An effective Hamiltonian approach for Donor-Bridge-Acceptor electronic transitions: Exploring the role of bath memory

Abstract

We present here a formally exact model for electronic transitions between an initial (donor) and final (acceptor) states linked by an intermediate (bridge) state. Our model incorporates a common set of vibrational modes that are coupled to the donor, bridge, and acceptor states and serves as a dissipative bath that destroys quantum coherence between the donor and acceptor. Taking the memory time of the bath as a free parameter, we calculate transition rates for a heuristic 3-state/2 mode Hamiltonian system parameterized to represent the energetics and couplings in a typical organic photovoltaic system. Our results indicate that if the memory time of the bath is of the order of 10-100 fs, a two-state kinetic (i.e., incoherent hopping) model will grossly underestimate overall transition rate.

9 pages, 2 figures

References in corpus (6)

• The Role of Driving Energy and Delocalised States for Charge Separation in Organic Semiconductors
• Direct observation of ultrafast long-range charge separation at polymer:fullerene heterojunctions
• Noise-induced quantum coherence drives photocarrier generation dynamics at polymeric semiconductor heterojunctions
• Phonon-driven ultrafast exciton dissociation at donor-acceptor polymer heterojunctions
• Exciton dissociation at donor-acceptor polymer heterojunctions: quantum nonadiabatic dynamics and effective-mode analysis
• Time-convolutionless master equation for mesoscopic electron-phonon systems