Advances in tuning band gap of graphene by potential doping using DFT: a review

Abstract

Graphene: a sp2 carbon system is a zero band gap semiconductor. In spite of having extraordinary properties, opening of band gap is the bottleneck in the path of graphene for becoming the heart of all modern electronics. Chemical doping can prove itself to be the fastest solution to this problem as it is one of the most informal approaches to induce band gap in pristine. Due to tiny nanostructures and dimensions of graphene, modelling and simulative study of graphene is more effective and confirmative than experimental results. In this study we have compared our results with the previous works, our simulation matches well with the previous works. The main concern is on the substitution and pair doping of BN, B and N open up an energy band gap up to (0.379eV) and (0.386eV). Codoping of B-N create a band gap up to (0.712eV) and pair doping shows that 1BN(0.616eV), 2BN(0.386eV), 3BN pair create a sharp increase in band gap up to (1.457eV) when substitute on graphene, while the substitution doping and increased in the super cell models with the same doping concentration of silicon induced a band gap of 1.019eV, where Si doping on different super cell shows a band gap enhancement from 0.57eV at (6x6) model to 1.90eV at (5x5) model and change its nature from semimetal to semiconductor. The present review article focuses on the alteration of electronic and optical properties by adding different dopants on to the graphene sheets, using density functional theory (DFT) calculations. Doping can improve the electronic properties of graphene by producing a small band gap in it, resulting in the appropriateness of this interesting material for modern electronics. Different codes and approximations have been applied to tune the band structure of graphene that has been discussed in the article.