Effect of the reflection by the silicon aggregates on the photoluminescence from silicon nitride film embedded silicon nanocrystals

In this work, the effect of the high silicon nanocrystals density as well as the radiated waves interference on the photoluminescence (PL) spectrum of silicon nanocrystal (Si-nc) embedded in silicon nitride film is studied. The film is prepared using low pressure chemical vapor deposition (LPCVD) following by a high temperature annealing. It was found that for silicon nitride of a high silicon content sample, the interference effect based on only the thickness of the film is unable to satisfactory explain the distortion on the PL spectrum. Using Monte Carlo analysis, it was shown that the simulated and the experimental PL spectra accurately superpose when taking into account the contribution of the reflection from silicon nanocrystals as well as the distance traveled by the radiated waves.