STO-Si Interface Modulation Paper Published in Phys Rev Mater

Our team’s latest paper, led by Matthew Chrysler, has just been published in Physical Review Materials! We explore interface modulation of the band structure of STO-Si using a combination of high spatial and chemical resolution probes, providing new insight into the design of semiconducting heterojunctions.

From the abstract:

We demonstrate that the interfacial dipole associated with bonding across the SrTiO3/Si heterojunction can be tuned through space charge, thereby enabling the band alignment to be altered via doping. Oxygen impurities in Si act as donors that create space charge by transferring electrons across the interface into SrTiO3. The space charge induces an electric field that modifies the interfacial dipole, thereby tuning the band alignment from type-II to type-III. The transferred charge, resulting in built-in electric fields, and change in band alignment are manifested in electrical transport and hard x-ray photoelectron spectroscopy measurements. Ab initio models reveal the interplay between polarization and band offsets. We find that band offsets can be tuned by modulating the density of space charge across the interface. Functionalizing the interface dipole to enable electrostatic altering of band alignment opens new pathways to realize novel behavior in semiconducting heterojunctions.

To view the manuscript, visit: https://journals.aps.org/prmaterials/abstract/10.1103/PhysRevMaterials.5.104603

To download the manuscript directly, click here.