Tunable electronic structure in dilute magnetic semiconductor Sr{sub 3}SnO/c-YSZ/Si (001) epitaxial heterostructures

Journal Article · Tue Oct 28 00:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4899438· OSTI ID:22308200

Lee, Y. F.; Narayan, J.; Schwartz, J. ^[1]

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1. Department of Materials Science and Engineering, North Carolina State University, 911 Partners Way, Raleigh, North Carolina 27695-7907 (United States)

We report a systematic study of the structural, physical, and chemical properties of epitaxial thin films of emerging dilute magnetic semiconductor (DMS) Sr{sub 3}SnO (SSO) integrated with Si (100) prepared by various post-growth annealing treatments. The transport properties of these films are primarily governed by oxygen vacancies and the results are explained with the variable-range hopping model. The increased oxygen vacancy concentration generated by post-growth vacuum annealing results in a shorter hopping distance and reduced hopping energy and Coulomb gap, leading to lower resistivity; oxygen annealing shows the opposite effects. The work function ranges from 4.54 to 4.02 eV and shows a negative linear relationship with oxygen vacancy concentration, accompanied by a 0.42 eV shift in the surface Fermi level. The transport and ultraviolet photoelectron spectroscopy probes agree quantitatively on measurement of the resistivity and surface electronic structure. The results provide a direct and consistent explanation that the property changes in the bulk and at the surface are primarily attributed to oxygen vacancies, which are believed to be the carriers in the SSO thin films. The ability to manipulate the work function and oxygen vacancy concentration in epitaxial DMS SSO thin films offers great potential for the development of spintronic devices.

• OSTI ID: 22308200
• Journal Information: Journal of Applied Physics, Vol. 116, Issue 16; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANNEALING
CHEMICAL PROPERTIES
ELECTRONIC STRUCTURE
EPITAXY
FERMI LEVEL
MAGNETIC SEMICONDUCTORS
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
PHYSICAL PROPERTIES
SILICON
STRONTIUM COMPOUNDS
SURFACES
THIN FILMS
TIN COMPOUNDS
ULTRAVIOLET RADIATION
WORK FUNCTIONS
YTTRIUM COMPOUNDS
ZIRCONIUM COMPOUNDS