CN110112227A - A kind of preparation method of the double layer antireflection coating for silicon solar cell - Google Patents

Abstract

The invention relates to a method for preparing a double-layer anti-reflection film for silicon solar cells, and belongs to the technical field of new energy materials. The present invention adopts polyurethane acrylate to modify _SiO2 film. Polyurethane acrylate has urethane bond, which is characterized in that various hydrogen bonds can be formed between polymer molecular chains, and has high wear resistance, adhesion, flexibility, High peel strength and excellent low temperature resistance, as well as the excellent optical properties and weather resistance of polyacrylate, make the modified second anti-reflection film have excellent mechanical wear resistance and flexibility, and high elongation at break; this The invention uses silver mirror reaction combined with annealing to prepare silver nanoparticles on the surface of the substrate as the first layer of anti-reflection coating. The formation of randomly distributed silver nanoparticles is the result of the joint action of metal thermodynamics and kinetics. When rapid annealing, silver Membrane systems gain sufficient kinetic energy, tending to nanoparticle structures with smaller surface areas.

Description

A kind of preparation method of double-layer anti-reflection film for silicon solar cell

technical field

The invention relates to a method for preparing a double-layer anti-reflection film for silicon solar cells, and belongs to the technical field of new energy materials.

Background technique

Effective and full use of solar energy to improve the conversion efficiency of silicon solar cells is an urgent problem to be solved for silicon solar cells. Solar energy is an inexhaustible renewable energy source for human beings. It is also a clean energy source and does not cause environmental pollution. Silicon solar cells are devices that directly convert solar energy into electrical energy. The refractive index of silicon is 3.42, and it is irradiated on the silicon substrate. A large part of the sunlight is reflected, and the utilization rate of sunlight by silicon cells is not high, which reduces the conversion efficiency of the cells. The conversion efficiency has been improved, and the common method is to coat one or more layers of anti-reflection film with good optical performance on the surface of the solar cell, which can eliminate or reduce the reflection of light on the surface of the device to increase the transmittance of light, and then in the display, laser There are a wide range of applications in areas such as systems and solar cells.

Anti-reflection coating is an optical coating with a wide range of applications. It is widely used in daily life, industry, astronomy, military science, electronics and other fields, such as: coating a thin film on the surface of glasses to prevent the reflection of glasses and improve The optical properties of glasses; in order to prevent counterfeit banknotes, some film debris is used to reduce reflection to identify authenticity, electrophotographic equipment, precision instrument probe lenses, etc. will use anti-reflection film; The development of various films with different properties has been studied, and anti-glare and anti-static films for displays and computer screens have become new application fields for anti-reflection films and have broad market prospects. The anti-reflection film used for solar cells should not only have low anti-reflection rate, but also have good physical and chemical properties. There are two commonly used ways to improve the efficiency of solar cells: (1) coating anti-reflection coating; (2) making the surface of solar cells have an uneven structure. Increase the light transmittance and improve the efficiency of the battery by coating, such as: the porous silicon dioxide film increases the conversion efficiency of the battery by 5-6%, and the porous structure can also improve the crack resistance of the matrix; the silicon nitride film The conversion efficiency of the battery is increased to 16.7%, the film is dense and can passivate the defects on the surface of the silicon wafer; the titanium dioxide and zirconia films can improve the alkali resistance and waterproof and moisture-proof performance of the glass substrate; secondly, the surface of the battery can also be treated , so that it has a certain concave-convex structure, so that the incident sunlight from all directions can enter the solar cell after multiple reflections, thereby increasing the incident sunlight and greatly improving the conversion efficiency of the battery.

