Density functional theory study on the electronic, optical and adsorption properties of Ti-, Fe- and Ni- doped graphene

Abstract

Graphene has attracted widespread attention for its excellent physicochemical properties and a bright application prospect. However, the zero bandgap of graphene limits its application in optoelectronic devices. The Ti-, Fe- and Ni-doped graphene (Ti-G, Fe-G and Ni-G) with a non-zero bandgap catches our eyes. Therefore, the geometrical structures, electronic, optical and adsorption properties of Ti-G, Fe-G and Ni-G configurations are systematically investigated. Our results show that Ti-G, Fe-G and Ni-G systems are nonmagnetic semiconductors with the bandgaps of 0.441/0.443/0.338 eV. The reasons of the systems own bandgaps mainly originate from the hybridization between the d orbital of Ti/Fe/Ni atoms and p orbital of C atoms, which break the equivalent sublattices of intrinsic graphene. Furthermore, the doped systems exhibit good thermal stability, high Young's modulus and remarkable charge transfer. Optical adsorption spectrum reveals that Ti-G, Fe-G and Ni-G systems occur redshift and possess large light absorption range (up to 3000 nm). Adsorption energies demonstrate that they are highly sensitive to SO2, NO and NO2. The work provides a theoretical guidance for developing Ti-G, Fe-G and Ni-G systems with flexible application in optoelectronic devices and efficient gas detectors.