A front film layer structure and preparation method for improving the conversion efficiency of perc batteries

Abstract

Disclosed is a front-side film layer structure for improving the conversion efficiency of a PERC cell, the structure comprising: a silicon wafer; a first silicon nitride film layer having a thickness of 10 ± 2nm and a refractive index of 2.67 ± 0.05; a second silicon nitride film layer having a thickness of 15 ± 2nm and a refractive index of 1.91 ± 0.05; a third silicon nitride film layer having a thickness of 5 ± 2nm and a refractive index of 1.33 ± 0.05; and a fourth silicon nitride film layer having a thickness of 50 ± 3nm and a refractive index of 0.86 ± 0.05. Also disclosed is a manufacturing method for manufacturing the front-side film layer structure and thus improving the conversion efficiency of a PERC cell, the method comprising the following steps: S1, pre-processing a silicon wafer; S2, manufacturing the first silicon nitride film layer; S3, manufacturing the second silicon nitride film layer; S4, manufacturing the third silicon nitride film layer; and S5, manufacturing the fourth silicon nitride film layer. The film layer structure of the present invention improves the shortwave response of cells and increases light absorption and the short-circuit current of cells, thereby enhancing photoelectric conversion efficiency of cells and lowering costs while increasing efficiency.

Description

technical field [0001] The invention relates to the technical field of photovoltaic cells, in particular to a front film structure and a preparation method for improving the conversion efficiency of PERC cells. Background technique [0002] With the continuous advancement of battery technology, the path to achieve high conversion efficiency has been pursued by industry researchers. At present, the conventional PERC battery process route is basically mature, but the front coating process based on the high square resistance process needs to be improved and optimized. The current PERC battery front coating method The conventional P-type aluminum back field (BSF) battery front coating method is adopted. [0003] For PERC batteries, the battery conversion efficiency is closely related to the structure of the front film layer. Different film layers, film thicknesses and film layer refractive indices all have an impact on the battery conversion efficiency. In the prior art, the app...

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Problems solved by technology

[0003] For PERC batteries, the battery conversion efficiency is closely related to the structure of the front film layer. Different film layers, film thicknesses and film layer refractive indices all have an impact on the battery conversion efficiency. In the prior art, the application number is " 2011101824819", the preparation method of double-layer silicon nitride anti-reflection film, the preparation method of a PERC battery front anti-reflection film with application number "2016111688207", the solar cell front film structure with application number "2013200124804", and the application number For the three-layer silicon nitride thin-film cell of "2017200134734", the PERC cell made of the front film structure of the above-mentioned cells has low diffusion resistance, deep junction depth, and poor short-wave response of the PERC cell. The short-circuit current and open-circuit voltage of the battery are both low, which cannot improve efficiency or reduce costs, and is a waste of resources

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