Acceptor modulation for improving a spiro-type thermally activated delayed fluorescence emitter. Issue 25 (5th June 2020)

• Record Type: Journal Article
• Authors: Zhu, Xiang-Dong; Peng, Chen-Chen; Kong, Fan-Cheng; Yang, Sheng-Yi; Li, Hong-Cheng; Kumar, Sarvendra; Wang, Tong-Tong; Jiang, Zuo-Quan; Liao, Liang-Sheng
• Is Part Of: Journal of materials chemistry. Volume 8:Issue 25(2020)
• Page Start: 8579
• Page End: 8584
• Publication Date: 2020-06-05
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d0tc00743a
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : A novel donor (D)–spiro-acceptor (A) emitter, namely 10-phenyl-10 H -spiro[acridine-9, 9′-fluorene]-2′, 4′, 7′-tricarbonitrile (SAF-3CN ), was synthesized for high efficiency, yellowish green third-generation thermally activated delayed fluorescence (TADF) organic light-emitting diodes (OLEDs). Abstract : A novel donor (D)–spiro-acceptor (A) emitter, namely 10-phenyl-10 H -spiro[acridine-9, 9′-fluorene]-2′, 4′, 7′-tricarbonitrile (SAF-3CN ), was synthesized for high efficiency, yellowish green third-generation thermally activated delayed fluorescence (TADF) organic light-emitting diodes (OLEDs). The CN-modulation of the fluorene was adopted for the modification of the singlet state with minor modifications of the triplet state. Compared to the reference material 10-phenyl-10 H -spiro[acridine-9, 9′-fluorene]-2′, 7′-dicarbonitrile (ACRFLCN ), the electron-withdrawing –CN substituent on the C4 site of the fluorene results in a sufficiently small singlet–triplet energy gap (Δ E ST ) and obvious TADF characteristics of SAF-3CN in the doped films. Encouragingly, the device performance achieves an external quantum efficiency (EQE) of 19.4% and small roll-off, which is better than that of ACRFLCN and closer to the best performance in this system.