Dramatic reduction of surface recombination by in situ surface passivation of silicon nanowires

Abstract

Nanoires have unique optical properties(1-4)and are considered as important building blocks for energy harvesting applications such as solar cells.(2, 5-8)However, due to their large surface-to-volume ratios, the recombination of charge carriers through surface states reduces the carrier diffusion lengths in nanowires a few orders of magnitude,(9)often resulting in the low efficiency (a few percent or less) of nanowire-based solar cells.(7, 8, 10, 11)Reducing the recombination by surface passivation is crucial for the realization of high-performance nanosized optoelectronic devices but remains largely unexplored.(7, 12-14)Here we show that a thin layer of amorphous silicon (a-Si) coated on a..