Speaker
Dr
Edwin Mapasha
(University of Pretoria)
Description
Recently, the two-dimensional (2D) material systems such as graphene, graphane, hexagonal boron nitride and various transition metal dichalconides monolayers have attracted great research interests owing to their peculiar properties. Graphane, a fully hydrogenated graphene, is a wide band gap semiconductor with a large exciton binding energy according to density functional theory (DFT) prediction. Modulating the electronic structure of a semiconductor material is essential for device operations. Doping is recently considered to be a powerful tool to fine tune the band gap of various semiconductor materials. Using the hybrid density functional theory (DFT) approach, we study the electronic properties of a graphane monolayer substitutionally doped with B (BCH) and Al (AlCH) atoms. The density of states (DOS) plot reveals that the band gap of graphane is slightly tuned down due to the BCH doping. Different scenario is observed on the AlCH DOS, where the metallic character has been noted due to the Al dependant spin states crossing the Fermi level. We further examine the response of the Al dependant spin states on the multiple charge states. An addition of the electrons retains the metallic character of AlCH, while the positive charges re-open the band gap, although in a small amount of magnitudes. Our findings suggest the possibility of fine tuning the band gap of graphane through the defect and charge doping.
Level for award<br> (Hons, MSc, <br> PhD, N/A)?
N/A
Apply to be<br> considered for a student <br> award (Yes / No)?
no
Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?
no
Primary author
Dr
Edwin Mapasha
(University of Pretoria)
Co-authors
Mr
Emmanuel Igumbor
(University of Pretoria)
Ms
NOELIARINALA FELANA ANDRIAMBELAZA
(University of Pretoria)
Prof.
Nithaya Chetty
(University of Pretoria)
