Novel technique for fabrication of n-type crystalline silicon selective emitter for solar cell processing

Abstract

A new way of realizing crystalline silicon selective emitter by simultaneous formation of front side selective emitter as well as rear back surface field (BSF) layer in rear side diffusion step has been presented in this work. In this paper, we have demonstrated a novel technique to achieve a selective emitter having a highly diffused region with lower sheet resistance around 30–32 Ω sq−1 along with peak doping concentration 7.34 × 1019 atoms cm−3, junction depth around 0.97 μm and lightly diffused region with higher sheet resistance around 78–80 Ω sq−1 along with peak doping concentration 4.57 × 1019 atoms cm−3, junction depth around 0.64 μm. These results show that selective emitter has been formed in single diffusion process without any extra heat treatment and chemical etching process, thus this process becomes cost effective.