Highly efficient carbazolylgold(iii) dendrimers based on thermally activated delayed fluorescence and their application in solution-processed organic light-emitting devices

Abstract

A new class of carbazolylgold(iii) C^C^N dendrimers with thermally activated delayed fluorescence properties has been designed and synthesized for the realzaqtion of operationally stable solution-processed organic light-emitting devices.

Carbazolylgold(iii) complexes with thermally activated delayed fluorescence switched on by ligand manipulation as high efficiency organic light-emitting devices with small efficiency roll-offs

“…4b). As TADF compounds are well known to show luminescence intensity growth and blue-shied emission with increasing temperature and behave just like other TADF-active gold(III) complexes previously reported, 35,36 it is likely that 2 and 6 could possibly be TADF emitters. Yet the experimental DE ST cannot be obtained since the non-radiative decay is not negligible 56 and the excited state lifetimes show insignicant changes in the achievable temperature range.…”

“…[19][20][21] Although copper(I) complexes have relatively lower thermal stabilities, 22 their TADF OLEDs have been found to show rather attractive external quantum efficiencies (EQEs), 23,24 providing the impetus for the development of metal-TADF emitters. Since then, various classes of metal-TADF emitters based on palladium(II), 25,26 silver(I), 17,[27][28][29] gold(I) 30,31 and gold(III) systems [32][33][34][35][36][37] have been designed and synthesized. Of particular interest are examples involving tetradentate ligand-containing palladium(II) complexes that were reported to show phosphorescence and delayed uorescence simultaneously.…”

“…38,39 A variety of cyclometalating C^N^C [40][41][42] and C^C^N gold(III) complexes 43,44 and tetradentate gold(III) complexes 45,46 showing high performances and a wide range of emission colours have been reported. Since 2017, gold(III) emitters have also been reported to show TADF behavior, including alkynylgold(III) 33,35 and arylgold(III) C^N^C complexes, 32 carbazolylgold(III) C^C^N complexes 36,37 and tetradentate gold(III) complexes. 34 All of them are found to exhibit promising electroluminescence (EL) performance with maximum EQEs reaching 25%.…”

“…Recently, new classes of alkynylgold(III) C^N^C complexes 35 and carbazolylgold(III) C^C^N complexes with thienopyridine and thienoquinoline moieties in the pincer ligand 37 have been demonstrated as metal-containing TADF emitters. Based on our development of various cyclometalating C^C^N ligand-containing carbazolylgold(III) complexes, 36,37,43,44 instead of modifying the pincer ligand, a new class of carbazolylgold(III) complexes with different ancillary ligands has been designed and synthesized. Specically, substituted carbazolyl ligands with various electron-donating and electron-accepting moieties have been incorporated into the gold(III) precursor complex to yield complexes 1-6, as shown in Chart 1.…”

Customized Orthogonal Solvent System with Various Hole-Transporting Polymers for Highly Reproducible Solution-Processable Organic Light-Emitting Diodes

“…The importance and usefulness of solution-processed organic light-emitting diodes (OLEDs) as replacements for vacuum-deposited OLEDs have been emphasized in numerous studies. − The solution process is known to be particularly advantageous for relatively inexpensive device manufacturing processes, large areas, and flexible device applications. Owing to these advantages, many types of soluble charge transport materials and emitting materials suitable for solution processing have been developed. − …”