Al-doped ZnO Thin Films for Ethanol Sensors

Al doped ZnO (AZO) is done to understand the effect of Al dopant on ZnO. The sensor response condition will be analyzed for ethanol detection. Chemical Bath Deposition (CBD) method is used to fabrication pure ZnO and AZO thin films. Al dopant concentrations used in this study is 2.9 at% Al. The crystallinity, composition and morphology were investigated by using XRD, EDS and SEM. The ZnO and AZO gas sensors were exposed to different concentrations of ethanol at room temperature, 2.5%, 5% and 7.5% volume ethanol, respectively. The sensor response at low concentrations (2.5% V) for pure ZnO sample is 70.88% and 88.57% for high concentrations of ethanol (7.5% V). The highest sensor response for AZO sample is 95.29% at low concentrations (2.5% V) and 96.68% V at the high concentration (7.5% V).