Influence of additional gas flow on size distribution of Si nanoparticles deposited by pulsed laser ablation

A new method for controlling the size distribution of Si nanoparticles during the process of pulsed laser ablation is proposed. The nanocrystalline silicon films were prepared by pulsed laser ablating a high resistivity single crystalline Si target in argon gas of 10 Pa. A bunch of argon gas flow was introduced at 2.0 cm above the ablation point within the axial range from 03 cm to 3.0 cm, and the as-prepared Si nanoparticles were deposited on single crystalline Si substrates located at 2.0 cm under the ablation point. Surface morphology of films was observed by scanning electron microscopy (SEM). It is found that the size of grain, without introducing gas flow, increases initially and then decreases with increasing distance between target and substrate, and the peak appears at the dista