Processing and Function of the Sulfide Phosphor

Abstract

The purpose of this work is to present processing and function of the sulfide phosphor. Phosphors of rock salt structure such as SrS and CaS and alkaline earth thiogallates with the formula M^IIGa₂S₄, where M^II=Ca, Sr and Ba have been investigated for full-color inorganic thin film electroluminescence. More recently sulfide phosphors were used as phosphors in phosphor converted light emitting diodes for solid state lighting. Various Eu²⁺ doped phosphors were prepared by solid state reactions between alkaline earth carbonates and gallium oxides mixed in stoichiometric compositions. Phosphors were treated at 900°C for 5h under a H₂S stream, then doped with Eu²⁺ luminescent center and retreated at 1100°C under similar conditions. The emission spectra of YAG:Ce³⁺, SrGa₂S₄:Eu²⁺ and CaS:Eu²⁺ are presented as a function of the temperature from 20°C to 100°C. The emission intensities of phosphors slightly decreased with increasing temperature.