Gas-phase synthesis of nanostructured particulate films

Abstract

Nanostructured films find increasing industrial application for instance in membranes, gas sensors, fuel cells, catalytic layers, biocompatible surfaces, batteries, and electronic components. The performance of these functional layers can be improved by using nanoparticles as building blocks and thereby incorporating their extraordinary physical and chemical properties into the three-dimensional film structure. This article presents an overview of recent research on gas-phase methods for the production of such nanostructured films. Nanoparticle synthesis, methods for gas-phase particle manipulation as well as particle deposition are addressed. Emphasis is placed on flame and hot wall reactors for nanoparticle production along with cluster-beam deposition techniques. Means for gas-phase particle size selection and nanoparticle beam formation by expansion nozzles, aerodynamic lenses or electric charging are introduced. It is highlighted how the deposition process can be controlled to yield either highly porous nanostructured films or precisely ordered arrays of 1D, 2D and 3D nanostructures to fabricate microsensors, catalytic microreactors or of semiconductor nanowires.