Covalent dyads of porphyrin–fullerene and perylene–fullerene for organic photovoltaics: Spectroscopic and photocurrent studies

Supermolecular complexes of zinc porphyrin or perylenediimide as covalent dyads with fullerene (C60) in chloroform and as Langmuir–Blodgett layers on an Au substrate were studied. In our studies we have used following spectroscopic methods: electronic absorption, fluorescence and electron spin resonance in solution. Also infrared absorption spectra in a KBr pellet and reflectance–absorption in Langmuir–Blodgett layers were monitored. Photocurrent generation in a photoelectrochemical cell was also studied. The redistribution of charge both upon porphyrin linkage to C60 and when the systems are deposited on the Au substrate was shown. Photocurrent examinations show a great influence of the fullerene presence on photoresponse of the systems.

Research highlights
► Porphyrin-fullerene and perylene-fullerene as electron-donor-acceptor systems.
► Charge redistribution in chromophores upon linkage to fullerene.
► The presence of fullerene enhances photocurrent.