Humidity dependent impedance characteristics of SbSeI nanowires

A humidity sensor has been successfully fabricated through a sonochemical synthesis of antimony selenoiodide (SbSeI) nanowires and their high pressure (100 MPa) compression at room temperature. For the first time, this nanomaterial has been investigated using impedance spectroscopy. The effect of water vapor on the impedance characteristics of the SbSeI sensor has been studied for different temperatures (293 K divided by 343 K) in the range of relative humidity (RH) from 30% to 80%. Fabricated device has been also subjected to periodic humidity fluctuations. The transient characteristics of an impedance of the SbSeI sensor have been highly correlated to humidity input cycles. The response has exhibited an excellent repeatability, long-term stability, and a maximum hysteresis of 3.7% RH for humidity changing rate of 0.083%.min(-1). The least-square fitting of Nyquist characteristics of the sensor has allowed determining an equivalent electric model of SbSeI xerogel. The humidity sensing mechanism has been explained with reference to a proton hopping. Presented results demonstrate a great potential of SbSeI nanowires for humidity sensing applications.