Microsecond response of electroluminescent cells

Microsecond rise of electroluminescent, EL, output to greater than the steady state value for a-c sine-wave excitation has been achieved in plastic-embedded powder phosphor cells by application of an a-c burst having a dc component. The decay time for the EL flash, 7 microseconds, is somewhat longer than the rise time. The phosphor used is ZnS:Cu, Cl dispersed in a polyvinyl chloride acetate plastic and sprayed onto a conducting tin oxide-coated glass. The back electrode is a circle of evaporated aluminum 0.2 cm²in area. Electrical contact to the tin oxide is made through silver print painted onto the tin oxide-coated glass around the Al electrode. Light output from the cell is monitored by an RCA 7102 photomultiplier fitted with a cathode-follower output.