High efficiency n-type silicon solar cells with passivating contacts based on PECVD silicon films doped by phosphorus diffusion

Abstract

Carrier-selective contacts based on silicon films deposited onto a thin SiO x layer combine high performance with a degree of compatibility with industrial solar cell metallization steps. This paper demonstrates an approach to form electron-selective passivating contacts that maximises the overlap with common industrial equipment; it is based on depositing an intrinsic amorphous silicon (a-Si) layer by PECVD and then doping and re-crystallizing it by means of a thermal phosphorus diffusion. By optimizing the intrinsic a-Si thickness and the phosphorus diffusion temperature, a low recombination current density J oc ≈ 3 fA/cm 2 and a low contact resistivity of ρ c ≈ 3 mΩ-cm 2 have been achieve..