Reaching the 5% theoretical limit of fluorescent OLEDs with push-pull benzophospholes

Nicolas Ledos (1) , Denis Tondelier (2) , Bernard Geffroy (3, 4) , Denis Jacquemin (5) , Pierre-Antoine Bouit (1) , Muriel Hissler (1)

1 ISCR - Institut des Sciences Chimiques de Rennes
2 LPICM - Laboratoire de physique des interfaces et des couches minces [Palaiseau]
3 LICSEN UMR 3685 - Laboratoire Innovation en Chimie des Surfaces et NanoSciences
4 NIMBE UMR 3685 - Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M)
5 CEISAM - Chimie Et Interdisciplinarité : Synthèse, Analyse, Modélisation

We report the synthesis and characterization of benzophosphole oxides featuring an ethoxy substituent on the P atom and electro-donating amino groups on the lateral phenyl groups. The optical and redox properties of these compounds are studied experimentally and computationally (TD-DFT). In particular, we show how the nature of the donor allows fine-tuning the internal charge transfer (ICT) and, thus, the optical properties. Considering the intense fluorescence in the solid state (powder or thin film) and the favorable redox and thermal properties, these compounds were introduced in multilayered organic light emitting devices. All compounds display high efficiency and one compound even exhibits an external quantum efficiency (EQE) of 5%, which represents the theoretical limit of the EQE of purely fluorescent emitters. These results highlight the potential of this novel family of fluorophores to develop next generation optoelectronic/photonic devices.

Domaines: Chimie

Nicolas Ledos, Denis Tondelier, Bernard Geffroy, Denis Jacquemin, Pierre-Antoine Bouit, et al.. Reaching the 5% theoretical limit of fluorescent OLEDs with push-pull benzophospholes. Journal of Materials Chemistry C, 2023, 11, pp.3826-3831. ⟨10.1039/D3TC00245D⟩. ⟨hal-04004191⟩