Perovskite quantum dots as fluorescent materials for multi-colored lighting

Halide perovskite quantum dots (PQDs) have been intensively studied because of their superior optical properties and have great potential applications in laser, display technology and light-emitting diodes (LEDs). Presently, high-efficiency green emissive CH₃NH₃PbBr₃ PQDs have been successfully fabricated. However, the synthesis of stable iodide-based CH₃NH₃PbX₃ (MAPbX₃ (X = Cl, Br, I), MA = CH₃NH₃) QDs still faces significant challenges because they are sensitive to the moisture in open air. Herein, we investigated the effect of the solvent and ligand on the growth of the as-prepared MAPbBr₃ and MAPbI₃ sample, mainly involved in the volume ratio of N,N-dimethylformamide (DMF) and γ-butyrolactone (GBL) and the amount of n-octylamine in toluene. The results show that the low volume ratio of DMF and GBL is beneficial to prepare highly luminescent, stable and full-colored MAPbX₃ PQDs in open air. Besides, the PL emission peak of MaPbBr₃ PQDs can be adjusted from 430 to 513 nm via precisely controlling the amount of n-octylamine in toluene because of quantization. The obtained MAPbX₃ PQDs show high quantum yield and a wide range of tunable light emission from ultraviolet to near-infrared region. The MAPbX₃ PQDs, especially iodide-based MAPbX₃ PQDs, obtained from this method remain stable more than 3 months at ambient condition. We further demonstrated the multi-colored LEDs by using different color emissive MAPbX₃ PQDs as color converters and being subjected to excitation through a blue GaN chip. Furthermore, MAPbX₃ PQDs are expected to show interesting nanoscale optical properties and have great potential applications in electroluminescence devices, lasers and optical sensors.