An efficient material via meta-position connection as thermally activated delayed fluorescence emitter for organic light-emitting diodes. Issue 16 (19th April 2017)

• Record Type: Journal Article
• Authors: Cui, Yuting; Liu, Jianhui
• Is Part Of: Tetrahedron letters. Volume 58:Issue 16(2017)
• Page Start: 1579
• Page End: 1584
• Publication Date: 2017-04-19
• Subjects: TADF -- Donor-acceptor structure -- meta-Position connection -- OLED; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tetlet.2017.03.018
• Languages: English
• ISSNs: 0040-4039

Abstract

Graphical abstract: Highlights: A dimethylacridines and dicyanobenzene based molecule has been designed and synthesized as a novel TADF emitter. The optical, electrochemical and thermal properties were investigated. The molecule shows a singlet-triplet energy gap as small as 0.04 eV. The doped OLEDs exhibited a high EQE of 16.5%. Abstract: A novel compound was designed and synthesized by connecting a dicyanobenzene acceptor and two 9, 9-dimethyl-9, 10-dihydroacridine donors to the 1, 3, 5-position of a phenyl ring by meta -position connection. This compound, which is a novel emitter for OLED devices, exhibits preferable heat stability. Moreover, the energy gap between its singlet and triplet states is as small as 0.04 eV, resulting in this molecule possesses thermally activated delayed fluorescence. Therefore, the corresponding device showed efficient electroluminescent performances. The maximum external quantum efficiency, maximum current efficiency, maximum power efficiency and maximum luminance were 16.5%, 40.8 cd A −1, 45.8 lm W −1 and 5120 cd m −2, respectively. In addition, the CIEx, y only changed from (0.22, 0.38) to (0.22, 0.39) over the entire operating voltage range, which confirms that the device possesses highly stable chromaticity with respect to the current density. Based on these experimental results, meta -connected type structures may provide a new approach for developing high-performance TADF emitters for OLED applications.