Highly-twisted pyrene derivative for pure-blue organic light emitting diodes

• Published in: Journal of industrial and engineering chemistry (Seoul, Korea) Vol. 78; pp. 239 - 245
• Main Authors: Sohn, Sunyoung, Wu, Xinwei, Park, Kwang Hun, Ahn, Hyungju, Jung, Sungjune, Kwon, Soon-Ki, Kim, Yun-Hi
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 25.10.2019; 한국공업화학회
• Subjects: Blue fluorescence; Color purity; Grazing incidence wide-angle X-ray diffraction; Organic light emitting diodes; Pyrene; 화학공학; Organic light emitting diodes; Pyrene; Blue fluorescence; Grazing incidence wide-angle X-ray diffraction; Color purity
• ISSN: 1226-086X; 1876-794X
• DOI: 10.1016/j.jiec.2019.06.007

[Display omitted] The new fluorescent blue host material, 1,3,6,8-tetrakis(2,5-dimethylbiphenyl-4-yl)pyrene (BD4PP), was synthesized for pure-blue organic light-emitting diodes (OLEDs). BD4PP has highly twisted and steric structure for efficient fluorescence, and has high thermal stability of 492°C. BD4PP host doped with 5wt.% 4,4′-bis(9-ethyl-3-carbazovinylene)-1,1′-biphenyl (BCzVBi) or 5wt. % 1,4-bis[2-(3-N-ethylcarbazoryl)-vinyl]benzene (BCzVB) showed high device efficiencies due to wide bandgap (˜ 3.1eV) and electron-rich host. An OLED with the BD4PP:BCzVB emitter showed higher current and external quantum efficiencies of 4.41cd/A and 3.80% with color coordinates (0.16, 0.13) compared to those of the BD4PP:BCzVBi (3.63cd/A and 3.62%) with color coordinates (0.16, 0.11) and non-doped BD4PP (2.01cd/A and 1.61%) with color coordinates (0.18, 0.13).