Organic−Inorganic Hybrids Based on Pyrene Functionalized Octavinylsilsesquioxane Cores for Application in OLEDs

Abstract

Traditional materials for application in organic light emitting diodes (OLEDs) are primarily based on small molecules and polymers, with much fewer examples of intermediate molecular weights materials. Our interest lies in this intermediate molecular weight range, specifically in hybrids based on 3-dimensional silsesquioxane (SSQ) cores that represents a new class of versatile materials for application in solution processable OLEDs. We report here SSQ based hybrids (P8-OVS and P14-OVS) that are easily prepared in one high-yield step from the Heck coupling of commercially available 1-bromopyrene with octavinyl-SSQ. The resulting materials offer numerous advantages for OLEDs including amorphous properties, high-glass-transition temperatures (Tg), low polydispersity, solubility in common solvents, and high purity via column chromatography. Solution processed OLEDs prepared from P8-OVS provide blue-green emission with external quantum efficiencies, current efficiencies, maximum brightness, and turn-on voltages of 2.63%, 8.28 cd/A, 36183 cd/m2, and 3.1 V, respectively.