A novel green-emitting phosphor Ca_(10)Na(P0_4)_7:Eu~(2+) for near ultraviolet white light-emitting diodes

摘要

A novel green phosphor Ca_(10)Na(PO_4)_7:Eu~(2+) was synthesized by the solid state reaction. The crystal structure, photoluminescence properties and concentration quenching of the as-prepared Ca_(10)Na(PO_4)_7:Eu~(2+) phosphor were systematically investigated. The phosphors show trigonal structure and the optimal Eu~(2+) concentration in Ca_(10)Na(PO_4)_7:xEu~(2+) is 0.075. The phosphors present two broad emission bands from 380 to 710 nm in which the peak profiles actually centered at about 412 and 531 nm under the near ultraviolet excitation of 400 nm. The calculated results indicate that the mechanism for concentration quenching of fluorescence emission of Eu~(2+) ions in Ca_(10)Na(PO_4)_7 phosphor is the dipole-dipole interaction. All the present work suggests that Ca_(10)Na(PO_4)_7:Eu~(2+) phosphor is a potential green-emitting phos-phor for near ultraviolet white light-emitting diodes.