Red-emitting fluorescent organic light emitting diodes with low sensitivity to self-quenching Available to Purchase

Concentration quenching is a major impediment to efficient organic light-emitting devices (OLEDs). We herein report on OLEDs based on a fluorescent amorphous red-emitting starbust triarylamine molecule [4-di(⁠$4′$-tert-butylbiphenyl-4-yl)amino-$4′$-dicyanovinylbenzene, named FVIN], exhibiting a very small sensitivity to concentration quenching. OLEDs are fabricated with various doping levels of FVIN into $Alq3$⁠, and show a remarkably stable external quantum efficiency of 1.5% for doping rates ranging from 5% up to 40%, which strongly relaxes the technological constraints on the doping accuracy. An efficiency of 1% is obtained for a pure undoped active region, along with deep red emission (⁠$x=0.6$⁠; $y=0.35$ in the Commission Internationale de l'Energie (CIE) coordinates). A comparison of FVIN with the archetypal 4-dicyanomethylene-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran dye is presented in an identical multilayer OLED structure.