Effect of interface alloying and band-alignment on the Auger recombination of heteronanocrystals

We report a numerical study of the effect of interface alloying and band alignment on the Auger recombination processes of core/shell nanocrystals. Smooth interfaces are found to suppress Auger recombination, the strength of the suppression being very sensitive to the core size. The use of type-II structures constitutes an additional source of suppression, especially when the shell confines electrons rather than holes. We show that magic sizes leading to negligible Auger recombination [Cragg and Efros, Nano Letters 10, 313 (2010)] should be easier to realize experimentally in nanocrystals with extended interface alloying and wide bandgap. (C) 2012 American Institute of Physics. [doi:10.1063/1.3684981]