Structure and size distribution of silicon nanocrystals prepared by pulsed laser ablation in inert background gas

Abstract

Silicon nanocrystals have been synthesized using pulsed laser ablation in argon background gas. The morphology structure and the size distribution of the silicon nanocrystals depending on the background gas pressure (0.1 Pa-100 Pa) have been studied. Experiment results show that the morphology of the silicon nanograins transits from amorphous-like continuous thin film to dispersed nanocrystals with the decreasing of argon pressure. The size of the silicon nanograins increases with the increase of argon pressure (less than 100 Pa). Under higher pressure the size of the silicon nanograins does not increase with the increase of the background pressure monotonously, it comes to a maximum at a critical gas pressure, then begins to decrease when increasing the gas pressure.