Self-heating oxidized suspended Pt nanowire for high performance hydrogen sensor

In this work, joule-self-heating of a suspended Pt nanowire, under oxygen ambient, is utilized to form PtOx/Pt nanostructure to develop a new type of 1-dimensional sensor device architecture for detection of hydrogen at room temperature. An optimum design space for the sensor is elucidated with the initial Pt nanowire thickness ranging between 10 nm and 80 nm. Single PtOx/Pt nanowire sensor, based on optimum metal (Pt) to metal-oxide (PtOx) junction can detect down to 100 ppm H-2 with ultra-low power consumption of similar to 45 nW. This study also investigates hydrogen sensing characteristics of an array of oxidized Pt nanowires, which enhances the response with the maximum sensitivity of similar to 936%, compared to single PtOx/Pt nanowire sensor sensitivity of similar to 13% for 100 ppm hydrogen. Nanowire array sensor provides the minimum detection limit of 500 ppb (similar to 18.1%) with very fast response (similar to 25 s) and recovery (similar to 108 s) time. A phenomenological model is proposed to elaborate the nature of oxidation of joule-self heated Pt nanowire in oxygen ambient. (C) 2017 Elsevier B.V. All rights reserved