Probing of charge and energy transfer in hybrid systems of aniline - 3-methylthiophene copolymer with CdS and CdSe nanoparticles

The processes of intramolecular and polymer-to-particle energy transfer as well as charge separation at the organic/inorganic interface in acetonitrile dispersions and composite films based on a novel processible copolymer of aniline with 3-methylthiophene and US or CdSe nanoparticles have been studied. The copolymer was synthesized by chemical oxidative polymerization, and its structure was analyzed using IR and electronic absorption spectroscopy. The contribution of the aniline and methylthiophene moieties to intramolecular electronic transitions was derived based on electronic absorption, photoluminescence, and photoluminescence excitation spectra of the copolymer. It was found that both US and CdSe nanoparticles induce the copolymer-to-particle energy transfer and charge transfer. The CdSe nanoparticles were more effective in the above processes and initiated a complex energy transfer route with an intramolecular energy transfer in the copolymer as an intermediate step. However, heterostructures based on the copolymer-CdS composite showed comparable or even higher photovoltaic performance than those based on the copolymer-CdSe composite.