The nature of photoinduced intermolecular charger transfer in fluorescence resonance energy transfer

In this paper, we report time resolved fluorescence resonance energy transfer (FRET) using femtosecond ultrafast transient absorption spectroscopy. The lifetimes of FRET are strongly dependent on the molecular concentration and ratio of donor and acceptor. Also, in the FRET, photoinduced intermolecular charge transfer (PICT) is also investigated theoretically. The driving force for PICT in FRET system equals the reorganization energy, which gives barrier-less charge transfer according to Marcus theory. The rates of PICT in the FRET system can be estimated with our simplified Marcus equation. Our results of PICT in FRET system provide a new efficient way for the charge transfer in donor-acceptor system. (C) 2018 Elsevier B.V. All rights reserved.