Dynamical exciton decay in organic materials: the role of bimolecular recombination. Issue 4 (8th January 2019)

• Record Type: Journal Article
• Authors: de Sousa, Leonardo Evaristo; Bueno, Fernando Teixeira; da Silva Filho, Demétrio Antônio; Ribeiro Junior, Luiz Antônio; de Oliveira Neto, Pedro Henrique
• Is Part Of: Physical chemistry chemical physics. Volume 21:Issue 4(2018)
• Page Start: 1711
• Page End: 1716
• Publication Date: 2019-01-08
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c8cp05951a
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : Excitons play a critical role in light emission when it comes to organic semiconductors. Abstract : Excitons play a critical role in light emission when it comes to organic semiconductors. In high exciton concentration regimes, monomolecular and bimolecular routes for exciton recombination can yield different products affecting significantly the material's optical properties. Here, the dynamical decay of excitons is theoretically investigated using a kinetic Monte Carlo approach that addresses singlet exciton diffusion. Our numerical protocol includes two distinct exciton–exciton interaction channels: exciton annihilation and biexciton cascade emission. Our findings reveal that these channels produce different consequences concerning diffusion and spectroscopic properties, being able to explain diverging experimental observations. Importantly, we estimate critical exciton densities for which bimolecular recombination becomes dominant and investigate its effect on average exciton lifetimes and diffusion lengths.