Effect of TiO₂ Nanotubes on Polymer-Fullerene Bulk Heterojunction Solar Cells

We investigate the photovoltaic properties of hybrid organic solar cell based on the blend of poly2-methoxy-5-(2_-ethylhexoxy-1,4-phenylenevinylene) (MEH-PPV), C₆₀ and titanium dioxide (TiO₂) nanotubes. In comparison of the composite devices with different TiO₂:MEH-PPV +C₆₀ weight ratios of 1wt.% (D_1-1), 2wt.% (D_1-2), 3wt.% (D_1-3), 5wt.% (D_1-4), 10wt.% (D_1-5) and 20wt.% (D_1-6), it is found that the device D_1-3 exhibits the best performance. The
conversion efficiency is improved by a factor of 3 compared with the MEH-PPV:C60 device.