Preparation of bright-emissive hybrid materials based on light-harvesting POSS having radially integrated luminophores and commercial π-conjugated polymers

Abstract

We found that modified polyhedral oligomeric silsesquioxane (POSS) possessing radially integrated rigid luminophores at each vertex can have high miscibility to a series of conventional π-conjugated polymers. Homogeneous hybrid films composed of modified POSS and π-conjugated polymers were easily obtained by a simple spin-coating method from mixed solutions at arbitrary ratios between POSS and the polymers. The resulting hybrid films showed high thermal stability similar to that of commercial organic–inorganic hybrid materials. According to photochemical analyses, it was revealed that modified POSS is capable of working as a light-harvesting antenna toward π-conjugated polymers in hybrid films. Excited energy at modified POSS was effectively transferred to π-conjugated polymers through the mechanism of fluorescence resonance energy transfer (FRET). Moreover, the modified POSS played a significant role in disturbing aggregation-caused quenching (ACQ). Owing to both light-harvesting effect and suppression of ACQ, the performances as a luminescent material were dramatically enhanced by loading modified POSS. It was suggested that the compact size and radially arranged structure of the modified POSS should enhance thermal and luminescent properties as well as improve miscibility. This novel strategy for enhancing the potential of π-conjugated polymers by simple blend of POSS can be applicable for developing a wide variety of robust luminescent materials.