The recent advent of atomically thin 2-dimensional materials such as graphene, hexa boronitride, layered transition metal chalcogenide and many strongly correlated materials, has provide a new opportunity of studying novel quantum phenomena in low dimensional systems and utilizing them for novel electronic devices. In particular, graphene has been provided us opportunities to explore exotic transport effect in low-energy condensed matter systems and the potential of carbon based novel device applications. In this presentation I will first discuss the exotic quantum transport behavior discovered in graphene nanostructures in the relation to the device applications beyond CMOS operation. In addition, I will discuss the new type of material classes based on 2-dimensional van der Waal materials and their heterostructures including atomically thin vertical Schottky junction and p-n heterojunction based on the vdW assembly of transition metal dichalcogenides and graphen. Unlike conventional p-n junctions, here charge transport and photovoltaic response of the devices are found to critically depend on the interlayer recombination process between majority carriers mediated by tunneling across the interface. We demonstrate the enhanced optoelectronic performances in the vdW heterostructures, suggesting that these a few atom thick interfaces may provide a fundamental platform to realize efficient, fast and tunable bipolar electronics, photovoltaics, and optoelectronics.
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