Photoluminescence emission in zirconium-doped calcium copper titanate powders

Intense photoluminescence (PL) emission was observed in Zr-doped calcium copper titanate powders. The compounds were synthesized by a soft chemical method and heat treated at temperatures between 300 and 850 °C. The decomposition of the precursors was examined by X-ray diffraction, Fourier transform infrared, Fourier transform Raman, and ultraviolet-visible spectroscopies; as well as PL analysis. Here, we discuss the role of the structural ordering, which facilitates the self-trapping of electrons and charge transfer, and review the mechanism that triggers the PL. The most intense PL emission was obtained for the sample with 5% Zr calcined at 750 °C, which is neither highly disordered nor completely ordered at ~520 nm.