Stabilization of n-Si electrodes by surface alkylation and metal nano-dot coating for use in efficient photoelectrochemical solar cells

Surface methylated and Pt nano-dotted single crystal n-Si (1 1 1) electrodes yielded efficient photocurrent density (j) vs. potential (U) characteristics for more than 6 h in a highly corrosive electrolyte of aqueous 8.6 M HBr+0.05 M Br2. On the other hand, H-terminated and Pt nano-dotted n-Si electrodes degraded seriously in about 15 min. Surface methylated but non-Pt-dotted n-Si electrodes yielded only poor j–U characteristics with low Voc. The results clearly show that a combination of surface alkylation and metal nano-dot coating is an effective way to obtain efficient and stable Si photoelectrodes and hence photoelectrochemical solar cells.