A reverse intersystem crossing managing assistant dopant for high external quantum efficiency red organic light-emitting diodes. Issue 12 (19th January 2022)

• Record Type: Journal Article
• Authors: Shin, Dong Jin; Kim, Seung Chan; Lee, Jun Yeob
• Is Part Of: Journal of materials chemistry. Volume 10:Issue 12(2022)
• Page Start: 4821
• Page End: 4830
• Publication Date: 2022-01-19
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d1tc04875a
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : Assistant dopants with reduced Dexter energy transfer rates were designed by replacing the donor moiety of 2, 3, 5, 6-tetra(9 H -carbazol-9-yl)terephthalonitrile (4CzTPN) with 5 H -benzo[4, 5]thieno[3, 2- c ]carbazole (BTCz). Abstract : Thermally activated delayed fluorescence (TADF) materials that can serve as assistant dopants with reduced Dexter energy transfer rates were designed by replacing the donor moiety of 2, 3, 5, 6-tetra(9 H -carbazol-9-yl)terephthalonitrile (4CzTPN) with 5 H -benzo[4, 5]thieno[3, 2- c ]carbazole (BTCz). The employment of the BTCz donor strengthened the charge transfer character, inducing high reverse intersystem crossing (RISC) rate. Careful management of the number of BTCz donor moieties optimized the RISC rates and photoluminescence quantum yield value for high efficiency in TADF-assisted fluorescent devices. A TADF-assisted fluorescent device with the BTCz-modified TADF assistant dopant exhibited a high external quantum efficiency of 13.0% compared with 11.3% for that with the 4CzTPN assistant dopant due to suppressed Dexter energy transfer.