In this work, two novel thermally activated delayed fluorescence (TADF) emitters have been designed for very high-efficiency organic light-emitting diodes (OLEDs). The two emitters have a tilted face-to-face alignment of donor (D)/acceptor (A) units presenting intramolecular noncovalent interactions. These charge transfer (CT) interactions are the heart of the present design. Owing to the enforced face‐to‐face D/A/D pattern, effective charge transfer interactions are realized, which lead to high photoluminescence quantum yields (above 90%), small singlet–triplet energy splitting (ΔEST ) and fast reverse intersystem crossing process. The resulting external quantum efficiencies are very high (28.0%/26.6) and appear to be higher than classical D/A‐type analogues, commonly used in TADF OLEDs. This new design appears very promising for high performance TADF OLEDs.
Highly Efficient Thermally Activated Delayed Fluorescence via an Unconjugated Donor–Acceptor System Realizing EQE of Over 30%
Chen‐Chen Peng, Sheng‐Yi Yang, Hong‐Cheng Li, Guo‐Hua Xie, Lin‐Song Cui, Sheng‐Nan Zou, Cyril Poriel, Zuo‐Quan Jiang, Liang‐Sheng Liao
Adv. Mater., 2020, in press https://onlinelibrary.wiley.com/doi/10.1002/adma.202003885
Published November 30, 2020