Luminescence simulations of ensembles of silicon nanocrystals

Abstract

The luminescence of silicon nanocrystals (NCs) has attracted a great deal of interest due to the numerous potential photonic applications of light-emitting silicon. However, the excitation mechanisms and cluster-cluster interactions in densely-packed ensembles, as well as the recombination processes that influence the emission spectrum and lifetime are not yet well understood. In order to generate a more complete picture of the controlling parameters in the luminescence, a dynamic Monte Carlo model that incorporates several key physical processes for luminescent nanocrystal ensembles is devel-oped. The model simulates Forster-type multipole energy transfer, tunnelling interactions, radiative decay and non-radiative trapping in physically realistic (lognormal) distribu-tions of silicon NCs. The results of the simulation illustrate the effects of the NC size distribution, homogeneous and in-homogeneous broadening, NC packing density, and non-radiative trapping on the ensemble luminescence spectrum. © 2009 WILEY-VCH Verlag GmbH & Co. KGaA,.