The photoluminescence and X-ray luminescence of ZnS:Mn, ZnS:Mn,Eu and ZnS:Eu were investigated and it was found that the luminescence intensity of Mn2+ in ZnS:Mn,Eu co-doped phosphors is highly dependent on the doping concentration of Eu2+. At the optimized Eu2+concentration (0.2%), the photoluminescence of Mn2+ shows about a 5.5 times enhancement and its X-ray luminescence is enhanced by a factor of 2.5. Both wurtzite and zinc blend phases are present in the samples with wurtzite phase dominant. Co-doping of Eu2+ into ZnS:Mn does not change appreciably the ratio of the two phases or the Mn2+ emission luminescence lifetime; however, the doping of Eu2+ into ZnS:Mn does change the phonon activity. Furthermore, it was found that the defect-related blue emission of ZnS:Eu overlaps with the excitation bands of Mn2+ in ZnS:Mn and there is likely energy transfer from these defect states to Mn2+ in ZnS:Mn,Eu. This energy transfer and the phonon modification are considered to be the two main reasons for the luminescence enhancement and the intensity dependence of Mn2+ emission on Eu2+ doping concentration in ZnS:Mn,Eu.
Revised: August 27, 2013 |
Published: June 1, 2013
Citation
Hossu M., R.O. Schaeffer, L. Ma, W. Chen, Y. Zhu, R. Sammynaiken, and A.G. Joly. 2013.On the Luminescence Enhancement of Mn2+ By Co-doping of Eu2+ in ZnS:Mn,Eu.Optical Materials 35, no. 8:1513-1519.PNNL-SA-94692.doi:10.1016/j.optmat.2013.03.014