Modifications of Pyridine-3,5-dicarbonitrile Acceptor for Highly Efficient Green-to-Red Organic Light-Emitting Diodes

Sheng-Lin Deng; Yi-Kuan Chen; Jian Lei; Jayachandran Jayakumar; Chang-Lun Ko; Wen-Yi Hung; Tien-Lin Wu; Chien-Hong Cheng

doi:10.1021/acsami.3c05243

Modifications of Pyridine-3,5-dicarbonitrile Acceptor for Highly Efficient Green-to-Red Organic Light-Emitting Diodes

ACS Appl Mater Interfaces. 2023 Jul 19;15(28):33819-33828. doi: 10.1021/acsami.3c05243. Epub 2023 Jul 7.

Authors

Sheng-Lin Deng¹, Yi-Kuan Chen¹, Jian Lei^{1

2}, Jayachandran Jayakumar¹, Chang-Lun Ko³, Wen-Yi Hung³, Tien-Lin Wu^{1

4}, Chien-Hong Cheng^{1

5}

Affiliations

¹ Department of Chemistry, National Tsing Hua University, Hsinchu 300044, Taiwan.
² Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan.
³ Institute of Optoelectronic Sciences, National Taiwan Ocean University, Keelung 20224, Taiwan.
⁴ College of Semiconductor Research, National Tsing Hua University, Hsinchu 300044, Taiwan.
⁵ Department of Chemistry, National Sun Yat-sen University, Kaohsiung 80424, Taiwan.

PMID: 37418573
DOI: 10.1021/acsami.3c05243

Abstract

The strategy of acceptor modification is a powerful technique for tuning the emission color of thermally activated delayed fluorescence (TADF) emitters. In this study, we have successfully designed and synthesized three TADF emitters with donor-acceptor (D-A) structures using a 4-(diphenylamino)-2,6-dimethylphenyl (TPAm) donor and various pyridine-3,5-dicarbonitrile (PC) acceptor units. As a result, three compounds named TPAmbPPC, TPAm2NPC, and TPAmCPPC exhibited greenish-yellow to orange-red emissions with high photoluminescent quantum yields (76-100%) in thin films. Remarkably, a greenish-yellow device based on TPAmbPPC and TPAm2NPC showed a high maximum external quantum efficiency (EQE_max) of 39.1 and 39.0%, respectively. Furthermore, benefiting from the suitable steric hindrance between the acceptor and donor, the nondoped organic light-emitting diodes (OLEDs) based on TPAmbPPC demonstrated an exceptional EQE_max of 21.6%, indicating its promising potential as an efficient emitter for the application of OLED applications. Furthermore, orange-red OLED devices based on TPAmCPPC exhibited a high EQE_max of 26.2%, a CE of 50.1 cd A^-1, and a PE of 52.4 lm W^-1.

Keywords: TADF; acceptor modification; orange-red emission; organic light-emitting diode; pyridine-3,5-dicarbonitrile.