Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Texture etching method for quasi-monocrystalline silicon wafer

A quasi-single crystal, silicon wafer technology, applied in the field of solar cells, can solve the problems of random orientation of polycrystalline silicon grains, large grain boundaries and defects, low conversion efficiency, etc., and achieve the best effect of texturing.

Inactive Publication Date: 2011-04-27
JA SOLAR +2
View PDF2 Cites 15 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the grain orientation in polycrystalline silicon is random, and there are a large number of grain boundaries and defects. As a base material for batteries, the quality is not as good as that of monocrystalline silicon.
On the other hand, due to the different orientations of the crystal grains in the polycrystalline silicon wafer, the alkali texturing method with good comprehensive benefits cannot be used in the subsequent production process of the battery sheet.
In production, the isotropic acid texturing method is generally used for polysilicon, which can achieve a better texturing effect through improvement, but compared with the above alkali texturing method, there is still a big gap.
At present, the conversion efficiency of polycrystalline silicon solar cells is about 1.5-2% lower than that of monocrystalline silicon cells.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] The silicon wafer used in the experiment is a 156×156 P-type quasi-single crystal silicon wafer, and the (100) grain area accounts for about 2 / 3 of the entire silicon wafer area.

[0019] Acid texturing: choose HF, HNO 3 Prepare a mixed solution with water, the volume percentage of the mixed acid is 68%, HF and HNO 3 The volume ratio of the silicon wafer is 1:3, the texturing temperature is 7°C, the texturing time is adjusted so that the etching depth of the silicon wafer is 7.5-8.5 μm, and then blow-dried after cleaning.

[0020] Alkali texturing: put the above acid texturized silicon wafers into NaOH alkali solution for further alkali texturing, the weight percentage of alkali in the solution is 2%, and additives can also be added to the alkali solution to improve the texturing effect ; Heating to 80°C, adjusting the corrosion depth of alkali texturing to 6.5-7μm through time control.

[0021] The average reflectance of (100) crystal grains in the silicon wafer obta...

Embodiment 2

[0023] The silicon wafer used in the experiment is a 156×156 P-type quasi-single crystal silicon wafer, and the (100) grain area basically occupies 3 / 4 of the entire silicon wafer.

[0024] Acid texturing: choose HF, HNO 3 Prepare a mixed solution with water, the volume percentage of the mixed acid is 70%, HF and HNO 3 The volume ratio is 1:2.5, the texture temperature is 8°C, the corrosion depth is controlled by time to 5-6μm, and it is washed and dried.

[0025] Alkali texturing: put the above acid texturized silicon wafer into KOH alkali solution for further alkali texturing, the weight percentage of alkali in the solution is 2%, add additives to improve the texturing effect, heat to 80°C, The corrosion depth is 8-9 μm by time control.

[0026] In the silicon wafer obtained through the above texturing process, the reflectivity of (100) crystal grains is less than 11-13%, and the reflectivity of other crystal grains is about 23-26%. The conversion efficiency of the final ...

Embodiment 3

[0028] The silicon wafer used in the experiment is a 156×156 P-type quasi-single crystal silicon wafer. The (100) grain area basically occupies the entire silicon wafer, and the other grains have a small area (less than 1 / 5).

[0029] Acid texturing: choose HF, HNO 3 Prepare a mixed solution with water, the volume percentage of the mixed acid solution is 75%, HF and HNO 3 The volume ratio is 1:3, the texturing temperature is 8°C, the corrosion depth is controlled by time to 3-4μm, and it is washed and dried.

[0030] Alkali texturing: Put the above acid texturized silicon wafers into KOH alkali solution for further alkali texturing, the weight percentage of alkali in the solution is 2%, and add additives to achieve better texturing effect, heating To 80°C, the corrosion depth is 8-9μm through time control.

[0031] In the silicon wafer obtained through the above texturing process, the reflectivity of (100) crystal grains is less than 12%, and the reflectivity of other crysta...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
Corrosion depthaaaaaaaaaa
Corrosion depthaaaaaaaaaa
Corrosion depthaaaaaaaaaa
Login to View More

Abstract

The invention discloses a texture etching method for quasi-monocrystalline silicon wafer. In the method, quasi-monocrystalline silicon wafer with (100) crystalline grains predominantly are treated by a texture etching process of performing acid texture etching before performing alkali texture etching, and the degree of the acid texture etching and the alkali texture etching is regulated according to the rate of occupied areas of the (100) crystalline grains in the quasi-monocrystalline silicon wafer so as to achieve the optimal effect of comprehensive texture etching. The method has a simple process, and the integral texture etching effect is high.

Description

technical field [0001] The invention belongs to the field of solar cells, and in particular relates to a texturing method for a quasi-single crystal silicon wafer. Background technique [0002] Texturing is a method of preparing a silicon surface with the function of reducing reflection. In the production process of silicon solar cells, texturing is generally used to texture the surface of silicon wafers, and the light trapping effect of the surface is used to promote the absorption of sunlight. Improve the conversion efficiency of the battery. [0003] Monocrystalline silicon has the characteristics of low defects and high conversion efficiency. Especially, the wide application of alkali texturing method makes monocrystalline silicon cells more advantageous. The pyramid-shaped textured surface formed by this texturing method makes the incident light reflect multiple times. , greatly enhanced the absorption of light and improved the conversion efficiency. As early as the 1...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): H01L31/18
CPCY02P70/50
Inventor 黄新明钟根香王松李志辉
Owner JA SOLAR
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com