Qualitative Analysis of the Valence and Conduction Band Offset Parameters in FeNiO/CuNiO Bilayer Film Using X-Ray Photoelectron Spectroscopy

The valence and conduction band offset in FeNiO/CuNiO bilayer film are studied utilizing X-ray photoelectron spectroscopy and UV-vis spectroscopy. The bilayer film is grown on Si substrate employing ion beam sputtering technique using a mixture of argon and oxygen gases at 25% oxygen partial pressure. From the precise knowledge of the valence band maxima energies and core-level energy positions in the single-layer film and the corresponding shifts in the bilayer film, the valence and conduction band offsets are estimated to be 0.8 and 0.3 eV, respectively. From the computed band offset data, a type-I band alignment is identified at the interface of the grown bilayer film, which facilitates the knowledge of carrier transport mechanism and is highly attractive for the realization of efficient room-temperature optoelectronic device.