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 °C (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.