The difference of energies of Si atoms with single-crystalline, amorphous, free and nanoparticle configurationsY. L. Wang1, Z. C. Deng1, L. Z. Chu1, G. S. Fu1 and Y. C. Peng2
1 College of Physics Science and Technology, Hebei University - Baoding 071002, PRC
2 College of Electronic and Informational Engineering, Hebei University - Baoding 071002, PRC
received 15 February 2009; accepted in final form 11 March 2009; published April 2009
published online 8 April 2009
Nanocrystalline silicon (nc-Si) films were systematically prepared via three ways: a) laser anneal or b) thermal anneal of the amorphous silicon (-Si) films deposited by pulsed-laser ablation (PLA) in base vacuum, c) direct PLA in high-purity Ar gas with pressure of 10 Pa. The anneal-laser fluence, thermal-anneal temperature and ablation-laser fluence thresholds corresponding to the beginning of nanoparticles formation were respectively determined by using scanning electron microscopy (SEM), Raman and X-ray diffraction (XRD) techniques. Incorporated with crystallization mechanism, energies compensated for the formation of one Si nanoparticle in the three ways were calculated approximately. The result shows that for different crystallization ways, the potential barriers during the formation of one ~ 16 nm nanoparticle are on the order of 10-9 mJ.
52.38.Mf - Laser ablation.
61.46.-w - Structure of nanoscale materials.
79.20.Ds - Laser-beam impact phenomena.
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