title: Electron-Rich 4-Substituted Spirobifluorenes: Toward a New Family of High Triplet Energy Host Materials for High-Efficiency Green and Sky Blue Phosphorescent OLEDs.
abstract: We report herein a detailed structure-properties relationship study of the first examples of electron-rich 4-substituted spirobifluorenes for organic electronic applications, namely, 4-phenyl-N-carbazole-spirobifluorene (4-PhCz-SBF) and 4-(3,4,5-trimethoxyphenyl)-spirobifluorene (4-Ph(OMe)3-SBF). The incorporation of the electron-rich moieties in the ortho position of the biphenyl linkage (position C4) induces unique properties, very different from those previously described in the literature for this family of semiconductors. Both dyes can be readily synthesized, possess high triplet energies and excellent thermal stability, and their HOMO energy levels are highly increased compared to those of other 4-substituted SBFs. We also provide in this work the first rationalization of the peculiar fluorescence of 4-substituted SBFs. Finally, the present dyes have been successfully incorporated as host in green and blue phosphorescent organic light-emitting diodes with high performance either for the green (EQE of 20.2%) or the blue color (EQE of 9.6%). These performances are, to the best of our knowledge, among the highest reported to date for 4-substituted SBF derivatives.
authors.affiliation: Institut des Sciences Chimiques de Rennes - UMR CNRS 6226, Université Rennes 1 , 35042 Rennes, France.
authors.forename: Cassandre
authors.initials: C
authors.lastname: Quinton
authors.affiliation: Institut des Sciences Chimiques de Rennes - UMR CNRS 6226, Université Rennes 1 , 35042 Rennes, France.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Thiery
authors.affiliation: Institut des Sciences Chimiques de Rennes - UMR CNRS 6226, Université Rennes 1 , 35042 Rennes, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Jeannin
authors.affiliation: LPICM, CNRS, Ecole Polytechnique, Université Paris Saclay , 91128 Palaiseau, France.
authors.forename: Denis
authors.initials: D
authors.lastname: Tondelier
authors.affiliation: LPICM, CNRS, Ecole Polytechnique, Université Paris Saclay , 91128 Palaiseau, France.|LICSEN, NIMBE, CEA, CNRS, Université Paris-Saclay, CEA Saclay , Gif-sur-Yvette CEDEX 91191, France.
authors.forename: Bernard
authors.initials: B
authors.lastname: Geffroy
authors.affiliation: UMR CNRS 6164-Institut d'Électronique et des Télécommunications de Rennes- Département Microélectronique & Microcapteurs, Bât. 11B, Université Rennes 1 , Campus de Beaulieu, Rennes CEDEX 35042, France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Jacques
authors.affiliation: Institut des Sciences Chimiques de Rennes - UMR CNRS 6226, Université Rennes 1 , 35042 Rennes, France.
authors.forename: Joëlle
authors.initials: J
authors.lastname: Rault-Berthelot
authors.affiliation: Institut des Sciences Chimiques de Rennes - UMR CNRS 6226, Université Rennes 1 , 35042 Rennes, France.
authors.forename: Cyril
authors.identifier: http://orcid.org/0000-0002-6036-1778
authors.initials: C
authors.lastname: Poriel
keywords: 4-substituted spirobifluorene; blue phosphorescent organic light-emitting diode; conjugation disruption; host materials; organic electronics; organic semiconductors