ROLE OF SPACE-CHARGE IN SRS-CE THIN-FILM ELECTROLUMINESCENT DEVICES STUDIED BY THE PHOTOIRRADIATION EFFECT

The role of space charge in SrS:Ce thin-film electroluminescent devices was studied by photoirradiation effects on capacitance-voltage and charge-voltage curves. Unique electrical and optical characteristics, such as relaxation of phosphor field and leading and trailing edge emission, are well interpreted by the model based on the formation of uniform space charge. The density of ionized traps, which cause positive space charge, was estimated to be 5.6x10(16) cm(-3). The polarization charge of 0.94 mu C/cm(2) due to the space charge is more than half of the total polarization charge. (C) 1995 American Institute of Physics.