CO_2 laser-driven pyrolysis synthesis of silicon nanocrystals and applications

摘要

Applications of silicon quantum dots in various fields need weighable quantities of high quality small Si nanocrystals (nc-Si) in terms of size control, purity and size distribution width. We show that CO_2 laser-driven pyrolysis of SiH_4 can provide a precise size control of powders by way of CO_2 laser pulse length adjustment while keeping the laser average power and all the other synthesis parameters constant. This parameter can be considered as a new simple to use synthesis parameter to finely control the size of nc-Si around 4-5 nm. Two applications currently in progress in the photovoltaic and the biomedical fields are given as examples considering the laser pyrolysis method as an adequate first step for the synthesis of complex silicon-based nanostructures and suspensions.