Investigation of capacitive humidity sensing behavior of silicon nanowires

In this paper, the fabrication and the sensing characteristics of the humidity sensors based on the electroless chemical deposition-etched silicon nanowires had been studied. The humidity sensors were constructed by the selectively electrochemically etched silicon nanowires. The sensing mechanism is based on the capacitance variations due to the adsorption/desorption of water vapor of silicon nanowires. The frequency–capacitance conversion circuit had been set up to convert the capacitance variation into the frequency shift. Labview system had been employed to monitor and record the frequency. The study indicated that the humidity sensors had the simple structure and the high performance such as the high sensitivity, the wide humidity detection range, the good stability and repeatability.