Preparation and humidity sensing behaviors of nanostructured potassium tantalate: titania films

Nanostructured-bilayered potassium tantalate (KT): titania (TiO2) films are prepared by the sol-gel process, and the humidity sensing behaviors of the films are investigated. The films possess nanosized grains and nanoporous structure. Bilayered KT/TiO2 and TiO2/KT films exhibit improved linearity with narrow hysteresis loop in the resistance variation for relative humidity compared to monolayered TiO2 and KT films. The bilayered KT/TiO2 and TiO2/KT films show over three orders of change in the resistance during the relative humidity variation from 20 to 90%. The humidity sensing properties in the nanostructured KT: TiO2 films are discussed.