In-situ synthesis of In2O3-based heterojunction thin films for enhanced visible light photoelectrochemical performance

Abstract

Indium oxide (In2O3) based heterojunction thin films with enhanced visible light photoelectrochemical (PEC) performance were successfully grown on c-Si substrate by plasma assisted in-situ thermal annealing at three different filament temperatures, Tf. The in-situ thermal annealing has significantly changed the grainy morphology of InN/In2O3 heterojunctions to sharp crystallites of W2N/In2O3 with increase in Tf from 1300 to 1700 °C, respectively. It is shown that the formation InN, WO3, and W2N on In2O3 nanostructures has significantly improved the photocurrent to 0.966, 0.429, and 1.84 mA/cm2 at 1 VAg/AgCl which are 4.2, 1.86, and 8 times higher than the photocurrent density measured for intrinsic In2O3 (0.23 mA/cm2), respectively. The effects of the band alignments in charge separation and thus improving the photoelectrochemical properties of the heterojunction films are discussed.