Composition-tuned MAPbBr3 nanoparticles with addition of Cs+ cations for improved photoluminescence

Hybrid organic-inorganic lead halide perovskite nanoparticles are promising candidates for optoelectronic applications. This investigation describes the structural and optical properties of MA(x)Cs(1-x)PbBr(3) mixed cation colloidal nanoparticles spanning the complete compositional range of Cs substitution. A monotonic progression in the cubic lattice parameter (a) with changes in the Cs+ content confirmed the formation of mixed cation materials. More importantly, time-resolved photoluminescence (TRPL) revealed the optimized 13 mol% Cs nanoparticle composition exhibits the longest charge carrier lifetime and enhancement in radiative pathways. This sample also showed the highest photoluminescence quantum yield (PLQY) of similar to 88% and displays similar to 100% improvement in the PLQY of pure MAPbBr(3) and CsPbBr3. Prototype LEDs fabricated from MA(0.87)Cs(0.13)PbBr(3) were demonstrated.

Automated summary

The investigation explores the structural and optical properties of MA(x)Cs(1-x)PbBr(3) mixed cation colloidal nanoparticles, revealing that the nanoparticle composition optimized at 13 mol% Cs exhibits the longest charge carrier lifetime and highest photoluminescence quantum yield. Prototype LEDs fabricated from MA(0.87)Cs(0.13)PbBr(3) demonstrate the promising potential of these mixed cation perovskite nanoparticles for optoelectronic applications.