Eur. Phys. J. D 34, 291-294 (2005)
https://doi.org/10.1140/epjd/e2005-00161-2

Growth, structure and electrical properties of tungsten oxide nanorods

Université D'Aix-Marseille III, L2MP-UMR CNRS 6137, Faculté des sciences et techniques, case 151, 52 avenue Escadrille Normandie Niemen, 13397 Marseille Cedex 20, France

Corresponding author: ^a marcel.gillet@univ.u-3mrs.fr

Received: 6 September 2004
Published online: 13 July 2005

Abstract

Tungsten trioxide has shown good sensing properties towards various gases. Recently thin nanostructured WO₃ films have been tested. Due to their large surface area to volume ratio they exhibit good sensitivity depending on the grain size. However in conventional WO₃ thin films the average grain size exceeds the thickness of the surface space charge layer, so the electrical conduction is mainly controlled by the carriers transport across the grain boundaries. An alternative way seems to be in a monocrystalline material with nanometric dimensions. Our objective is to fabricate nanosized tungsten oxide rods and to test their sensing properties under gas adsorption. In this work, we focus on the growth, the structure and the electrical properties of tungsten nanorods. The tungsten oxide nanorods were grown by vapour transport from a WO₃ layer onto a substrate (Mica). The nanorods growth was controlled by the temperature gradient between the WO₃ layer and the substrate. Their morphology was investigated by AFM and their structure by TED and TEM. We have investigated the conductivity of the WO₃ nanorods with a technique derived from Atomic Force Microscopy operating in contact mode with a conductive tip (Resiscope).