Poly(3-hexylthiophene):TiO2 nanocomposites for solar cell applications

The properties of organic/inorganic poly(3-hexylthiophene) (P3HT):TiO2 nanocomposite films and nanocomposite based solar cells as a function of TiO2 concentration and the solvent used for the film fabrication were studied. For low nanoparticle concentration (20-30%) the device performance was worse compared to pure P3HT, while for nanoparticle concentration of 50% and 60% significant improvements were obtained. P3HT photoluminescence quenching in 600-800 nm spectral region changes by a factor of two for the increase in TiO2, concentration from 20% to 60%, while the AM1 power conversion efficiency increases similar to35 times. Photoluminescence quenching and solar cell efficiency were found to be strongly dependent not only on nanoparticle concentration but also on the solvent used for spin-coating. The changes in the film and device properties were explained by the change in the film morphology. For optimal fabrication conditions, external quantum efficiency up to 15% and AM1 power conversion efficiency of 0.42% were obtained.