If the material is sensitized with the appropriate molecules, it becomes interesting for an electrode material for solar energy conversion in dye sensitized solar cells, various sensor application i.e. gas sensors and biosensors or in photocatalytic applications. In the present work, the nanostructured dye adsorbed ZnO (ZnO/dye) films prepared by doctor blade method have been investigated in conductivity and photoconductivity measurements in view of applications in dyesensitized solar cells (DSSC) and in optoelectronics, since electron transport in these devices plays a decisive role for the electron collection efficiency and therefore for the overall efficiency. Dyes of two different colors have been chosen for film preparation: Acridine orange (AO) and Fast Green (FCF). All the dyes and electrodes are examined for their absorbance in the visible region. Pure ZnO films are prepared and investigated for comparison. After the dye is adsorbed on the ZnO electrode, absorption spectra of FCF sensitized film broadened in visible region slightly with a red shift in the peak position compared to the absorbance spectra in ethanol. Highly porous ZnO films are found to have high dark conductivity, probably because of a higher ndoping, which is due to a higher concentration of Zn atoms in the film. On the other hand, dye sensitized films are found to show higher sensitivity to illumination with visible light in photoconductivity measurements due to a higher absolute photoconductivity and lower conductivity in the dark. It can be seen that the photosensitivity for ZnO/FGF is higher than that for the ZnO/AO film.
ZnO, absorption, photocounductivity
