clean it successively with acetone, absolute ethanol and deionized water, then wipe it with lens paper, and then treat it with oxygen plasma for 5 min. Then, spin-coat reaction solution C on the treated glass surface at a coating amount of 0.02 mL / cm 2The coating amount of [substance] was spin-coated on the treated glass surface with a spin coating speed of 2000 r / min for 20 s. After pre-curing in an oven at 65°C for 10 min, the other surface of the glass was spin-coated with the reaction solution C again in the same manner. After pre-curing in an oven at 65°C for 10 min, it was placed in a muffle furnace at 450°C and calcined for 120 min.

[0073] Figure 1 SEM images of the coatings prepared in Comparative Example 1, Comparative Example 2, and Example 1 are shown. It can be observed from the SEM images that the antireflective coating prepared only with silicone has relatively large pores, which may lead to insufficient hardness. After adding ZnO nanoparticles to the coating, the large pores in the coating are filled, and a dense protrusion layer can be formed, solving the problem of insufficient hardness. The introduction of polyethylene glycol can further form micron-sized pores on the coating, solving the problem of insufficient transmittance of the coating.

[0074] Figure 2 The transmittance comparison diagram of the coatings prepared in Comparative Example 1 and 2 is shown. As Figure 2 shown, Comparative Example 2 can improve the antireflective effect of the coating by introducing ZnO. This may be because the filling of pores by ZnO significantly reduces the light scattering, resulting in the average transmittance of Comparative Example 2 being better than that of Comparative Example 1. At the same time, the energy of sunlight is the highest around 500 nm. By shifting the curve, it can be clearly seen that the coating prepared without ZnO in Comparative Example 1 shows a peak-valley form in the range of 400 - 550 nm, while the waveform of the coating prepared with the introduction of ZnO has changed significantly, and the original trough position has become a peak. This indicates that the introduction of ZnO can increase the light transmittance by adjusting the peak position of the curve, thereby improving the utilization of sunlight by the antireflective coating.

[0075] Figure 3 The antireflection effect diagram of the antireflective coating prepared in Example 1 is shown. As shown in the figure, when light is incident on the surface of the coated glass, the text below is still clearly visible, while on the bare glass, there is a dazzling white light and the text below cannot be seen clearly, proving that the obtained coating has excellent antireflection effect.

[0076] Figure 4 The transmittance (a) of the antireflective coating prepared in Example 1, the commercial coating (mainly made of polyethylene terephthalate (PET)), and the bare glass, and the power-voltage schematic diagram (b) when they are applied in solar cells are shown. It can be seen from the figure that the average transmittances of the three samples in the range of 380 - 1100 nm are 93.71%, 90.5%, and 88.91% respectively. The transmittance of the antireflective coating is increased by 3.21% and 4.80% compared with the commercial coating and the bare glass respectively. At the same time, the above three samples are respectively placed on the surface of the solar cell, and the light intensity is 100 mW / cm 2The solar cells were irradiated with a xenon lamp equipped with an AM1.5 filter. The results showed that the powers of the three samples were 82.4 mW, 71.0 mW and 69.4 mW, respectively. The power conversion efficiency of the anti-reflective coating was increased by 1.23% and 1.08% compared with the commercial coating and bare glass, respectively, proving that the prepared coating has excellent anti-reflective effect and can significantly improve the power conversion efficiency of solar cells.

[0077] Figure 5 The experimental figure (a) shows the degradation of organic methylene blue by the antireflection coating prepared in Example 1, and the comparison of the absorbance (b) and degradation rate (c) of the degradation of organic methylene blue by bare glass. The coated glass and bare glass were placed in a methylene blue solution with a concentration of 5 ppm, and a light intensity of 100 mW / cm 2 The xenon lamp equipped with a filter that stops at 420 nm was used for irradiation, and samples were taken every 30 minutes to measure the absorbance of the methylene blue solution treated with the anti-reflection coating and the bare glass. The results show that after 150 minutes of light irradiation, the absorbance of methylene blue in the bare glass changed from 0.92 to 0.38, with a degradation rate of 58.51%; while the absorbance of methylene blue in the anti-reflection coating changed from 0.90 to 0.08, with a degradation rate of 90.70%. This shows that the coating can accelerate the degradation of methylene blue and reduce the impact of organic pollutants on the coating surface.

[0078] Figure 6 This is a comparison chart of the liquid repellency (a) and dust removal effect (b) of the anti-reflective coating prepared in Example 1 and the bare glass. By tilting the glass at 30° and dropping 70 μL of deionized water on the bare glass and anti-reflective coating surfaces respectively, the results show that obvious wetting occurs on the bare glass surface, while the water droplets on the surface of the anti-reflective coating of Example 1 can slide off quickly without any wetting residue, indicating that the coating has excellent liquid repellency (a). At the same time, dust is randomly sprinkled on the anti-reflective coating and bare glass surfaces, and rinsed with 70 μL of water droplets. The results show that the dust on the bare glass surface is difficult to remove after being wetted by water, while the dust on the surface of the anti-reflective coating of Example 1 is effectively removed under the gravity of the water droplets, indicating that the coating has excellent dust removal effect (b).

