Photon Reabsorption and Surface Plasmon Modulating Exciton-to-Dopant Energy Transfer Dynamics in Mn:CsPb(BrCl)₃ Quantum Dots

Exciton-to-dopant energy transfer (ET) dynamics of Mn:CsPbX₃ quantum dots (QDs), which is dominated by diverse physical factors, requires more comprehensive understanding. Here, the concentration-dependent photon reabsorption effect on ET dynamics has been meticulously analyzed in colloidal Mn:CsPb(BrCl)₃ QDs. The results indicate that the photons emitted by the smaller QDs are absorbed by the larger QDs, effectively providing additional excitation light to the latter. The reabsorbed photons play a crucial role in significantly enhancing the ET process in the larger QDs. Additionally, the Mn:CsPb(BrCl)₃ QDs/Poly(methyl methacrylate)/Ag/SiO₂ multilayer films were fabricated to study the influence of the surface plasmon (SP) on ET dynamics. The results reveal that resonant energy transfer between excitons and SP via dipole interactions can regulate the ET process and Mn²⁺ emission intensity by controlling the distance between the SP and excitons. These findings provide insights into Mn:CsPbX₃ QD ET dynamics and potential methods for controlling their luminescence performance in practical applications.