Photoluminescence of the SrS:Mn2+ phosphor and Pb 2+-sensitized luminescence of the SrS:Pb2+, Mn 2+ phosphor

Article abstract of DOI:10.1143/JPSJ.58.741

Emission and excitation spectra of the Mn²⁺ ion in the SrS:Mn²⁺ and SrS:Pb²⁺ ,Mn²⁺ phosphor are investigated at various temperatures. The analysis of the excitation spectra of the Mn²⁺ emission band leads to the Racah parameters 5=712 cm ^-1, C= 3352 cm^-1 and the crystal field parameter Dq=516 cm^-1 with the covalency parameter ε=0.046. By the transient spectroscopy technique, it is found that the emision band due to the single Mn²⁺ ion center has a peak at 553 nm and a decay time of ～5.5 ms, while that due to the paired Mn²⁺ center has a peak at 565 nm and a decay time of 0.6 ms. Energy transfer from Pb²⁺ ion to Mn ²⁺ ion is observed in SrS:Pb²⁺,Mn²⁺. By observing the change of band shapes, the intensities and decay characteristics of both the Pb²⁺ and Mn²⁺ luminescence, it is concluded that the transfer is of resonance type. It is found that the energy of Pb ²⁺ ion is transferred preferentially to the isolated Mn²⁺ ion.