Semiconductor gas sensor based on Pd-doped SnO2 nanorod thin films

SnO2 nanorod thin films have been prepared by plasma-enhanced chemical vapor deposition (PECVD) with postplasma treatment. The SnO2 nanorod thin films were surface modified with Pd nanoparticles and their sensing properties towards H2 and ethanol gas were studied. It was found that the Pd-doped SnO2 nanorod thin film sensor exhibits 6 and 2.5 times better response to 1000 ppm H2 and ethanol at 300 °C compared to the un-doped sample. The improved gas-sensing properties were believed to result from the formation of electron depletion layer and enhanced catalytic dissociation of molecular adsorbates on the Pd nanoparticle surfaces.