Humidity sensitive properties of nanostructured Al-doped ZnO:TiO2 thin films

Nanostructured Al-doped ZnO(AZ):TiO2 films are prepared using a sol–gel process and the humidity sensitive properties of the films are investigated. The films possess nanostructure. Nanostructured-bilayered TiO2/AZ film exhibits improved linearity with narrow hysteresis loop in the resistance variation for relative humidity than single layered film. The resistance of the bilayered TiO2/AZ film changes by nearly three orders of magnitude during the relative humidity variation of 30–90%. The humidity sensitive properties in the nanostructured AZ:TiO2 films are discussed.