Photoluminescence of Si-rich silicon nitride: Defect-related states and silicon nanoclusters

The photoluminescence (PL) from defect-related states and Si nanoclusters was observed in the Si-rich silicon nitride films simultaneously. The weaker red-light emission of Si nanoclusters was obtained in the 1100°C annealed films with the 514.5nm excitation. Due to the quantum confinement effect, the PL peaks redshift with the increase of the excess Si concentration. Excited by the 325nm line, strong PL from N and Si dangling bond centers was observed in either the as-deposited films or the 1100°C annealed ones. The results demonstrate that the luminescence from defect-related states or Si nanoclusters is selected by the excitation energy.