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In environment air quality monitoring, toxic and flammable gas detection plays an important role. Due to the extreme concern for safety standards in industrial and residential applications, real-time observation of toxic gas and notification of inadvertent leaks is necessary. This paper delves into a simple and cost-effective way for fabricating extremely sensitive zinc oxide (ZnO) thin film gas sensors for the detection of Liquefied Petroleum Gas (LPG) at low concentrations. Sol-gel method is used to fabricate the ZnO thin films. Platinum (Pt) nanoparticles have been placed on the semiconducting material to behave as catalysts in order to enhance sensing performance. The platinum doping is done via the RF Sputtering technique. For different concentration of LPG, the variation in electrical resistance of a semiconductor material was evaluated. Sensor characterization was carried out using XRD, and FESEM. ZnO thin films are optimized at different thickness varying from 70 nm to 550 nm. Then annealing of thin films of ZnO is carried out at temperatures range from 450 °C to 675 °C. LPG shows a maximum response for thin film of 170 nm annealed at 625 °C, at operating temperature of 150 °C, for 1000 ppm concentration. Sensing response for ZnO thin film has been enhanced to 2.586 post doping which was 1.896 for annealed bare ZnO thin film. Comparing to bare ZnO thin films, there had been a significant improvement in sensor response with platinum doped ZnO thin films. |
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