Assessing the interaction of alcohol homologs with InAs nanowires in contact with gas-permeable SWCNT electrode: Towards a novel sensing platform

We report the approach to designing the hybrid gas sensor based on the array of vertically-oriented InAs nanowires and gas-permeable film made of single-walled carbon nanotubes (SWCNTs). We probe the sensor performance at room temperature towards isopropyl alcohol analyte, whose highest occupied molecular orbital energy to be in-between the Fermi levels of SWCNTs and InAs, to check the main contributing mechanism. Our theoretical analysis revealed that electronic systems of both materials contribute to sensor response. Our findings indicate that the sensor response to isopropyl alcohol in a mixture with dry and humid air primarily stems from its interaction with carbon nanotubes, although it also involves an interplay between the electron energy states of SWCNTs and InAs. We also test the sensor response to methanol, ethanol, and butanol analytes and demonstrate that it enhances with a molecule weight. The proposed sensor design can be further optimized to capture vector signals under a multivariate approach to selectively determine various analytes.