On the measured optical bandgap values of inorganic oxide semiconductors for solar fuels generation

Abstract This article focuses on variation in the values for the optical bandgaps ( E g ) experimentally reported for fourteen oxide semiconductors that have been studied for solar photoelectrochemical and photocatalytic environmental remediation applications. Both binary and ternary compounds have been included in this study. The variance in the reported values is much more severe for the ternary compounds relative to the binary counterparts. Factors related to semiconductor doping and size quantization have been carefully removed from playing a role in the presented data. Instead the variability is attributed to intrinsic errors associated with the extraction of E g values from spectral data (for example, via Tauc plots), and to other sample-related factors such as surface functional groups and compound non-stoichiometry. Finally, suggestions for future, follow-up study are also given.