Structure, photoluminescence and abnormal thermal quenching behavior of Eu2+-doped Na3Sc2(PO4)3: a novel blue-emitting phosphor for n-UV LEDs

Abstract

A novel blue-emitting phosphor Na₃Sc₂(PO₄)₃:Eu²⁺ was successfully synthesized by solid-state reaction. The crystal structure, bandgap, and photoluminescence properties were investigated in detail. Under n-UV excitation, the NSP:Eu²⁺ phosphor exhibits a narrow blue emission peaking at 458 nm with a FWHM of about 50 nm. The concentration quenching mechanism of the NSP:Eu²⁺ is dominated by the dipole–dipole interaction. Moreover, the NSP:Eu²⁺ shows better PL intensity, colour purity and thermal quenching properties compared to the commercial BAM phosphor. Non-equivalence replacement of Eu²⁺ ions for Na⁺ ions causing defects, inducing the abnormal thermal quenching behaviour. All these results suggest that the NSP:Eu²⁺ phosphor can be a potential candidate for n-UV LED applications.