Luminescence enhancement of ZnS:Mn nanoclusters in zeolite

The luminescence intensity of ${\mathrm{Mn}}^{\mathrm{2+}}$ in the ZnS:Mn nanoclusters formed in an ultrastable zeolite-Y is seven orders of magnitude stronger than that of other nanoparticles deposited out of solutions. This remarkable effect is attributed to a strong quantum size confinement, the location of ${\mathrm{Mn}}^{\mathrm{2+}}$ ions at the near-surface sites, and good surface passivation. The lowering of the energy loss in the ${}^4{\mathrm{E(}}^4\mathrm{D),}$ or/and ${}^4{T}_2{(}^4\mathrm{D)}$ states during the energy transfer from the ZnS host to the emitting state ${}^4{T}_1{(}^4\mathrm{G)}$ of ${\mathrm{Mn}}^{\mathrm{2+}}$ may also contribute to the observed fluorescence enhancement.