(Invited) Modification of Properties of N- and B-Doped Graphene by Heteroatom Functionalization

Abstract

Since its discovery in 2004, the graphene has attracted great attention owing to its unique chemical bonding structure, which has excellent chemical, thermal, mechanical, electrical and optical properties. Due to the graphene being a zero band-gap material, it has a limited development in the field of nano electronics. Therefore, to broaden its application scope, it is very important to carry out a study on opening the band gap of graphene. One general strategy for achieving this goal is doping graphene with heteroatoms; in this approach, the properties of graphene are controlled by the nature of the dopant elements and by the percentage of doping being N-doped graphene is of n-type doping, while B-doped graphene is of p-type doping. Compared with that of the intrinsic graphene, the Fermi level of N doped graphene moves up 5 eV; on the contrary, the Fermi level of B doped graphene moves down 3 eV.However, it would be convenient to develop additional tools to achieve further control of the electronic properties of graphene materials. In this context, one of the possibilities would be to functionalize those dopant elements on the graphene sheet in such a way that the electron density and electronegativity of the heteroatom are effectively controlled. This objective could, in principle, be achieved by applying concepts from organic chemistry. Organic synthesis offers proven chemical reactions that are applicable to different types of nitrogen and boron compounds.In the work described here, we´ll present our results on the covalent functionalization of the nitrogen atom or boron atom of N-doped and B-doped graphene. In a simple strategy, electron-donating and -withdrawing groups present on aromatic rings can be used to modulate the electronic properties of the material.