Porous TiO2 thin films prepared by spray pyrolysis deposition (SPD) technique and their application to UV sensors

Porous TiO2 thin films were prepared from titanium(IV)oxy acetylacetonate solutions by spray pyrolysis deposition (SPD) technique in air. The surface morphology and grain size of the film was easily controlled by changing species of solvent in the source solution. The TiO2 film was employed as a light absorbing i-layer for UV sensor to deposit CuO/TiO2/SnO2 p–i–n junction by SPD technique. We found that the surface morphology of TiO2 layer was very much affective on UV response, attributing to the light confinement within TiO2 layer. Additionally, the response was further improved by reducing a carrier density in the TiO2 layer.