Electrical and material properties of hydrothermally grown single crystal (111) UO2

Authors

Christina L. Dugan, Air Force Institute of TechnologyFollow
George Glenn Peterson, University of Nebraska - Lincoln
Alyssa Mock, University of Nebraska - LincolnFollow
Christopher Young, Air Force Institute of Technology
J. Matthew Mann, Wright-Patterson Air Force Base
Michael Nastasi, University of Nebraska-Lincoln & Air Force Institute of TechnologyFollow
Mathias Schubert, University of Nebraska - LincolnFollow
Lu Wang, University of Science and Technology of China & University of Nebraska at Omaha,
Wai-Ning Mei, University of Nebraska at OmahaFollow
Iori Tanabe, University of Science and Technology of China
Peter A. Dowben, University of Nebraska-LincolnFollow
James Petrosky, Air Force Institute of Technology

Date of this Version

4-16-2018

Citation

U.S. Government work

Comments

Eur. Phys. J. B (2018) 91: 67 https://doi.org/10.1140/epjb/e2018-80489-x

Abstract

The semiconductor and optical properties of UO2 are investigated. The very long drift carrier lifetimes, obtained from current-voltage I(V) and capacitance-voltage C(V) measurements, along with the well-defined optical properties provide little evidence of an abundance of material defects away from the surface region. Schottky barrier formation may be possible, but very much dependent on the choice of contact and surface stoichiometry and we find that Ohmic contacts are in fact favored. Depth resolved photoemission provided evidence of a chemical shift at the surface. Density functional theory, with the Heyd-Scuseria-Ernzerhof (HSE) functional, indicates a band gap of a 2.19 eV and an anti-ferromagnetic ground state. Ellipsometry measurements indicates at UO2 is relatively isotropic with a band gap of approximately 2.0 eV band gap, consistent with theoretical expectations.