From Quantum Electronics to Light-Matter Interaction with Van der Waal Heterostructures
|Speaker||:||Prof. Arindam Ghosh, IISc, Bengaluru|
|Date||:||May 18, 2016|
The impact of graphene on both fundamental science and potential device applications has rejuvenated interest in other layered materials, where individual atomic or molecular planes are weakly coupled through Van der Waal forces. Atomically thin films of transition metal dichalcogenides, bismuth chalcogenide alloys, boron nitride and other similar materials promise devices with diverse functionality, ranging from field-effect transistors to optoelectronic detectors or Spintronic elements. Recently, multi-component two-dimensional hybrids have gained particular importance, where the physical attachment of dissimilar atomically thin membranes create devices that combine advantages of ultimate miniaturization and multiple functionality. Here I shall outline some of the recent advances in both new fundamental phenomena as well as novel device functionality with such hybrids. I shall present evidence of new quantum many-body effects in extremely high mobility field-effect transistors, conceived in the graphene/h-BN (boron nitride) binary hybrids, wherein electron transport can become sensitive even to a single charged impurity in the vicinity of the graphene channel. In the second design, comprising of graphene/MoS2 (molybdenum disulphide) binary heterostructures, a new paradigm in light-matter interaction will be presented, which displays an ultra-sensitive photodetection capability, as well as nearly non-volatile persistent photoconductivity. An outlook to layer-by-layer material engineering beyond binary hybrids will also be discussed.