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. ©1995 American Institute of Physics.