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.