On the Role of Cs(4)PbBr(6) Phase in the Luminescence Performance of Bright CsPbBr(3) Nanocrystals

CsPbBr(3) nanocrystals have been identified as a highly promising material for various optoelectronic applications. However, they tend to coexist with Cs(4)PbBr(6) phase when the reaction conditions are not controlled carefully. It is therefore imperative to understand how the presence of this phase affects the luminescence performance of CsPbBr(3) nanocrystals(.) We synthesized a mixed CsPbBr(3)-Cs(4)PbBr(6) sample, and compared its photo- and radioluminescence properties, including timing characteristics, to the performance of pure CsPbBr(3) nanocrystals. The possibility of energy transfer between the two phases was also explored. We demonstrated that the presence of Cs(4)PbBr(6) causes significant drop in radioluminescence intensity of CsPbBr(3) nanocrystals, which can limit possible future applications of Cs(4)PbBr(6)-CsPbBr(3) mixtures or composites as scintillation detectors.