Luminescence properties of CaZn2(PO4)2:Sm3+ phosphor for lighting application

Abstract

A high-temperature solid state reaction route was employed to synthesize the phosphate based new orange-red emitting trivalent samarium (Sm3+) ions doped calcium zinc phosphate (CZP: CaZn2(PO4)2) phosphor. The crystalline phase formation was studied by X-ray diffraction analysis. The surface properties of the phosphor were investigated by X-ray photoelectron spectroscopy. Under the excitation of 402 nm, the emission spectra of CZP:Sm3+ has several peaks and the dominant peak at 596 nm was ascribed to 4G5/2 → 6H7/2 transition. The concentration quenching effect of Sm3+ in CZP phosphor was observed for 5 at%. The mechanism of energy transfer between similar Sm3+ ions was determined to be quadrupole-quadrupole interaction. The decay curves of all phosphors were well fitted to the first-order exponential function. The chromaticity coordinates were located in the orange-red region of the chromaticity diagram. Therefore, these results suggest that the orange-red emitting new CZP:Sm3+ phosphor to be used in the phosphor-converted white light emitting diodes.