P +/N high-efficiency silicon solar cells

Abstract

A novel boron‐diffusion process is described for the fabrication of high‐efficiency P⁺/N silicon solar cells. Over the range of diffusion parameters investigated this diffusion process results in a boron‐rich surface layer and shallow junctions (0.15–0.4 μm) having two properties important to the formation of high‐efficiency solar cells—relatively low values of sheet resistance (35–140 Ω/⧠) which facilitates the front‐surface grid‐metal design and large resultant lifetimes approaching 60 μs. The characteristics of P⁺/N solar cells, fabricated using this diffusion process in single‐crystal (CZ) silicon wafers, having AM1 efficiencies ranging from 14 to 17% are presented.