Alex Voznyy

Submitted by admin on mar, 04/05/2011 - 21:52
Quantum Theory Group, Institute for Microstructural Sciences, NRC
date: 
12/03/2010
sujet: 
Semiconductor nanocrystals for photovoltaics, lasers and bio-imaging: problems and perspectives, a theoretical viewpoint
résumé: 

Optical properties of the colloidal semiconductor nanocrystals (NCs) can be tuned via modification of their size, shape, composition, and formation of heterostructures. Their production is cheaper and more scalable than that of epitaxial quantum dots, making them attractive candidates for LEDs and lasers. Generation of multiple excitons in a NC from a single absorbed photon holds a great promise to reduce the losses to heat in the next-generation solar cells.
This talk will present our recent efforts at NRC to develop the tools for atomistic modeling of the NC photoexcited properties, addressing quantum confinement, Coulomb scattering, and surface effects. Our simulations uncovered the role of correlations in biexciton binding, allowed to estimate the coupling strength between excitons and biexcitons, and discover the mobile surface traps.