Nowadays, several two dimensional (2D) material was studied with its unique properties. The figure shows various 2D materials such as Graphene, Molybdenum disulfide (MoS2), Boron nitride (BN), and hybrid structure of 2D materials (graphene on BN in this figure). The graphene has been experimentally discovered few years ago by Phillip Kim, A.K. Geim and their coworkers. They used mechanically exfoliation method for separating layers from graphite as shown in Figure (a). Graphene has various unique properties such as high mobility, possibility of quantum effect at room temperature, ambipolar electric field effect and application for flexible and transparent devices. Recently, the MoS2 field-effect transistor shows fantastic performance with Hafnium Oxide used for dielectric layer, (It was published in Nature nanotechnology). It has not only higher mobility than silicon but also high On/Off ratio. The BN was suggested to replace silicon dioxide deposited substrate which is usually used for graphene substrate. The graphene devices show enhanced properties on BN due to elimination of charge trapping, rough surface, and the same hexagonal structure (It was also published in Nature nanotechnology). The figure (d) shows BN/graphene structure by using stacking process which had been posted yesterday on my blog.
Optical images for (a) Graphene, (b) MoS2, (c) BN, and (d) hybrid 2D structure.
