High colour purity single-phased full colour emitting white LED phosphor Sr₂V₂O₇:Eu³⁺

Single-phased white-light-emitting phosphor Sr₂V ₂O₇:Eu³⁺ was successfully synthesized by the solid-state method. The result of x-ray diffraction analysis indicated that the obtained phosphor has the same crystal structure as that of Sr₂V ₂O₇. The synthesized Sr₂V₂O ₇:Eu³⁺ was combined with near-UV light (365nm) chips and then assembled into ligtht-emitting diodes (LED) devices, which generated white light with colour coordinates of (0.324, 0.317). The white light was generated from yellow-green and red emissions, which should be attributed to the host Sr₂V₂O₇ and dopant Eu ions, respectively. The effects of the concentration of Eu ions and charge compensation on the emission intensity were carefully investigated. The results show that the energy migrates from the host to the dopant and also that Li₂CO₃ should be the best charge compensator for this single-phased phosphor. In addition, the colour rendering index and luminescence efficiency of the fabricated LED devices with Sr1.90V2Sr2V₂O₇O7Sr₂V ₂O₇:0.10Eu³⁺ phosphor were 91 and 32lmW ^-1, respectively, suggesting that Sr1.90Sr₂V ₂O₇V₂Sr₂V₂O ₇O7Sr₂V₂O₇:0.10Eu³⁺ phosphor is a potential candidate for the phosphor-converted white-light-emitting diodes with near-UV chips.