Photoactive Polythiophene:Titania Hybrids with Excellent Miscibility for Use in Polymer Photovoltaic Cells

A series of poly{(3‐hexylthiophene)‐ co ‐[3‐(6‐hydroxyhexyl)thiophene]}:titania (P3HT‐OH:TiO 2 ) hybrids were synthesized via the in situ polycondensation of titanium (IV) n ‐butoxide in the presence of P3HT‐OH. Introducing a hydroxyl moiety onto the side‐chain of poly(3‐hexylthiophene) (P3HT) significantly promotes the polymer‐titania interaction, resulting in the formation of homogeneous hybrid colloids. The UV‐vis spectra of P3HT‐OH:TiO 2 films demonstrate that TiO 2 markedly affects the stacking structure and the chain conformation of P3HT‐OH. The maximum absorption wavelength of these hybrid materials can be tailor‐made by merely varying the weight percentage of TiO 2 . Moreover, P3HT‐OH:TiO 2 can be further utilized as an efficient compatibilizer in preparing photoactive P3HT:P3HT‐OH:TiO 2 films with excellent miscibility. The photovoltaic cell based on such a hybrid exhibited a 2.4‐fold higher value of power‐conversion efficiency compared to the cell based on P3HT:TiO 2 .