Optical anti-reflection films are usually obtained by single-layer anti-reflection coatings, double-layer anti-reflection coatings, multi-layer alternating anti-reflection coatings with alternating high and low refractive indices, and gradient refractive index films. According to the coating method, it can be divided into acid etching method, magnetron sputtering method, vapor deposition method and sol-gel method. The acid etching method uses methods such as alkali analysis and silicon removal to etch the glass surface to obtain a porous surface film with a low refractive index, and the refractive index of the film is adjusted by the porosity. The magnetron sputtering method refers to the sputtering of high and low refractive index materials onto the glass surface under vacuum conditions. Double-layer, three-layer, four-layer or more anti-reflection film systems can be selected. By controlling the refractive index of the film layer and thickness to achieve the purpose of destructive interference. Vapor deposition technology is a technology that uses the physical and chemical reaction process that occurs in the gas phase to form decorative or functional metal, non-metal or compound films on the glass surface. It is one of the commonly used methods for preparing multi-layer anti-reflection films. Film layers with different packing densities can be obtained by changing the deposition angle. The refractive index of the film layer is graded, but the scratch resistance of the film layer is weak. The sol-gel method is one of the common methods for preparing thin film materials in the wet chemical method. The metal compound is solidified by solution, sol, and gel, and is heat-treated at a lower temperature to form nanoparticles.

Under the current technical conditions, it is difficult to increase the power of the battery simply through the processing of silicon wafers and the improvement of packaging technology. However, increasing the transmittance of photovoltaic glass can increase the energy of photoelectric conversion and improve the power generation efficiency, which is the current industry concern. hotspots and important development directions. The anti-reflection ultra-clear patterned glass with high transmission within the response spectrum range of solar cells has been developed, which can improve the power generation efficiency of solar cells to the same extent, and has very good economic prospects. The popularization and application of anti-reflection film glass for solar photovoltaic has a positive effect on improving the efficiency of solar cells, reducing costs, enhancing the competitiveness of solar cell power generation, and shortening the cost recovery period of grid-connected power generation.

Contents of the invention

Technical problem to be solved by the present invention: Aiming at the problems of low hardness and poor friction resistance of the existing anti-reflection film, a method for preparing a double-layer anti-reflection film for silicon solar cells is provided.

In order to solve the problems of the technologies described above, the technical solution adopted in the present invention is:

(1) Mix 2% sodium formate solution and silver ammonia solution on the surface of the substrate, heat treatment to obtain a metal film, and quickly anneal the metal film to obtain the first layer of anti-reflection film;

(2) Take ethyl orthosilicate, absolute ethanol, hydrochloric acid with a mass fraction of 3%, deionized water, and polyurethane acrylate, and ethyl orthosilicate, absolute ethanol, hydrochloric acid with a mass fraction of 3% and deionized water Mix, stir and age to obtain a sol, add polyurethane acrylate to the sol, stir and mix, and cool to room temperature to obtain a modified sol;

(3) Preheat the substrate with the first layer of anti-reflection film, drop the modified sol on the surface of the first layer of anti-reflection film, and spin-coat to obtain a semi-finished film; perform etching on the semi-finished film , that is, the second layer of anti-reflection film is obtained, which is a double-layer anti-reflection film for silicon solar cells.

The preparation step of the silver-ammonia solution described in step (1) is: mix the mass fraction of 2% silver nitrate solution, mass fraction of 1% sodium hydroxide solution and mass fraction of 10% ammonia water in a mass ratio of 1:1:1 Evenly, the silver ammonia solution is obtained.

The heat treatment step in step (1) is as follows: mix 2% sodium formate solution and silver ammonia solution with a mass fraction of 1:1 on the surface of the substrate, and heat in a water bath at a temperature of 50-70°C for 1-2 minutes.

The rapid annealing step in the step (1) is: rapid annealing the metal film at a temperature of 300-350° C. and a nitrogen flow rate of 2 L/min for 1-2 hours.

The proportions of tetraethyl orthosilicate, absolute ethanol, hydrochloric acid with a mass fraction of 3%, deionized water, and polyurethane acrylate in step (2) are respectively: by weight parts, weigh 30 to 40 Parts of ethyl orthosilicate, 50-60 parts of absolute ethanol, 1-10 parts of hydrochloric acid with a mass fraction of 3%, 20-30 parts of deionized water, and 10-20 parts of polyurethane acrylate.

