A High Performance Nondoped Blue Organic Light-Emitting Device Based on a Diphenylfluoranthene-Substituted Fluorene Derivative

A new blue light-emitting fluorene derivative 2,7-di[8-(7,10-diphenylfluoranthenyl)]-9,9-dimethylfluorene (DFDF) with good thermal stability at 420 °C has been synthesized and characterized. An organic light-emitting device (OLED) with the structure of ITO/NPB (70 nm)/DFDF (30 nm)/TPBI (20 nm)/LiF (0.5 nm)/Al (100 nm) has been investigated, where DFDF serves as a nondoped host emitter. Such a device possesses high current and power efficiencies of 3.8 cd/A and 2.6 lm/W, respectively, and stable bright blue-light emission at λ = 474 nm with Commission Internationale de L’Eclairage coordinates of (0.16, 0.23) over a wide range of operating voltages. The present results verify that DFDF is a promising candidate for a fluorescent blue-light-emitting OLED.