A Model of Charge Transfer Excitons: Diffusion, Spin Dynamics, and Magnetic Field Effects

TL;DR

This paper presents a numerical framework to simulate how external magnetic fields influence charge transfer excitons in disordered semiconductors, revealing microscopic mechanisms behind observed magnetic effects.

Contribution

The authors develop a combined quantum spin and stochastic charge transport model to analyze magnetic field effects on charge transfer excitons in disordered materials.

Findings

Model reproduces experimental magnetic field effects.

Predicts impact of magnetic fields on organic electronic efficiency.

Provides insights into spin-charge interplay in exciton dynamics.

Abstract

In this letter we explore how the microscopic dynamics of charge transfer (CT) excitons are influenced by the presence of an external magnetic field in disordered molecular semiconductors. This influence is driven by the dynamic interplay between the spin and spatial degrees of freedom of the electron-hole pair. To account for this interplay we have developed a numerical framework that combines a traditional model of quantum spin dynamics with a coarse-grained model of stochastic charge transport. This combination provides a general and efficient methodology for simulating the effects of magnetic field on CT state dynamics, therefore providing a basis for revealing the microscopic origin of experimentally observed magnetic field effects. We demonstrate that simulations carried out on our model are capable of reproducing experimental results as well as generating theoretical predictions related to the efficiency of organic electronic materials.