Hydrothermal synthesis and photoluminescence properties of Eu3+ doped Na4La2(CO3)5 rod-like nanophosphors

Eu3+-doped Na4La2(CO3)5 rod-like nanophosphors were prepared by a hydrothermal method, and the photoluminescence excitation and emission spectra, the concentration quenching of the phosphors, the luminescence color chromaticity and the activation energy for thermal quenching were measured. The results indicate that all samples possess the pure monoclinic phase. Na4La2−2xEu2x(CO3)5 (x=0–1) phosphors exhibit reddish luminescence with the dominant 5D0→7F2 transition of Eu3+ at 617 nm. Na4Eu2(CO3)5 has the strongest emission without luminescence quenching, which is benefited from its structural characteristics: long distance between Eu3+ ions and the average La–O–La bond angle of 128.10°. Moreover, the activation energy of thermal quenching and quantum efficiency of Na4Eu2(CO3)5 nanophosphors are 0.356 eV and 13.5%, respectively.