Preparation and luminescent properties of Eu~(2+)-activated glass ceramic phosphor precipitated with β-Ca_2SiO_4 and Ca_3Si_2O_7

摘要

Eu~(2+): calcium silicate glass ceramics (GC) containing β-Ca_2SiO_4 and Ca_3Si_2O_7 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-Ca_2SiO_4 crystal phases with size of about 20-40 μm. After post-ceramization, Ca_3Si_2O_7 crystals were also precipitated. Judging from the cathodoluminescence (CL) mapping images, two emission bands peaked at 515 nm and 600 nm werernobserved from different parts in the GC. The observed photo-luminescence (PL) have two broad emission bands at 515 nm from Eu~(2+): β-Ca_2SiO_4 and at 600 nm from Eu~(2+):Ca_3Si_2O_7 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. Eu~(2+) doped calcium silicate GC containing β-Ca_2SiO_4 and Ca_3Si_2O_7 are suitable phosphor as the use of phosphor converting white light emitting diode (pc-wLED) with high color rendering.