Transient characteristics and negative photoconductivity of SbSI humidity sensor

This paper presents the influence of water vapor on the photoconductivity of antimony sulfoiodide (SbSI) nanowires obtained sonochemically. It is done to explore the applicability of SbSI photoconductor as a humidity sensor. Character of the response of DC photoconductivity current on the switching on and switching off illumination of SbSI gel depends on relative humidity (RH) of nitrogen environment. While positive photoconductivity is observed for low RH, the negative effect occurs for high RH. The least square fitting of the transient characteristics of photoconductivity allowed to present equivalent photoelectric model of SbSI gel. The changes of the parameters of the model with increasing humidity and illumination intensity are presented. Mechanism of light-induced desorption of H2O from SbSI nanowires' surface is discussed.