Boron doped nanocrystalline silicon/amorphous silicon hybrid emitter layers used to improve the performance of silicon heterojunction solar cells

Abstract

Boron doped nanocrystalline silicon/amorphous silicon hybrid thin films were deposited by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) to improve the performance of silicon heterojunction (SHJ) solar cells. Electrical and optical properties as well as structural and passivation characteristics of these thin films were systematically researched as a function of TMB gas mixture ratio. A high dark conductivity of 6.5×10−4S/cm and minority carrier lifetime (τs) of 1740μs on Czochralski (Cz) Si wafers were obtained with the hybrid p-type Si films. We applied this optimized film as an emitter layer on SHJ solar cells based on Cz silicon wafers; a significant improvement in the solar cell wavelength response at 400nm and output performance have been achieved.