FIRST-PRINCIPLES STUDY OF ELECTRONIC AND OPTICAL PROPERTIES IN A NEW
SEMICONDUCTING OXYTELLURIDE Ba2OTe
Jifeng Sun, Daniel Ramirez, Jeffrey Whalen, Theo Siegrist
Department of Chemical and Biomedical Engineering, Florida State University, 2525 Pottsdamer Street,
Tallahassee, FL 32310 USA
National High Magnetic Field Laboratory, Florida State University
1800 E Paul Dirac Dr, Tallahassee, FL 32310
A first-principles study has been performed to investigate the electronic and optical properties of a new
semiconducting material, Ba2OTe. In order to compare and get the right band-gap, we employed both the
traditional PBE type GGA functional and Modified Becke-Johnson (MBJ) potential implemented in the
full potential linearized augmented plane wave (FP-LAPW) method within the framework of density
functional theory (DFT). Our band structure calculations show a direct band gap with 1.9 ev (PBE) and
2.6 eV (MBJ) at point, respectively, which is formed by Ba-d states in the conduction band and Te-p
states in the valence band. The dielectric tensors are derived within the random phase approximation
(RPA). The results of the dielectric function, absorption coefficient, and reflectivity are all along both x
and z directions. The optical band gap calculated (2.6 eV) agree well with the experimental value (~3
eV).
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