Sputter deposition of tungsten trioxide for gas sensing applications

Tungsten trioxide thin films were grown by reactively sputtering a circular WO3 target in different Ar-O-2 atmospheres. After deposition, data an the structural, optical and electrical properties were obtained by using transm ission electron microscopy (TEM) to examine the structure and the morpholog y of the films, UV-VIS spectrophotometry to determine optical absorption ed ge characteristics, and Hall effect measurements to determine the change ca rrier mobility and the film resistivity. In addition, the film resistance v ariations in controlled atmospheres were examined and the gas sensing prope rties of films grown under different conditions were compared. The aim of t he study was to examine the effect of O-2 concentration in the sputtering a tmosphere on structural, optical, electrical and sensing properties. (C) 19 98 Kluwer Academic Publishers.