Effect of the microstructure on the NOx gas-sensing characteristics of WO3 thin-film sensors

Abstract

WO3 thin-film sensors were deposited by using a high-vacuum resistance heating evaporator at ambient temperature and at 300 degrees C, and then annealed at 500 degrees C for 4 hours in air. The annealed WO3 films had a polycrystalline triclinic structure. In the case of the films deposited at 300 degrees C, the microstructure of the annealed films, the NOx sensitivities, and the response characteristics were improved.