Fabrication method of P-type crystal-silicon solar cell with passivation back surface

Abstract

The invention discloses a fabrication method of a P-type crystal-silicon solar cell with a passivation back surface. Planarization recovery processing is performed on a bottom surface and a side wallof a laser groove in a back surface of a silicon wafer by a chemical etching method with regard to the silicon wafer after being grooved by laser, a diffusion layer on a front surface of the silicon wafer is simultaneously etched, the concentration gradient of doping phosphate atoms in the diffusion layer is optimized, an emitter is optimized, and a SiO2 thin film and a second silicon nitride anti-reflection film are deposited on the front surface of the silicon wafer. According to the fabrication method, the open-circuit voltage and the photovoltaic conversion efficiency of a solar cell pieceare improved by recovering a damage layer.

Description

technical field [0001] The invention belongs to the field of solar photovoltaic cell manufacturing, and in particular relates to a method for manufacturing a P-type crystalline silicon solar cell with passivation on the back. Background technique [0002] During the manufacturing process of solar cells, the lattice defects on the surface of the silicon wafer will reduce the photoelectric conversion efficiency of the solar cell, so a back passivation technology is used to deposit a dense oxide film on the surface of the cell to reduce the surface of the silicon wafer. compound center. Since the electrode should be fully in contact with the silicon wafer, it is necessary to perform laser grooving on the oxide film on the surface of the silicon wafer in the area where the electrode passes. However, since the laser is a light source with high energy and high heat, the surface of the silicon wafer will A layer of oxide film will be formed, which increases the ohmic contact betwe...

AI Technical Summary

Problems solved by technology

Since the electrode should be fully in contact with the silicon wafer, it is necessary to perform laser grooving on the oxide film on the surface of the silicon wafer in the area where the electrode passes. However, since the laser is a light source with high energy and high heat, the surface of the silicon wafer will A layer of oxide film will be formed, which increases the ohmic contact between the electrode and the silicon wafer. At the same time, the laser will also cause certain mechanical damage to the passivation layer, and generate new recombination centers, resulting in a decrease in the minority carrier lifetime.

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