48. Graphene

More than a decade has passed since the graphene was synthesized for the first time but still there are many applications that have not been explored. The first intended application for graphene was its high mobility property for high-speed electronics. This task became more difficult when the problem with zero bandgap of graphene made an obstacle to close the current flow of transistor. Different remedies, for example, downscaling the dimensions to nano-ribbons and bilayer structures were proposed to create a reasonable bandgap in graphene for electronic applications. The main idea was to improve the figure of merit I_on ∕ I_off for RF devices. Although many important achievements were made, but later graphene was considered as a better choice for photonic applications. For example, graphene was used as light absorber in the lateral direction for modulators, or sensitive to light in photodetectors when it is vertically illuminated. Nowadays the graphene has inaugurated a new platform in flexible and transparent electronics. As example, electronics giant producers have already integrated graphene for flexible screens.

During recent years, many research efforts have been spent on other two-dimensional (2-D) crystals (transition metal dichalcogenides, silicene, and germanene) as competitors to graphene but it is still a long way to integrate such materials for industrial applications.