Charge-Transfer Mobility Parameters in Photoelectronic Devices: The Advanced Miller-Abrahams Computation

The local hopping step of the electron transfer (ET) reaction is investigated for a real organic material composed of molecules M (N,N'-di(1-naphthyl)-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine). This material is implemented in light-emitting photoelectronic devices. The conductivity effect is simulated and calculated at a molecular level. We have studied the ET mechanism alternative to that suggested by the usually employed Marcus-like polaron model. The ion-molecular binary complex M(+)M (for hole transfer) is considered as a reaction center. The reaction dynamics is carried through the low-frequency intermolecular vibration coordinate connecting its fragments (the promotion mode). Its coupling to the acoustic phonon bath serves for a dissipation of the reaction energy misfit. The high-frequency intramolecular vibrations (the reorganization modes) modulate the reaction kinetics via Franck-Condon factors induced by their polarization. The ET rate constants are evaluated in terms of the computational algorithm described earlier (Basilevsky, M. V.; et al. J. Chem. Phys. 2013 139, 234102). Standard quantum-chemical and molecular dynamical techniques are used for a calculation of all necessary parameters of this model. The macroscopic charge-carrier mobility of the material is estimated by properly averaging the rate constants over the total simulation cell.