Ultra-low power hydrogen sensor by suspended and palladium coated silicon nanowire

Abstract

This paper reports silicon nanowire sensor decorated with palladium nanoparticles for the low temperature hydrogen detection with self-heating for fast response and recovery. Hydrogen gas responses of the palladium coated silicon nanowire (Pd-SiNW) were measured with Joule heating of Pd-SiNW. Even though the Pd-SiNW can detect hydrogen gas at room temperature, transient response is slow and even slower in humid conditions. Self-heating of the Pd-SiNW reduces the response and recovery times by consuming low power without any significant change of sensitivity. Power consumption is further reduced to sub-100 mu W by suspending the Pd-SiNW from substrate. Humidity effect on hydrogen sensing was also reduced by Joule heating. Joule heated Pd-SiNW device is a promising hydrogen gas sensor to apply mobile device.