Photoluminescence Properties of Mn²⁺‐Doped CdS/ZnS Core/Shell Nanocrystals with Controlled Concentration and Doping Position

This study investigates the photoluminescence (PL) properties of Mn 2+ ‐doped CdS/ZnS core/shell nanocrystals, focusing on the effects of Mn 2+ concentration and doping position on energy transfer dynamics. A fast decay component in the PL decay profiles, attributed to energy transfer from the CdS core to Mn 2+ ions, is observed and characterized by a single‐exponential function with a lifetime of ≈10–20 ns. The results show that increasing Mn 2+ concentration leads to a decrease in the PL intensity of CdS excitons and a corresponding enhancement of Mn 2+ emission. Additionally, the energy transfer efficiency is found to decrease as the Mn 2+ ions are positioned further from the CdS core, highlighting the importance of the doping position. These findings provide deeper insights into nanosecond‐scale energy transfer dynamics and emphasize the significance of optimizing both dopant concentration and position to tailor the optical properties of nanomaterials.