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.
Contact
Cyril Poriel, Univ Rennes, CNRS, ISCR-6226, F-35000 Rennes, France
+33(0)223235977
cyril [dot] porieluniv-rennes1 [dot] fr
Reference
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