Optoelectrical properties of high-performance low-pressure chemical vapor deposited phosphorus-doped polysilicon layers for passivating contact solar cells

•Analysis of low pressure chemical vapor deposited phosphorus doped polysilicon layers.•Optimization of diffusion recipe for each thickness to obtain excellent passivating properties.•Excellent passivation provided by doped polysilicon layers with ultrathin interfacial oxide.•Ʈeff ~ 14–17 ms. J0 ~ 1.2 −1.8 fA/cm2, iVOC ~ 742–747 mv. We examine the optical behavior and electrical performance of ultra-thin interfacial oxide (iOx) and polysilicon (poly-Si) layers deposited using industrial tube-type low-pressure chemical vapor deposition (LPCVD). The intrinsic and doped poly-Si layers of different thicknesses are examined for their optical, electrical and passivation properties at different conditions. We present an outstanding surface passivation result with in-situ iOx and n+doped poly-Si layers of thickness ranging from 150 nm to 250 nm. Intrinsic poly-Si layers are deposited using LPCVD and doped at high temperature in a tube furnace. An excellent effective minority carrier lifetime of 17 ms, implied open-circuit voltage of 747 mV and an ultralow dark saturation current density of 1.2 fA/cm2 are obtained for a 150 nm thick n+ poly-Si after fast-firing at a peak temperature of 745 °C.