Development of a Reliable Zinc Oxide Thin-Film-Based Ammonia Gas Sensor

In this work, a simple ZnO thin-film-based ammonia gas sensor fabricated via a straightforward and cost-effective sol-gel technique has been demonstrated. The as-prepared device was found to be extremely sensitive toward ammonia gas and has shown a high response of 13.5% at concentrations as low as 10 ppm at an optimal temperature of 180? (much lower than the threshold value of 25 ppm). The device response was observed to be linear up to 70 ppm ammonia concentration with a response of 51% corresponding to it. The simplicity, repeatability, low production cost, and high efficiency have made the device a potential candidate for various future applications, especially in industries where ammonia sensing is critical.