Novel Mn4+-activated NaLiTi3O7 far-red emitting phosphors

Novel and efficient broadband excited far-red emitting NaLiTi3O7:Mn4+ phosphors were synthesized by solid state reaction. Phase purity of NaLiTi3O7 was analyzed using X-ray powder diffraction technique. The luminescence properties and fluorescence decay curves were explored to characterize the phosphors. Under UV/VIS excitation, Mn4+ doped NaLiTi3O7 shows intense emission around 681 nm. To analyze the nephelauxetic impact of Mn4+ in the NaLiTi3O7 host lattice, the crystal field strength (Dq) and the Racah parameters (B and C) are determined. The estimated findings are in good agreement with the linear dependency of 2E on the β1 parameter, which may provide an indicative of the position of the Mn4+ emission based on β1. A Tanabe-Sugano energy level diagram was also used to evaluate the luminescence process. Fluorescence decay measurement was used to discuss the concentration quenching phenomenon.