Mc-Si thin film solar cells by fast CVD on low cost SSP pre-ribbons

Abstract

Silicon films 40-90 /spl mu/m thick were epitaxially deposited on fast-grown mc-SSP pre-ribbons. Special attention was focused on the design of the authors' self-constructed CVD system. It is principally convertable into a conveyer-belt system for a high continuous throughput, which is needed to be economically competitive. With high deposition rates of up to 10 /spl mu/m/min, the epi-layers revealed diffusion lengths of 250 /spl mu/m on <100>-Cz substrates, 150 /spl mu/m on SILSO and 11-30 /spl mu/m on SSP pre-ribbons (all substrates highly doped). Solar cells were manufactured using the authors' standard cell process. No passivation or gettering steps were performed and no texturing was applied. Solar cell efficiencies of 12.8% on Cz, 11.1% on SILSO wafers and 6.1% on SSP were achieved.