One-step preparation of excellent flexible ethyl cellulose composite film for LED

Perovskite quantum dots (PQDs) has been attracted enormous attention in optoelectronic fields, especially as highly efficient narrow-band phosphors for lighting and next-generation display devices, attributed by high photoluminescence quantum yield, tunable emission colors and high color purity. However, poor stability seriously impeded their practical applications. Here, we described a robust-stable CH 3 NH 3 PbBr 3 PQDs/Ethyl Cellulose (EC) composite films with adjustable amounts of PQDs by ligand-assisted precipitation EC in one-step. The key to the preparation of CH 3 NH 3 PbBr 3 PQDs/EC composite film is to achieve the supersaturated recrystallization of CH 3 NH 3 PbBr 3 PQDs and the dissolution of EC in toluene. Combined with experimental results and investigated material characterization unveiles that the synthetic composite film possessed very high transparency, excellent down-conversion luminescence function and strong specific absorption in the ultraviolet region, which benefits form the excellent stability & hydrophobicity of EC, and long-term stable fluorescence performance in air or water under the protection of EC. Moreover, the fluorescence intensity maintained significantly stablility even after 1000 folds. In addition, the CH 3 NH 3 PbBr 3 PQDs/EC composite film exhibited excellent flexibility, which made our composite film showed great potential in the field of flexible display.