Electroluminescence of evaporated ZnS and ZnSe films

Electroluminescent films of ZnS and ZnSe activated by manganese were prepared and studied. The films were deposited on to a high-temperature substrate and were electroluminescent without further treatment. Several conditions were found to be necessary if a film was to show this effect. The presence of mixed crystal structure was shown by the use of x-ray and electron diffraction techniques. The crystallite size was measured as a function of substrate temperature, evaporation rate and film thickness. An explanation of the results in terms of a re-evaporation process from the substrate surface is given.