Herein are described the synthesis, photophysical properties and applications of a series of luminescent cyclometalated Au complexes having an auxiliary aryl ligand. These complexes show photoluminescence with emission quantum yields of up to 0.79 in solution and 0.84 in thin films (4 wt % in PMMA) at room temperature, both of which are the highest reported values among Au complexes. Thermally activated delayed fluorescence (TADF) is the emission origin for some of these complexes. Solution-processed OLEDs made with these complexes showed sky-blue to green electroluminescence with external quantum efficiencies (EQEs) of up to 23.8 %, current efficiencies of up to 70.4 cd A , and roll-off of down to 1 %, highlighting the bright prospect of Au -TADF emitters in OLEDs.

Thermally stable, strongly luminescent gold‐TADF emitters are the clue to realize practical applications of gold metal in next generation display and lighting technology, a scarce example of which is herein described. A series of donor–acceptor type cyclometalated gold(III) alkynyl complexes with some of them displaying highly efficient thermally activated delayed fluorescence (TADF) with Φ up to 88% in thin films and emission lifetimes of ≈1–2 µs at room temperature are developed. The emission color of these complexes is readily tunable from green to red by varying the donor unit and cyclometalating ligand. Vacuum‐deposited organic light‐emitting diodes (OLEDs) with these complexes as emissive dopants achieve external quantum efficiencies (EQEs) and luminance of up to 23.4% and 70 300 cd m−2, respectively.

Structurally robust tetradentate gold(III)‐emitters have potent material applications but are rare and unprecedented for those displaying thermally activated delayed fluorescence (TADF). Herein, a novel synthetic route leading to the preparation of highly emissive, charge‐neutral tetradentate [C^C^N^C] gold(III) complexes with 5‐5‐6‐membered chelate rings has been developed through microwave‐assisted C−H bond activation. These complexes show high thermal stability and with emission origin (3IL, 3ILCT, and TADF) tuned by varying the substituents of the C^C^N^C ligand. With phenoxazine/diphenylamine substituent, we prepared the first tetradentate gold(III) complexes that are TADF emitters with emission quantum yields of up to 94 % and emission lifetimes of down to 0.62 μs in deoxygenated toluene. These tetradentate AuIII TADF emitters showed good performance in vacuum‐deposited OLEDs with maximum EQEs of up to 25 % and LT95 of up to 5280 h at 100 cd m−2.

A series of luminescent cyclometalated gold(III) complexes having alkyls as auxiliary ligands has been prepared. The alkyl ligand was found to effectively increase the emission quantum yields and lifetimes of luminescent cyclometalated gold(III) complexes by circumventing the population of LLCT excited states that are found in complexes supported by arylacetylide ligands. These gold(III) alkyl complexes exhibit emission quantum yields and lifetimes of up to 0.40 and 180 μs, respectively, in solution at room temperature. The triplet emission color of these complexes is tunable from yellow to sky blue by modifying the cyclometalating ligand.

Herein are described the synthesis, photophysical properties and applications of a series of luminescent cyclometalated AuIII complexes having an auxiliary aryl ligand. These complexes show photoluminescence with emission quantum yields of up to 0.79 in solution and 0.84 in thin films (4 wt % in PMMA) at room temperature, both of which are the highest reported values among AuIII complexes. Thermally activated delayed fluorescence (TADF) is the emission origin for some of these complexes. Solution‐processed OLEDs made with these complexes showed sky‐blue to green electroluminescence with external quantum efficiencies (EQEs) of up to 23.8 %, current efficiencies of up to 70.4 cd A−1, and roll‐off of down to 1 %, highlighting the bright prospect of AuIII‐TADF emitters in OLEDs.

In this contribution, recent advances in new classes of efficient metal-TADF complexes, especially those of Au(I), Au(III), and W(VI), and their application in OLEDs are reviewed. The high performance (EQE = 25%) and long device operational lifetime (LT 95 = 5,280 h) achieved in an OLED with tetradentate Au(III) TADF emitter reflect the competitiveness of this class of emitters for use in OLEDs with practical interest. The high EQE of 15.6% achieved in solution-processed OLED with W(VI) TADF emitter represents an alternative direction toward low-cost light-emitting materials. Finally, the design strategy of metal-TADF emitters and their next-stage development are discussed.

Herein is described a blue-emitting gold(III)-TADF complex Au-1 that could act as a sensitizer for a solution-processed organic light-emitting diode (SP-OLED), in which a multi-resonance TADF emitter ν-DABNA is employed...

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.