Method for passivating back of crystal silicon solar cell

Abstract

The invention discloses a method for passivating the back of a crystal silicon solar cell. The method comprises the following steps of: depositing a SiN* anti-reflection film on the front of the solar cell, corroding the back of the solar cell in heated alkali liquor by using the SiN* anti-reflection film as a mask to obtain a polished surface required by passivation, then depositing double film passivation layers on the polished surface to form a back passivation layer, forming an electrode window on the back passivation layer by adopting laser etching or screen printing of corrosive slurry, and finally forming a local contact back electrode on the electrode window by adopting a screen printing or sputtering method. The method greatly improves the long wave response of the solar cell and improves the conversion efficiency of the solar cell; moreover, a full-aluminum back field structure is canceled, so the method reduces the bending of the solar cell and is more adaptive to the thinning tendency of the solar cell.

Description

technical field [0001] The invention relates to the technical field of photovoltaic utilization of solar energy, in particular to a preparation method of a crystalline silicon solar cell. Background technique [0002] The current commercial solar cell production process is simple and the manufacturing cost is relatively low. Its production process: remove the damaged layer on the surface of the silicon wafer, make texture → in POCl 3 Diffusion of P in the atmosphere to form n + Diffusion layer → use plasma etching or wet etching to remove the PN junction around the silicon wafer → use PECVD technology to deposit SiNx anti-reflection film on the front → screen print the back electrode, back electric field, and positive electrode → form by sintering in a sintering furnace Ohmic contact → test sorting. This commercial solar cell manufacturing technology is relatively simple, low in cost, suitable for industrialized and automated production, and thus widely used. However, th...

AI Technical Summary

Problems solved by technology

SiNx has a good passivation effect, but there is no passivation measure on the back side, so the recombination is serious, resulting in poor long-wave response of the battery

And with the further thinning of the silicon wafer, the adverse effect of the recombination on the back side on the solar cell will become particularly prominent

The current all-aluminum back field structure is likely to cause uneven stress and make the battery sheet bend, which is not conducive to the production of components

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