Thrust Areas

With the accelerating revolution in semiconductor industry, nanoscale solid-state device research currently entails a shift from simple transistor scaling to developing emerging heterogeneous systems with new physics, materials, and devices having unique functionalities and possibly operating in beyond von Neumann computing frameworks or quantum-inspired technological frameworks. Besides, clean energy alternatives are also on the verge of a new era of sustainable energy development in powering the future. In light of that, our current research focuses on three primary directions, (a) quantum materials, (b) quantum devices, and (c) green energy generation & storage, with a variety of imperative subdomains  (see above) of fundamental and applied research. 

Research Highlights

Realization of layered group III-nitrides 

Group-III nitrides have typically 3D nature in crystal formation, except for the hexagonal boron nitride (hBN). Previously, wurtzite GaN was theoretically predicted to reconstruct into a 2D graphitic structure when thinned down to a few atomic layers, however, there was an obscurity in its crystal stability. Therefore, in this work, we have theoretically demonstrated and experimentally validated the atomic structure of 2D GaN. We have here shown the exact crystallographic and electronic nature and thermodynamic stabilities of group III-nitrides. (Nature Materials, vol. 15, pp. 1166-1171, 2016)

Atomically thin resonant tunnel diodes 

Vertical integration of two-dimensional van der Waals materials is predicted to lead to novel electronic and optical properties not found in the constituent layers. Here, we have demonstrated that when two different pristine TMD monolayers assemble to form a heterostructure, then the individual layers become n or p-type in nature and form type II staggered gap heterojunction due to the interlayer van der Waals (vdW) interaction. The vertical transport in this heterostructure leads to a resonant tunneling with spectrally narrow negative differential resistance characteristics. (Nature communications, vol. 6, pp. 7311, 2015)

MIT-based tunneling junctions

We have demonstrated here a correlated phase transition material (like VO2) based tunnel junction switches that exploit the abrupt opening and collapse of the band gap in the correlated material to sharply turn ON and OFF. Here, we have carried out non-equilibrium transport calculations using density functional theory combining with the non-equilibrium Green’s function formalism to make a direct comparison between the measurements and the quantum mechanical transport in VO2 based tunnel junction which shows an excellent agreement in the signature shape of the tunnel conductance. (ACS Nano-Letters, vol. 14, pp. 6115–6120, 2014)

National and International Collaborators

Press Coverage