Wet chemical synthesis of ZnO thin films and sensitization to light with N3 dye for solar cell application

Simple wet chemical synthesis of ZnO thin films has been carried out at room temperature (27 degrees C) from an aqueous alkaline bath followed by annealing in air at 100 degrees C on fluorine doped tin oxide coated glass substrates. The deposited film showed an optical band gap of 3.28 eV with a thickness of about 40 mu m with a hexagonal crystal structure. A flower-like surface morphology consisting of petals was observed. These petals are made up of a fibrous network with interconnected nanoparticles leading to a high surface area. This obliged us to use this structure for dye-sensitized solar cells with lower fabrication process cost than conventional high temperature sintered methods which are commonly used for ZnO and TiO2. It would be advantageous to use a flexible plastic substrate instead of routine glass in future. ZnO showed a current conversion efficiency (eta) of 0.34% with chemically adsorbed N3 dye at standard AM 1.5 condition with illumination of light intensity 100mW cm(-2).