Intramolecular excimer emission as a blue light source in fluorescent organic light emitting diodes: a promising molecular design

Damien Thirion (1) , Maxime Romain (1) , Joëlle Rault-Berthelot (1) , Cyril Poriel (1)

1 ISCR - Institut des Sciences Chimiques de Rennes

Intramolecular excimer emission arising from organic molecules as a blue light source in fluorescent Small Molecule Organic Light Emitting Diodes (SMOLEDs) is almost absent from the literature. In this work, three aryl-substituted DiSpiroFluorene-IndenoFluorenes (DSF-IFs 1-3) possessing different fluorescent properties due to their different main emitters have been investigated through a structure-property relationship study. Due to its particular geometry, the rigid DSF-IF platform 2 allows an 'aryl/fluorene/aryl' dimer to be preformed in the ground state leading, in the excited state, to a deep blue fluorescent emission through strong π-π intramolecular interactions between the two 'aryl/fluorene/aryl' arms. 2 has been successfully used as an emitting layer in a SMOLED with electroluminescence arising from electrogenerated intramolecular excimers and the properties of these excimer-based OLEDs have been compared to those of two model compounds (1 and 3). The simple and non-optimized double-layer device displays a deep blue colour (CIE coordinates: 0.19; 0.18) exhibiting a luminance of 510 Cd m−2 with a luminous efficiency of ca. 0.1 Cd A−1. This work is, to the best of our knowledge, the first rational and comparative study describing an intramolecular excimer based-SMOLED.

Domaines: Chimie organique

Damien Thirion, Maxime Romain, Joëlle Rault-Berthelot, Cyril Poriel. Intramolecular excimer emission as a blue light source in fluorescent organic light emitting diodes: a promising molecular design. Journal of Materials Chemistry, 2012, 22, pp.7149-7157. ⟨10.1039/c2jm16774c⟩. ⟨hal-00687064⟩