Molecular Engineering of Blue Fluorescent Molecules Based on Silicon End-Capped Diphenylaminofluorene Derivatives for Efficient Organic Light-Emitting Materials

• Published in: Advanced functional materials 2010-04, Vol.20 (8), p.1345-1358
• Main Authors: Lee, Kum Hee, Kang, Lee Kyung, Lee, Jin Yong, Kang, Sunwoo, Jeon, Soon Ok, Yook, Kyoung Soo, Lee, Jun Yeob, Yoon, Seung Soo
• Format: Article
• Language: English
• Subjects: Aluminum; Derivatives; Devices; Dopants; Electroluminescence; Emittance; fluorescent materials; molecular engineering; organic light-emitting diodes; Quantum efficiency; silicone; Silicones
• ISSN: 1616-301X; 1616-3028; 1616-3028
• DOI: 10.1002/adfm.200901895

Blue fluorescent materials based on silicone end‐capped 2‐diphenylaminofluorene derivatives are synthesized and characterized. These materials are doped into a 2‐methyl‐9,10‐di‐[2‐naphthyl]anthracene host as blue dopant materials in the emitting layer of organic light‐emitting diode devices bearing a structure of ITO/DNTPD (60 nm)/NPB (30 nm)/emitting layer (30 nm)/Alq3 (20 nm)/LiF (1.0 nm)/Al (200 nm). All devices exhibit highly efficient blue electroluminescence with high external quantum efficiencies (3.47%–7.34% at 20 mA cm−2). The best luminous efficiency of 11.2 cd A−1 and highest quantum efficiency of 7.34% at 20 mA cm−2 are obtained in a device with CIE coordinates (0.15, 0.25). A deep‐blue OLED with CIE coordinates (0.15, 0.14) exhibits a luminous efficiency of 3.70 cd A−1 and quantum efficiency of 3.47% at 20 mA cm−2. Highly efficient blue organic light‐emitting diodes are developed using dopant materials based on a 2‐diphenylaminofluoren‐7‐yl‐vinylarene core with various silicon‐substituted end‐capping groups. The best luminous efficiency of 11.2 cd A−1 and highest quantum efficiency of 7.34% at 20 mA cm−2 are obtained in a device with CIE coordinates (0.15, 0.25). A deep‐blue OLED with CIE coordinates (0.15, 0.14) exhibits a luminous efficiency of 3.70 cd A−1 and a quantum efficiency of 3.47% at 20 mA cm−2.