Speaker
Mr
Okikiola Olaniyan
(UP)
Description
Ab-initio calculations within the framework of density functional have been performed to study the electronic properties of Be and N co-doped graphene. The results have been compared with that of Be-doped, N-doped and pristine graphene. The effect of doping and isomerization on the electronic properties of these systems have been studied by varying the impurity concentrations of Be-doped and N-doped graphene systems from 3.13 through 12.5 %, while for Be and N co-doped graphene, the concentration have been varied from 6.25 through 25.0 % impurity concentration.The formation energies of the systems with different impurity configurations were calculated to examine their relative stabilities. It was found that for Be-N co-doped graphene, N and Be coexisting as the nearest neighbours is energetically the most favourable configuration. Moreover, at the same impurities concentration, Be-N co-doped graphene was observed to be more stable than Be-doped graphene due to its lower formation energy. Thus these results reveal that it is much easier to synthesize Be-N co-doped graphene than to synthesize Be-doped graphene. Hence, the relatively high formation energy of Be-doped graphene could be the reason why the system is yet to be synthesis experimentally.
The results of the electronic structure calculations reveal that Be-N co-doped and Be-doped graphene are p-type semiconductors while N-doped graphene has been verified to be n-type semiconductor.
For all the doped systems considered, it was observed that the size of the band gap increases with impurity concentration with respect to the aforementioned energetically most favourable isomer. At impurity concentration of 3.13 %, a minimum band gap of 0.44 eV and 0.21 eV was realised for Be-doped and N-doped graphene respectively while at 12.5 % corresponding maximum gap of 1.41 eV and 0.6 eV were observed. Besides, Be-N co-doped graphene were found to have a minimum band gap of 0.43 eV at 6.25 percent and a maximum gap of 1.54 eV at 25.0 % impurity concentration.
The results of our study demonstrate that the band gap of graphene can be tailored to meet the requirements of specific applications in nanoelectronic devices.
Main supervisor (name and email)<br>and his / her institution
Prof. Ncholu Manyala
ncholu.manyala@up.ac.za
University of Pretoria
Level for award<br> (Hons, MSc, <br> PhD, N/A)?
PhD
Apply to be<br> considered for a student <br> award (Yes / No)?
Yes
Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?
No
Primary author
Mr
Okikiola Olaniyan
(UP)
Co-authors
Mr
Abubakar Khaleed
(University of Pretoria)
Dr
Edwin Mapasha
(University of Pretoria)
Mr
Emmanuel Igumbor
(University of Pretoria)
Dr
Ncholu Manyala
(University of Pretoria)
