Gold(I) Multi‐Resonance Thermally Activated Delayed Fluorescent Emitters for Highly Efficient Ultrapure‐Green Organic Light‐Emitting Diodes

• DOI: 10.1002/anie.202213392
• Publication Date: 2022-10-26T16:42:23Z
• Authors: Siyuan Cai; Glenna So Ming Tong; Lili Du; Gary Kwok‐Ming So; Faan‐Fung Hung; Tsz‐Lung Lam; Gang Cheng; Hui Xiao; Xiaoyong Chang; Zong‐Xiang Xu; Chi‐Ming Che
• Keywords: Intersystem crossing; Quantum Efficiency

Acceleration of singlet-triplet intersystem crossings (ISC) is instrumental in bolstering triplet exciton harvesting multi-resonance thermally activated delayed fluorescent (MR-TADF) emitters. This work describes a simple gold(I) coordination strategy to enhance the spin-orbit coupling green and blue BN(O)-based MR-TADF emitters, which results notable increase rate constants spectroscopically observed ISC process 3×109 s-1 with nearly unitary quantum yields. Accordingly, resultant thermally-stable AuI emitters attained large values fluorescence radiative constant up 1.3×105 /1.7×105 THF/PMMA film while preserving narrowband emissions (FWHM=30-37 nm) high emission yields (ca. 0.9). The vapor-deposited ultrapure-green OLEDs fabricated these delivered luminance 2.53×105 cd m-2 as well external efficiencies 30.3 % roll-offs low 0.8 long device lifetimes (LT60 ) 1210 h at 1000 .