Controlled Preparation, Characterization, and Bandgap Modulation of RF Sputtered Antimony Vanadium Oxide (SbVO4) Thin Films

TL;DR

This study reports the fabrication and characterization of RF sputtered SbVO4 thin films, demonstrating tunable bandgaps and potential for water oxidation catalysis in photoelectrochemical applications.

Contribution

It introduces a method to control the bandgap of SbVO4 thin films via oxygen incorporation during sputtering, enabling optimized photoanodes for water oxidation.

Findings

SbVO4 exhibits an indirect band gap of 1.89-2.36 eV.

Bandgap modulation is achieved through oxygen stoichiometry control.

Optimized SbVO4 photoanodes show promising catalytic behavior.

Abstract

In this paper, RF sputtered antimony vanadium oxide (SbVO4) thin films and its characterization are reported. High purity sputtering targets were fabricated by sintering a mixture of Sb2O3 and V2O5 powders. Thin films were deposited by reactive sputtering at various temperature and argon/oxygen partial pressures. Several growth parameters and surface chemistry were studied by applying numerous optical and electrochemical characterization technique. It is found that SbVO4 exhibits an indirect band gap in the range of 1.89 eV to 2.36 eV and has desirable valence band position to drive water oxidation reaction under illumination. The bandgap depends heavily on stoichiometry of the film and can be modulated by incorporating controlled amount of oxygen gas in plasma environment. Optimized SbVO4 photoanodes was designed and tested for photoelectrochemical water oxidation catalysis. Preliminary studies show that these electrodes possess n-type catalytic behavior in alkaline media. The prepared SbVO4 thin films, with typical film thickness was around 400 nm, contain nanoparticles having the sizes of 10-15 nm.