Stoichiometry-dependent surface electronic structure of SrTiO3 films grown by hybrid molecular beam epitaxy
Abstract
We investigate the surface electronic structure of SrTiO3 (STO) films grown by a hybrid molecular beam epitaxy that are both stoichiometric and nonstoichiometric by means of x-ray photoelectron spectroscopy and electron energy loss spectroscopy. Increasing the fraction of the surface that is terminated with an SrO layer is correlated with a decrease in the chemical potential whereby the valence band maximum moves closer to the Fermi level, but without a significant change in the bandgap. Inasmuch as SrO-terminated STO (001) has previously been shown to act as an electron scavenger in which carriers from the bulk are trapped, we argue that the high fraction of SrO in the terminal layer is what lowers the chemical potential in Sr-rich STO. Our experimental results provide important insights into various physical phenomena that can occur on STO (001) surfaces and their effect on bulk electronic properties.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Mar 21, 2022
- Source ID
- 10.1063/5.0082636
Entities
People
- Bharat Jalan
- Dooyong Lee
- Fengdeng Liu
- Scott A. Chambers
- Tristan K. Truttmann
Organizations
- Air Force Office of Scientific Research
- Pacific Northwest National Laboratory
- United States Department of Energy
- University of Minnesota