Abstract

The main objective of this study was to model electroluminescence behavior of ACTFEL display devices. Qualitative comparison of the predicted results with measurable characteristics is given. It is intended to explain certain unusual behavior that other models cannot explain fully. In particular, aspects of leading and trailing edge luminance peaks, oscillations in luminance, luminance peaks due to denting in applied voltage and multiple interfacial states are analyzed.

Also, optimum concentration of activators has been analytically modeled for any phosphor to get maximum light output without causing appreciable quenching. Maximum light output for ZnS:Mn yellow devices is at about 2% Mn by weight.

The beginning trailing edge peak (BTE) in SrS:Ce devices can be explained based on capture of electrons by ionized activators from the bulk traps due to their proximity. Oscillations in luminance are modeled due to distinct, widely separated and deep interfacial energy states when interface of two materials is rough. It has been observed that leading edge peak and luminance peak due to denting at leading edge are intercoupled and are partially created due to impact excitation and partially due to capture of electrons by ionized activators. Luminance vs. time graph of two interfacial energy states does not match very well with the experimental results. Luminance vs. time graph for multiple energy states matches better with experimental results.