Band discontinuities at epitaxial SrTiO3/Si(001) heterojunctions

We have used photoemission methods to directly measure the valence and conduction band offsets at SrTiO3/Si(001) interfaces, as prepared by molecular-beam epitaxy. Within experimental error, the measured values are the same for growth on n- and p-Si, with the entire band discontinuity occurring at the valence band edge. In addition, band bending is much larger at the p-Si heterojunction than at the n-type heterojunction. Previously published threshold voltage behavior for these interfaces can now be understood in light of the present results.