High-Efficiency Circularly Polarized Electroluminescence from TADF-Sensitized Fluorescent Enantiomers

Meng Li; Mei-Ying Wang; Yin-Feng Wang; Liheng Feng; Chuan-Feng Chen

doi:10.1002/anie.202108011

High-Efficiency Circularly Polarized Electroluminescence from TADF-Sensitized Fluorescent Enantiomers

Angew Chem Int Ed Engl. 2021 Sep 13;60(38):20728-20733. doi: 10.1002/anie.202108011. Epub 2021 Aug 13.

Authors

Meng Li^{1

2}, Mei-Ying Wang³, Yin-Feng Wang^{1

2}, Liheng Feng³, 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.
³ School of Chemistry and Chemical Engineering Department, Shanxi University, Taiyuan, 030006, China.

PMID: 34288304
DOI: 10.1002/anie.202108011

Abstract

A couple of fluorescent enantiomers, which are suitable for the emitters of high-efficiency TADF-sensitized CP-OLEDs, have been developed. The enantiomers show configurational stability, high PLQY of 98 %, large k_r of 7.8×10⁷ s^-1 , and intense CPL activities with |g_lum | values of about 2.5×10^-3 . Notably, by using matchable TADF sensitizer, the enantiomers were then exploited as emitter to fabricate CP-OLEDs. The TADF-sensitized CP-OLEDs not only show mirror-image CPEL activities with g_EL values of +1.8×10^-3 and -1.4×10^-3 , but also display fast start-up featuring with low V_T of 3.0 V as well as driving voltage of 4.8 V at 10 000 cd m^-2 . Meaningfully, the TADF-sensitized fluorescent devices show high EQE_max of 21.5 % and extremely low efficiency roll-off, whose EQEs are 21.2 % and 15.3 % at 1000 and 10 000 cd m^-2 , respectively. The obtained EQEs are comparable to those of CP-TADF emitters, which provides a promising perspective to break through the EL efficiency limit of CP-FL emitters.

Keywords: circularly polarized luminescence; electroluminescence; fluorescent enantiomer; organic light-emitting diode; thermally activated delayed fluorescence sensitizer.

Abstract

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