Preparation, characterization and luminescent properties of red-emitting phosphor: LiLa2NbO6 doped with Mn4+ ions

Highlights: • We provide a comprehensive study of the luminescence mechanism of the Mn⁴⁺ ion. • Sharp emission lines belong to vibrational modes are observed at low temperature. • The LiLa₂NbO₆:Mn⁴⁺ phosphor shows special anti-thermal stability at low temperature. Series of Mn⁴⁺-activated LiLa₂NbO₆ red emitting phosphors were prepared by the solid state method. The structural and luminescence properties are investigated on the basis of X-ray diffraction (XRD), emission and excitation spectra, and luminescence decay curves. The LiLa₂NbO₆:Mn⁴⁺ phosphors can be efficiently excited by near-UV to blue light and exhibit bright red emission at around 712 nm, which can be assigned to the ²E_g→⁴A_2g transition of the 3 d³ electrons in [MnO₆] octahedra. Temperature dependent emission spectra and decay curves from 10 to 480 K are analyzed to understand the luminescence mechanism of Mn⁴⁺ in LiLa₂NbO₆ lattice. Notably, such a novel red emitting phosphor shows special anti-thermal quenching behavior.