Synthesis of zinc oxide nanoparticles by pulse laser deposition technique for gas sensing applications.

The current trends of gas sensors made of metal oxide (MO) nanomaterial were widely investigated over the past years as a good candidate for an ecofriendly gas detecting technique. This research deals with prepare of zinc oxide (ZnO) nanoparticles (NPs) from ZnO powder by pulsed laser deposition (PLD) techniques under annealing temperature of 200 °C and 300 °C. Scanning electron microscopy (SEM) was used to examine the morphological characteristics. X-ray diffraction (XRD) patterns revealed the crystal structure. The transmittance was also examined using UV–visible spectrophotometers. The produced MO was then applied and examined as thin films to investigate its effect for gas sensing applications. This study focused on examining the effect of ZnO particles on photoconductivity in the sensing area, using a 365 nm UV-light beam to examine the photoconductivity of samples at annealing temperatures of 200 °C and 300 °C. The researchers found that the resistance/conductivity ratio of the sample prepared at 300 °C increased quickly upon excitation by UV rays, which resulted in the liberation of oxygen ions and free electrons from the material, further accelerating the photoconductivity process. The sensors exhibit their maximum CO response within the temperature range of 300–400 °C. In this work, the photoconductivity process, as a function of time, depended on the mechanism of recombining the carriers. [ABSTRACT FROM AUTHOR]