Photoluminescence properties of LiBaPO4:M3+ phosphor for near-UV light-emitting diode (M = Eu and Dy).

A novel phosphor LiBaPO4 doped with rare earths Eu and Dy prepared by high temperature solid-state reaction method is reported. The phosphors were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL). The emission and excitation spectra of these materials were measured at room temperature with a spectrofluorophotometer. The excitation spectra of LiBaPO4:Eu(3+) phosphor can be efficiently excited by 394 nm, which is matched well with the emission wavelength of near-UV light-emitting diode (LED) chip. PL properties of Eu(3+)-doped LiBaPO4 exhibited the characteristic red emission coming from (5) D0 → (7) F1 (593 nm) and (5) D0 → (7) F2 (617 nm) electronic transitions with color coordinations of (0.680, 0.315). The results demonstrated that LiBaPO4:Eu(3+) is a potential red-emitting phosphor for near-UV LEDs. Emission spectra of LiBaPO4:Dy(3+) phosphors showed efficient blue (481 nm) and yellow (574 nm) bands, which originated from (4) F9/2 → 6) H15/2 and (4) F9/2 → (6) H13/2 transitions of the Dy(3+) ion, respectively. The 574 nm line is more intense than the 481 nm lines, which indicates that the site Dy(3+) is located with low symmetry. This article summarizes fundamentals and possible applications of optically useful inorganic phosphates with visible photoluminescence of Eu(3+) and Dy(3+) ions.