Two- and three-photon absorption and excitation phosphorescence of oligofluorene-substituted Ir(ppy)3

Abstract

A series of triscyclometalated iridium complexes with oligofluorene-substituted ppy ligands manifest impressive two- and three-photon absorption properties. In particular, a star-shaped complex bearing three carbazole-terminated trifluorenyl ppy demonstrates a large three-photon absorption cross section up to 81 × 10⁻⁷⁸ cm⁶ s² photon⁻². In combination with optimal phosphorescence quantum yields (0.5–0.8), such iridium complexes are effective two- and three-photon excited phosphorescence emitters.