Preparation of CH3NH3PbBr3 perovskite quantum dots composites with high photoluminescence quantum yield and good stability

The poor stability always restricts the application of organic halide perovskite quantum dots (PQDs). Herein, hexagonal boron nitride (h-BN) was utilized to stabilize CH3NH3PbBr3 PQDs at low temperature. With the layered structure of h-BN material, CH3NH3PbBr3 PQDs were encapsulated to obtain the h-BN/CH3NH3PbBr3 PQDs nanocomposite powder, which has excellent optical properties and physical stability. The investigated nanocomposites display good green emitting performance with a full width at half maximum (FWHM) of about 27.0 nm, high color purity of 89.0% and high photoluminescence quantum yield (PLQY) of 93.7%. Duo to the excellent thermal conductivity and unique layered structure of the h-BN material, the nanocomposite powder exhibits excellent thermal stability and humidity stability. The assembled white LEDs with green-emitting h-BN/CH3NH3PbBr3 PQDs nanocomposite powder, a commercial red phosphor, and a blue phosphor possess a correlated color temperature (CCT) of 4742 K and 63.1 lm/W luminous efficacy. Besides, the color gamut of the synthetic white light based on green-emitting h-BN/CH3NH3PbBr3 PQDs nanocomposite powder, commercial red phosphor, and blue phosphor is 99.8% of the NTSC standard. In summary, the h-BN/CH3NH3PbBr3 PQDs nanocomposite powder synthesized by the LARP method overcomes the shortcomings of poor stability of PQDs, and has been successfully applied to the preparation of LEDs, expanding the application range of PQDs.