A Versatile Triphenylamine/Fluoranthene-Based Derivative as a Nondoped Green-Emitting, Hole-Transporting Interlayer for Electroluminescent Devices.

A new triphenylamine-bridged fluoranthene derivative, 4-(7,10-diphenylfluoranthen-8-yl)- N-[4-(7,10-diphenylfluoranthen-8-yl)phenyl]- N-phenylaniline (BDPFPA), with a high glass transition temperature of 220 °C has been synthesized and characterized. BDPFPA is a highly fluorescent and versatile material that can be used as a nondoped green emitter and as a hole transporter. BDPFPA was used in a standard trilayer device as the emitting layer, which showed a low turn-on voltage (<3 V) and a high efficiency of 11.6 cd A⁻¹. The device also shows little efficiency roll-off at high brightness. For example, the efficiency can still be maintained at 11.4 cd A⁻¹ (5.4 lm W⁻¹) at a brightness of 10 000 cd m⁻². These results are among the best reported for nondoped fluorescent green organic light-emitting diodes. A simple bilayer device, in which BDPFPA serves as a hole-transporting layer, has a maximum power efficiency of 3.3 lm W⁻¹ and the performance is nearly 40 % higher than that of an N, N′-bis(1-naphthyl)- N, N′- diphenyl-1,1′-biphenyl-4,4′-diamine (NPB)-based standard device. [ABSTRACT FROM AUTHOR]