Direct Current Electroluminescence at Low Voltages

Abstract

Electroluminescence due to dc excitation occurs in activated ZnS films at 2.0 volts. Since in the dc case no ambiguity is introduced by possible transient potential differences within the phosphor layer, these experiments show that electroluminescence can occur at applied voltages corresponding to about half the band gap (3.8 electron volts) of the ZnS phosphor. The acceleration-collision theory of electroluminescence is thus ruled out at low voltage, and since no appreciable difference is found to be characteristic of the electroluminescence at low voltages, the acceleration-collision mechanism may not be important in any voltage range.