Alkaline Treatment of Silicon Nanostructures for Efficient PEDOT:PSS/Si Heterojunction Solar Cells

Abstract

Silicon organic heterojunction solar cells have lower thermal budget and are less time consuming as compared to traditional dopant diffusion based silicon solar cells. In this study such heterojunction solar cells have been fabricated over nanotextured silicon by spin-coating a thin layer of co-solvent stabilized PEDOT:PSS polymer. To enhance conformal coating of the polymer, nanotextured silicon was treated with aqueous alkaline etchant. Alkali treated hybrid nanotextured device showed enhanced fill factor and photocurrent arising from better conformal coating, and hence higher efficiency as compared to without alkali treated device (control sample). A 0.47% absolute and 13% relative increase in efficiency have been observed.