Study of Ethanol Gas Sensing Characteristics of An Al-Doped SnO₂ Thin Film Decorated With Gold Nanoparticles

The ethanol ( <tex-math notation="LaTeX">C_2H_5 </tex-math> OH) gas sensing characteristics of an interesting sensor have been studied and reported. The studied sensor is manufactured by the deposition of an Al-doped SnO2(ATO) thin film via sputtering, followed by the addition of evaporated gold nanoparticles (Au NPs) on a sapphire (Al2O3) substrate. The utilization of Au NPs is found to significantly enhance the sensor's ethanol gas sensing capabilities, attributed to the augmented specific surface area and catalytic capability of the Au metal. In-depth characterization of the intrinsic material properties is achieved through compositional, morphological, and structural analyses. Experimentally, the proposed sensor demonstrates a higher sensing response of 1436, accompanied by a response time of 23 s and a recovery time of 17 s when exposed to 1000 ppm <tex-math notation="LaTeX">C_2H_5 </tex-math> OH/air gas at 275 °C. Notably, the sensor exhibits an exceptionally lower detectable content of 40 ppb <tex-math notation="LaTeX">C_2H_5 </tex-math> OH/air. The research further delves into the replicable and long-term (90 days) sensing properties concerning ethanol gas. In addition, the proposed sensor has the advantages including a simplistic sensor structure, cost-effectiveness, and a relatively straightforward fabrication process.