Band Alignment at Interface of ZnO/Si Heterojunction Investigated by X‐Ray Photoelectron Spectroscopy

ABSTRACT Because the valence band offset and conduction band offset determine the energy band alignment of heterojunction, they exert a critical influence on carrier transport, recombination processes, interface behaviors, and device performance. Therefore, it is indispensable to obtain the band offsets to establish the energy band alignment at the heterojunction interface. ZnO/Si heterojunction has been prepared through depositing nano ZnO film on the p‐type silicon substrate by radio‐frequency magnetron sputtering method. The valence band offset and conduction band offset of ZnO/Si heterojunction have been investigated by x‐ray photoelectron spectroscopy (XPS), which are determined to be and respectively. These results indicate that a typical II band‐aligned heterostructure forms at the ZnO/Si heterojunction interface. Through deeply understanding and establishing the band alignment of the ZnO/Si heterojunction, it is anticipated that ZnO/Si heterojunction will be potential candidate material in the optoelectronic field.