Affiliation:
1. Department Key Laboratory of Rubber‐Plastics Ministry of Education/Shandong Provincial Key Laboratory of Rubber‐Plastics School of Polymer Science and Engineering Qingdao University of Science & Technology Qingdao 266042 P. R. China
2. State Key Laboratory of Chemical Resource Engineering College of Materials Science and Engineering Beijing University of Chemical Technology Beijing 100029 P. R. China
Abstract
AbstractThe concept of thermally activated delayed fluorescence (TADF) conjugated polymers has the advantage of enabling solution‐processable devices and harnessing singlet and triplet excitons simultaneously, whereas the resultant redshift of emission spectra and inevitable drop‐off of triplet excited states are detrimental to exploring high‐efficiency blue conjugated polymeric emitters. Herein, a feasible molecular design strategy is proposed by combining a spatially confined conjugated backbone and a TADF moiety isolated by a saturated spiro spacer to enable blue emission in newly designed partly conjugated TADF polymers, simultaneously achieving an excellent photoluminescence quantum yield of over 80% and a relatively high reverse intersystem crossing rate of 4.2 × 105 s−1. Endowed by superior photophysical properties and balanced carrier mobility, a maximum external quantum efficiency of 20.5% is achieved with emission at 486 nm and Commission Internationalede l'Eclairage coordinates of (0.18, 0.31), which is so far the highest efficiency for solution‐processed blue TADF polymer light‐emitting diodes.
Funder
National Natural Science Foundation of China
Natural Science Foundation of Shandong Province
Subject
Atomic and Molecular Physics, and Optics,Electronic, Optical and Magnetic Materials