Li2SrSi2N4:Eu2+: Electronic structure and luminescence of a red phosphor

Rare earth doped lithium containing nitridosilicates have become a hot spot in phosphors research because of their excellent luminescent properties. Here, the nitridolithosilicate Li2SrSi2N4:Eu2+ was successfully synthesized by solid-state reaction. Li2SrSi2N4:Eu2+ shows a red emission at 615 with an FWHM = 100 nm at the excitation of the near ultraviolet spectral region. Rietveld refinement on the powder XRD pattern revealed that Li2SrSi2N4 crystallizes in the cubic space group Pa3̄ (no. 205) [Z = 12, a = 10.7242(3) Å, V = 1233.37(9) Å3] and exhibits a three-dimensional network with solely vertex-sharing [SiN4] tetrahedral. The electronic structure of Li2SrSi2N4 was explored using density functional theory (DFT) methods. The results show that Li2SrSi2N4:Eu2+ can benefit the development of the novel red luminophor.