Band gap of corundumlike alpha-Ga2O3 determined by absorption and ellipsometry

This work has been supported by the Spanish MINECO/FEDER under Contracts No. MAT2015-71035-R and No. MAT2016-75586-C4-1-P. We acknowledge T. Yamaguchi from the Department of Electrical Engineering and Electronics of Kogakuin University, Tokyo, Japan, for supplying us with the samples used in this study.