Specific features of the kinetics of singlet fission in organic semiconductors. The effect of kinetic curves crossing

TL;DR

This paper investigates the crossing of kinetic fluorescence curves in singlet fission processes within organic semiconductors, revealing it as a general feature of geminate reactions influenced by magnetic fields.

Contribution

It demonstrates that kinetic curves crossing is a universal characteristic of geminate reactions, providing detailed analysis within singlet fission models.

Findings

Kinetic curves crossing occurs in magnetic field-dependent singlet fission.

KCC is a general feature of geminate condensed phase reactions.

Analysis of KCC provides insights into SF process mechanisms.

Abstract

Experimental investigations of magnetic field dependent kinetics of singlet fission (SF)processes in some organic semiconductors [i.e. splitting of excited singlet (S_1) state into a triplet exciton pair] have revealed the important specific feature of obtained kinetic curves, associated with decaying intensities I(t) of fluorescence from S_1-state. Kinetic curves, measured in different magnetic fields, are found to cross each other. We show that this kinetic curves crossing (KCC) effect is a general feature of geminate condensed phase reactions, resulting from simple characteristic properties of kinetic schemes of processes. Specific features of the KCC-effect are analyzed in detail with some models of SF-processes.