Operation voltage behavior of organic light emitting diodes with polymeric buffer layers doped by weak electron acceptor

We present polymeric buffer materials based on poly[2,7-(9,9-dioctyl-fluorene)-co-(1,4-phenylene-((4-sec-butylphenyl)imino)-1,4-phenylene)] (TFB) for highly efficient solution processed organic light emitting diodes (OLEDs). Doped TFB with 9,10-dicyanoanthracene, a weak electron acceptor results in significant improvement of current flow and driving voltage. Maximum current- and power-efficiency value of 12.6 cd/A and 18.1 lm/W are demonstrated from phosphorescent red OLEDs with this doped polymeric anode buffer system.