High Efficiency Sky‐Blue Gold(III)‐TADF Emitters

Abstract

Highly efficient sky-blue luminescent gold(III) complexes with emission quantum yields up to 82 %, lifetimes down to 0.67 μs and emission peak maxima at 470–484 nm were prepared through a consideration of pincer gold(III) donor–acceptor complexes. Photophysical studies and time-dependent density functional theory (TDDFT) calculations revealed that the emission nature of these gold(III) complexes is most consistent with TADF. Solution-processed OLEDs with these gold(III) complexes as dopants afforded electroluminescence maxima at 465–473 nm with FWHM of 64–67 nm and maximum external quantum efficiencies (EQEs) of up to 15.25 %. This research demonstrates the first example of gold(III)-OLEDs showing electroluminescence maxima at smaller than 470 nm, and highlights the potential of using gold(III)-TADF emitters in the development of high efficiency blue OLEDs and blue emissive dopant in WOLEDs.