An electroluminescent phosphor is sandwiched by a pair of insulating layers which are sandwiched by a pair of electrode layers to provide an AC TFEL device. The phosphor consists of a host material and an activator dopant that is preferably a rare earth. The host material is an alkaline earth ...http://www.google.se/patents/US5677594?utm_source=gb-gplus-sharePatent US5677594 - TFEL phosphor having metal overlayer
