Electron-withdrawing group modified carbazolophane donors for deep blue thermally activated delayed fluorescence OLEDs. Issue 20 (21st September 2021)

• Record Type: Journal Article
• Authors: Gupta, Abhishek Kumar; Zhang, Zhen; Spuling, Eduard; Kaczmarek, Maria; Wang, Yichuan; Hassan, Zahid; Samuel, Ifor D. W.; Bräse, Stefan; Zysman-Colman, Eli
• Is Part Of: Materials advances. Volume 2:Issue 20(2021)
• Page Start: 6684
• Page End: 6693
• Publication Date: 2021-09-21
• Subjects: 620.11
• DOI: 10.1039/d1ma00738f
• Languages: English
• ISSNs: 2633-5409

Abstract

Abstract : We report two blue-emitting thermally activated delayed fluorescence (TADF) compounds employing a substituted carbazolophane (Czp) donor (indolo[2.2]paracyclophane). Abstract : We report two blue-emitting thermally activated delayed fluorescence (TADF) compounds employing a substituted carbazolophane (Czp) donor (indolo[2.2]paracyclophane). The compounds CNCzpPhTRZ and CF3 CzpPhTRZ show emission maxima of 426 nm and 432 nm, respectively, with high photoluminescence quantum yields ( Φ PL ) of 73% and 80%, respectively. The singlet–triplet energy gap (Δ E ST ) of both emitters is 0.22 eV, resulting in long-delayed lifetimes of 132 μs for CNCzpPhTRZ and 158 μs for CF3 CzpPhTRZ in PPT as the host matrix. Blue organic light-emitting diodes (OLEDs) showed maximum external quantum efficiencies (EQEs) of 7.4% for CNCzpPhTRZ and 11.6% for CF3 CzpPhTRZ with electroluminescence maxima of ca. 460 nm.