Band alignment of Ga₂O₃/Si heterojunction interface measured by X-ray photoelectron spectroscopy

Ga₂O₃ thin films were deposited on (111) Si substrate by pulsed laser deposition method. X-ray photoelectron spectroscopy has been used to determine the valence band offset at Ga₂O₃/Si heterojunction interface. We measured the binding energies of Si 2p and Ga 2p_3/2 core levels and the valence band maxima energies. The valence band offset is determined to be 3.5 ± 0.1 eV. As a consequence a type heterojunction with a conduction band offset of 0.2 ± 0.1 eV is found. The determination of the band alignment of Ga₂O₃/Si heterojunction facilitates the design of optical and electronic devices based on the Ga₂O₃/Si structure.