In this work, we present fabrication of ZnO nanostructures by pulsed laser deposition in air at atmospheric pressure. The use of this technology leads to formation of nanostructures composed by nanoparticles and nanoaggregates. These nanostructures possess a large surface-to-volume ratio, which makes them suitable for gas-sensor application. The samples were exposed to NH<sub>3</sub> and the effect was investigated of light irradiation on the gas response and recovery time of the sensor element. It was found that the response of the sensor element increases even by irradiation by sunlight. The gas sensing properties of the ZnO nanostructures were compared when irradiated by light of different wavelengths.
We report the fabrication of gas sensor elements by pulsed laser deposition in air at atmospheric pressure. We focused our attention on metal-oxide semiconductors, namely, SnO<sub>2</sub>, TiO<sub>2</sub> and MoO<sub>3</sub> and studied the samples’ structure and morphology. The deposition technology applied leads to the formation of nanostructures composed of nanoparticles and nano-aggregates. We report preliminary results on the gas-sensing properties of the metal-oxide nanostructures. The sensors were exposed to CO, acetone and ethanol, with the TiO<sub>2</sub> nanostructure demonstrating the highest response to CO exposure.