Inherent memory effects in ZnS:Mn thin film EL devices

Remarkable hysteresis were found to excist in a thin film multilayer EL device consisting of a ZnS:Mn active layer sandwiched between a pair of Y
₂
O
₃
, insulating layers. Due to its particular construction, hysteresis was observed between the brightness vs. amplitude of the exciting alternating voltage, which is instrumental to realizing the memory function. Electrical Writing and Erasing are possible by the amplitude modulation of the sustaining voltage. The typical memory margin observed here is about 10 to 30 volts (rms) under operating voltage of 170 to 280 volts (rms) with frequency of 1 to 5 kHz. Gray scale display as well as Optical Writing are possible.