Impact of particle interactions on the photoluminescent stability of silicon nanocrystal clusters

We combine experiments, Monte Carlo simulations and ab initio calculations to explore the influence of inter-particle interactions on the photoluminescent stability of silicon nanocrystal (SiNC) clusters. The time-dependent photoluminescence (PL) emitted by structures ranging in size from a single nanocrystal to collections of several thousand SiNCs is compared with Monte Carlo simulations of non-interacting nanocrystal ensembles. The discrepancy is modeled using calculations of the energy transfer rate between neighboring SiNCs as a function nanocrystal size, separation, and size disparity, and the influence of surface defects and excitation power on PL stability is explained.