Charge Transfer Excitons in Soft Matter

Abstract

Charge transfer excitons (CTEs) play important roles in different fields of physics, chemistry, biology and medicine. They take part in a process of fundamental importance—photosynthesis: at one stage after absorption of a photon separated in space, an electron-hole pair appears. Energy of this state involves Coulomb contribution of the separated charges. The last depends significantly on the atom shifts; therefore, CTEs strongly interact with phonon modes (strong exciton-phonon coupling). It becomes of crucial importance in soft matter where this interaction forms self-trapped states, which change drastically CTE kinetics. Typical examples of a soft matter are polymer materials and biological systems. Considerable atom displacements appear in these systems under action by external forces, therefore phonon modes are involved significantly and play key roles in CTE behavior.