Influence of organic solvent on optical and structural properties of ultra-small silicon dots synthesized by UV laser ablation in liquid
Authors: Intartaglia R., Bagga K., Genovese A., Athanassiou A., Cingolani R., Diaspro A., Brandi F.
Autors Affiliation: Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova, Italy; Nanochemistry, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova, Italy; Center for Biomolecular Nanotechnologies UniLe, Istituto Italiano di Tecnologia, via Barsanti, 73010 Arnesano Lecce, Italy
Abstract: Ultra small silicon nanoparticles (Si-NPs) with narrow size distribution are prepared in a one step process by UV picosecond laser ablation of silicon bulk in liquid. Characterization by electron microscopy and absorption spectroscopy proves Si-NPs generation with an average size of 2 nm resulting from an in situ photofragmentation effect. In this context, the current work aims to explore the liquid medium (water and toluene) effect on the Si-NPs structure and on the optical properties of the colloidal solution. Si-NPs with high pressure structure (s.g. Fm3m) and diamond-like structure (s.g. Fd3m), in water, and SiC moissanite 3C phase (s.g. F (4) over bar 3m) in toluene are revealed by the means of High-Resolution TEM and HAADF-STEM measurements. Optical investigations show that water-synthesized Si-NPs have blue-green photoluminescence emission characterized by signal modulation at a frequency of 673 cm-1 related to electron-phonon coupling. The synthesis in toluene leads to generation of Si-NPs embedded in the graphitic carbon-polymer composite which has intrinsic optical properties at the origin of the optical absorption and luminescence of the obtained colloidal solution.
Journal/Review: PHYSICAL CHEMISTRY CHEMICAL PHYSICS (PRINT)
Volume: 14 (44) Pages from: 15406 to: 15411
KeyWords: Silicon Nanoparticles; Nanocrystals; Hydrogen; Water; TolueneDOI: 10.1039/c2cp42195jCitations: 28data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2019-11-17References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here