PhD Research Summary
During my Ph.D, I worked on the electronic structure of semiconductor nanoparticles of different forms such as nanowire, nanotubes, QDs etc. In this particular project we have developed a complete set of self-consistent charge density-functional tight-binding (SCCDFTB) parameters for zinc-chalcogenides (ZnX ; X = O, S, Se and Te) and their interaction with C, N, and H. By using this parameter set we have explored the role of size, shape and surface passivated groups in tuning the electronic energy levels of ZnO and ZnO/ZnS core/shell quantum dots (QDs) to develop the novel nanostructures with desired properties and specific applications. We have also studied the electronic structure of ZnO/ZnS core/shell NW as a function of core diameter and shell thicknesses and its interaction with Anthraquinone dye molecule to understand the suitability of this nanocomposite system in solar cell. The electronic structure for interaction of different nucleotide bases with different ZnO nanoparticles has also been explored to understand about the site specificity of nucleobases with different ZnO nanoparticles.
Post Doctoral Research
In my 1st postdoctoral research I mainly investigated the selective carbon nanotube growth using density-functional tight-binding (DFTB) method based on non-equilibrium quantum mechanical molecular dynamics (QM/MD) simulation. Our motivation was to investigate the detail growth dynamics towards chirality controlled growth of single wall carbon nanotube (SWCNT) using different catalysis. We have investigated the SWCNT nucleation on the surface of Al2O3 nanoparticle by chemical vapor deposition (CVD) of CH4 within an aim to find out a more suitable catalyst towards chirality-controlled SWCNT growth. We have explored the role of spin properties of catalytic-transition metal elements in the SWCNT growth dynamics. We have also developed DFTB parameters for binary metals based on Fe, Co, Ni and Cu for surface catalysis and bimetallic alloy catalysts as these parameters are not available yet. Apart from this, we have also studied the surface catalysis related to nanoscale self-assembly using density-functional theory.
My 2nd postdoctoral research mainly focused on heterogeneous catalysis for energy conversion. Our goal was to design and production of highly selective heterogeneous (electro-) catalysts with a long lifetime which can make better use of the world's limited resources and become more environmentally benign..
