Interface structure at polar-nonpolar interfaces has been shown to be a key factor in controlling emergent behavior in oxide heterostructures, including the ${\mathrm{LaFeO}}_3/n\text{−}{\mathrm{SrTiO}}_3$ system. We demonstrate via high-energy-resolution x-ray photoemission that epitaxial ${\mathrm{LaFeO}}_3/n\text{−}{\mathrm{SrTiO}}_3(001)$ heterojunctions engineered to have opposite interface polarities exhibit very similar band offsets and potential gradients within the ${\mathrm{LaFeO}}_3$ films. However, differences in the potential gradient within the ${\mathrm{SrTiO}}_3$ layer depending on polarity may promote hole diffusion into ${\mathrm{LaFeO}}_3$ for applications in photocatalysis.

• Received 16 August 2016

DOI:https://doi.org/10.1103/PhysRevLett.117.226802