Room temperature ethanol sensing properties of ZnO nanorods prepared using an electrospinning technique

In recent years, the design of room temperature gas sensors has received major attention from researchers considering their deployment for real-time monitoring and power consumption. In this context, a novel and simple electrospinning route has been proposed to control the growth of ZnO nanorods with definite planes for achieving an enhanced room temperature response to ethanol vapor. The composite nanofibers [polyvinyl alcohol (PVA)-zinc oxide (ZnO)] were transformed to hexagonal wurtzite structured ZnO nanorods with flat, sharp pencil and blunt end shaped morphologies. X-ray diffraction patterns revealed the formation of high c-axis orientation with (002) (polar), (100) (nonpolar), and (101) (semi-polar) plane orientation towards the flat and pencil tip ended ZnO nanorods, respectively. The electrical parameters like carrier concentration, mobility, grain and grain boundary resistances and activation energy of the nanorods were measured and correlated with the room temperature (299 K) ethanol sensing performance of the ZnO nanorods. The flat-end loosely populated nanorods showed a higher sensing response of 26.4 for 500 ppm of ethanol, which is comparatively higher than previously reported responses.