Halide-Rich Synthesized Cesium Lead Bromide Perovskite Nanocrystals for Light-Emitting Diodes with Improved Performance

Abstract

To improve the quality and durability of inorganic halide perovskite nanocrystals (NCs), ammonium halide and lead oxide (PbO) were separately employed for the synthesis of NCs with a tunable ratio of metal to halide. The halide-rich circumstance was therefore successfully set up and found to be beneficial for obtaining good quality NCs with high photoluminescence quantum yields and remarkable stability against purification compared to those qualities of previous regular methods with lead halide. The fabricated light-emitting diode (LED) devices with NCs made in a halide-rich circumstance demonstrated performance better than that of devices with NCs made in a halide-poor circumstance. A LED with CsPbBr3 NCs with a 1:4 Pb:Br ratio showed an obvious improved maximal luminance of 12090 cd m–2, a current efficiency of 3.1 cd A–1, and an external quantum efficiency of 1.194%, which were much higher than those of devices with NCs synthesized by the regular method.