The stirring and aging treatment step described in step (2) is: mix ethyl orthosilicate, absolute ethanol, hydrochloric acid with a mass fraction of 3% and deionized water, and stir at a stirring speed of 400-500r/min for 1 ~2h later, let stand and age at room temperature for 1~2 days.

The stirring and mixing treatment step in step (2) is: adding polyurethane acrylate to the sol, stirring and mixing for 20-30 minutes at a temperature of 110-120° C. and a stirring speed of 300-400 r/min.

The preheating step in step (3) is: preheating the substrate with the first layer of anti-reflection film at a temperature of 180-190° C. for 3-5 minutes.

The spin-coating process described in step (3) is as follows: drop the modified sol on the surface of the first layer of anti-reflection film, repeat spin-coating 3-5 layers at a rotation speed of 3000-3100r/min, and spin-coat each time The time for the coating is 30-40s, and after each spin coating, the temperature is 400-600°C and returned for 20-40 minutes, and cooled to room temperature.

The etching treatment step described in step (3) is: using SF6 as the etching gas, and performing etching treatment on the semi-finished film under the condition of a power supply of 200-250W.

Compared with other methods, the present invention has beneficial technical effects as follows:

(1) The present invention uses silver mirror reaction combined with annealing treatment to prepare silver nanoparticles on the surface of the substrate as the first layer of anti-reflection film, and uses tetraethyl orthosilicate and ethanol to prepare silica sol under acidic catalytic conditions. The silica sol prepared by modifying high-efficiency polyurethane acrylate is pulled by spin coating and reactive ion etching to form a layer of nanometer moth-eye anti-reflection structure on the surface of the substrate as the second layer of anti-reflection film. Two layers of anti-reflection film are combined to prepare a double-layer anti-reflection film with good mechanical strength and friction resistance;

(2) The present invention adopts an ion etching process to form a layer of nano-moth-eye anti-reflection structure on the surface of the substrate. As the etching time increases, the etching depth increases, and at the same time, the nano-structure changes from columnar to cone-shaped. Nano-moth-eye The width of the structure increases, the sidewall of the upper half is steep, and the bottom is gradually smooth. This shape has a continuous refractive index gradient, which is conducive to the realization of anti-reflection effect. As the etching depth further increases, the average reflectance decreases. This will help improve the absorption efficiency of silicon-based solar cells; due to the randomness of the random structure in shape and arrangement, it will help achieve a smoother refractive index gradient, and thus will also obtain a more superior anti-reflection and anti-reflection effect; The moth-eye structure, by forming a nanostructure with a characteristic size below 200nm on the surface of the object, is equivalent to a layer of gradient refractive index interface, which can effectively reduce surface reflection;

(3) In the present invention, the sol-gel method is used to prepare the silicon dioxide anti-reflection film. The sol-gel method is easy to operate, the ambient temperature is low, and the doping amount and the performance of the film to be prepared can be well controlled. Films of various sizes and shapes are prepared on various substrates. SiO ₂ films have the characteristics of low density, adjustable refractive index, high thermal stability, low sound propagation velocity and easy preparation;

(3) The present invention adopts polyurethane acrylate to modify _SiO2 film. Polyurethane acrylate has urethane bond, which is characterized in that various hydrogen bonds can be formed between polymer molecular chains, and has high wear resistance, adhesion, Flexibility, high peel strength and excellent low temperature resistance, as well as the excellent optical properties and weather resistance of polyacrylate, make the modified second layer of anti-reflection film have excellent mechanical wear resistance and flexibility, elongation at break high;

(4) The present invention uses silver mirror reaction combined with annealing treatment to prepare silver nanoparticles on the surface of the substrate as the first layer of anti-reflection coating. The formation of randomly distributed silver nanoparticles is the result of the joint action of metal thermodynamics and kinetics. During annealing, the silver film system acquires sufficient kinetic energy and tends to a nanoparticle structure with a smaller surface area.

