Band offset studies in Cr2O3/Ti0.02Cr1.98O3 bilayer film using photoelectron spectroscopy

Realization of oxide/oxide semiconductor heterostructures based high performance electronic/optoelectronic/ magneto-optical devices warrants in-depth understanding of energy band alignment at their interface. Herein, we report energy band alignment in pulsed laser ablated Cr2O3/Ti0.02Cr1.98O3 bilayer film from the knowledge of core level energies and valence band maxima positions in the corresponding Cr2O3 and Ti0.02Cr1.98O3 single layer films and their respective shifts in Cr2O3/Ti0.02Cr1.98O3 bilayer film. A type II (staggered) band alignment was identified, with the valence band offset and conduction band offset equals to 1.40 eV and 1.13 eV, respectively. This investigation will provide further insights into the fundamental properties of Cr2O3/Ti0.02Cr1.98O3 heterojunction, which can be effectively utilized for the design, modelling and analysis of optoelectronic/magneto-optical devices.