Donor disubstituted trifluoromethyl benzenes for various electroluminescent devices. (February 2022)

• Record Type: Journal Article
• Authors: Keruckiene, Rasa; Lin, Bo-Yen; Chen, Chia-Hsun; Chu, Chun-Chieh; Lin, Chi-Feng; Chiu, Tien-Lung; Lee, Jiun-Haw; Grazulevicius, Juozas Vidas
• Is Part Of: Dyes and pigments. Volume 198(2022)
• Publication Date: 2022-02
• Subjects: Thermally activated delayed fluorescence -- Room-temperature phosphorescence -- Exciplex -- Dimethylacridan -- Phenothiazine; Dyes and dyeing -- Periodicals; Pigments -- Periodicals; 667.2
• DOI: 10.1016/j.dyepig.2021.109956
• Languages: English
• ISSNs: 0143-7208

Abstract

Abstract: New derivatives of trifluoromethyl benzene and tert -butyl disubstituted acridan or phenothiazine were designed and obtained by single-step synthesis, i.e., by Buchwald-Hartwig cross-coupling reactions of 1, 3-dibromo-5-(trifluoromethyl)benzene with 3, 7-di-tert-butyldimethylacridan, or 3, 7-di-tert-butyl-10H-phenothiazine. The advantages in high thermal and photophysical characteristics were utilized in exciplex emission based OLEDs. In the optimal case, device showed maximum current, power, and external quantum efficiencies of 27.4 cd/A, 28.6 lm/W and 7.6%, respectively. Taking into account that successful employment of acridan or phenothiazine derivatives as donors in exciplex-forming systems remains scarce, the proposed design of donor compounds in this work shows their potential for successful implementation in complex emissive systems of OLEDs. Highlights: Derivatives of trifluoromethyl benzene and tert -butyl disubstituted acridan or phenothiazine were synthesized. . They exhibited thermally activated delayed fluorescence and exciplex forming properties. The compounds also showed room-temperature phosphorescence. Exciplex emission based OLEDs with external quantum efficiency reaching 7.6% were obtained.