A new technology to fabricate high-efficiency silicon concentrator solar cells

A new procedure to fabricate silicon concentrator solar cells based on phosphorus diffusion into the semiconductor through a thin-polysilicon film is described. The polysilicon reduces the high-diffusivity tail of the conventional phosphorus-doping profile and avoids interdiffusion phenomena at the metal-semiconductor interface during sintering, thus allowing Al to be used as front grid contact. Outdoor testing of 2 × 2-cm²solar cells computer designed to operate at 50 suns showed conversion efficieneies higher than 17 percent.