Sensor photoresponse of thin-film oxides of zinc and titanium to oxygen gas

Response of steady-state photoconductivity to changes in oxygen partial pre ssure (10(-3) to 1 atm) has been quantitatively studied in thin-film polycr ystalline TiO2:Nb and ZnO at 80-120 degrees C. The magnitude of photoconduc tivity varied as a square root of illumination intensity regardless of oxyg en pressure. Both materials showed fast response to oxygen, although in dif ferent pressure ranges. Zinc oxide was more sensitive to lower oxygen press ures while titanium dioxide worked better at pressures close to 1 atm. (C) 2000 The Electrochemical Society. S0013-4651(99)07-1 19-0. All rights reser ved.