In 2 O 3 nanowires as chemical sensors

We present an approach to use individual ${\mathrm{In}}_2{\mathrm{O}}_3$ nanowire transistors as chemical sensors working at room temperature. Upon exposure to a small amount of ${\mathrm{NO}}_2$ or ${\mathrm{NH}}_3,$ the nanowire transistors showed a decrease in conductance up to six or five orders of magnitude and also substantial shifts in the threshold gate voltage. These devices exhibited significantly improved chemical sensing performance compared to existing solid-state sensors in many aspects, such as the sensitivity, the selectivity, the response time, and the lowest detectable concentrations. Furthermore, the recovery time of our devices can be shortened to just 30 s by illuminating the devices with UV light in vacuum.