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 CH3NH3PbBr3 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 CH3NH3PbBr3 PQDs/EC composite film is to achieve the supersaturated recrystallization of CH3NH3PbBr3 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 CH3NH3PbBr3 PQDs/EC composite film exhibited excellent flexibility, which made our composite film showed great potential in the field of flexible display. •A simple synthesis method of EC/CH3NH3PbBr3 composite films is proposed to improve the stability of PQDs.•The composite film has high stability and retains the high PLQY of PQDs.•Composite film has very high application prospects in the field of flexible display.