Detailed ways

According to the mass ratio of 1:1:1, the mass fraction is 2% silver nitrate solution, the mass fraction is 1% sodium hydroxide solution and the mass fraction is 10% ammonia water, and the silver ammonia solution is obtained, and the volume ratio is 1:1. The mass fraction is 2% sodium formate solution and silver ammonia solution are mixed and placed on the surface of the substrate, and heated at a water bath temperature of 50-70°C for 1-2min to obtain a metal film. Rapid annealing treatment at 2L/min for 1-2 hours to obtain the first layer of anti-reflection coating; in parts by weight, weigh 30-40 parts of ethyl orthosilicate, 50-60 parts of absolute ethanol, 1-10 parts The mass fraction is 3% hydrochloric acid, 20-30 parts deionized water, 10-20 parts polyurethane acrylate, mix ethyl orthosilicate, absolute ethanol, 3% hydrochloric acid and deionized water at a stirring speed Stir at 400-500r/min for 1-2 hours, then stand and age at room temperature for 1-2 days to obtain a sol. Add polyurethane acrylate to the sol at a temperature of 110-120°C and a stirring speed of 300-400r Stir and mix at 180-190°C for 20-30 minutes, cool to room temperature to obtain the modified sol; preheat the substrate with the first layer of anti-reflection film at a temperature of 180-190°C for 3-5 minutes, and drop the modified sol on On the surface of the first layer of anti-reflection film, spin-coat 3-5 layers repeatedly at a speed of 3000-3100r/min, the time of each spin-coating is 30-40s, and the temperature after each spin-coating is 400-600°C Back down for 20-40 minutes, and cool to room temperature to obtain a semi-finished film; use SF6 as etching gas to etch the semi-finished film under the condition of a power supply of 200-250W to obtain the second layer of anti-reflection film, namely It is a double-layer anti-reflection coating for silicon solar cells.

Mix the sodium formate solution with a mass fraction of 2% and the silver ammonia solution on the surface of the substrate, heat treatment to obtain a metal film, and quickly anneal the metal film to obtain the first layer of anti-reflection film; take ethyl orthosilicate, no Water ethanol, hydrochloric acid with a mass fraction of 3%, deionized water, polyurethane acrylate, mixed ethyl orthosilicate, absolute ethanol, hydrochloric acid with a mass fraction of 3% and deionized water, stirred and aged to obtain a sol , add urethane acrylate to the sol, stir and mix, and cool to room temperature to obtain the modified sol; preheat the substrate with the first layer of anti-reflection film, and drop the modified sol on the first layer of anti-reflection film Spin-coating on the surface of the semi-finished film to obtain a semi-finished film; etching the semi-finished film to obtain the second layer of anti-reflection film, which is a double-layer anti-reflection film for silicon solar cells. The preparation steps of the silver ammonia solution are: according to the mass ratio of 1:1:1, the mass fraction is 2% silver nitrate solution, the mass fraction is 1% sodium hydroxide solution and the mass fraction is 10% ammonia water, and the silver ammonia solution is obtained. . The heat treatment step is: mix 2% sodium formate solution and silver ammonia solution with a mass fraction of 1:1 on the surface of the substrate, and heat for 1 min at a water bath temperature of 50°C. The rapid annealing treatment step is as follows: the metal film is subjected to rapid annealing treatment for 1 hour at a temperature of 300° C. and a nitrogen gas flow rate of 2 L/min. The proportions among tetraethyl orthosilicate, dehydrated alcohol, mass fraction of 3% hydrochloric acid, deionized water, and polyurethane acrylate are respectively: in parts by weight, take 30 parts of tetraethyl orthosilicate, 50 parts of Absolute ethanol, 1 part of hydrochloric acid with a mass fraction of 3%, 20 parts of deionized water, and 10 parts of polyurethane acrylate. The stirring and aging treatment steps are as follows: mix ethyl tetrasilicate, absolute ethanol, hydrochloric acid with a mass fraction of 3% and deionized water, stir at a stirring speed of 400r/min for 1 hour, and then leave to age at room temperature for 1 hour sky. Stirring and mixing treatment steps are as follows: add urethane acrylate to the sol, and stir and mix for 20 minutes at a temperature of 110° C. and a stirring speed of 300 r/min. The preheating step is: preheating the substrate with the first layer of anti-reflection film at a temperature of 180° C. for 3 minutes. The spin-coating process is as follows: drop the modified sol on the surface of the first layer of anti-reflection film, repeat the spin-coating of 3 layers at a speed of 3000r/min, and the time of each spin-coating is 30s. The temperature is 400°C and returned for 20 minutes, and cooled to room temperature. The etching treatment step is: use SF6 as the etching gas, and perform etching treatment on the semi-finished film under the condition of a power supply of 200W.

