ELECTROLUMINESCENCE IN ZNS/CU MONOCRYSTALS .1. CONNECTION WITH CRYSTAL STRUCTURE AND DOPING

Electroluminescence (EL) in ZnS:Cu-crystals often occurs in the shape of comets and double-comets, which are orientated perpendicular to the pseudohexagonal c-axis, mostly within the (10.0) directions. Crystals with strong stacking disorder (drawn from the melt) contain a great deal of luminescing lines. The EL of crystals with well built cubic structure (grown by iodine transport) however consists of few long double-comets (up to 2.3 mm). EL of crystals doped after growth and its comparison with photoluminescence, optical birefringence and the result of Cu-diffusion measurements confirm the assumption that EL occurs along Cu-decorated dislocation lines. It is shown that the local distribution of brightness essentially is not affected by a variable Cu-concentration along the dislocation lines but by the field distribution in the crystals. © 1969, Walter de Gruyter. All rights reserved.