Back contact battery with local high-conductivity polycrystalline structure and preparation method of back contact battery

Abstract

The invention belongs to the technical field of back contact cells, and particularly relates to a back contact cell with a local high-conductivity polycrystalline structure and a preparation method thereof, and the preparation method comprises the steps: S2, sequentially forming a first tunneling oxide layer and an N-type doped amorphous silicon layer on the back surface of a silicon wafer, and then depositing an anti-plasma mask layer; s3, forming an opening in a partial region, corresponding to the metal electrode, of the anti-plasma mask layer to form an opening region W0; then annealing is carried out; s4, carrying out phosphorane plasma treatment to form a high-conductivity polycrystalline region; depositing an alkali-resistant mask layer on the back surface; s5, forming a second semiconductor opening region; s6, texturing and cleaning; and S9, depositing a second semiconductor layer on the back surface. A local high-conductivity polycrystalline structure can be formed, carrier transmission is facilitated, meanwhile, the non-electrode contact area film layer can be thinned and can be suitable for low doping and low crystallinity, parasitic absorption of the film layer can be reduced, high FF and high current density are both considered, and therefore the overall conversion efficiency of the cell can be improved.

Images