Mix the sodium formate solution with a mass fraction of 2% and the silver ammonia solution on the surface of the substrate, heat treatment to obtain a metal film, and quickly anneal the metal film to obtain the first layer of anti-reflection film; take ethyl orthosilicate, no Water ethanol, hydrochloric acid with a mass fraction of 3%, deionized water, polyurethane acrylate, mixed ethyl orthosilicate, absolute ethanol, hydrochloric acid with a mass fraction of 3% and deionized water, stirred and aged to obtain a sol , add urethane acrylate to the sol, stir and mix, and cool to room temperature to obtain the modified sol; preheat the substrate with the first layer of anti-reflection film, and drop the modified sol on the first layer of anti-reflection film Spin-coating on the surface of the semi-finished film to obtain a semi-finished film; etching the semi-finished film to obtain the second layer of anti-reflection film, which is a double-layer anti-reflection film for silicon solar cells. The preparation steps of the silver ammonia solution are: according to the mass ratio of 1:1:1, the mass fraction is 2% silver nitrate solution, the mass fraction is 1% sodium hydroxide solution and the mass fraction is 10% ammonia water, and the silver ammonia solution is obtained. . The heat treatment step is: mix 2% sodium formate solution and silver ammonia solution with a mass fraction of 1:1 on the surface of the substrate, and heat for 1 min at a water bath temperature of 60°C. The rapid annealing treatment step is as follows: the metal film is subjected to rapid annealing treatment for 1 hour at a temperature of 325° C. and a nitrogen flow rate of 2 L/min. Tetraethyl orthosilicate, dehydrated ethanol, mass fraction are 3% hydrochloric acid, deionized water, the ratio between urethane acrylate is respectively: by weight, weigh 35 parts of tetraethyl orthosilicate, 55 parts Absolute ethanol, 5 parts of hydrochloric acid with a mass fraction of 3%, 25 parts of deionized water, and 15 parts of polyurethane acrylate. The stirring and aging treatment steps are: mix ethyl tetrasilicate, absolute ethanol, hydrochloric acid with a mass fraction of 3% and deionized water, stir at a stirring speed of 450r/min for 1 hour, and then leave to age at room temperature for 1 hour sky. Stirring and mixing treatment steps are as follows: add urethane acrylate to the sol, and stir and mix for 25 minutes at a temperature of 115° C. and a stirring speed of 350 r/min. The preheating step is: preheating the substrate with the first layer of anti-reflection film at a temperature of 185° C. for 4 minutes. The spin-coating process is as follows: drop the modified sol on the surface of the first layer of anti-reflection film, repeat the spin-coating of 4 layers at a speed of 3050r/min, and the time of each spin-coating is 35s. The temperature is 500°C and returned for 30 minutes, and cooled to room temperature. The etching treatment steps are: use SF6 as the etching gas, and perform etching treatment on the semi-finished film under the condition of a power supply of 225W.

