A novel Na 3 La 2 (PO 4 ) 3 :xEu (Na 3 La(PO 4 ) 2 /LaPO 4 :xEu) blue-red dual-emission diphasic phosphor with high thermal stability is successfully synthesized by a high temperature solid state reaction. X-ray powder diffraction (XRD) analysis verified that the host of this dual emitting phosphor is a composite material composed of two crystals: Na 3 La(PO 4 ) 2 and LaPO 4 , which would realize the energy transfer between the two phases and then greatly enhance the luminescence properties. When compared with the single-phase phosphor Na 3 La(PO 4 ) 2 :xEu, the photoluminescence (PL) spectra of the as-synthesized diphasic phosphor showed significantly enhanced blue emission peaking at 422 nm of Eu 2+ (5d-4f, a broadband at around 422 nm) and red emission peaking at 594 nm of Eu 3+ ( 5 D 0 - 7 F 1,2 , 594 and 621 nm) under UV excitation. Moreover, the phosphor exhibited a high thermal stability at 150 °C with up to 98.5% luminescence retention after Li + co-doping, which should be attributed to the introduction of several defects. The emission spectra matched well with the photosynthetic action spectra (PAS) in plants, indicating that the Na 3 La 2 (PO 4 ) 3 :xEu phosphor has a promising application in plant growth LED lighting.
ASJC Scopus subject areas
- Materials Chemistry