The role of ZnS in ZnS/SrS:Ce,Cl multilayered TFEL devices



Different ZnS/SrS:Ce,Cl multilayered electroluminescent devices have been prepared by a multisource deposition method. The highest luminance achieved in this investigation is 1540 cd m−2 at 1 kHz using a stack of nine alternating layers of ZnS and SrS:Ce,Cl; the highest luminance in the blue exceeds 14 cd m−2 at 60 Hz, 50 μs pulse excitation. The influence of the ZnS thickness on device performance and stability has been investigated. The electrical and optical behaviour of standard and multilayered devices in time-resolved measurements is compared.