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

Abstract

The properties of organic/inorganic poly(3-hexylthiophene) (P3HT):TiO 2 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 ∼35 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 AMI power conversion efficiency of 0.42% were obtained.