Luminescent gold(III) exciplexes enable efficient multicolor electroluminescence.

The control of excited states and related emissive properties of gold(III) complexes mainly depends on the modulation of intramolecular electronic interactions among gold(III) metal center, chelating ligands and/or peripheral groups. However, luminescent gold(III) systems based on intermolecular electronic interactions have never been explored. Here we report a series of proof-of-concept gold(III) exciplexes using a simple gold(III) complex, AuDPPy, as an electron acceptor. The emissive properties of gold(III) exciplexes can be regulated by combining AuDPPy with different donors. Inspiringly, these gold(III) exciplexes have donor-dependent emission mechanisms: dominant phosphorescence or dual radiative channels of thermally activated delayed fluorescence (TADF) and phosphorescence. Consequently, these gold(III) exciplexes deliver green-to-red electroluminescence with external quantum efficiencies (EQEs) of up to 10.1%. More importantly, using these gold(III) exciplexes to host multi-resonance TADF emitters results in narrowband yellow, orange, and deep-red electroluminescence with high EQEs of 23.5%, 24.4%, and 27.4%, respectively, competitive to the highest values for gold(III) OLEDs in similar color gamut. [ABSTRACT FROM AUTHOR]