Solution processable nanocomposites based on silsesquioxane cores for use in organic light emitting diodes(QLEDs)

摘要

A new family of materials that synergistically combine the attributes of both organic and inorganic properties for use in organic light emitting diodes(OLEDs)is presented.The hybrid materials are based on 3-D inorganic cores of octavinylsilsesquioxanes(OVS).The resultant materials have high Tg's(120-210 deg C),are formed from minimal step/high yield reactions and readily available starting reagents,are monodisperse(PDI<1.1),can be highly purified via common chroma-tographic techniques,and form defect-free amorphous films via spin-dip coating.For example TPD is known for its good hole injection/transport properties in OLED applications but suffers from a low Tg(65 deg C).TPD-OVS hybrid material has a Tg of 142 deg C while maintaining similar injection/transport properties to TPD.Photoluminescence analysis of the hybrid thin film reveals:1)a 30 nm blue shift versus their dilute solution counterparts;and 2)5 hour annealing cycles to within 10 deg C of their Tg show no indication of eximer formation(no red shift)that often causes reduced efficiencies in polymer LEDs.