Gasochromic Response of Electron-beam Deposited WO3 Thin Films Towards Low Concentrations of Hydrogen

The gasochromic performance of tungsten oxide (W03) films coated with 25 A catalytic palladium (Pd) layer were investigated for low concentration H2 sensing. The electron beam deposition was carried out to create the W03 and Pd nanostructures on quartz substrates. It was found that the Pd/W03 films show remarkable gasochromic response when exposed to H2 at 100oe. The response was increase with the increase of optical wavelengths. Integrating the absorbance change over a range of visible - near infra red (NIR) wavelengths (500-800 nm), has enabled very low concentrations of H2 (0.06%) to be sensed in real time. Pd/W03 T SO% response towards 0.06% and 1.0% H2 in a balance of synthetic air was approximately 60 sand 120 s, respectively, at 100oe. The film Tgo% recovery was found to be 300 sand 180 s for H2 concentrations of 0.06% and 1.0%, respectively.