The P-N junction is the "heart" of photovoltaic cells. According to the type of P-N junction, photovoltaic cells can be divided into homojunction cells and heterojunction cells. Among them, the homojunction cell mainly achieves doping on the same type of silicon wafer (P-type or N-type) by means of diffusion, thereby obtaining a P-N junction. The P-type region and N-type region of the heterojuncti...