Dye sensitization of nanocrystalline TiO₂ by perylene derivatives

New sensitizing dye-semiconductor system comprised of 3,4,9,10-perylene tetracarboxylic acid (PTCA) or perylene 3,4-dicarboxylic-9,10-(n-butylamine) carboximide (PNDCA) on titanium dioxide (TiO₂) had been prepared and characterized. Good energy conversion efficiency was obtained. The film of PTCA on TiO₂ yielded an incident photo-to-current efficiency (IPCE) of approximately 40% in the wavelength region of 440 to 530 nm, while that for PNDCA was approximately 14% at the wavelength region from 460 to 510 nm. Further studies concentrated on the doping of this system with bromine (Br₂). The results indicated that the sensitizing wavelength region was red shifted, which was advantageous for solar light harvesting. Furthermore, the doped films gave lower quantum conversion efficiency than the non-doped films.