Exhibition of Förster resonance energy transfer from CdSe/ZnS quantum dots to zinc porphyrazine studied in solution

Abstract Molecular level interaction between CdSe/ZnS core-shell quantum dots (QD) and zinc porphyrazine ( 1 ) is studied in solution by means of UV–vis spectroscopy, steady state emission and time-resolved fluorescence decay measurements. Appreciable value of red shift of the Soret absorption band of 1 (~4 nm) in presence of QD is indicative of ground state interaction between these two species in solution. Photoluminescence (PL) of QD is quenched considerably in presence of 1 upon formation of QD– 1 system and average value of lifetime of QD is reduced considerably following the addition of 1 in increasing concentration. The PL quenching mechanism may be identified as Forster resonance energy transfer from QD to 1 in solution. Evaluation of bimolecular quenching constant ( k q ) value of QD– 1 system ( k q (av) ~ 3.2 × 10 12  dm 3 ·mol −1 ·sec −1 ) establishes that static quenching mechanism predominates over diffusion controlled pathway behind quenching of PL of QD in presence of 1 in solution. The results demonstrate that 1 may be selectively employed as an energy accepting unit in combination with quantum dots for possible application in organic photovoltaics.