Mix the sodium formate solution with a mass fraction of 2% and the silver ammonia solution on the surface of the substrate, heat treatment to obtain a metal film, and quickly anneal the metal film to obtain the first layer of anti-reflection film; take ethyl orthosilicate, no Water ethanol, hydrochloric acid with a mass fraction of 3%, deionized water, polyurethane acrylate, mixed ethyl orthosilicate, absolute ethanol, hydrochloric acid with a mass fraction of 3% and deionized water, stirred and aged to obtain a sol , add urethane acrylate to the sol, stir and mix, and cool to room temperature to obtain the modified sol; preheat the substrate with the first layer of anti-reflection film, and drop the modified sol on the first layer of anti-reflection film Spin-coating on the surface of the semi-finished film to obtain a semi-finished film; etching the semi-finished film to obtain the second layer of anti-reflection film, which is a double-layer anti-reflection film for silicon solar cells. The preparation steps of the silver ammonia solution are: according to the mass ratio of 1:1:1, the mass fraction is 2% silver nitrate solution, the mass fraction is 1% sodium hydroxide solution and the mass fraction is 10% ammonia water, and the silver ammonia solution is obtained. . The heat treatment step is as follows: mix 2% sodium formate solution and silver ammonia solution with a mass fraction of 1:1 on the surface of the substrate, and heat for 2 minutes at a water bath temperature of 70°C. The rapid annealing treatment step is as follows: the metal film is subjected to rapid annealing treatment for 2 hours at a temperature of 350° C. and a nitrogen flow rate of 2 L/min. Tetraethyl orthosilicate, dehydrated ethanol, mass fraction are 3% hydrochloric acid, deionized water, the ratio among urethane acrylate is respectively: by weight parts, weigh 40 parts of orthosilicate ethyl ester, 60 parts respectively Absolute ethanol, 10 parts by mass fraction of 3% hydrochloric acid, 30 parts of deionized water, 20 parts of polyurethane acrylate. The stirring and aging treatment steps are as follows: mix ethyl tetrasilicate, absolute ethanol, hydrochloric acid with a mass fraction of 3% and deionized water, stir at a stirring speed of 500r/min for 2 hours, and then leave to age at room temperature for 2 hours. sky. Stirring and mixing treatment steps are as follows: add urethane acrylate to the sol, and stir and mix for 30 minutes at a temperature of 120° C. and a stirring speed of 400 r/min. The preheating step is: preheating the substrate with the first layer of anti-reflection film at a temperature of 190° C. for 5 minutes. Spin-coating treatment steps are: drop the modified sol on the surface of the first layer of anti-reflection film, repeat spin-coating 5 layers at a rotating speed of 3100r/min, and the time of each spin-coating is 40s. The temperature is 600°C and returned for 40 minutes, and cooled to room temperature. The etching treatment steps are: use SF6 as the etching gas, and perform etching treatment on the semi-finished film under the condition of a power supply of 250W.

Comparative example: a double-layer anti-reflection film produced by a company in Dongguan.

The double-layer anti-reflection film prepared by the embodiment and the comparative example is detected, and the specific detection is as follows:

The transmittance of the film was tested with a UV-Vis spectrometer.

The friction resistance test of the film: the friction resistance of the film is tested by the wiping method. In the experiment, the surface of the film is wiped with a cotton ball dipped in ethanol, the surface morphology of the film is observed and the light transmittance is tested to determine the strength of the film's friction resistance.

Use a pencil hardness tester to test the hardness of the film (scratch the surface of the sample with a force of 1kg). First, place the installed pencil hardness tester lightly on the surface of the object to be tested, and then move forward at a certain speed to observe the sample with the naked eye. Whether the surface is scratched, the pencil is tested from hard to soft, and finally until the tip of the pen does not scratch the surface of the film at all.

The specific test results are shown in Table 1.

Table 1 Performance Characterization Comparison Table

Test items Example 1 Example 2 Example 3 Comparative example Transmittance/% 88.9 88.8 86.2 50.1 Friction resistance no damage no damage no damage damaged Hardness/H 4 4 4 3

It can be known from Table 1 that the double-layer anti-reflection film prepared by the present invention has good hardness and friction resistance.

