Au···H-C Interactions Support a Robust Thermally Activated Delayed Fluorescence (TADF) Gold(I) Complex for OLEDs with Little Efficiency Roll-Off and Good Stability

摘要

The practical use of luminescent mononuclear gold(I) complexes as optoelectronic materials has been limited by their inferior stability. Herein we demonstrate a strategy to improve the stability of gold(I) complexes which display thermally activated delayed fluorescence (TADF). A highly rigid and groove-like o-donating aryl ligand has been used to form dual Au-H-C hydrogen bonds. The secondary metal-ligand interactions have been authenticated by single-crystal structure, NMR spectroscopy and theoretical simulations. The TADF Au1 complex exhibits appealing emission properties (photoluminescence quantum yield = 76%; delayed fluorescence lifetime = 1.2 μs) and much improved thermal and photo-stability. Vacuum-deposited organic hght-emitting diodes (OLEDs) show promising electroluminescence with a maximum external quantum efficiency (EQE) over 23 % and negligible efficiency roll-off even at 10000 cd m~(-2). An estimated LT_(50) longer than 77000 h with initial luminance of 100 cd m~(-2) reveals good operational stability. This work suggests a way for design of stable luminescent gold(I) complexes.