Effect of charged imperfections on electroluminescence of the ZnS:Cu,Cl phosphor

Electroluminescence is very much dependent on the concentration of imperfections created inside the host crystal. The effect of imperfections in ZnS:Cu,Cl is considered for different temperatures and compared with experimental curves. The resemblance supports our theoretical approach, i.e. the impact ionisation mechanism. The phosphor is most sensitive in the concentration range 10¹⁷ to 10¹⁹ per cm³.