Optoelectronic Properties of Heterostructures: The Most Recent Developments Based on Graphene and Transition-Metal Dichalcogenides

The extremely high chargecarrier mobility in graphene has motivated the exploration of unique properties in other two-dimensional (2-D) materials, such as hexagonal boron nitride (h-BN), phosphorene, silicine, and the transition-metal dichalcogenides (TMDs). The latter compounds have generated great interest due to their potential for optoelectronic applications, since their band gaps are tunable as a function of the number of layers, even as the compounds remain flexible and nearly translucent when composed of a few atomic layers.