Highly Luminescent Phosphine Oxide-Containing Bipolar Alkynylgold(III) Complexes for Solution-Processable Organic Light-Emitting Devices with Small Efficiency Roll-Offs

Abstract

We report the synthesis of alkynylgold(III) complexes with electron-transporting phosphine oxide moiety in the tridentate ligand and hole-transporting triarylamine moieties as auxiliary ligands to generate a new class of phosphine oxide-containing bipolar gold(III) complexes for the first time. Such gold(III) complexes feature high photoluminescence quantum yields of over 70 % in MCP thin films with relatively short excited-state lifetimes of less than 3.9 s at 20 wt% dopant concentration. Highly efficient solution-processable organic lightemitting devices have been prepared with superior current efficiencies of up to 51.6 cd A–1 and external quantum efficiency of up to 15.3 %. Notably, triplet-triplet annihilation has been significantly reduced, as exemplified by a very small efficiency roll-off of ~1 % at practical brightness of 500 cd m2. Reference: 1. Lee, C.-H.; Tang, M.-C.; Cheung, W.-L.; Lai, S.-L.; Chan, M.-Y.; Yam, V. W.-W. Chem. Sci., 2018, 9, 62286232.