Highly efficient blue light-emitting diodes containing spirofluorene derivatives end-capped with triphenylamine/phenylcarbazole

作者：Lee Kum Hee; Kim Seul Ong; Yook Kyoung Soo; Jeon Soon Ok; Lee Jun Yeob; Yoon Seung Soo^*

来源：Synthetic Metals, 2011, 161(17-18): 2024-2030.

DOI：10.1016/j.synthmet.2011.07.020

• OLEDs
• Blue fluorescent dopant
• Spirofluorene derivatives
• Triphenylamine/phenylcarbazole moiety

A series of blue fluorescent emitters based on spirofluorene were synthesized via the Horner-Wadsworth-Emmons reaction in moderate yields. Multilayered OLEDs were fabricated with a device structure of ITO/DNTPD (60 nm)/NPB (30 nm)/MADN: Blue dopant materials 1-5 (30 nm)/Alq(3) (20 nm)/LiF (1.0 nm)/Al (200 nm). All devices showed efficient blue emission. Among those, device using compound 1 as a dopant material give the best performance with high brightness (2778 cd/m(2) at 8.5 V) and high efficiency (4.9 cd/A, 2.3 lm/W, and 4.0% EQE at 20 mA/cm(2)). The peak wavelength of electroluminescence was 473 nm with ClEx,y coordinates of (0.15, 0.17) at 8.5 V. A deep blue device with ClEx,y coordinates of (0.15, 0.12) at 8.5 V showed a luminous efficiency of 1.8 cd/A and an external quantum efficiency of 1.9% at 20 mA/cm.

• 出版日期2011-9