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Crystalline silicon solar cell polished wafer processing method

A technology of solar cells and processing methods, which is applied in the field of solar cells, can solve the problems of waste of raw materials, scrapping, shallow damage layer on the surface of polished silicon wafers, etc., and achieve the effect of improving the utilization rate

Active Publication Date: 2017-12-26
GUANGDONG AIKO SOLAR ENERGY TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0015] However, the damaged layer on the surface of the polished silicon wafer is relatively shallow. After being treated by this mixed acid system, the reflectivity is still high, which cannot meet the rework requirements.
Therefore, the above-mentioned polished silicon wafer cannot form the required suede on the surface of the silicon wafer by the existing rework method, and flows into the subsequent process. The appearance and electrical properties of the cell cannot meet the current process requirements. are all scrapped, resulting in a waste of raw materials

Method used

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  • Crystalline silicon solar cell polished wafer processing method

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Comparison scheme
Effect test

Embodiment 1

[0056] A kind of processing method of crystalline silicon solar cell polished sheet, such as figure 1 As shown, it specifically includes the following steps:

[0057] The first step is to use an RIE plasma etching machine to generate a damaged layer on the surface of the silicon wafer;

[0058] The specific process is:

[0059] A. Establish process formula, RF1-RF8 (high frequency power) parameter setting 1800W, RF9 (low frequency power) parameter setting 450W, transmission speed setting 110cm / min, MFC flow setting Cl 2 / 1000sccm, O 2 / 2500sccm, SF 6 / 1600sccm;

[0060] B. Use automated equipment to pass the silicon wafer through the RIE plasma etching machine to form a damaged layer;

[0061] The second step is to etch the surface of the silicon wafer with a surface etching solution to form micron pits on the surface;

[0062] The specific process is:

[0063] A. Prepare surface corrosion solution, in which the volume fraction of HF is 10%, HNO 3 The volume fraction o...

Embodiment 2

[0083] A method for processing a polished wafer of a crystalline silicon solar cell, specifically comprising the steps of:

[0084] The first step is to use an RIE plasma etching machine to generate a damaged layer on the surface of the silicon wafer;

[0085] The specific process is:

[0086] A. Establish process formula, RF1-RF8 (high frequency power) parameter setting 1500W, RF9 (low frequency power) parameter setting 450W, transmission speed setting 100cm / min, MFC flow setting Cl 2 / 1000sccm, O 2 / 2400sccm, SF 6 / 1400sccm;

[0087] B. Use automated equipment to pass the silicon wafer through the RIE plasma etching machine to form a damaged layer;

[0088] The second step is to etch the surface of the silicon wafer with a surface etching solution to form micron pits on the surface. The specific process is:

[0089] A. Prepare surface corrosion solution, in which the volume fraction of HF is 30%, HNO 3 The volume fraction of DI water is 30%, the volume fraction of DI w...

Embodiment 3

[0108] A method for processing a polished wafer of a crystalline silicon solar cell, specifically comprising the steps of:

[0109] The first step is to use an RIE plasma etching machine to generate a damaged layer on the surface of the silicon wafer;

[0110] The specific process is:

[0111]A. Establish process formula, RF1-RF8 (high frequency power) parameter setting 1600W, RF9 (low frequency power) parameter setting 450W, transmission speed setting 110cm / min, MFC flow setting Cl 2 / 1100sccm, O 2 / 2400sccm, SF 6 / 1200sccm;

[0112] B. Use automated equipment to pass the silicon wafer through the RIE plasma etching machine to form a damaged layer;

[0113] The second step is to etch the surface of the silicon wafer with a surface etching solution to form micron pits on the surface. The specific process is:

[0114] A. Prepare surface corrosion solution, in which the volume fraction of HF is 10%, HNO 3 The volume fraction of DI water is 30%, the volume fraction of DI wa...

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Abstract

The invention discloses a crystalline silicon solar cell polished wafer processing method. The method comprises steps: 1) RIE etching is used to form a damage layer on the surface of the cell polished wafer; 2) a surface corrosion liquid is used for carrying out surface corrosion on the silicon wafer processed in the first step, and micron pits are formed; 3) an HF-HCl mixed acid solution is used to remove impurities and metal ions generated during the corrosion process in the second step; 4) the silicon wafer processed in the third step is subjected to RIE etching, and a nanoscale texture is prepared; and 5) a cleaning liquid is used to remove residues generated during the etching process in the fourth step. After the polished wafer is processed by the processing method, re-diffusion and back-end production are carried out, the conversion efficiency of the polished wafer finally basically reaches the level of the normal cell sheet, the appearance of the cell sheet is the same as that of the normal cell sheet, and the purpose of polished wafer rework is achieved. Through the processing method of the invention, the cell polished wafer which is discarded and rejected originally can be used as a rework wafer, and the qualification rate can reach 95%.

Description

technical field [0001] The invention relates to the technical field of solar cells, in particular to a method for processing polished wafers of crystalline silicon solar cells. Background technique [0002] At present, crystalline silicon solar cells have high cost requirements. During the production process, the cleaning equipment is abnormally shut down due to equipment instability and human error. Surface polishing of silicon wafers. [0003] Typically rework is performed on the faulty wafer. The existing rework method of crystalline silicon solar cells (polysilicon) is to use HF / HNO 3 / H 2 O mixed acid system for secondary texturing, removing the surface diffusion layer to obtain an ideal textured surface; the reaction of this mixed acid system starts from the damaged layer, and the textured surface structure depends entirely on the surface morphology of the silicon wafer. [0004] The principle and function of polycrystalline cleaning and texturing: [0005] 1) Rem...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01L31/18H01L31/0236
CPCH01L31/02363H01L31/1804Y02E10/547Y02P70/50
Inventor 胡茂界夏利鹏秦崇德方结彬何达能陈刚
Owner GUANGDONG AIKO SOLAR ENERGY TECH CO LTD