Abstract
The photoelectrochemical splitting of water into hydrogen and oxygen requires a semiconductor to absorb light and generate electron-hole pairs, and a catalyst to enhance the kinetics of electron transfer between the semiconductor and solution. A crucial question is how this catalyst affects the band bending in the semiconductor, and, therefore, the photovoltage of the cell. We introduce a simple and inexpensive electrodeposition method to produce an efficient n-Si/SiOx/Co/CoOOH photoanode for the photoelectrochemical oxidation of water to oxygen. The photoanode functions as a solid-state, metal-insulator-semiconductor photovoltaic cell with spatially non-uniform barrier heights in series with a low overpotential water-splitting electrochemical cell. The barrier height is a function of the Co coverage; it increases from 0.74 eV for a thick, continuous film to 0.91 eV for a thin, inhomogeneous film that has not reached coalescence. The larger barrier height leads to a 360mV photovoltage enhancement relative to a solid-state Schottky barrier.
Recommended Citation
J. C. Hill et al., "An Electrodeposited Inhomogeneous Metal-insulator-semiconductor Junction for Efficient Photoelectrochemical Water Oxidation," Nature Materials, vol. 14, no. 11, pp. 1150 - 1155, Nature Research, Nov 2015.
The definitive version is available at https://doi.org/10.1038/nmat4408
Department(s)
Chemistry
International Standard Serial Number (ISSN)
1476-4660; 1476-1122
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2024 Nature Research, All rights reserved.
Publication Date
01 Nov 2015
