The invention relates to a preparation method for a black-
silicon poly-
silicon PERC
cell structure with a selective emitter. The preparation method is characterized by comprising the following steps of (1) forming a nanometer texturing surface on a front surface of a
silicon wafer, wherein a back surface is a
polishing surface; (2) performing front-
surface diffusion of the silicon
wafer to form anN-type layer, and removing front-surface phosphorosilicate glass and a back-surface pn junction; (3) depositing a
silicon nitride anti-reflection film layer on the front surface of the silicon
wafer,and depositing a
passivation dielectric layer on the back surface; (4) dotting or routing the back surface of the silicon wafer, and printing a
silver electrode and
aluminum paste; (5) performing low-temperature
sintering to form a local aluminum back field; (6) spraying a
mixed solution of
phosphoric acid and
alcohol on the front surface of the silicon wafer, and forming a main grid line regionand a secondary grid line region after heavy
doping by
laser; and (7) immersing the front surface of the silicon wafer in an
electroplating solution,
electroplating the front surface of the silicon wafer under an illumination condition, and annealing after
electroplating. By the preparation method, the defects that a high-quality fine grid line is difficult to form by silk-
screen printing and thegrid line and a selective emitter cannot be enabled to be accurately aligned are overcome, and shielding and leakage current caused by an
electrode are minimum.