π-Stacked polybenzofulvene derivatives as hosts for yellow and red emitting OLEDs

•the electroluminescence properties of new π-stacked polybenzofulvenes are studied•polybenzofulvenes are compared to PVK as hosts in fully solution processed OLEDs•one of the polymers shows peculiar ability to envelope the dyes in blends•this polymer shows better performances with respect to PVK in OLEDs•the good red and yellow OLED performances are due to low dye microaggregation

A new class of π-stacked polymers possessing interesting charge transport properties is represented by polydibenzofulvene derivatives. We study the electroluminescence properties of three π-stacked polybenzofulvene derivatives and compare them to those of the standard π-stacked poly(N-vinylcarbazole). Solution processable devices using one of these polymers as host with benzothiadiazole based dyes display performances overcoming those of the standard poly(N-vinylcarbazole) host. From a photophysical study, the superior performances of the polybenzofulvene containing a fluorene unit at the position 6 of the indene nucleus are explained to arise from its ability to self-assemble with the dyes in supramolecular organizations that reduce their microaggregation.