SAIP2012

Van der Waals density functional studies of hydrogen adatoms on bilayer graphene

10 Jul 2012, 11:00

20m

Oral Presentation Track A - Division for Condensed Matter Physics and Materials DCMPM2

Speaker

Mr Edwin Mapasha (University of Pretoria)

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

no

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

Prof Nithaya Chetty
nithaya.chetty@up.ac.za
University of pretoria

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

PhD

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

Yes

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

We present a comparative density functional study of the adsorption of hydrogen atoms on bilayer graphene.
Two different exchange-correlation functionals are employed to explore the possible configurations of
hydrogen adsorption at 50% coverage. Using the non-local van der Waals density functional, we identify three distinct competing configurations that retain the coupled bilayer structure at 0 K. One of the configurations undergoes a spontaneous transformation from hexagonal to tetrahedral structure, under hydrogenation, with the energy of formation of -0.06 eV (GGA) and -0.37 eV (vdW-DFC09x).This configuration has a finite band gap of around 3 eV, whereas all other competing configurations are semi-metallic.