The improved method to determine the nucleation region of Si nanoparticles formed during pulsed laser ablation

Abstract

The determination of the region for Si nanoparticles synthesized by pulsed laser ablation was helpful to find proper parameter to obtain the high quality nanocrystalline silicon (nc-Si) thin films. A XeCl excimer laser was used to ablate high-resistively single crystalline Si target under a deposition pressure of 10 Pa. Glass or single crystalline (111) Si substrates, in parallel with the axial direction of silicon target, were located at a distance of 2.0 cm under the plasma to collect a series of nc-Si thin films. The Raman spectra, X-ray diffraction spectra (XRD) and Scanning electron microscopy (SEM) images show that Si nanoparticles deposited in substrates were only formed in the range 0.3~3.0cm away from the target. In this the size of the nanoparticles increased firstly and then reduced, meanwhile, the distributions for the size of the nanoparticles were also changed. According to the character of the beginning and the terminus of nucleation area, combining with the Horizontal Projectile Motion, the range and position of nucleation area were determination.