A unique ionization gas sensor with extraordinary susceptibility of sub-1-volt

In this study, an ionization gas sensor device assembled by a nanoneedle array and a single nanowire is reported. Each nanoneedle is hybridized and consists of the Si nanorod with platinum nanocrystallites on the top. In the device, nanoneedle arrays serve as one electrode and the single silicon nanowire as the counter electrode to form a unique asymmetric discharge space. We believe that gas between this electrode pair is polarized and directly ionized in an extremely high electrical field, which is confirmed by the microstructure characterization, gas-sensing test and theoretic calculation. The advantage of ultralow operation voltage, power consumption with trace sensing ability renders the device an extraordinary ionization gas sensor.