Structural and optical properties of electrospun ZnO nanofibres applied to P3HT:PCBM organic photovoltaic devices

Electrospun ZnO nanofibres with a diameter in the range of 74-125nm were synthesised by optimising various parameters. Zinc acetate was used as a precursor and optimised to obtain a homogeneous and interconnected porous ZnO nanofibres network. The ZnO/poly(vinylpyrrolidone) composite nanofibres were calcined at 450 degrees C for 2.5h to obtain continuous nanofibres network. The morphology of the nanofibres was studied by scanning electron microscopy and imageJ software. The structural and optical properties of the synthesised nanofibres were studied by surface profiler, X-ray diffraction and ultraviolet-visible spectroscopy. The grain size increased while the bandgap was observed to decrease with increased precursor concentration. The effect of precursor concentration was also studied to improve the power conversion efficiency of ZnO nanofibres/poly(3-hexylthiophene) (P3HT): [6,6]-phenyl C61-butyric acid methyl ester (PCBM) photovoltaic device. The efficiency was improved from 0.896 +/- 0.007% to 2.29 +/- 0.03% by introducing the electrospun ZnO nanofibres.