The size distribution of Si nanoparticles prepared by pulsed-laser ablation in pure He, Ar or Ne gas

Nanocrystalline silicon films were prepared by pulsed-laser ablation in high-purity He, Ar or Ne gas at room temperature under a deposition pressure of 10 Pa. The Raman and X-ray diffraction spectra indicate that the films are nanocrystalline. Scanning electron microscopy images show that Ar or Ne gas, compared to He gas, yields smaller and more uniform-sized Si nanoparticles at the same deposition conditions, which is also confirmed by the blue-shifted and narrower peaks obtained in photoluminescence measurement. Ne gas induces the smallest and most uniform, in size, Si nanoparticles among all the three gases, which may be attributed to a more effective energy transfer between Si and Ne atoms resulting from the adjacent degree of the atomic weights.