A kind of secondary corrosion texturing process on the surface of solar cells

Abstract

An etching technology of twice etching on surface of a solar battery comprises the following steps: step 1, placing a silicon chip in an HF and HNO3 mixed solution richly containing HNO3 to conduct first etching; step 2, placing the silicon chip subjected to the first etching into NaOH solution to soak; step 3, washing the silicon chip subjected to soaking in the step 2 with deionized water; step 4, placing the silicon chip in mixed solution of HF of rich HF and HNO3 to conduct second etching; step 5, placing the silicon chip subjected to the second etching in NaOH solution to soak to remove porous silicon; step 6, washing the silicon chip subjected to soaking in the step 5 with mass deionized water, and drying; step 7, placing the silicon chip in mixed solution of HF and HCL to soak to remove oxidizing layer and metal ions; step 8, drying the silicon chip after being cleanly washed by the deionized water. According to the method, the silicon chip is subjected to the first etching in a rich HNO3 system, and then is subjected to the second etching in a rich HF system; therefore, not only the cost can be saved, but also the etching is uniform and stable.

Description

technical field [0001] The invention relates to a treatment process for the surface of a solar cell, in particular to a secondary corrosion texturing process for the surface of a solar cell. Background technique [0002] In the treatment of the surface of solar cells, texturing is the process of pre-cleaning the silicon surface and corroding it into a pyramid-like or honeycomb-like structure with strong alkali or strong acid. The function of texturing is to remove the damaged layer and form an anti-reflection texture (light-trapping structure). The purpose of texturing is to use the principle of light trapping to increase light absorption, increase short-circuit current, and increase the area of ​​the PN junction. For this reason, people have tried many new wool-making processes, and these methods all can obtain better suede effect, but there are various deficiencies. Mechanical grooving is not suitable for thin-substrate solar cells due to its large groove depth and high r...

AI Technical Summary

Problems solved by technology

Mechanical grooving is not suitable for thin-substrate solar cells due to its large groove depth and high requirements on the thickness of silicon wafers, which increases the cost in disguise; although the honeycomb textured structure technology has excellent light-trapping effects, the process is complicated and unsuitable. Industrial production; the uniformity of texturing on large-area silicon wafers by electrochemical etching is unstable

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