Laser boron doping is one of the directions for future upgrade of PERC cell technology. It uses CVD deposition or printing to form a layer of boron doping source on the back of PERC blue tape. Through the thermal effect generated in the laser grooving process, boron element is doped into the silicon substrate synchronously to form the P++ layer, that is, the heavily doped region. For one thing, the heavily doped region forms the P++P high-low junction to generate a field passivation effect; for another, it can effectively reduce the aluminum-silicon contact resistance, and increase Voc and FF, thus improving the solar cell conversion efficiency.