Research on electronic and optical properties of pristine and Ag/Au/ Cu-doped graphene/MoS2 heterostructures

The Dirac cone in the single-layer graphene limits its application in electronic devices such as Schottky barrier diodes and field-effect transistors. Thus, we make the novel heterostructures based on graphene to solve this problem. The electronic and optical properties of pristine and Ag/Au/Cu-doped graphene/MoS2 heterostructures are investigated by using the density functional theory. For the Ag/Au/Cu-doped MoS2 monolayer, the results show that they are magnetic. Their bands across the Fermi level, which indicates these systems are metallic. For the Ag/Au/Cu-doped graphene/MoS2 heterostructures, they are metallic and nonmagnetic. Especially in the Audoped graphene/MoS2, the Dirac cone opens about 66 meV. It means that Au-doped graphene/MoS2 has the potential to be a candidate material for high speed electronic devices. Compared with pristine heterostructure, the probability of electron transition in the low energy region is the enhanced in Ag/Au/Cu-doped systems. The optical absorption coefficient of doped heterostructure is enhanced in the range of 0-0.4 eV and 1.7-2.7 eV. This work indicates that these heterostructures have a certain potential in the application of nanodevices.