Quantum simulation of multiple-exciton generation in a nanocrystal by a single photon

Wayne M. Witzel, Andrew Shabaev, C. Stephen Hellberg, Verne L. Jacobs, Alexander L. Efros

Published 2010-05-21, updated 2010-09-22Version 2

We have shown theoretically that efficient multiple exciton generation (MEG) by a single photon can be observed in small nanocrystals (NCs). Our quantum simulations that include hundreds of thousands of exciton and multi-exciton states demonstrate that the complex time-dependent dynamics of these states in a closed electronic system yields a saturated MEG effect on a picosecond timescale. Including phonon relaxation confirms that efficient MEG requires the exciton--biexciton coupling time to be faster than exciton relaxation time.