2-D Materials Modelling: from Transistors to Majorana Fermions

Since the first experimental demonstration of a monolayer MoS₂ transistor in 2011, transition metal dichalcogenides (TMDs) have received a wide attention from the scientific community as potential replacement for Silicon FinFETs at the end of the semiconductor roadmap. As graphene, TMDs exhibit excellent electrostatic properties due to their 2-D nature, but contrary to it, they are characterized by large band gaps, while keeping acceptable mobilities. However, so far, no transistor based on a TMD channel could outperform the Si technology. While this limitation can be partly attributed to technical issues, the TMD bandstructure also explains this behavior: electrons/holes are not fast enough to allow for large ON-state currents. 

Through density functional theory (DFT), the existence of more than 1,800 2-D materials was recently predicted. Among them there might be components with better transport properties than TMDs. We therefore selected 100 monolayers out of this database of 2-D materials, combined DFT and quantum transport to simulate their “current vs. voltage” characteristics, and identified 13 candidates with both n- and p-type ON-state currents larger than what Si FinFETs are expected to deliver in the future. The results of these theoretical investigations will be presented in this talk, together with the possible application of conventional and exotic 2-D materials as hosts for Majorana Fermions.