The role of quantum confinement and crystalline structure on excitonic lifetimes in silicon nanoclusters

The emission energy dependence of the photoluminescence (PL) decay rate at room temperature has been studied in Si nanoclusters (Si-ncl) embedded in Si oxide matrices obtained by thermal annealing of substoichiometric Si oxide layers SiyO1−y, y=(0.36,0.39,0.42), at various annealing temperatures (Ta) and gas atmospheres. Raman scattering measurements give evidence for the formation of amorphous Si-ncl at Ta=900 °C and of crystalline Si-ncl for …