Efficient Light-Emitting Devices Based on Phosphorescent Polyhedral Oligomeric Silsesquioxane Materials

Synthesis, photophysical, and electrochemical characterizations of iridium complex anchored polyhedral oligomeric silsesquioxane (POSS) macromolecules are reported. Monochromatic organic light-emitting devices based on these phosphorescent POSS materials show peak external quantum efficiencies in the range of 5-9%, which can be driven at a voltage less than 10 V for a luminance of 1000 cd m(-2). The white-emitting devices with POSS emitters show an external quantum efficiency of 8%, a power efficiency of 8.1 lm W-1, and Commission International de'lEclairage coordinates of (0.36, 0.39) at 1000 cd m(-2). Encouraging efficiency is achieved in the devices based on hole-transporting and Ir-complex moieties dual-functionalized POSS materials without using host materials, demonstrating that triplet-dye and carrier-transporting moieties functionalized POSS material is a viable approach for the development of solution-processable electrophosphorescent devices.