Photoelectrochemical oxygen evolution improved by a thin Al2O3 interlayer in a NiOx/n-Si photoanode

Thin Solid Films 599, 54-58

https://doi.org/10.1016/j.tsf.2015.12.062

Min-Joon Park, Jin-Young Jung, Sun-Mi Shin, Jae-Won Song, Yoon-Ho Nam, Dong-Hyung Kim, Jung-Ho Lee

Abstract

We employ a thin Al2O3 interlayer between p-NiOX catalyst/n-Si photoanode interfaces to realize an effective oxygen evolution reaction (OER). The Al2O3 interlayer is used to reduce the interface defect density, enhance the band bending by suppressing the Fermi-level pinning effect, and enhance photovoltage at the catalyst/semiconductor rectifying junction. Our NiOX/Al2O3/n-Si photoanodes generated a photocurrent of 3.36 mA/cm2 at the equilibrium potential of OER (EOER = 1.23 V vs. reversible hydrogen electrode in 1 M NaOH solution) and a solar-to-oxygen conversion efficiency of 0.321%. Moreover, the photoanode showed no sign of decay over 20 h of photoelectrochemical water oxidation.