Electron beam evaporated gold doped tungsten oxide nanostructured films for sensor applications

Abstract

Gas sensors play a vital role in monitoring environmental pollution for human health, safety, and the detection of various gasses in the environment. Nanostructured metal oxide thin films have been widely used in sensor applications owing to their unique properties. In this study, pure and gold (Au) doped nanostructured tungsten trioxide (WO₃) films were deposited on glass substrates by electron beam evaporation at room temperature. The microstructure of the WO₃ films changed from nanoflakes to nanorods upon variation of the wt% of Au. The sensing properties of WO₃ based nanostructure films were measured using a computer-controlled system. The gas sensing results showed that the Au-doped WO₃ films exhibited a higher sensitivity than the undoped films. The 15 wt% Au-doped WO₃ nanostructure films showed high sensitivity towards ethanol and the response (sensitivity) value was 89. The response and recovery times for 15 wt% Au-doped WO₃ were 8 and 10 s, respectively.