Light sensitivity in PANi/TiO2 double nanolayer

Abstract A double layer of polyaniline (PANi) and titanium dioxide (TiO2) made on glass substrate is used to study the effect of photoinduction in TiO2 on the double layer conductance. The light sources are LEDs emitting monochromatic light peaking around 369, 396, 447 and 663 nm. Raman and UV-Vis spectra show that the electronic structure of PANi in the double layer is modified as a result of the TiO2 coupling. The conductance of the PANi and PANi/TiO2 double layer is found to be sensitive to the light irradiated and depends on the light wavelength. Upon exposure to the light, the conductance of the PANi monolayer is increased while the PANi/TiO2 double layer is decreased with 369, 396 and 447 nm but increased with 663 nm monochromatic light. The change in conductance of the PANi and PANi/TiO2 double layer is accounted for the combination of the carriers arisen from photoelectric effect in PANi and the carrier added/extracted from PANi as a result of photoinduced effect in TiO2 as the layer activated by light.