Method for preparing textured polycrystalline silicon wafer

A polycrystalline silicon wafer and suede technology, applied in chemical instruments and methods, crystal growth, final product manufacturing, etc., to achieve the effect of increasing light conversion efficiency and increasing lifespan

Active Publication Date: 2011-01-05
BYD CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] But the reflectivity of the suede surface of the prepared polysil

Method used

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Examples

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Effect test

preparation example Construction

[0011] The method for preparing the suede polysilicon wafer provided by the present invention comprises that the polysilicon wafer is subjected to alkali etching in an alkali etching solution, and the condition of the alkali etching is such that the corrosion amount of the polysilicon wafer is 0.01-0.1 mg / cm 2 , preferably 0.01-0.08mg / cm 2 . Carry out acid etching to the polycrystalline silicon sheet after alkali etching under acid etching condition, the condition of described acid etching makes the corrosion amount of polycrystalline silicon sheet be 0.5-5mg / cm 2 , preferably 0.8-3mg / cm 2 , to obtain a polysilicon wafer after acid etching, and the etching amount is only the etching amount produced in the acid etching process.

[0012] In the present invention, the corrosion amount is calculated by dividing the weight difference before and after corrosion of the sample by the corrosion area of ​​the sample.

[0013] According to the preparation method provided by the presen...

Embodiment 1

[0029] Select a polysilicon wafer with a size of 156×156mm and a thickness of 200μm;

[0030] All chemical reagents used are electronic grade;

[0031] The water used is electronic grade pure water (resistivity 18 megohms).

[0032] 1. Cleaning

[0033] Rinse the polysilicon wafer with water for 300 seconds;

[0034] 2. Alkali corrosion

[0035] The cleaned polysilicon wafers are dipped in sodium hydroxide (NaOH) aqueous solution for slight corrosion. Then rinse with water for 300 seconds to remove the residual alkaline etching solution on the surface of the polysilicon wafer.

[0036] The concentration of the aqueous sodium hydroxide solution was 1% by weight, the temperature of the alkali etching was 50° C., and the time of the alkali etching was 50 seconds. The corrosion amount of polysilicon wafer is 0.04mg / cm 2 .

[0037] 3. Acid corrosion

[0038] The alkali-etched polysilicon wafer is immersed in an acid etching solution for etching. Then rinse with water for 300...

Embodiment 2

[0050] A polycrystalline silicon wafer with the same size as in Example 1, the same level of chemical reagents and water were selected for use.

[0051] 1. Cleaning

[0052] Rinse the polysilicon wafer with water for 900 seconds;

[0053] 2. Alkali corrosion

[0054] The cleaned polysilicon wafers are dipped in sodium hydroxide (NaOH) aqueous solution for slight corrosion. Then rinse with water for 300 seconds to remove the residual alkaline etching solution on the surface of the polysilicon wafer.

[0055] The concentration of the aqueous sodium hydroxide solution was 4% by weight, the temperature of the alkali etching was 40° C., and the time of the alkali etching was 150 seconds. The corrosion amount of polysilicon wafer is 0.06mg / cm 2 .

[0056] 3. Acid corrosion

[0057] The alkali-etched polysilicon wafer is immersed in an acid etching solution for etching. Then rinse with water for 300 seconds to remove the residual acid etching solution on the surface of the pol...

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Abstract

The invention provides a method for preparing a textured polycrystalline silicon wafer, which comprises the following steps of: performing alkaline corrosion on the polycrystalline silicon wafer in alkaline corrosion solution to ensure that the corrosion amount of the polycrystalline silicon wafer is 0.01 to 0.1mg/cm<2>; and performing acid corrosion on the cleaned polycrystalline silicon wafer under the acid corrosion condition to ensure that the corrosion amount of the polycrystalline silicon wafer is 0.5 to 5mg/cm<2> so as to obtain the polycrystalline silicon wafer subjected to the acid corrosion. By the method for preparing the textured polycrystalline silicon wafer, the reflectivity of the texture can be lower than 18 percent when the wavelength is between 300 and 1,100nm; meanwhile, part of damaged layers left when the polycrystalline silicon wafer is cut can be removed, so the life of a minority carrier can be prolonged to increase the optical conversion efficiency of a solar cell.

Description

technical field [0001] The invention relates to a method for preparing a textured polycrystalline silicon wafer. Background technique [0002] A solar cell is a semiconductor device that can directly convert the sun's light energy into electrical energy. Because it does not need water, oil, gas, or fuel when it works, it can generate electricity as long as there is light, so it can be called a contemporary clean, pollution-free renewable energy source, and it is simple to install and maintain, and has a long service life. It can be unattended. Therefore, solar cells are favored by people and are the leader in new energy sources. In recent years, the application of solar energy has become more and more extensive all over the world, especially in the field of communication. Solar power supply systems are gradually replacing some traditional power supply equipment and are becoming more and more widely used. [0003] Improving the conversion efficiency of solar cells has alway...

Claims

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Application Information

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IPC IPC(8): C30B33/10H01L31/18
CPCY02P70/50
Inventor 胡宇宁王胜亚姜占锋
Owner BYD CO LTD
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