Fe–tannic acid complex dye as photo sensitizer for different morphological ZnO based DSSCs

•Different ZnO nanostructures were synthesized by microwave hydrothermal methods.•The tannic acid and Fe–tannic acid complex dye were used for the first time in DSSCs.•ZnO plate has higher photovoltaic efficiency than rods and nanoparticles in DSSC.•Fe–tannic acid complex dye display broad spectrum responses.•Fe–tannic acid complex dye exhibited better photovoltaic performance than tannic acid.

In this paper we have synthesized different morphological ZnO nanostructures via microwave hydrothermal methods at low temperature within a short time. We described different morphologies of ZnO at different Zn(NO3)2/KOH mole ratio. The ZnO nanostructures were characterized via X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and UV–vis spectrophotometry. All ZnO structures have hexagonal wurtzite type structures. The FESEM images showed various morphologies of ZnO such as plate, rod and nanoparticles. Dye sensitized solar cells have been assembled by these different morphological structures photo electrode and tannic acid or Fe–tannic acid complex dye as sensitizer. We have achieved at maximum efficiencies of photovoltaic cells prepared with ZnO plate in all dye systems. The conversion efficiencies of dye sensitized solar cells are 0.37% and 1.00% with tannic acid and Fe–tannic acid complex dye, respectively.

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