Sandrine Bernardini

An easy method of preparing ozone gas sensors based on ZnO nanorods

One-dimensional (1D) ZnO nanorod-like structures were successfully grown via a hydrothermal method to be used as an ozone gas sensor. X-ray diffraction measurements (XRD) and field-emission scanning electron microscopy (FE-SEM) analysis revealed a preferential growth of the nanorod-like structures along the [002] direction. Electrical resistance measurements indicated a good sensitivity to different ozone concentrations (0.06–1.19 ppm) as well as long-term stability over a 6 month period at 250 °C. In addition, it was observed that the nanorods had a good sensitivity to ozone at room temperature when the sensor was exposed to UV illumination. This study provides an easy and efficient way to obtain 1-D ZnO nanorods exhibiting remarkable properties for applications as ozone gas sensing materials.

Thickness effects of ZnO thin films on flexible ozone sensors

ZnO nanoparticles thin films were deposited with different thicknesses on Kapton flexible substrates by drop coating method. The flexible platform consists in Ti/Pt interdigitated electrodes for gas detection and a heater device fabricated by Magnetron Sputtering and photolithography process. The thickness effects of the ZnO thin film on the gas sensing properties by ozone exposure at 200 °C has been studied. In order to test a deposit methodology used in large scale industrial production, an ultrasonic spray deposition was done. It was found that the sensitivity towards ozone gas is strongly dependent of the ZnO thin film thicknesses.