Composition-tuned MAPbBr3nanoparticles with addition of Cs+cations for improved photoluminescence

Abstract

Hybrid organic-inorganic lead halide perovskite nanoparticles are promising candidates for optoelectronic applications. This investigation describes the structural and optical properties of MAxCs1−xPbBr3mixed 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 ∼88% and displays ∼100% improvement in the PLQY of pure MAPbBr3and CsPbBr3. Prototype LEDs fabricated from MA0.87Cs0.13PbBr3were demonstrated.