Size-Controllable Si Nanocrystals by Modulating Nitride Component in a-SiNx Films for Light-Emitting Devices

Size-controllable Si nanocrystals were fabricated by thermal annealing a-SiN_x films that contain various Si/N ratios. The Raman spectra measurements show that the average grain size mainly relies on the Si/N ratios, and it can be reduced down to ~4nm by decreasing the Si/N ratio. It is also found that threshold crystallization temperature increases with the decrease in the Si/N ratios. The Fourier transform infrared spectra further indicate that the Si nanocrystals are passivated by nitrogen. The present advancement opens up the possibility of developing efficient Si-based light-emitting devices.