Structural Optimization of BODIPY Derivatives: Achieving Stable and Long-Lived Green Emission in Hyperfluorescent OLEDs

• Published in: ACS applied materials & interfaces 2024-05, Vol.16 (17), p.22274-22281
• Main Authors: Gawale, Yogesh, Palanisamy, Paramasivam, Lee, Hyun Seung, Chandra, Ajeet, Kim, Hae Ung, Ansari, Rasheeda, Chae, Mi Young, Kwon, Jang Hyuk
• Format: Article
• Language: English
• Subjects: Organic Electronic Devices
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.4c02002

Boron dipyrromethene (BODIPY) derivatives are widely studied as terminal emitters in organic light-emitting diodes (OLED) due to their narrow emission and high photoluminescence quantum yield (PLQY). However, the strategy for precisely tuning their emission toward a high color purity is still challenging. Herein, we developed a new design strategy to regulate the emission of BODIPY derivatives by modifying the electronic and steric dominance using functionalities, such as nitrile, pentafluorophenyl, diethyl, and monobenzyl. These rational modifications yielded a series of four novel green BODIPY emitters, namely, tPN-BODIPY, tPPP-BODIPY, tPBn-BODIPY, and tPEN-BODIPY, each benefited with a tuned emissions range of 517 to 542 nm with a narrow fwhm of 25 nm and high photoluminescence quantum yield up to 96%. Among these synthesized BODIPYs, an unsymmetrical tPBn-BODIPY was chosen as a final dopant (FD) to explore its application in OLED devices. The fabricated TADF sensitized fluorescence-OLED (TSF-OLED) exhibits a narrow band pure green emission at 531 nm with corresponding CIE coordinates of (x, y) = (0.27, 0.68) and a maximum external quantum efficiency (EQE) of 20%. Furthermore, the TSF-OLED displayed an exceptionally prolonged device operational lifetime (LT90) of 210 h at an initial luminescence of 3000 cd m–2.