Mechanism of Optical and Electrical HS Gas Sensing of Pristine and Surface Functionalized ZnO Nanowires.

In this work, the sensing ability and the underlying reaction pathways of HS adsorption on two nanomaterial systems, pristine zinc oxide (ZnO) nanowires (NWs) and gold functionalized zinc oxide nanowires (Au@ZnO NWs), were explored in a side-by-side comparison of optical and electrical gas sensing. The properties of optical sensing were analyzed by photoluminescence intensity-over-time measurements (-) of as-grown ZnO NW samples, and the electrical gas-sensing properties were analyzed by current-over-time measurements (-) of ZnO NW chemically sensitive field-effect transistor (ChemFET) structures with a gas-sensitive open gate. The ZnO NWs were grown by high-temperature chemical vapor deposition (CVD) and thereafter surface-functionalized with a thin Au nanoparticle layer by magnetron sputtering.