Linearly resistive humidity sensor based on quasi one-dimensional ZnSe nanostructures

A resistive-type relative humidity sensor based on one-dimensional ZnSe nanostructures is reported. The sensor is fabricated by a two-step thermal evaporation – first the growth of a polycrystalline ZnSe substrate and then the growth of ZnSe nanowires. Ohmic contacts have been made to the sensor by simple silver painting. The sensor has a linear response of relative humidity over the range of 11.3–97.3%, which offers better sensitivity than the commonly reported exponential response, particularly at low relative humidity below 20%. A model based on capillary condensation is given to explain this feature.