Comprehensive analysis of electronic properties due to N, O, Be, and B elements doped and adsorbed on graphene from DFT calculations

Abstract

Doping and adsorption of impurities affect the electronic properties of graphene. In this paper, using density functional theory (DFT) calculations, we present a comprehensive analysis of the effects of substitutional doping as well as atomic and diatomic adsorption on the electronic properties in graphene. Four elements, i.e., N, O, Be and B are considered. We find that (1) the substitutional doping with either of the four elements results in opening of the bandgap, and the bandgap increases with increase in the doping concentration. (2) The N, O and B atoms chemisorb on the graphene surface and open the bandgap, whereas Be atom physisorbs without changing the bandgap of pristine graphene. (3) Diatomic N2 and O2 physisorb on graphene and do not alter the bandgap, whereas both Be2 and B2 chemisorb on graphene but only B2 opens the band gap. The differences in the properties due to LDA and GGA exchange-correlation functionals, van der Waals correction terms, and system sizes are also presented. These results are compared with the existing literature, and possible underlying reasons for the existing significant discrepancies among literature are discussed.