Enhanced Optical Properties of Green‐Emitting InP Quantum Dots with Matched Junctions of the Core and Mn‐Doped Novel Shells

Abstract Indium phosphide (InP) quantum dots (QDs) offer a promising alternative to (Restriction of Hazardous Substances) restricted cadmium‐based QDs, however, their performance is limited by surface defects and weak quantum confinement. This study introduces a novel approach to enhance the optical properties of InP QDs through manganese (Mn) doping into the zinc selenide and zinc sulfide shell. This aims to expand the bandgap of the shells and adjust its lattice constant to better match the InP core. A comprehensive investigation of the effect of Mn‐doping concentration reveals that optimal properties are developed at a 10% feed ratio, resulting in improved crystallinity, reduced interfacial defects, and enhanced quantum confinement. X‐ray diffraction and transmission electron microscopy confirm the structural improvements and spectroscopic analyses demonstrate remarkable enhancement of optical properties. Notably, the photoluminescence quantum yield reaches 83% in the green emission region (λ ≈535 nm), a significant improvement over undoped QDs. Time‐resolved photoluminescence measurements indicate extended carrier lifetimes, supporting the effect of defect reduction. This strategy not only addresses the long‐standing challenges of InP QDs but also opens new avenues for designing high‐performance, environmentally friendly nanomaterials for various optoelectronic applications, including displays, lighting, and photovoltaics.