Fig. 1. Crystal structure and characterization of Sc₄Zr₃O₁₂∶Cr. (a)(b) XRD patterns; (c) crystal structure of Sc₄Zr₃O₁₂

Fig. 2. Diffuse reflectance spectra of Sc₄Zr₃O₁₂∶xCr

Fig. 3. Luminescence of Sc₄Zr₃O₁₂∶Cr. (a) Excitation spectra; (b) emission spectra; (c) relationship between Cr mole fraction and emission intensity; (d) Gaussian fitting resluts for the PLE and PL spectra

Fig. 4. Dependence of crystal field parameters and Stokes shift of ⁴T₁ level on ratio of C/B

Fig. 5. Crystal field parameters and Tanabe-Sugano diagram

Fig. 6. Luminescence decay curves of Sc₄Zr₃O₁₂∶Cr

Fig. 7. Temperature characteristic of Sc₄Zr₃O₁₂∶Cr. (a) Temperature-dependent emission spectra; (b) emission peak position of temperature-dependent spectra ; (c) integral intensity of temperature-dependent emission spectra; (d) plot of ln(I₀/I-1) versus 1/T

Fig. 8. NIR pc-LED fabricated by CaMgSi₂O₆∶Cr. (a) Luminescent spectra of pc-LED; (b) NIR luminescent spectra of pc-LED; (c) photoelectric efficiency of pc-LED; (d) output power ratio of pc-LED