Reorganization energies and spectral densities for electron transfer problems in charge transport materials

Abstract

In describing the dynamics of electron transfer or charge transport, the reorganization energy and the spectral density function describe the influence from nuclei motion to the transporting electron. The spectral...

Dielectric continuum methods for quantum chemistry

“…The solvent parameter ε ∞ also makes an appearance in Marcus' theory of electron transfer, 572–577 in which the “outer‐sphere” reorganization energy is given by This formula is derived from what is essentially a nonequilibrium formulation of the Born ion model [Equation ()], combined with a Coulomb interaction between charges centered in a donor sphere (radius R D centered at r D ) and an acceptor sphere (radius R A centered at r A ). The electron transfer is assumed to occur instantaneously—before the orientational motion of the solvent molecules can respond—hence the change in involves ε ∞ in addition to ε s .…”

“…Comparison to the model of a dipole in a spherical cavity [Equation (2.18)] shows that the physical content of Equation (5.4) is to take the difference dipole moment Δμ and solvate it using permittivity ε ∞ rather than ε s . The solvent parameter ε ∞ also makes an appearance in Marcus' theory of electron transfer, [572][573][574][575][576][577] in which the "outer-sphere" reorganization energy is given by…”

Designs and understanding of small molecule-based non-fullerene acceptors for realizing commercially viable organic photovoltaics

“…134 The molecular reorientation (i.e., intermolecular reorganization) occurs at the D/A interface during the CT process, changing the charge distribution of the donor and the acceptor. In this regard, the electronic polarization, or the dielectric response, influences the λO in CT exciton splitting, which can be simplified in terms of the spherical cavity model established by Marcus: [134][135][136]…”

Energetics of the Charge Generation in Organic Donor-Acceptor Interfaces

“…The coupling of electrons and holes with the quantum bath is described by the Holstein model, [38][39][40][41][42][43][44] which has been used, together with the Peierls model, to describe polaronic effects in molecular crystals. 45,46 For the intra-molecular electron-phonon relaxation, we have…”

“…42,47 The Drude cutoff frequency was set to ω −1 c = 25 fs, due to the coupling of the electronic degrees of freedom with the high energy phonon modes associated to the stretch normal mode of the C=C bond. 42,44 . It determines the peak of the spectral density; when the relevant frequencies of the system are much lower than then ω c the reservoir behaves like an Ohmic heat bath.…”