Gas sensing studies of thick and thin films of WO3

Screen-printing technique and spray pyrolysis method were used to prepare thick and thin films of WO
₃
(Tungsten Oxide). The gas sensing performance of the both films were tested for various gases at different temperatures and results are correlated. The WO
₃
thick film showed good response (S=191.31) to H
₂
S at 3500C and WO
₃
thin film showed poor response (S=6.48) at 3500C for 400 ppm. The gas response, selectivity and thermal stability of the sensor were measured and presented.