Blue-emitting phosphor M2B5O9Cl: Eu2+ (MSr, Ca) for white LEDs

Eu2+ doped M2B5O9Cl (MCa, Sr) phosphors were prepared by a solid-state reaction method. Luminescent properties of as-synthesized phosphors were investigated under the excitation of near-ultraviolet (n-UV) light. Photoluminescence (PL) spectra revealed a blue emission band, and the emission band shifted to a longer wavelength region as Ca2+ substituted Sr2+. The photoluminescence excitation (PLE) spectra of M2B5O9Cl: Eu2+ (MCa, Sr) showed broadband absorptions in the n-UV region. Moreover, the as-prepared phosphors were also compared with commercial BaMgAl10O17: Eu2+ (BAM) blue phosphor. The present phosphors showed a narrower full width at half-maximum and higher PL intensity than the reference BAM under the n-UV light excitation.