Probing the band alignment in rectifying SrIrO3/Nb:SrTiO3 heterostructures

Abstract

We have examined the band alignment in SrIrO3/Nb:SrTiO3 (001) heterojunctions at room temperature using three independent techniques: current-voltage and capacitance-voltage measurements and internal photoemission spectroscopy. We find near-ideal rectifying behavior across the junction, which provides the opportunity to establish the band alignment via Schottky barrier height extractions in the metal-semiconductor junction approximation. The Schottky barrier height deduced from these measurements agrees well with each other within ∼14%, with an average value of 1.44 ± 0.11 eV. These results provide a foundation for designing oxide heterostructures to harness the strong spin-orbit coupling and electrochemical properties of strontium iridate.