63^rd ANNUAL CONFERENCE OF THE SA INSTITUTE OF PHYSICS

First principles investigation of structural, dynamic, electronic and optical properties of Barium seleno-germanate Ba₂GeSe₄

28 Jun 2018, 15:00

2h

Poster Presentation Track A - Physics of Condensed Matter and Materials Poster Session 2

Speaker

Abdu Barde (The National Institute for Theoretical Physics, School of Physics and Mandelstam Institute for Theoretical Physics, University of the Witwatersrand, Johannesburg, Wits 2050, South Africa.)

Description

Ternary and quaternary chalco-germanates and stannates have a rich structural chemistry. Experimental studies of their nonlinear optical properties have been reported, but there are few published computational studies on their structural, dynamic, electronic and optical properties. In this work, we investigate the structural, dynamic, electronic and optical properties of Ba₂GeSe₄ using Density Functional Theory (DFT) and post-DFT many body perturbation theory. The ground state energy and properties, including equilibrium lattice parameters, bulk modulus, band gap and phonon dispersion were calculated at the DFT level of approximation. The fundamental gap was determined at the post DFT G₀W₀ level of approximation while optical absorption was determined within the Bether-Salpeter Equation approximation. The ground state energy, mechanical and phonon dispersion results show that Ba₂GeSe₄ is a stable compound while the calculated optical absorption results show that it is a wide band gap material that is well-situated for photon absorption in visible range.

Supervisor details<br><b>If not a student, type N/A.</b><br>Student abstract submision<br>requires supervisor permission:<br>please give their name,<br> institution and email address.

Daniel P. Joubert, University of the Witwatersrand, Johannesburg
Daniel.Joubert2@wits.ac.za

Peer reviewing

Paper

Accepted on 8 Jun 2019 by Japie Engelbrecht

Paper files:

• Revised2.pdf
• Reviewer's_report_ID_58_(1).pdf