9-13 July 2012
Africa/Johannesburg timezone
<a href="http://events.saip.org.za/internalPage.py?pageId=11&confId=14"><font color=#ff0000>SAIP2012 PROCEEDINGS AVAILABLE</font></a>

Structural and Electronic Properties of ZnO: a hybrid density functional study

13 Jul 2012, 12:00
20m
Oral Presentation Track G - Theoretical and Computational Physics Theoretical

Speaker

Mr Mahlaga Molepo (University of the Witwatersrand)

Apply to be<br> consider for a student <br> &nbsp; award (Yes / No)?

No

Main supervisor (name and email)<br>and his / her institution

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

Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?

Yes

Abstract content <br> &nbsp; (Max 300 words)

We present results of ab initio total energy calculations for the bulk structural phases of ZnO under high pressure. The study is based on density functional theory (DFT), using the projector augmented wave (PAW) potentials, and the Heyd-Scuseria-Ernzerhof (HSE06) screened hybrid density functional for electron exchange and correlation. Apart from the ambient pressure B4 (hexagonal wurtzite) structure, and the B3 (cubic zinc blende) structures, a tetragonal B10 (PbO-type) structure is predicted to be an intermediate phase (at about 273 GPa) between the high-pressure B1 (cubic rocksalt) and B2 (cubic CsCl) phases. It is shown that the HSE functional yields lattice constants and bulk moduli in better agreement with experiment than the widely used conventional exchange correlation functionals. Most importantly, HSE band structure calculations result in significantly improved semiconducting energy band gaps for ZnO over the widely used semilocal functionals, thus improving agreement with experiments.

Primary author

Mr Mahlaga Molepo (University of the Witwatersrand)

Co-author

Prof. Daniel Joubert (University of the Witwatersrand)

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