DI-UMONS : Dépôt institutionnel de l’université de Mons

Recherche transversale
(titres de publication, de périodique et noms de colloque inclus)
2017-12-27 - Article/Dans un journal avec peer-review - Anglais - 6 page(s)

Olivier Yoann , Yurash B., Muccioli L., D'Avino G., Mikhnendo O., Sancho-Garcia Juan Carlos, Adachi C., Nguyen T.Q., Beljonne David , "Nature of the Singlet and Triplet Excitations Mediating Thermally Activated Delayed Fluorescence" in Physical review materials, 1, 075602, 10.1103/PhysRevMaterials.1.075602

  • Codes CREF : Physico-chimie générale (DI1320), Chimie théorique (DI1311)
  • Unités de recherche UMONS : Chimie des matériaux nouveaux (S817)
  • Instituts UMONS : Institut de Recherche en Science et Ingénierie des Matériaux (Matériaux), Institut de Recherche sur les Systèmes Complexes (Complexys)
  • Centres UMONS : Centre d’Innovation et de Recherche en Matériaux Polymères (CIRMAP)
Texte intégral :

Abstract(s) :

(Anglais) Despite significant efforts, a complete mechanistic understanding of thermally activated delayed fluorescence (TADF) materials has not yet been fully uncovered. Part of the complexity arises from the apparent dichotomy between the need for close energy resonance and for a significant spin-orbit coupling between alike charge-transfer singlet and triplet excitations. Here we show, in the case of reference carbazole derivatives, that this dichotomy can be resolved in a fully atomistic model accounting for thermal fluctuations of the molecular conformations and microscopic electronic polarization effects in amorphous films. These effects yield electronic excitations with a dynamically mixed charge-transfer and localized character, resulting in thermally averaged singlet-triplet energy differences and interconversion rates in excellent agreement with careful spectroscopic studies.