Positive dielectric film of sandwich structure suitable for RIE (reactive ion etching) texture and manufacturing method thereof

Abstract

The invention relates to the technical field of crystalline silicon solar cell technologies, and in particular relates to a positive dielectric film of a sandwich structure suitable for an RIE (reactive ion etching) texture and a manufacturing method thereof. The positive dielectric film comprises a SiO2 (silicon dioxide) film at a bottom layer, wherein a SiNx (amorphous silicon nitride) film at an intermediate layer is covered on the surface of the SiO2 film at the bottom layer; and a SiO2 film at a surface layer is covered on the surface of the SiNx film at the intermediate layer. The manufacturing method of the positive dielectric film comprises the following steps of: 1, using a dry-oxygen oxidation method to grow a SiO2 film layer on a silicon texture; 2, adopting a PECVD (plasma enhanced chemical vapor deposition) method to deposit a SiNx film layer rich in silicon; and 3, adopting the PECVD method to deposit a SiO2 film. According to the invention, a crystalline silicon cell textured by RIE can be passivated effectively, the open-circuit voltage of the cell can be increased by 3-5mV, and the conversion efficiency of the cell can be increased by 0.2%-0.4%.

Description

technical field [0001] The invention relates to the technical field of crystalline silicon solar cell technology, in particular to a front dielectric film with a sandwich structure suitable for RIE suede and a preparation method thereof. Background technique [0002] In the current production of crystalline silicon solar cells, the PECVD method is generally used to grow single-layer SiN x The thin film is used as a front passivation layer and an anti-reflection film, which has the functions of reducing surface reflection, surface passivation, and bulk passivation. But SiN x After deposition on the surface of the silicon wafer, the interface defect density is higher, compared with SiO 2 The surface passivation effect is poor. At the same time, the suede surface prepared by RIE method has serious surface damage and high surface recombination rate, so the single-layer SiN x The effect of thin film as a front passivation layer applied to RIE suede is not ideal. [0003] In ...

AI Technical Summary

Problems solved by technology

However, thermal oxidation of SiO 2 The refractive index of the film is 1.46, while PECVD deposited SiN x The refractive index of the film is relatively high, about 2.05±0.05, that is to say, SiO 2 / SiN x Double-layer thin film structure as a front anti-reflection film is not conducive to light absorption of solar cells

Images