摘要： Transparent metal oxide thin films were synthesized on indium tin oxide (ITO) substrates via the sol-gel spin coating method using various precursor solutions. The types of metal oxides investigated were zinc oxide (ZnO), titanium dioxide (TiO2) and molybdenum oxide (MoOx) whose purpose was to serve as buffer layers in organic solar cells. ZnO and TiO2 layers were to serve as electron transport layers (ETL), and the MoOx layer served as a hole transport layer (HTL). Compared to conventional ordering, in this set-up, the sequence of the buffer layers is inverted to improve the stability of the polymer solar cells. The annealing temperature during the preparation of the ETL metal oxide layers was varied in order to investigate the effect on the morphological properties of the thin films. The HTL layer was both spin-coated and thermally evaporated and the results were compared. The surface morphology and elemental analysis of the prepared samples were studied using a scanning electron microscope (SEM) equipped with energy dispersive spectroscopy (EDS) capability. The optical properties were investigated by UV–Vis spectroscopy and it was found that the metal oxide layers have high optical transparency in the visible range, as required. The crystal structures of the prepared metal oxides were investigated by X-ray diffraction (XRD). A comparative study on the effect of the ETLs individually in solar cells was done by incorporating them individually with active layers of blends of poly (3-hexylthiophene) (P3HT), as electron donor and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) as electron acceptor respectively. The device performance was subsequently measured and compared.