Claims (10)

1. a kind of preparation method of the double layer antireflection coating for silicon solar cell, it is characterised in that specific preparation step are as follows:

(1) it is that 2% sodium formate solution and silver ammino solution mix and be placed in matrix surface by mass fraction, heats to get metal Film handles metal film short annealing to get first layer antireflective coating；

(2) taking ethyl orthosilicate, dehydrated alcohol, mass fraction is 3% hydrochloric acid, deionized water, urethane acrylate, by positive silicon Acetoacetic ester, dehydrated alcohol, mass fraction are that 3% hydrochloric acid and deionized water mix, and stir and ripening is to get colloidal sol, in colloidal sol Middle addition urethane acrylate, is stirred processing, is cooled to room temperature to get modification sol；

(3) substrate preheating with first layer antireflective coating is handled, modification sol is dripped on the surface of first layer antireflective coating On, spin-coat process is to get semi-finished product film；Double of finished film performs etching processing to get second layer antireflective coating, is as used for silicon The double layer antireflection coating of solar battery.

2. a kind of preparation method of double layer antireflection coating for silicon solar cell according to claim 1, feature Be: the preparation step of silver ammino solution described in step (1) are as follows: in mass ratio 1: 1: 1 by mass fraction be 2% silver nitrate solution, Mass fraction is 1% sodium hydroxide solution and mass fraction is that 10% ammonium hydroxide is uniformly mixed to get silver ammino solution.

3. a kind of preparation method of double layer antireflection coating for silicon solar cell according to claim 1, feature It is: heat treatment step described in step (1) are as follows: mass fraction is that 2% sodium formate solution and silver-colored ammonia are molten by 1: 1 by volume Liquid mixing is placed in matrix surface, heats 1~2min at being 50~70 DEG C in bath temperature.

4. a kind of preparation method of double layer antireflection coating for silicon solar cell according to claim 1, feature Be: short annealing processing step described in step (1) are as follows: by metal film temperature be 300~350 DEG C, nitrogen flow 2L/ Short annealing handles 1~2h under min.

5. a kind of preparation method of double layer antireflection coating for silicon solar cell according to claim 1, feature Be: ethyl orthosilicate described in step (2), dehydrated alcohol, mass fraction are 3% hydrochloric acid, deionized water, polyurethane acroleic acid Ratio between ester is respectively as follows: according to parts by weight, weighs 30~40 parts of ethyl orthosilicates, 50~60 parts of dehydrated alcohols, 1 respectively ~10 parts of mass fractions are 3% hydrochloric acid, 20~30 parts of deionized waters, 10~20 parts of urethane acrylates.

6. a kind of preparation method of double layer antireflection coating for silicon solar cell according to claim 1, feature It is: stirring described in step (2) and ripening step are as follows: by ethyl orthosilicate, dehydrated alcohol, mass fraction be 3% hydrochloric acid It is mixed with deionized water, low whipping speed is still aging 1~2 day at room temperature after stirring 1~2h under 400~500r/min.

7. a kind of preparation method of double layer antireflection coating for silicon solar cell according to claim 1, feature Be: step is stirred processing step described in (2) are as follows: urethane acrylate is added in colloidal sol, temperature be 110~ 120 DEG C, mixing speed is to be stirred 20~30min under 300~400r/min.

8. a kind of preparation method of double layer antireflection coating for silicon solar cell according to claim 1, feature Be: the pre-heat treatment step described in step (3) are as follows: by with first layer antireflective coating matrix temperature be 180~190 DEG C 3~5min of lower preheating.

9. a kind of preparation method of double layer antireflection coating for silicon solar cell according to claim 1, feature It is: spin-coat process step described in step (3) are as follows: by modification sol drop on the surface of first layer antireflective coating, in revolving speed To repeat 3~5 layers of spin coating under 3000~3100r/min, the time of each spin coating is 30~40s, is in temperature after each spin coating 20~40min of processing is retracted at 400~600 DEG C, is cooled to room temperature.

10. a kind of preparation method of double layer antireflection coating for silicon solar cell according to claim 1, feature It is: etch processing steps described in step (3) are as follows: using SF6 as etching gas, under conditions of 200~250W of power Double of finished film performs etching processing.