Direct-current electroluminescence in zinc sulphide: State of the art

A review is made of the characteristics of direct-current electroluminescent (dc EL) displays based on powders of zinc sulfide doped with manganese and copper. These panels show yellow emission with efficiency of about 0.1 percent watt per watt and can be operated under both continuous and pulsed operation. The preparation of the panels is described and the brightness-voltage-current relationships are given. Under continuous operation, the brightness at 100 V falls from 100 fL to 50 fL in several thousand hours, while under pulsed operation little deterioration is noted in this time. So far, 36-character (each consisting of 35 dots) displays have been prepared. It is suggested that a large variety of useful displays, both analog and digital, or combinations of these, can be produced dc EL panels based on zinc sulphide.