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Atom Probe Tomography Studies on the Cu(In,Ga)Se2 Grain Boundaries
Published on: April 22, 2013
First-principles study of the structure and band structure of Ga2Se3
Gui-Yang Huang1, N M Abdul-Jabbar, B D Wirth
1Department of Nuclear Engineering, University of Tennessee, Knoxville, TN, USA. huangguiyang@gmail.com
Abstract:
Our first-principles calculations show that the ordering of stoichiometric cation vacancies in Ga2Se3 has a large influence on the bandgap, up to 0.55 eV. Therein, the zigzag-line vacancy-ordered Ga2Se3 has the maximum bandgap (∼2.56 eV direct bandgap), and the straight-line vacancy-ordered Ga2Se3 has the minimum bandgap (∼1.99 eV indirect bandgap) at 0 K, according to scGW calculations. The bandgap difference (0.55 eV) is almost the same for normal density functional theory (DFT) calculations, hybrid DFT calculations and GW calculations. The calculation results are consistent with the experimental bandgap range of 2.0-2.6 eV at room temperature. Also, hydrostatic pressure (<9 GPa) tends to increase the bandgap, consistent with the experiments in the literature.
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