NO₂ sensing properties of WO₃ nanorods grown on mica

Abstract One‐dimensional nanostructures of tungsten trioxide were prepared by a simple chemical vapour deposition technique. WO₃ is sublimated onto cleaved (0001) oriented mica substrates in air at atmospheric pressure. We obtained needle‐type crystals (‘nanorods’), epitaxially oriented in three directions along the principal symmetry axes of mica. Their morphology was investigated with atomic force microscopy (AFM). The WO₃ structures were electrically contacted by means of four gold electrodes which were fabricated by optical lithography. In our experiments, we have analysed the NO₂ sensing properties in a gas‐flow system with respect to stability, operation regimes, response and decay times, as well as cross‐sensitivity towards humidity.