Luminescence of Eu2+ in some fluorides prepared by reactive atmosphere processing

When phosphors are prepared by conventional solid-state route by heating in air, usually unwanted impurities like OH−, O2−, etc., get incorporated. Such impurities can be quite harmful to the luminescence processes. Especially, fluorides are highly susceptible to hydrolysis. It is necessary to use highly sophisticated procedures like high vacuum and HF or CF4 atmosphere for preparation of fluoride based phosphors. It is shown that using a simple wet chemical process and a modified reactive atmosphere processing (RAP) technique, fluorides showing intense Eu2+ photoluminescence can be prepared.