Preparation and Cathodoluminescence of CaS: Eu and Ca_1-xSr_xS: Eu Phosphors

Abstract

Red emitting phosphors, CaS: Eu and Ca 1- x Sr x S: Eu, have been prepared by the sulfurizing flux method. The products consist of well-crystallized and non-aggregated particles with smooth surfaces. CaS: Eu had the highest luminescence efficiency at 0.04 mole% of europium. The energy efficiency was about 50%, and the visual efficiency about 20% when compared with the standard red phosphor, Y 2 O 2 S: Eu. The relation between cathodoluminescence properties and activator concentration is discussed.