InN nanowires based multi-modal environmental sensors

High quality InN nanowires (NWs) have been investigated for sensing applications. The NWs were synthesized using a novel approach that enhanced the cracking of NH
₃
precursor and dramatically improving the growth rate and material quality. Field effect transistors (FETs) based on these high quality InN NWs showed excellent electrical characteristics and good average mobility (270 cm
²
/Vs). Preliminary sensing results for dilute acetone, diluted water vapor and NO
₂
at various concentrations are very encouraging. Because of high carrier density and mobility, these NWs are also good candidates for field emission based sensing. During the field emission experiments, sharp change in NW current was observed when supplied voltage increased to 2 V for ~1μm distance between NW and plate, demonstrating the suitability of these NWs for gaseous detection based on the field emission method, and for multimodal sensing in combination with FET based sensing method.