Ultrasensitive and selective Cr-doped ZnO thin films synthesized via spray pyrolysis technique for detection of ammonia gas

In the present study, we report the synthesis of undoped and Cr-doped ZnO thin films via spray pyrolysis for ammonia gas detection. The importance of work lies in addressing the need for ultrasensitive and selective gas sensors, particularly for ammonia detection, owing to their significance in various industrial and environmental applications. The utilization of Cr-doped ZnO thin films offers a promising approach, given their unique properties and potential for enhanced sensing performance. The prepared Cr-doped ZnO thin films exhibit remarkable response, selectivity, sensitivity and long-term stability towards 50 ppm of ammonia gas at room temperature. Also, 4% Cr-doped ZnO films show fast response (14 s) and recovery time (38 s). These findings emphasize the practical relevance and potential impact of Cr-doped ZnO thin films as efficient gas sensing materials.