Alkali polishing preparation method of PERC solar cell

A solar cell and laser technology, applied in the field of solar cells, can solve the problems of low cell conversion efficiency and low reflectivity of the backside of silicon wafers, and achieve the effects of improving passivation effect, increasing open voltage, and improving conversion efficiency.

Inactive Publication Date: 2020-05-08
ZHEJIANG AIKO SOLAR ENERGY TECH CO LTD
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  • Abstract
  • Description
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  • Application Information

AI Technical Summary

Problems solved by technology

[0014] The technical problem to be solved by the present invention is: the existing acid etching and polishing technology causes the problems of low reflectivity on the back of the silicon wafer and low conversion efficiency of the battery

Method used

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  • Alkali polishing preparation method of PERC solar cell
  • Alkali polishing preparation method of PERC solar cell
  • Alkali polishing preparation method of PERC solar cell

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Embodiment Construction

[0023] The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0024] Such as figure 1 Shown, a kind of PERC solar cell alkali polishing preparation method, comprises the steps:

[0025] S1: Polishing, using P-type silicon as the base material, putting the silicon wafer in a polishing solution with a KOH mass ratio of 2%-10% and a temperature of 65-85°C for 120-200s to polish, and the reflectance of the alkali-polished surface obtained is controlled At 40-50%, the weight loss after polishing is controlled between 0.2-0.6g;

[0026] S2: Deposit SiO2 film on the back, use PERC technology to deposit a dense SiO2 mask on the back of the silicon wafer, and control the thickness at 80-200nm;

[0027] S3: Texturing. Place the silicon waf...

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Abstract

The invention discloses an alkali polishing preparation method of a PERC solar cell. The method comprises texturing, diffusion, front laser processing, etching, annealing, back passivation film processing, front passivation film processing, back laser processing, silk-screen printing and sintering. The method is characterized in that, before the texturing step, an alkali polishing step and a silicon dioxide film deposition step are further included, wherein in the alkali polishing step, a potassium hydroxide solution is adopted to polish the silicon wafer, in the back surface silicon dioxide film deposition step, a layer of silicon dioxide mask is plated on the back surface of the silicon wafer by adopting a PECVD technology, and in the texturing step, a potassium hydroxide additive is added for texturing. According to the method, the flatness of the back surface of the prepared battery piece is improved, the passivation effect of the back film is improved, the open-circuit voltage isimproved, and the conversion efficiency of the battery is further improved.

Description

technical field [0001] The invention relates to the technical field of solar cells, in particular to a method for preparing PERC solar cells by alkali polishing. Background technique [0002] At present, PERC crystalline silicon solar cells are the mainstream products in the market, the production process is becoming more and more mature and perfect, and the cell efficiency is approaching the bottleneck. Such as figure 2 As shown, the preparation process of the existing PERC solar cell technology is as follows: [0003] 1. Texture making: use wet technology to form a textured surface on the surface of the P-type monocrystalline silicon wafer; [0004] 2. Diffusion: P-N junction is formed by diffusion; [0005] 3. Front laser: Prepare selective emitter, and use laser to do heavy doping on the surface of silicon wafer; [0006] 4. Etching: use HF / HNO3 solution for back polishing, and use HF to remove phosphosilicate glass (PSG) formed during the front and back diffusion ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01L31/18C23C16/40C30B33/10
CPCC23C16/402C30B33/10H01L31/1804H01L31/1868Y02E10/547Y02P70/50
Inventor 陈小兰张小明邵家骏林纲正陈刚
Owner ZHEJIANG AIKO SOLAR ENERGY TECH CO LTD
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