Realizing High Quantum Yield Blue Emission of Polycarbosilane Modified by Anthracene with Weak Intermolecular Interactions

Integration of high quantum yield blue emission and easy film-forming ability in organic emissive materials is challenging. Polycarbosilane (PCS) has received much attention as a model compound owing to its high stability, versatile optical properties, solvability, and film-forming ability; also, anthracene as a star material is the first organic molecule for electroluminescence (EL) devices. Herein, an ingenious strategy was successfully introduced to prepare PCSx with 9-ethylanthracene (referred as 9-EA-PCSx) by a hydrosilylation reaction using 9-vinylanthracene and PCS as starting materials, which transfer efficient energy from -Si-C- bonds to anthracene units. Grafted 9-ethylanthracene with extended pi-conjugation effectively improves optical property, morphological stability, and oxidation and ultraviolet (UV) radiation resistance of PCS. Particularly, 9-EA-PCSh powder displays excellent blue light emission (lambda(max) = 433 nm) with a high quantum yield (up to 80.06%), which is the highest value ever reported for organosilicon polymers to the best of our knowledge. For the first time, such a synergistic effect of PCS with anthracene in this way paves a practical way toward reliable emissive materials capable of forming facile coatings and providing useful low-cost emitting layers in developing foldable organic devices.