Preparation and luminescent properties of Eu2+-activated glass ceramic phosphor precipitated with β-Ca2SiO4 and Ca3Si2O7



Eu2+: calcium silicate glass ceramics (GC) containing β-Ca2SiO4 and Ca3Si2O7 crystal phosphors were fabricated by cerammization process from a GC that were prepared by a novel GC preparation; frozen sorbet method. The GC obtained (as-made GC) consisted of glass and spherical β-Ca2SiO4 crystal phases with size of about 20–40 μm. After post-ceramization, Ca3Si2O7 crystals were also precipitated. Judging from the cathodoluminescence (CL) mapping images, two emission bands peaked at 515 nm and 600 nm were observed from different parts in the GC. The observed photoluminescence (PL) have two broad emission bands at 515 nm from Eu2+: β-Ca2SiO4 and at 600 nm from Eu2+:Ca3Si2O7. With increasing heat-treatment temperature, the color coordinates shifted from green range to center region, which corresponds to pure white in the CIE chromaticity diagram. Eu2+ doped calcium silicate GC containing β-Ca2SiO4 and Ca3Si2O7 are suitable phosphor as the use of phosphor converting white light emitting diode (pc-wLED) with high color rendering. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)