Study of WO ₃ -SnO ₂ nanocomposites and their gas sensing properties

Abstract In this work, investigation is presented of nanostructures based on WO 3 and SnO 2 metal oxides produced by nanosecond pulsed laser deposition (PLD) carried out at atmospheric pressure in open air at wavelength of 1064 nm. We focused our attention on the changes in the structure, composition, morphology, electrical and gas sensing properties of WO 3 samples when a small amount (5wt% or 10wt%) of SnO 2 is added into the target used for ablation. High porous nanostructures organized in aggregated nanoparticles are observed to form hierarchal-like structure with high surface-to-volume ratio. The electrical characteristics are studied before and after annealing of the samples at 300° C for 10 minutes. I-V curves are measured in two working modes – dark current, and during illumination with UV diode light – photocurrent, before and after annealing. Gas sensitivity of the nanostructures is tested at room temperature under following exposure of NH 3 , CO, ethanol and acetone at fixed concentration of 30 ppm. The aim is to demonstrate by utilizing facilities of the nanosecond pulsed laser ablation in air, functional nanostructures based on WO 3 and SnO 2 metal oxides can be produced and realized as gas sensor elements.