High sensitivity ozone sensors for environmental monitoring produced using laser ablated nanocrystalline metal oxides

A series of gas sensors produced using the laser ablated nanocrystalline metal oxides. SnO/sub 2/, In/sub 2/O/sub 3/, and WO/sub 3/ have been studied. Devices were tested with a view to their potential use as ozone detectors. Initially, fabrication procedures and compositions were optimized. The investigation then focused on parameters important for environmental monitoring applications including sensitivity, selectivity, and response time. High sensitivities to ppb ozone levels were observed particularly in the case of devices produced using SnO/sub 2/ and In/sub 2/O/sub 3/. Good selectivity was also observed for all optimized materials together with fast response times. These latter characteristics were particularly good for devices produced using WO/sub 3/.