Abstract
Electron multiplication has been observed in ZnO using reverse‐biased electrolyte contacts to n‐type conducting crystals. Measurements have also been made of the surface potential of the free surface charged by a negative corona discharge in air. The surface charge is discharged by illumination. Under certain conditions electron multiplication contributes to the discharge process. The amount of surface charge discharged by illumination has been measured as a function of the energy of the light. This gives an approximate energy‐level spectrum for the localized electrons on the surface.