Silicene and germanene: advanced synthetic 2D materials for future electronics

Abstract

Atomically thin 2D materials are emerging as a new frontier of materials science. They offer ultimate thickness scaling for nanoelectronic devices that could substantially improve electrostatic control and enable a number of low-power versatile applications, such as ultra-thin-channel field-effect transistors, optoelectronic devices, and solar cells.1 Graphene, the archetypal 2D material, cannot be used in conventional transistor technology because of the inherent difficulty of opening an electronic bandgap in this gapless material. Typically, the chalcogenides (that is, sulfides, selenides, and telluride), with bandgaps comparable to those of conventional group IV or group III–V semiconductors, may have the potential of scaling down to a truly atomic scale. However, in practice these materials are challenging to integrate with existing silicon-based electronics.