Fluorescence-enhanced Cs4 PbBr6 /CsPbBr3 composites films synthesized by double-films solid phase reaction method.

Due to indispensable ligands, polluted organic solution, or complex vapour deposition, stable CsPbBr3 film is hard to be prepared directly using a simple and environmentally friendly method. To improve the stability of CsPbBr3 film and its synthesis methods, the double-films solid phase reaction was developed, and Cs4 PbBr6 /CsPbBr3 composites were designed. Although the synthesized particle had a size of 2-5 μm, much larger than that of quantum dots, in ambient conditions the composites films still showed good photoluminescence properties, with the highest photoluminescence quantum yield of 80%. It had good stability against air, temperature and humidity, and even had interesting fluorescence-enhanced phenomenon after about 4 days.