Heterojunction cell texturing and washing method

Abstract

The invention provides a heterojunction cell texturing and washing method. The shape of the top and the bottom of a textured-surface pyramid formed by the method is more rounded; the passivation effect of amorphous silicon is improved under the condition that the reflectivity is not influenced. The heterojunction cell texturing and washing method is characterized by texturing a silicon wafer and washing the textured surface of the silicon wafer by using a mixed solution of hydrofluoric acid and nitric acid. Preferably, the heterojunction cell texturing and washing method successively comprises the following steps: S1, washing the silicon wafer for a first time; S2, removing damage of the silicon wafer and texturing the silicon wafer; S3, washing the silicon wafer for a second time; S4, treating the textured surface of the silicon wafer by using the mixed solution of hydrofluoric acid and nitric acid; S5, washing the silicon wafer for a third time; S6, washing the silicon wafer with acid; and S7, drying.

Description

technical field [0001] The invention relates to the field of solar photovoltaics, in particular to a texturing and cleaning method for heterojunction cells. Background technique [0002] Heterojunction cells are currently one of the photovoltaic cells with the highest mass production efficiency, and their cell structure is shown in the attached figure 1 shown. It includes sequentially stacked TCO layer 2 (transparent conductive oxide layer), p-type a-Si layer 3, i-type a-Si layer 4, n-type silicon substrate 5 (CZ, n-type), i-type a-Si Layer 4 , n-type a-Si layer 6 , TCO layer 2 , and gate electrodes 1 are respectively arranged on the two TCO layers 2 . The process flow for preparing heterojunction cells is generally as follows: [0003] N-type silicon wafer → texturing cleaning → double-sided i-type a-Si layer → p-type a-Si layer and n-type a-Si layer → double-sided TCO → metallization. [0004] The purpose of the texture cleaning process is the same as that of tradition...

AI Technical Summary

Problems solved by technology

[0010] 1. The simple HCl / HF pickling process cannot meet the technical requirements for cleanliness

[0011] 2. The formed suede pyramid tip and the bottom of the tower are relatively sharp acute angles (as shown in the attached figure 2 The part inside the circle), and the thickness of the subsequently deposited amorphous silicon passivation layer is only about 10nm, which is difficult to get a good coverage, thus affecting the passivation effect

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