Au-incorporated tungsten trioxide obtained by pulsed laser deposition

Abstract

Tungsten trioxide (WO3), an important n-type metal oxide semiconductor was intensively studied due to its physical and chemical proprieties in the field of gas sensors. To improve gas sensitivity and selectivity, noble metals such as Au are incorporated in metal oxides structures. The aim of this work is to prepare Au-incorporated WO3 thin films as sensing layers of resistive sensors using Pulsed Laser Deposition (PLD) technique. Au and WO3 targets were irradiated at 213 nm wavelengths in oxygen atmosphere. Thin films of Au incorporated WO3 have been explored to find the properties in terms of morphology and crystallinity. The XRD, SEM coupled with EDX and Raman spectroscopy studies indicate that the properties of thin films are strongly dependent on deposition conditions. The optical band gap of Au-doped WO3 was increased from 2.7eV to 2.82eV with increasing oxygen pressures.