Electroluminescent lines in ZnS powder particles

Existing theories of ZnS-powder-EL are shown to be unable to explain the new findings of electroluminescent striations or lines described in Part I of this work. Several new hypotheses are discussed. Among these, a model seems to be l ikely which is based on simultaneous bipolar f ield-emission from op-posite ends of conducting imperfection lines into the insulating crystall ite, with trapping of injected holes in activator centers, and recombination with mobile electrons at f ield-reversal. This model, which is shown to be consistent with facts, is discussed in detail. A new impact ionization model is also de-scribed which is very similar to that of the f ield-emission model. At present, it is exper imental ly indist inguishable from the field-emission model. Despite extens ive research efforts, the theoret ica l s i tuat ion about the now 26 year old Dest r iau effect is st i l l in a state of confusion. The main reason for this is the inaccess ib i l i ty of the ind iv idua l act iv