Something More than Graphene – Futuristic Two-Dimensional Nanomaterials

The race to scale down electronic circuits has resulted in the novel two-dimensional (2D) materials. Graphene, after its discovery in 2004, topped the list on account of its superior electronic, optical, mechanical and transport properties. Since, graphene possesses zero band gap, it could not be used in digital circuits; so other potential 2D materials have been studied. Materials like transition metal dichalcogenides (TMDs), 2D oxides, hexagonal boron nitride and 2D Xenes (silicene, borophene, stanene, phosphorene and borophene) belong to the plethora of materials following the discovery of graphene. They apparently show potential in quantum computing and superfast electronics. They display ballistic transport and relativistic properties due to the mass-less fermions. Quantum spin Hall effect too is observed along with quantum Hall effect in many of them, which advocates their use in spintronics. Owing to these superior properties, they appear to be promising candidates for a paradigm shift from microelectronics to nanoelectronics. The 2D structural analogues of graphene, i.e. silicene, borophene, stanene, phosphorene and germanene are fast emerging alternative 2D materials compared to 2D oxides and TMDs, since they have a better degree of integration with the existing silicon-based technology. This article surveys the emerging 2D materials which hold promise in the future.