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Title: Stoichiometry-dependent surface electronic structure of SrTiO 3 films grown by hybrid molecular beam epitaxy
We investigate the surface electronic structure of SrTiO 3 (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.  more » « less
Award ID(s):
2011401
PAR ID:
10411275
Author(s) / Creator(s):
; ; ; ;
Date Published:
Journal Name:
Applied Physics Letters
Volume:
120
Issue:
12
ISSN:
0003-6951
Page Range / eLocation ID:
121604
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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