Luminescent properties of novel Ca2.89Mg0.11(PO4)2:Eu2+ single-phase white light-emitting phosphor for white LEDs

A novel Ca2.89Mg0.11(PO4)2:Eu2+ single-phase white light-emitting phosphor was synthesized by solid-state reactions and its crystal structure and luminescence properties were investigated. The Ca2.89Mg0.11(PO4)2:Eu2+ phosphor was found to have a trigonal structure with a space group R3c. The broad excitation spectra, ranging from 250 to 400 nm, matched well with near-UV LED chips. The much wider emission bands from 365 to 675 nm included more than one peak. Furthermore, the intensity of the peak at about 413 nm gradually decreases, while those in longer wavelengths gradually increase with the increase in Eu2+ concentration. Correspondingly, the emission hue varied from purplish-white to white and eventually to yellowish-white under 365 nm excitation. These results suggested that the Ca2.89Mg0.11(PO4)2:Eu2+ phosphor was a color tone tuning single-phase white light-emitting phosphor. Therefore, Ca2.89Mg0.11(PO4)2:Eu2+ is expected to be a promising candidate for white LEDs.