Achieving 37.1% Green Electroluminescent Efficiency and 0.09 eV Full Width at Half Maximum Based on a Ternary Boron-Oxygen-Nitrogen Embedded Polycyclic Aromatic System

Xinliang Cai; Jianan Xue; Chenglong Li; Baoyan Liang; Ao Ying; Yao Tan; Shaolong Gong; Yue Wang

doi:10.1002/anie.202200337

Achieving 37.1% Green Electroluminescent Efficiency and 0.09 eV Full Width at Half Maximum Based on a Ternary Boron-Oxygen-Nitrogen Embedded Polycyclic Aromatic System

Angew Chem Int Ed Engl. 2022 Jun 7;61(23):e202200337. doi: 10.1002/anie.202200337. Epub 2022 Apr 5.

Authors

Xinliang Cai¹, Jianan Xue¹, Chenglong Li¹, Baoyan Liang², Ao Ying³, Yao Tan³, Shaolong Gong³, Yue Wang¹

Affiliations

¹ State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, China.
² Jihua Laboratory, 28 Huandao South Road, Foshan, 528200, Guangdong Province, P. R. China.
³ Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Department of Chemistry, Wuhan University, Wuhan, 430072, P. R. China.

PMID: 35302704
DOI: 10.1002/anie.202200337

Abstract

Herein, a ternary boron-oxygen-nitrogen embedded polycyclic aromatic hydrocarbon with multiple resonance thermally activated delayed fluorescence (MR-TADF), namely DBNO, is developed by adopting the para boron-π-boron and para oxygen-π-oxygen strategy. The designed molecule presents a vivid green emission with a high photoluminescence quantum yield (96 %) and an extremely narrow full width at half maximum (FWHM) of 19 nm/0.09 eV, which surpasses all previously reported green TADF emitters to date. In addition, the long molecular structure along the transition dipole moment direction endows it with a high horizontal emitting dipole ratio of 96 %. The organic light-emitting diode (OLED) based on DBNO reveals a narrowband green emission with a peak at 504 nm and a FWHM of 24 nm/0.12 eV. Particularly, a significantly improved device performance is achieved by the TADF-sensitization (hyperfluorescence) mechanism, presenting a FWHM of 27 nm and a maximum external quantum efficiency (EQE) of 37.1 %.

Keywords: Multiple Resonance Effect; Narrowband Emission; Organic Light-Emitting Diodes; Polycyclic Aromatic Hydrocarbon; Thermally Activated Delayed fluorescence.