Synthesis and spectral properties of germanate luminophors with the cationic-anionic substitution in the structure

In this work, a new phosphors Ca₂La_6.8Eu_1.2Ge_5.6W_0.4O_26.4-δ and CaLa_7.875Eu_1.125Ge_5.6W_0.4O_26.9-δ for the n-LED as well as Sr₂La_8-2xEr_xYb_xGe₆O₂₆, x=0.01; 0.05; 0.075; 0.1 0.15 solid solutions, that are for the conversion of the near infrared emission in the visible light, are described. Synthesis procedure, by the sol-gel method, of the studied compounds set out in detail. Photoluminescence spectra of the Ca₂La_6.8Eu_1.2Ge_5.6W_0.4O_26.4-δ and CaLa_7.875Eu_1.125Ge_5.6W_0.4O_26.9-δ compounds, and upconversion spectra of the Sr₂La_8-2xEr_xYb_xGe₆O₂₆ luminophors are measured. Present of the Eu³⁺ and Eu²⁺ ions in the Ca₂La_6.8Eu_1.2Ge_5.6W_0.4O_26.4-δ and CaLa_7.875Eu_1.125Ge_5.6W_0.4O_26.9-δ phosphors has been evidenced. Color coordinates of the Ca₂La_6.8Eu_1.2Ge_5.6W_0.4O_26.4-δ and CaLa_7.875Eu_1.125Ge_5.6W_0.4O_26.9-δ compounds were calculated.