Using azaacene as an acceptor unit to construct an ultraefficient red fluorophore with an EQE over 40

Xiao-Jing Wang; Han Liu; Kai Zhang; Dezhi Yang; Ze-Hui Pan; Chuan-Kui Wang; Man-Keung Fung; Dongge Ma; Jian Fan

doi:10.1039/d2mh01322c

Using azaacene as an acceptor unit to construct an ultraefficient red fluorophore with an EQE over 40

Mater Horiz. 2023 Mar 6;10(3):938-944. doi: 10.1039/d2mh01322c.

Authors

Xiao-Jing Wang¹, Han Liu¹, Kai Zhang², Dezhi Yang³, Ze-Hui Pan¹, Chuan-Kui Wang², Man-Keung Fung¹, Dongge Ma³, Jian Fan^{1

4}

Affiliations

¹ Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, China. mkfung@suda.edu.cn.
² Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China. ckwang@sdnu.edu.cn.
³ Institute of Polymer Optoelectronic Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, Guangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional Materials, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China. msdgma@scut.edu.cn.
⁴ State Key Laboratory of Structural Chemistry, Fujian Institute of Research on Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 35002, China.

PMID: 36598032
DOI: 10.1039/d2mh01322c

Abstract

Azaacenes, which have been known for a long time, are of scientific and practical importance in organic electronics. Azaacenes once shone as the luminophore in organic light-emitting diodes (OLEDs). However, due to the low exciton utilization efficiency and/or the aggregation induced quenching (ACQ) effect, N-heteroacene based OLEDs generally showed inferior device performance. In this work, azaacene has been revisited and applied as an acceptor for a red fluorophore (AZA-TPA), where the judicious connection pattern between donor and acceptor maximized the harvest of singlet and triplet excitons, resulting in a high photoluminescence efficiency of 94.6% in doped films (3 wt%). In addition, the linearly-fused polycyclic structure contributed to a high horizontal emitting dipole ratio (Θ_‖ = 90%). As a result, an AZA-TPA-based OLED achieved an unprecedented external quantum efficiency of 41.30% at 610 nm. This work will pave a new path for the development of efficient N-heteroacene-based fluorophores.