CN107964684A - A kind of etching method of monocrystalline silicon piece used for solar batteries - Google Patents

Abstract

The present invention provides a kind of etching method of monocrystalline silicon piece used for solar batteries, which includes the following steps：The copolymer of vinyl pyrrolidone vinyl imidazole, polyethylene glycol polypropylene glycol ethylene glycol copolymer, ethylenediamine tetra-acetic acid, monoethanolamine, sodium benzoate, paratoluenesulfonic acid sodium salt are dissolved into the water of surplus；By step 1）Obtained flocking additive is added in aqueous slkali, is uniformly mixed；Monocrystalline silicon piece is inserted into step 2）Making herbs into wool is carried out in obtained Woolen-making liquid, the flocking additive in the present invention is added in lye, you can realize quick making herbs into wool effect by this method according to a certain percentage when carrying out making herbs into wool to monocrystalline silicon piece.

Description

A method for making texturing of monocrystalline silicon wafers for solar cells

technical field

The invention relates to the technical field of solar photovoltaic cells, in particular to a texturing method for monocrystalline silicon wafers for solar cells.

Background technique

The lye etches the [100] crystal plane of the single crystal silicon wafer faster, but the etching of the [111] crystal plane is slower. The resulting difference in etching rate will lead to the formation of a pyramid structure on the surface of the single crystal silicon wafer during the process of etching the silicon wafer with alkaline solution. The structure can effectively reduce the light reflection of the silicon wafer. In the preparation process of solar cells, the lower the reflection of silicon wafers to light, the more the absorption of light by silicon wafers, and the higher the conversion efficiency of solar cells. Texturing the surface of a single crystal silicon wafer by the above alkali etching method is one of the commonly used effective ways to increase the light absorption of crystalline silicon. The existing monocrystalline silicon texturing process usually requires a texturing time of 600 s-900 s, and the efficiency is low. If the texturing time can be shortened, the production efficiency will be effectively improved. The texturing additive of this patent can greatly shorten the texturing time, and the size and distribution of the pyramids on the surface of monocrystalline silicon after texturing are close to those of the conventional process.

Contents of the invention

The invention provides a method for making texturing of monocrystalline silicon wafers for solar cells. In this method, when texturing monocrystalline silicon wafers, the texturing additives in this patent are added to the lye according to a certain proportion, and the process can be realized. Fast texturing effect, the texturing time is 300s-420s. The texturing method comprises the following steps: 1) Configuration of texturing additives: 0.5 parts of vinylpyrrolidone-vinylimidazole copolymer, 1 part of polyethylene glycol-polypropylene glycol-polyethylene glycol copolymer, ethylene glycol Dissolve 0.5 part of amine tetraacetic acid, 2 parts of monoethanolamine, 0.1 part of sodium benzoate, and 0.25 part of sodium p-toluenesulfonate into 100 parts of water, and mix well;

2) Configuration of the texturing liquid: Add the texturing additive prepared in step 1) to the aqueous sodium hydroxide solution and mix evenly; the mass ratio of the texturing additive to the alkali solution is 0.5:100, and the hydrogen The massfraction of sodium oxide aqueous solution is 1%;

3) Put the monocrystalline silicon wafer into the texturing solution prepared in step 2) for texturing, the texturing temperature is 75-88 ^o C, and the texturing time is 300-420 s.

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

The monocrystalline silicon wafer texturing method provided by the present invention can quickly texturize the surface of a single crystal silicon wafer, and the texturing time is shortened by more than 50% compared with the conventional process; Reduce costs while increasing cashmere efficiency. At the same time, the texture additive of this patent is non-toxic, non-corrosive, and harmless to human body and environment.

The present invention also has the advantages that the textured pyramids obtained after rapid texturing have small size, narrow distribution, low light reflectivity, and high photoelectric conversion efficiency of the assembled solar cells. The additive has low cost, high efficiency, remarkable effect and excellent practical value.

Description of drawings

Fig. 1 is the pyramid 1 on the monocrystalline silicon surface that the texturing method provided by the present invention obtains;

Fig. 2 is a pyramid 2 on the surface of monocrystalline silicon obtained by the texturing method provided by the present invention.

Detailed ways

Example 1

The process steps are as follows:

1. Configure texturing additives: 0.5 g of vinylpyrrolidone-vinylimidazole copolymer (number average molecular weight is ), 1 g of polyethylene glycol-polypropylene glycol-polyethylene glycol copolymer, 0.5 g of ethylenediaminetetra Acetic acid, 2 g monoethanolamine, 0.1 g sodium benzoate, and 0.25 g sodium p-toluenesulfonate were sequentially dissolved in 100 ml deionized water.

2. Prepare lye: dissolve 10 g of sodium hydroxide in 990 g of deionized water to obtain an aqueous solution of sodium hydroxide with a mass fraction of 1%.

