▎ 摘　　要

In this work, an electrically tunable mixed dimensional heterojunction of graphene and planar InN nanowires (NW) has been investigated as a potential candidate for highly sensitive gas sensing applications. The high surface carrier concentration of InN, which prevents it from forming good rectifying contact with graphene, has been effectively suppressed through controlled partial surface oxidation in a plasma reactor. The resulting surface modified InN NWs were found to form excellent Schottky junction with graphene, with a barrier height that is widely tunable by the gate voltage, turning it into a mixed dimensional barristor device. When utilized as a multimodal molecular sensor, utilizing both capacitive and conductive modes, it exhibited very high sensitivity, with detection limits reaching down to sub-ppb range for NO2 and low ppb range for NH3 and CO, tested in both N2 and dry air environments. Additionally, surface functionalization, using hemin/benzoic acid, of this nonconventional barristor device yielded excellent selectivity for specific analytes while maintaining the high sensitivity. The responses of the sensor were found to be minimally affected with long term exposure to atmospheric humidity, which underscores the potential of this barristor device as a highly sensitive gas sensor for practical applications.