High sensitivity, low operational temperature ITO nano gas sensor with integrated circuits

This paper presents the gas sensing characteristics of Indium-Tin-Oxide (ITO) nanofibers. ITO nanofibers were fabricated by electrospinning process and integrated with microheater, micro temperature sensor and interdigitated electrodes (IED). The morphology and crystal structure of ITO nanofibers were studied by SEM and XRD, respectively. The optimal working temperature and sensitivity of the ITO nanofiber gas sensors were investigated. The ITO nanofiber gas sensor exhibits a linear current-voltage relationship. The highest sensitivity of the sensor is about 34, which is obtained at a working temperature of 300degC; and this sensor can also work at room temperature, the sensitivity at room temperature is about 5.2. The detect limitation of this ITO nanofiber sensor is 10ppm. This sensor shows no response for H₂. These results show that ITO nanofiber gas sensor exhibits significantly better sensitivity for NO₂ at lower temperature and good selectivity for NO₂ and H₂.