3. Prepare alkaline texturing solution: mix the texturizing additive obtained in step 1 and the lye obtained in step 2 evenly at a mass ratio of 0.5:100.

4. Texturing process: immerse the monocrystalline silicon wafer for solar cells into the alkaline texturing solution prepared in step 3 for surface texturing, the texturing temperature is 85 ^o C, and the texturing time is 300 s.

Example 2

The process steps are as follows:

1. Configure texturizing additives: 1 g of vinylpyrrolidone-vinylimidazole copolymer, 2 g of polyethylene glycol-polypropylene glycol-polyethylene glycol copolymer, 0.1 g of ethylenediaminetetraacetic acid, 0.5 g of monoethanolamine , 0.05 g sodium benzoate and 0.5 g sodium p-toluenesulfonate were successively dissolved in 100 ml deionized water.

2. Prepare lye: dissolve 15 g of potassium hydroxide in 985 g of deionized water to obtain an aqueous solution of potassium hydroxide with a mass fraction of 1.5%.

3. Prepare alkaline texturing solution: mix the texturizing additive obtained in step 1 and the lye obtained in step 2 evenly at a mass ratio of 1:100.

4. Texturing process: immerse the monocrystalline silicon wafer for solar cells into the alkaline texturing solution prepared in step 3 for surface texturing, the texturing temperature is 75 ^o C, and the texturing time is 420 s.

Example 3

The process steps are as follows:

1. Configure texturizing additives: 2 g of vinylpyrrolidone-vinylimidazole copolymer, 1 g of polyethylene glycol-polypropylene glycol-polyethylene glycol copolymer, 0.5 ethylenediaminetetraacetic acid, monoethanolamine 3, benzene Dissolve 0.1 g of sodium formate and 0.5 g of sodium p-toluenesulfonate into 100 ml of deionized water in turn.

2. Prepare lye: dissolve 20 g of sodium hydroxide in 980 g of deionized water to obtain an aqueous solution of sodium hydroxide with a mass fraction of 2%.

3. Prepare alkaline texturing solution: mix the texturizing additive obtained in step 1 and the lye obtained in step 2 evenly in a mass ratio of 0.1:100.

4. Texturing process: immerse the monocrystalline silicon wafer for solar cells into the alkaline texturing solution prepared in step 3 for surface texturing, the texturing temperature is 88 ^o C, and the texturing time is 300 s.

Example 4

The process steps are as follows:

1. Configure texturing additives: 1.5 g of vinylpyrrolidone-vinylimidazole copolymer, 1.5 g of polyethylene glycol-polypropylene glycol-polyethylene glycol copolymer, 0.3 ethylenediaminetetraacetic acid, monoethanolamine 2, benzene Dissolve 0.2 sodium formate and 0.5 sodium p-toluenesulfonate in 100 ml deionized water in sequence.

2. Prepare lye: dissolve 30 g of sodium hydroxide in 970 g of deionized water to obtain an aqueous solution of sodium hydroxide with a mass fraction of 3%.

3. Prepare alkaline texturing solution: mix the texturizing additive obtained in step 1 and the lye obtained in step 2 in a mass ratio of 0.2:100.

4. Texturing process: immerse the monocrystalline silicon wafer for solar cells into the alkaline texturing solution prepared in step 3 for surface texturing, the texturing temperature is 83 ^o C, and the texturing time is 400 s.

By adopting the technical solution provided in this embodiment, a fine and uniform suede pyramid can be quickly obtained. As shown in Figure 1 and Figure 2, the obtained size reaches 10um; this method has low cost, high efficiency, remarkable effect and excellent practical value.

Claims (1)

1. A kind of 1. etching method of monocrystalline silicon piece used for solar batteries, it is characterised in that：The etching method includes the following steps：1） The configuration of flocking additive：Successively by 0.5 part of the copolymer of vinyl pyrrolidone-vinyl imidazole, polyethylene glycol the third two 1 part of alcohol-ethylene glycol copolymer, 0.5 part of ethylenediamine tetra-acetic acid, 2 parts of monoethanolamine, 0.1 part of sodium benzoate, p-methyl benzenesulfonic acid 0.25 part of sodium is dissolved into 100 parts of water, is uniformly mixed；

   2）The configuration of Woolen-making liquid：By step 1）Obtained flocking additive is added in sodium hydrate aqueous solution, is uniformly mixed；It is described Flocking additive and aqueous slkali mass ratio be 0.5:100, the mass fraction of the sodium hydrate aqueous solution is 1%；

   3）Monocrystalline silicon piece is inserted into step 2）Making herbs into wool is carried out in obtained Woolen-making liquid, making herbs into wool temperature is 75 ~ 88^oC, making herbs into wool time is 300~420 s。