Abstract
The current-voltage characteristic of a semiinsulating, monocrystalline ZnS film grown by metalorganic vapor-phase epitaxy is reported. High-field conduction is found to occur in the same field range (1.0-1.5 MV/cm) as in highly defected, electroluminescent material. It is concluded that the conduction mechanism underlying the operation of ZnS-based electroluminescent devices is bulk controlled.