Synthesis and photo- and electro-luminescent properties of Ir(iii) complexes attached to polyhedral oligomeric silsesquioxane materials

Abstract

This paper describes synthesis, photophysical, electrochemical characterizations of two new polyhedral oligomeric silsesquioxane (POSS)-based green-light phosphorescent materials, consisting of an emissive Ir(III) complex and carbazole moieties covalently attached to a polyhedral oligomeric silsesquioxane (POSS) core. These phosphorescent POSS materials offer many advantages including amorphous properties, good thermal stabilities, and good solubility in common solvents, and high purity via column chromatography. The photoluminescence spectra of the POSS materials in solutions and in the solid state indicate a reduction in the degrees of interactions among Ir(III) complex units and concentration quenching due to the bulky POSS core. Solution processed light-emitting devices with a configuration of ITO/PEDOT:PSS (45 nm)/CBP:POSS materials (50 nm)/TPBi (50 nm)/Liq (2 nm)/Al (150 nm) were fabricated. The devices based on these POSS materials exhibit a maximum external quantum efficiency (EQE) of 7.82% and a maximum luminance of 21 285 cd m⁻².