We report the optical properties and morphological structure of potential green phosphors (Sr1-xCaxGa2S4:Eu, x = 0.0-1.0) for application in phosphor-converted three-band white light emitting diodes (LEDs). A series of Sr1-xCaxGa2S4:Eu phosphors was synthesized using NaBr-aided solid-state reactions in a flowing H2S stream. They all crystallized with the orthorhombic PbGa2Se4 phase, and their emissions were efficiently excited up to 480 nm. The optical and morphological suitability of Sr1-xCaxGa2S4:Eu phosphors is discussed in terms of their application as coatings for altering the color of blue LEDs. (c) 2006 The Electrochemical Society.