Cs4PbBr6/CsPbBr3 Nanocomposites for All-Inorganic Electroluminescent Perovskite Light-Emitting Diodes

In this study, the facile synthesis and electroluminescent perovskite light-emitting diodes (PeLEDs) of highly luminescent Cs4PbBr6/CsPbBr3 nanocomposite has been demonstrated. With the addition of proper antisolvents, the nanocomposite with a production yield of >90% and quantum yield of >85% was readily derived from the transformation of CsPbBr3 powder. The obtained high quantum yield of the green nanocomposite originated from the fluorescent CsPbBr3 nanocrystals embedded in the Cs4PbBr6 matrix, which was verified by X-ray diffraction, absorption, photoluminescence (PL), and PL excitation spectra. The addition of large cation precursors, such as CsBr and CH­(NH2)2Br, could contribute to the transformation efficiency and had no influence on the composition of the embedded nanocrystals. Via the thermal evaporation of the nanocomposite, all-inorganic electroluminescent PeLEDs with CuSCN and Cu-doped NiO x (NiO x :Cu) nanoparticles were fabricated and characterized. A maximum luminance of 1780 cd/m2 and efficiency of 0.43 cd/A were achieved. Thus, the luminescent Cs4PbBr6/CsPbBr3 nanocomposite is a promising material for next-generation displays and lighting.