Studies of structural and morphological characteristics of flower-like ZnO thin film and its application as photovoltaic material

In this work a new method has been employed to synthesize nanocrystalline ZnO powder under hydrothermal conditions at 80 °C using aqueous Zn(NO3)2·6H2O solution and diethylamine (DEA) as the starting materials. The ZnO powder prepared by this novel method was characterized by XRD, energy dispersive X-ray spectroscopy (EDX), FTIR and UV–vis techniques. Calculation based on XRD data revealed ZnO particles to be of nanometer size (∼33 nm). The ZnO powder was subsequently used to make its thin film which exhibited flower like morphology when examined by SEM. Thin ZnO films were sensitized with N719 dye, (Bu4N)2[Ru(dcbpyH)2(NCS)2], and used as photo-anode to construct sandwich type dye-sensitized solar cell (DSSC). With such cells, VOC = 0.680 V, JSC = 0.61 mA cm−2, fill factor = 0.43 and overall conversion efficiency η = 0.23% were achieved on illumination with visible light (80 mW cm−2).