An effect of TiO2 morphology on performance of ITO/TiO2/MEH-PPV/Au solar cells

ITO/TiO₂/MEH-PPV/Au solar cells were fabricated using nano-porous titanium dioxide (TiO₂) infiltrated with poly(2-methoxy-5-(2´-ethylhexyloxy)-p-phenylene vinylene) (MEH-PPV). The TiO₂ films were prepared using poly(ethylene glycol) (PEG) having different molecular weights and spin coated onto indium tin oxide (ITO) coated glass substrates. Transmission electron microscopy (TEM) showed that the dip-coated TiO₂ films had uniform thickness of around 70 nm. Surface morphologies of the TiO₂ films were investigated using scanning electron microscopy (SEM). It was found that the low molecular weight PEG resulted in small pits in the TiO₂ film and increase contact area between TiO₂ and MEH-PPV improving the device efficiency of this solar cell.