Fluorescence‐enhanced Cs 4 PbBr 6 /CsPbBr 3 composites films synthesized by double‐films solid phase reaction method

Due to indispensable ligands, polluted organic solution or complex vapor deposition, stable CsPbBr3 film is hard to be prepared directly by a simple and environmentally friendly method. In order to improve the stability of CsPbBr3 film and the synthesis methods, the double-films solid phase reaction was developed, also Cs4 PbBr6 /CsPbBr3 composites were designed. Although, the synthesized particle had the size of 2~5 μm, much larger than that of quantum dots, in ambient condition, the composites films still showed the good photoluminescence property, with the highest photoluminescence quantum yield (PLQY) of 80%. It had good stability against air, temperature and humidity, even had an interesting fluorescence-enhanced phenomenon in about four days.