Hydrogen Ion Sensing Using Schottky Contacted Silicon Nanowire FETs

In this paper, we demonstrate the hydrogen ion sensing capability of Schottky contacted silicon nanowire (SiNW) FETs prepared by simple process steps. As a response to the pH level, a threshold voltage shift of 0.49 V/pH and a significant current variation of 19%/pH were acquired. The real-time measurement of the SiNWFETs for the various pH solutions reveals the response time of 1 min or less. An excellent reproducibility and the comparably stable current at each pH levels were observed, implying acute sensing ability.