<title>Synthesis of quantum nanostructures composed of monodispersed silicon nanoparticles and indium oxide thin films using pulsed laser ablation</title>

Abstract

We have developed a novel codeposition process system for producing quantum nanostructures composed of monodispersed silicon (Si) nanoparticles and indium oxide (In<SUB>2</SUB>O<SUB>3</SUB>) thin films. The codeposition process system consists of a chamber for the formation of nanoparticles by pulsed laser ablation (PLA) using a Nd: YAG SHG laser beam in inert background gas, a low-pressure differential mobility analyzer (LP-DMA) for classifying Si nanoparticles, and a chamber for the deposition of Si nanoparticles and In<SUB>2</SUB>O<SUB>3</SUB> thin films. The classified Si nanoparticles have sharp size distribution of which the geometrical standard deviation is 1.2; thus, we call the classified Si nanoparticles monodispersed. The monodispersed Si nanoparticles were deposited onto a substrate and In<SUB>2</SUB>O<SUB>3</SUB> was codeposited by PLA using an ArF excimer laser beam in the deposition chamber. By controlling background gas pressures in PLA and gas flow rates in LP-DMA, the codeposition of monodispersed Si nanoparticles and In<SUB>2</SUB>O<SUB>3</SUB> thin films was realized. Evaluation of the nanostructures was carried out using a high-resolution transmission electron microscope. From observation of the nanostructures by energy dispersive spectroscopy, we found that silicon, indium and oxygen were deposited homogeneously. Furthermore, we attempted to modify the surface of monodispersed Si nanoparticles by introducing oxygen gas in the deposition chamber.