Fabrication and Properties of Ce<sup>3+</sup> and Tb<sup>3+</sup> Co-Doped Ca<sub>2</sub>SrAl<sub>2</sub>O<sub>6</sub> Phosphor

Abstract

In this study, a novel green phosphor Ca2SrAl2O6:Ce3+,Tb3+ were prepared by solid state method. The crystal structure and particle morphology of phosphors were measured by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The result indicated that the phosphor belonged to a single Ca2SrAl2O6 phase and crystalline grain sizes were about 2.0~5.0 μm. The excitation and emission spectra were studied in this paper. Monitored at 545 nm, the excitation spectrum consisted of a broad band at UV region (320-400 nm), which was attributed to the abstract of Ce3+ and Tb3+ ions. Excited by 360 nm UV light, the emission spectrum was composed of four groups narrow band and the emission peaks located at 497, 545, 595 and 623nm, respectively. Luminescent intensity increased with Tb3+ and Ce3+ ions concentration and it would reach the maximum when the activator molar fraction was 0.04 for the highest emission intensity at 545 nm. Concentration quenching would occur if the activator concentration exceeded 0.04 mol-1. Li2CO3 could be used for flux and Li+ ion was used for charge compensation in this experiment. Thus, Ca2SrAl2O6:Ce3+, Tb3+ phosphor was a good candidate of green phosphor for UV based white LED.