A humidity sensor based on KCl-doped SnO2 nanofibers

A fast, simple and reliable humidity sensor based on ion-doped SnO2 nanofibers has been developed by screen-printing on ceramic substrates with Ag–Pd interdigital electrodes in this research. The optimized results show that the impedance of the sensor decreases by more than five orders of magnitude with increasing relative humidity (RH) from 11% to 95%, the response and recovery time of the sensor are about 5 and 6 s, respectively. Compared to the previous electrical conductivity-based SnO2 humidity sensors, the proposed sensor exhibits higher humidity sensitivity, more rapid response and recovery, smaller hysteresis, and better linearity and stability.