New observations on the luminescence decay lifetime of Mn~(2+) in ZnS:Mn~(2+) nanoparticles

摘要

A fast decay emission peaking at 645 nm with a decay lifetime within the experimental resolution of 0.14 mus is observed in ZnS :Mn~(2+) nanoparticles.This short-lived signal is also observed in pure ZnS and MgS:Eu~(3+) nanoparticles,which has nothing to do with Mn~(2+)-doped ions but is from the deep trap states of the host materials.The short-lived component decreases in intensity relative to the Mn~(2+) emission at higher excitation powers,while it increases in intensity at low temperatures and shifts to longer wavelengths at longer time delays.Our observations demonstrated further that the emission of Mn~(2+) in ZnS:Mn~(2+) nanoparticles behaves basically the same as in bulk ZnS:Mn~(2+);the fast decay component is actually from the intrinsic and defect-related emission in sulfide compounds.