Insulator issues in alternating-current thin-film electroluminescent devices

An n-sheet, state-space model is employed for the assessment of insulator i ssues of relevance to the operation of alternating-current thin-film electr oluminescent (ACTFEL) devices. The model presented herein has been refined by the inclusion of luminance, which is modeled as arising from impact exci tation of luminescent impurities. Simulation demonstrates that ACTFEL devic es which have large insulator capacitances and no space charge present in t he phosphor are optimal in terms of providing maximum luminance and efficie ncy. A method for estimating the phosphor space charge density from a singl e transferred charge curve is presented. Simulation indicates that the use of a leaky insulator in an ACTFEL device can result in an increase in lumin ance, but a decrease in efficiency and that measured charge-voltage and int ernal charge-phosphor field curves are misleading when one or more of the c onstituent insulator or phosphor layers is leaky. (C) 2001 American Institu te of Physics.