Metal co-doped cesium manganese chlorine nanocrystals with high efficiency and tunable red emission

Low photoluminescence efficiency and instability of lead-free halide perovskite nanomaterials are the main obstacles preventing their practical applications in the fields of optoelectronic devices and X-ray imaging. In this work, lanthanide-doped cesium manganese halide nanocrystals were synthesized by a simple hot injection method. The chemical composition and structural characteristics of the manganese-based perovskites were investigated in detail to prove that lanthanide ions successfully replaced partial manganese ions. As a result, red photoluminescence with a high photoluminescence quantum yield of 35% and a broad emission was obtained. More importantly, the roles of thulium and lead ions in enhancing the luminescence efficiency and tuning photoluminescence from 662 nm to 628 nm were studied in detail by modulating the molar ratios of thulium/lead. Furthermore, the thulium-doped NCs maintained a stable crystal phase and photoluminescence after two weeks. This work provides new insights into enhancing the photoluminescence and tuning the optical bandgap of a perovskite host with co-doping. Metal co-doped cesium manganese halide nanocrystals are synthesized to enhance the red emission depending on the transitional role of Tm3+ ions, and realize tunable red emission from 660 nm to 628 nm by controlling the Pb doping contents.