Influence of humidity on impedance of SbSI gel

This paper presents the effect of water vapor on the electrical response of antimony sulfoiodide (SbSI) nanowires obtained sonochemically to explore its application as a humidity sensor. For the first time this material has been studied using impedance spectroscopy. The measurements have been made in nitrogen for various humidities and temperatures. The real part of the total complex impedance is found to decrease by three orders of magnitude with the increase of humidity from 10% to 85%. Influence of temperature and humidity on relaxation time of SbSI is reported. The least square fitting of the Nyquist characteristics of the investigated gel allowed one to distinguish between different equivalent electric models of the SbSI gel. The changes of the parameters of the model with increasing temperature and humidity are presented. The polarization of water molecules is shown to be a major contributor to the capacitance-temperature characteristics of SbSI gel.