Cu2+‐doped ITO as a Novel Efficient, Transparent, and Fast‐Response Transducer for Ammonia Sensing

Abstract

As a novel approach, the effect of Cu2+‐doped indium tin oxide (ITO) on a flexible polycarbonate substrate is considered as an ammonia sensor. The sensor was fabricated using spin‐coating and subsequent annealing at 160°C for 60 min. The constructed sensor morphology accomplished by surface composition was explored using scanning electron microscopy (SEM) and energy dispersiveX‐ray (EDX) spectroscopy. Using the new strategy, a flexible sensor for ammonia determination with a fast response time of less than 7 s and a recovery time of 8 s was achieved. Sensor characteristics, such as sensitivity, recyclability, response/recovery time, selectivity, stability, flexibility, and transmittance of the layers, were examined. The impedance results showed high sensitivity when the constructed sensor was exposed to NH3 concentrations in the range 5–1000 ppm. The results showed that doping ITO with Cu2+ imparted higher electronic charge density to the sensor surface and enhanced the sensitivity of the sensor by a factor of 352% in comparison with that of pure ITO. The sensitivity, fast response, and recovery time with low‐cost materials and deposition procedure suggest an effective and disposable ammonia sensor at room temperature (23°C).