An investigation on photoluminescence and AC powder electroluminescence of ZnS:Cu,Cl,Mn,Te phosphor

Abstract

ZnS:Cu,Cl,Mn,Te, which shows red AC powder electroluminescence (ACPEL) emission, was synthesized using a conventional wet synthesis and a sealed vessel method. The photoluminescence (PL) and ACPEL were characterized. After the second firing, 0.5 wt% tellurium (Te)-doped ZnS: Cu, Cl, Mn, Te phosphor shows almost red PL emission from the (4)T(1)-(6)A(1) transition of Mn(2+) ions, which are affected by the Te. Extended x-ray absorption fine structure analysis on the Mn K edge proved that the substitution of sulfur (S) with Te changes the local crystal field of the Mn(2+) ions and shifts an orange emission (similar to 588 nm) to a red emission (similar to 650 nm). A red ACPEL emission is first shown in 0.5 wt% Te-doped ZnS:Cu,Cl,Mn,Te after the third firing phosphor even though its luminance is not very high. The origin of the ACPEL emission is assumed to be not a Cu(x)S-ZnS p-n junction but a Cu(x)Te-ZnS p-n junction. Raman spectra were characterized to support that the red ACPEL emission is probably attributed to a Cu(x)Te-ZnS p-n junction.