Synthesis, structure and optical performance of red-emitting phosphor Ba5AlF13:Mn4+

Abstract

Mn⁴⁺-activated cubic phase Ba₅AlF₁₃ red phosphors were prepared by the two-step coprecipitation method. The structural and optical features were characterized on the basis of X-ray diffraction (XRD), transmission electron microscopy (TEM), emission and excitation spectra, and luminescence decay curves. The Ba₅AlF₁₃:Mn⁴⁺ phosphors can be efficiently excited by near-UV to blue light and exhibit bright red emission at around 627 nm, which is assigned to the ²E_g → ⁴A_2g transition of the 3d³ electrons in [MnF₆] octahedra. Temperature dependent emission spectra and decay curves from 10 to 550 K were measured to deeply understand the luminescence mechanism of Mn⁴⁺ in the Ba₅AlF₁₃ lattice. Notably, this novel red phosphor shows excellent anti-thermal quenching behaviour (∼700% of emission intensity at 300 K relative to 10 K).