[0079] Figure 7Comparison chart of the anti-bird droppings pollution effects between the antireflection coating prepared in Example 1 and bare glass. 100 μL of artificial bird droppings were dropped onto the surface of bare glass with an inclination of 10° and the surface of the antireflection coating in Example 1. As shown in the figure, the artificial bird droppings on the surface of the bare glass quickly slid down and wetted the glass surface, while the artificial bird droppings on the surface of the antireflection coating in Example 1 stably adhered in the form of droplets (a). Subsequently, the samples were placed in an oven (45 °C, 1 h) to accelerate the curing of the artificial bird droppings, and then the surface was wiped with a tissue. The results showed that the artificial bird droppings on the surface of the bare glass were difficult to remove after curing, while the artificial bird droppings on the surface of the antireflection coating in Example 1 were easy to wipe clean, indicating that the coating has obvious advantages in dealing with bird droppings pollution.

[0080] The sandblasting experiment can investigate the wear resistance of the coating. Figure 8 Chart of the change in contact angle during the sandblasting experiment for the antireflection coating prepared in Example 1. As shown in the figure, when the coating withstood the impact of 10 g falling sand, it could still maintain a water contact angle of more than 80°, and after multiple sandblasting, the change range of the contact angle was controlled within 5°, fully confirming that the coating has good wear resistance.

[0081] Figure 9 Comparison chart of the average transmittance of the antireflection coatings prepared in Examples 1-5. As can be seen from the figure, when the introduction amounts of reaction liquid B in the coatings were 4 wt%, 8 wt%, 12 wt%, 16 wt%, and 20 wt% respectively, their average transmittances between 380 - 1100 nm were 92.44%, 92.81%, 93.71%, 92.27%, and 92.05% respectively. It shows that the content of ZnO has a significant influence on the average transmittance of the coating, and the transmittance effect is the best when the introduction amount is 12 wt%.

[0082] Figure 10 Comparison chart of the transmittance between the antireflection coating prepared in Example 1 and the coatings obtained in Comparative Examples 3-5. As can be seen from the figure, the average transmittance of the antireflection coating in Example 5 in the range of 380 - 1100 nm was 93.71%, while the average transmittance of Comparative Example 3 was 90.07% and that of Comparative Example 5 was 91.21%. In short, by optimizing the content of ZnO, the transmittance was significantly improved. Moreover, from the schematic diagram of Comparative Example 4, it can be obtained that the transmittance curve of the ZnO coating is a smooth curve, and it can be concluded that the change of the wave peak is the result of the combined action of ZnO and SiO2.

[0083] Figure 11Comparison chart of the transmittance of the antireflection coating prepared in Example 1 and the coating obtained in Comparative Example 6. According to the illustration, the average transmittance of the coating in Comparative Example 6 is 90.92% in the range of 380 - 1100 nm, while the average transmittance of the antireflection coating in Example 1 is 93.71%, which is 2.79% higher than that in Comparative Example 6. It shows that introducing ZnO into the coating has better antireflection performance than TiO2.

[0084] The above are only the preferred embodiments of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope covered by the present invention.

Claims

1. A preparation method of an anti-reflection and anti-fouling coating for a photovoltaic cell, characterized in that, The steps include: (1) Methyltrimethoxysilane, tetraethyl orthosilicate and hydrochloric acid are fully stirred in a mixed solvent to obtain a solution A; (2) Stir zinc acetate dihydrate, ethylene glycol methyl ether and ethanolamine to obtain solution B; (3) After stirring and mixing the solution A obtained in step (1) and the solution B obtained in step (2), polyethylene glycol is added and stirred continuously to obtain a solution C; (4) The solution C obtained in step (3) is coated on the surface of a clean glass substrate, and after pre-curing, it is placed in a muffle furnace for calcination to obtain a coating with anti-reflection and anti-fouling properties.

2. The preparation method of the antireflection and antifouling coating according to claim 1, wherein The mixed solvent in step (1) is an ethanol solution with a mass concentration of 90%.

3. The preparation method of the anti-reflection and anti-fouling coating according to claim 1, wherein The mass concentrations of methyltrimethoxysilane, tetraethyl orthosilicate and hydrochloric acid in the solution A obtained in step (1) are 1-30%, 1-25% and 0.1-1%, respectively.

4. The preparation method of the antireflection and antifouling coating according to claim 1, characterized in that, The mass concentrations of zinc acetate dihydrate, ethylene glycol methyl ether and ethanolamine in the solution B obtained in step (2) are 1-40 wt%, 1-80 wt% and 1-20 wt% respectively, and the sum of the three is 100%.

5. The preparation method of the antireflection and antifouling coating according to claim 1, characterized in that, In step (3), the amounts of solution B and polyethylene glycol used are 1-25% and 1-30% of the mass of solution A used, respectively.

6. The preparation method of the antireflection and antifouling coating according to claim 1, wherein, The glass substrate used in step (4) is pretreated with oxygen plasma before use; The pretreatment time was 5 min.

7. The preparation method of the antireflection and antifouling coating according to claim 1, characterized in that, In step (4), solution C is coated on the surface of the glass substrate by double-sided spin coating, and the single-sided coating amount is 0.02 mL / cm 2 .

8. The preparation method of the antireflection and antifouling coating according to claim 1, characterized in that, The pre-curing temperature in step (4) is 60-70°C and the time is 10 min.

9. The preparation method of the antireflection and antifouling coating according to claim 1, wherein The calcination temperature in step (4) is 250-550°C and the calcination time is 60-360 min.

10. An antireflective and antifouling coating for photovoltaic cells prepared by the method according to any one of claims 1 to 9.

Images