Enhancing photovoltaic characteristics of iron doped amphous carbon/Al 2O3/Si solar cell by al2o3 interface passivation

This letter reports the enhanced photovoltaic (PV) performance of Fe doped amorphous carbon (a-C) film/n-Si heterojunctions by depositing a thin Al2O3 layer at the interface of a-C:Fe and Si substrate. We demonstrate that a thin Al2O3 film at the interface of Fe-doped a-C/Si heterojunction allows significantly improving the devices' PV performances up to one order of magnitude under AM1.5 illumination. The enhancement of the PV effect on a-C:Fe/Al2O3/Si solar cells can be ascribed to the inserted Al2O3 layer which increases the built-in electric field barrier and realizes interface passivation by use of suppressing the charge recombination, reducing the interface states. (C) 2011 The Japan Society of Applied Physics