Effect of bulk space charge on the current and luminescence characteristics of ZnS:Mn ACTFEL display devices

Abstract

Analysis of ZnS:Mn ACTFEL (AC thin-film electroluminescent) devices with a deep level in the bulk of the phosphor layer was performed. Both donor-type and acceptor-type levels were considered. A trailing edge peak in luminescence waveform appears when the interface state level energy (E/sub CD/) is reduced to 0.5 eV. Under certain conditions, an acceptor-type bulk level can lead to oscillations in the device current. A reasonable match between theoretical and experimental luminescence waveforms could be obtained for E/sub CD/=0.88 eV. However, theory and experiment could not be matched simultaneously at three different drive conditions. Further refinement of the model is necessary for predicting the ACTFEL device response for all drive conditions.<>