SAIP2015

<i>Ab</i>-<i>initio</i> studies of Tm³⁺ interstitial defects in Germanium (Ge) using Hybrid Functional HSE06

30 Jun 2015, 14:00

20m

Oral Presentation Track A - Division for Physics of Condensed Matter and Materials DPCMM

Speaker

Mr Emmanuel Igumbor (University of Pretoria)

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

Prof Walter Meyer
wmeyer@up.ac.za

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

Yes

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

Yes

Abstract content <br> &nbsp; (Max 300 words)<br><a href="http://events.saip.org.za/getFile.py/access?resId=0&materialId=0&confId=34" target="_blank">Formatting &<br>Special chars</a>

In this work we present ab-initio calculations results of Tm³⁺ interstitial defects in Germanium (Ge) in the frame work of density functional theory (DFT) using hybrid (HSE06) exchange correlation functional. We calculate the formation and transition levels energy of different configurations and their charge states of -2, -1, 0, +1 and +2. In all the configurations, our result shows that the formation energies are relatively low and stable, revealing the T configuration to be the most stable. While the T configuration did not have a positive-U the H exhibit some properties of positive-U . We found transition levels that behave as deep and shallow donor and deep acceptor. The transition levels of (0/-1) and (+1/0) lies at the mid region of the band-gap which give rise to small optical peak, while the transition level of (+1/+2) lies close to the valence band maximum.

Level for award<br>&nbsp;(Hons, MSc, <br> &nbsp; PhD, N/A)?

PhD

Please indicate whether<br>this abstract may be<br>published online<br>(Yes / No)

Yes