Wet chemical treatment method for heterojunction battery

Abstract

The invention discloses a wet chemical treatment method for a heterojunction battery. The wet chemical treatment method comprises the following steps: firstly pre-cleaning a silicon wafer; then carrying out affected layer removal treatment on the silicon wafer; then carrying out texturing treatment on the silicon wafer; then putting the silicon wafer into a mixed solution of hydrochloric acid andhydrofluoric acid for carrying out acid-base neutralization cleaning; then carrying out rounded cleaning on the silicon wafer by using an HF / HCl / O3 mixed solution, removing organic matters and metallic ions and oxidized and etched silicon to round the silicon wafer; carrying out post-cleaning on the silicon wafer after rounded cleaning; and finally slowly pulling and dehydrating the silicon wafer,and drying by using nitrogen. According to the method, O3 is introduced into a wet chemical cleaning technology of the heterojunction battery, the ozone oxidation capacity is high, the oxidizing agents such as H2O2 and nitric acid are effectively replaced, and the application and discharge of highly-pure chemical products are reduced; and moreover, the HF / HCl / O3 mixed solution has multiple effects of removing the organic matters and removing the metal irons and oxidized and etched silicon, the steps and complexity of the cleaning technology are reduced, and the method has the advantages of simple technology process, small using amount of the highly-pure chemical products, small treatment quantity of waste liquid and the like.

Description

technical field [0001] The invention relates to the technical field of solar cells, in particular to a wet chemical treatment method for heterojunction cells. Background technique [0002] At present, solar cells are a research hotspot for many photovoltaic manufacturers, including PERC cells, MWT cells, IBC cells, and HJT cells. Among them, HJT battery has won the special favor of many institutions and production enterprises due to its conversion efficiency, low temperature process, low temperature coefficient and suitability for thinning, and the enthusiasm for research and development has always been high. [0003] Among them, the HJT battery uses N-type silicon wafers, and the production of the battery wafers is completed through a series of process steps such as texture cleaning, amorphous silicon deposition, transparent conductive film deposition, and electrode production. The traditional HJT battery texturing cleaning process is as follows: pre-cleaning - removing da...

AI Technical Summary

Problems solved by technology

The disadvantages of this cleaning method are: there are many process steps, and a large amount of high-purity chemicals is used to increase the production cost; the waste liquid discharge caused by the use of a large amount of chemicals requires a series of follow-up treatments to meet the discharge standards, which also increases the factory. Investment in equipment and facilities; the rounding of the CP surface in the HJT battery cleaning process may have certain patent risks

The disadvantages in these aspects undoubtedly increase the cost of the product, which has negatively affected the rapid development of HJT batteries.

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