Crystalline TiO2 protective layer with graded oxygen defects for efficient and stable silicon-based photocathode.

ABSTRACT: The trade-offs between photoelectrode efficiency and stability significantly hinder the practical application of silicon-based photoelectrochemical devices. Here, we report a facile approach to decouple the trade-offs of silicon-based photocathodes by employing crystalline TiO2 with graded oxygen defects as protection layer. The crystalline protection layer provides high-density structure and enhances stability, and at the same time oxygen defects allow the carrier transport with low resistance as required for high efficiency. The silicon-based photocathode with black TiO2 shows a limiting current density of ~35.3?mA?cm-2 and durability of over 100?h at 10?mA?cm-2 in 1.0?M NaOH electrolyte, while none of photoelectrochemical behavior is observed in crystalline TiO2 protection layer. These findings have significant suggestions for further development of silicon-based, III-V compounds and other photoelectrodes and offer the possibility for achieving highly efficient and durable photoelectrochemical devices.

SUBMITTER: Zheng J 

PROVIDER: S-EPMC6120862 | biostudies-other | 2018 Sep

REPOSITORIES: biostudies-other