Formation of silicon nanoparticles and web-like aggregates by femtosecond laser ablation in a background gas

Citation:

B. R. Tull, J. E. Carey, M. A. Sheehy, C. M. Friend, and E. Mazur. 2006. “Formation of silicon nanoparticles and web-like aggregates by femtosecond laser ablation in a background gas.” Appl. Phys. A, 83, Pp. 341–346. Publisher's Version

Abstract:

We show that the mechanism of nanoparticle formation during femtosecond laser ablation of silicon is affected by the presence of a background gas. Femtosecond laser ablation of silicon in a H2 or H2S background gas yields a mixture of crystalline and amorphous nanoparticles. The crystalline nanoparticles form via a thermal mechanism of nucleation and growth. The amorphous material has smaller features and forms at a higher cooling rate than the crystalline nanoparticles. The background gas also results in the suspension of plume material in the gas for extended periods, resulting in the formation (on a thin film carbon substrate) of unusual aggregated structures including nanoscale webs that span tears in the film. The presence of a background gas provides additional control of the structure and composition of the nanoparticles during short pulse laser ablation. PACS 81.16.-c
Last updated on 07/24/2019