Influence of grain environment on open circuit voltage of hot-wire chemical vapour deposited Si:H solar cells

Polycrystalline silicon films have been deposited by hot-wire chemical vapour deposition (HWCVD) at lower substrate temperatures. N–i–p cells, deposited on a flexible stainless steel substrate, yielded an efficiency of 4.15%, with increased open circuit voltage and fill factor (0.452 V and 0.65, respectively). The moderate efficiency is due to a thin i-layer of 600 nm, which delivers a current density of 14 mA/cm2. An increase of more than 20% in the Voc is achieved compared to our earlier n–i–p cell at high temperature (490 °C). Furthermore, for the first time, thin silicon films have been deposited by HWCVD using rhenium (Re) as filament material.