Chiral Conjugated Thermally Activated Delayed Fluorescent Polymers for Highly Efficient Circularly Polarized Polymer Light-Emitting Diodes

Jin-Ming Teng; Da-Wei Zhang; Yin-Feng Wang; Chuan-Feng Chen

doi:10.1021/acsami.1c20244

Chiral Conjugated Thermally Activated Delayed Fluorescent Polymers for Highly Efficient Circularly Polarized Polymer Light-Emitting Diodes

ACS Appl Mater Interfaces. 2022 Jan 12;14(1):1578-1586. doi: 10.1021/acsami.1c20244. Epub 2021 Dec 28.

Authors

Jin-Ming Teng^{1

2}, Da-Wei Zhang^{1

2}, Yin-Feng Wang^{1

2}, Chuan-Feng Chen^{1

2}

Affiliations

¹ Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
² University of Chinese Academy of Sciences, Beijing 100049, China.

PMID: 34962755
DOI: 10.1021/acsami.1c20244

Abstract

Two novel chiral conjugated polymers R-P and S-P designed and synthesized from a pair of circularly polarized thermally activated delayed fluorescence (CP-TADF) enantiomers are presented in this work. The two polymers exhibited excellent TADF properties with small singlet-triplet energy gaps (ΔE_ST) of 0.045 and 0.061 eV and relatively high photoluminescence quantum yields (PLQYs) of 72 and 76%, respectively. Besides, intense mirror-image circularly polarized luminescence signals were detected from R-P and S-P in both solution and film states with dissymmetry factors (|g_lum|) of up to 1.9 × 10^-3. Furthermore, solution-processed circularly polarized polymer light-emitting diodes (CP-PLEDs) fabricated with R-P and S-P achieved high maximum external quantum efficiencies of 14.9 and 15.8% and high maximum brightness (L_max) of 8940 and 12,180 cd/m² with yellowish-green emission peaks at 546 and 544 nm, respectively. Moreover, intense circularly polarized electroluminescence signals with electroluminescence dissymmetry factors (g_EL) of -1.5 × 10^-3 and +1.6 × 10^-3 were detected from the CP-PLED devices fabricated with R-P and S-P, respectively.

Keywords: circularly polarized electroluminescence; conjugated polymer; polymer light-emitting diodes; solution-processed; thermally activated delayed fluorescence.