Influence of synthesis conditions on the structural and optical properties of passivated silicon nanoclusters

First-principles molecular dynamics and quantum Monte Carlo techniques are employed to gain insight into the effect of preparation conditions on the structural and optical properties of silicon nanoparticles. Our results demonstrate that (i) kinetically limited nanostructures form different core structures than bulk-derived crystalline clusters, (ii) the type of core structure that forms depends on how the cluster is passivated during synthesis, and (iii) good agreement with measured optical gaps can be obtained for nanoparticles with core structures different from those derived from the bulk.