Silicon Nanocrystals Produced by Nanosecond Laser Ablation in an Organic Liquid

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• 作者：Kamal Abderrafi ; Rau虂l Garci虂a Calzada ; Maxim B. Gongalsky ; Isaac Sua虂rez ; Rafael Abarques ; Vladimir S. Chirvony ; Victor Yu. Timoshenko ; Rafael Iba虂ñ ; ez ; Juan P. Marti虂nez-Pastor
• 刊名：Journal of Physical Chemistry C
• 出版年：2011
• 出版时间：March 31, 2011
• 年：2011
• 卷：115
• 期：12
• 页码：5147-5151
• 全文大小：840K
• 年卷期：v.115,no.12(March 31, 2011)
• ISSN：1932-7455

文摘

Small (3鈭? nm in diameter following HRTEM images) Si nanocrystals were produced in a two-stage process including (1) nanosecond laser ablation of a Si target in an organic liquid (chloroform) that results in formation of big composite polycrystalline particles (about 20鈭?00 nm average diameter) and (2) ultrasonic post-treatment of Si nanoparticles in the presence of HF. The post-treatment is responsible for disintegration of the composite Si particles, release of small individual nanocrystals, and reduction of their size due to HF-induced etching of Si oxide. The downshift and broadening of the 520 cm^鈭? Raman phonon band of the small Si nanocrystals with respect to the bulk Si Raman band is consistent with the presence of 4.5 nm Si nanocrystals. The photoluminescence spectra (450鈭?00 nm) and decay kinetics of small Si nanocrystals were detected, and the possible origin of the luminescence is discussed.