Semiconductor gas sensors based on nanostructured tungsten oxide

• Published in: Thin solid films Vol. 391; no. 2; pp. 255 - 260
• Main Authors: Solis, J.L, Saukko, S, Kish, L, Granqvist, C.G, Lantto, V
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Lausanne Elsevier B.V 16.07.2001; Elsevier Science
• Subjects: Analytical chemistry; Chemistry; Exact sciences and technology; Gas deposition; Gas sensor; General equipment and techniques; General, instrumentation; H2S sensing; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Nanocrystalline; Physics; Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing; Tungsten oxide; Tungsten oxide; Gas sensor; H2S sensing; Gas deposition; Nanocrystalline; Chemical sensors; Inorganic compounds; Electrical properties; Reactive evaporation; Binary compounds; Hydrogen sulfides; Tungsten oxides; XRD; Nanostructures; Experimental study; Sensor materials; Sintering; Gas detector; THICK-FILM; gas deposition nanocrystalline; tungsten oxide; gas sensor; SENSITIVITY; NITROGEN-OXIDES
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/S0040-6090(01)00991-9

Semiconductor gas sensors based on nanocrystallline WO 3 films were produced by two different methods. Advanced reactive gas evaporation was used in both cases either for a direct deposition of films (deposited films) or to produce ultra fine WO 3 powder which was used for screen printing of thick films. The deposited films sintered at 480 °C and the screen-printed films sintered at 500°C displayed a mixture of monoclinic and tetragonal phases and had a mean grain size of approximately 10 and 45 nm, respectively. We studied the influence of the sintering temperature T s of the films on their gas sensitivity. Unique and excellent sensing properties were found upon exposure to low concentrations of H 2S in air at room temperature for both deposited and screen-printed films sintered at T s =480°C and at T s =500°C, respectively.