We have investigated the excitation and recombination machanism of Mn and Cu centers for two kinds of EL panels:alternating current

<

ZnS:Mn

Cu) and direct current. By measuring the emission spectra

time-resolved emission spectra

current waveform

luminescence brightness waveform

luminescence decay and the relationship between luminescence intensity and Mn or Cu concentration

etc. Both ZnS:Mn

Cu and ZnS:Mn

Cu(Cu) were made from the same powder phosphor. But the latter one was treated with copper coating procedure. Mn ion concentration

from 3×10

-5

to 2×10

-2

Cu concentration:from 2×10

-4

to 2×10

-2

mol.