Because of relatively low electron mobility of Ga2O3, it is important to identify proper current spreading materials. Fluorine-doped SnO2 (FTO) offers superior properties to those of indium tin oxide (ITO) including higher thermal stability, larger bandgap, and lower cost. However, the Ga2O3/FTO heterojunction including the important band offset and the I-V characteristics have not been reported. In this work, we have grown the Ga2O3/FTO heterojunction and performed X-ray photoelectron spectroscopy (XPS) measurement. The conduction and valence band offsets were determined to be 0.11±0.10 and 0.42±0.10 eV, indicating a minor barrier for electron transport and a type-I heterojunction. The subsequent I-V measurement of the Ga2O3/FTO heterojunction exhibited ohmic behavior. The results of this work manifests excellent candidacy of FTO for current spreading layers of Ga2O3 devices for high temperature and UV applications.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): BAS/1/1664-01-01, REP/1/3189-01-01, URF/1/3437-01-01, URF/1/3771-01-01
Acknowledgements: The authors would like to acknowledge the support of KAUST Baseline BAS/1/1664-01-01, KAUST Competitive Research Grant URF/1/3437-01-01 and URF/1/3771-01-01, and GCC Research Council REP/1/3189-01-01