Preparation method of SE-PERC solar cell with high conversion efficiency

Abstract

The invention discloses a preparation method of an SE-PERC solar cell with high conversion efficiency, and relates to the technical field of solar cells. The method comprises preparation steps of 1) texturing; 2) phosphorus diffusion; 3) laser heavy doping; 4) oxidation; (5) PSG removal; 6) alkali etching and polishing, carrying out alkali etching and polishing on a back surface of a silicon wafer; 7) removing the phosphorosilicate glass on a front surface of the silicon wafer; 8) annealing; 9) plating a double-sided aluminum oxide passivation film on a surface of the silicon wafer; 10) depositing an antireflection film on the front surface; 11) depositing a passivation film on a back surface; 12) performing back laser grooving; 13) silk-screen printing; and 14) sintering. The method is advantaged in that the alkali etching technology is utilized, compared with acid etching, the use amount of etching acid can be reduced, acid wastewater cost treatment is reduced, environmental protection is facilitated, an oxidation procedure is added after laser heavy doping and before PSG removal, PN junctions can be prevented from being damaged, the good passivation effect can be achieved on thesilicon wafer, and conversion efficiency is obviously improved.

Description

technical field

[0001] The invention relates to the technical field of solar cells, in particular to a preparation method of a high conversion efficiency SE-PERC solar cell. Background technique

[0002] PERC solar cells are currently one of the most mainstream high-efficiency cells on the market. Among them, the SE-PERC battery is a laser heavy doping technology (SE) process added on the basis of PERC, which realizes the selective doping of solar cells. Combining the front laser heavy doping technology (SE) with fine grid lines improves the passivation effect and significantly increases the open circuit voltage, thus greatly improving the conversion efficiency of solar cells. One of the existing SE-PERC solar energy preparation methods is alkali etching and back polishing, and its preparation process is: texturing-diffusion-laser doping-removing back silicon-phosphorus glass-back alkali etching polishing-removing front-side silicon-phosphorus glass-annealing - Aluminum ox...

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