Modulation of the Pr 3+ luminescence in the SrTi 1-x Zr x O 3 solid solution

In this work ceramic samples of Sr0.9955Pr0.003Ti1-xZrxO3 (0.0 ≤ x ≤ 1.0) solid solution were synthesized by the Pechini method. Samples calcined at 800 °C for 1 h were characterized by X-ray diffraction; scanning electron microscopy, diffuse reflectance and photoluminescent spectroscopies. The compounds exhibit three different crystal perovskite-like structures as a function of the chemical composition: Cubic (0.0 ≤ x ≤ 0.2), tetragonal (0.3 ≤ x ≤ 0.6) and orthorhombic (0.7 ≤ x ≤ 1.0). The substitution of Ti4+ by Zr4+ in the solid solution results in an increase in the energy of the transition associated with the host. The presence of a ligand-to-metal charge transfer state between O2− and Ti4+ and its effect on the Pr3+ luminescence is shown. The photoluminescence response of Pr3+ is explained by using the chemical shift model. A remarkable consequence of the chemical variation in the series compounds, is the color-modulation of the emission under excitation at 447 nm (3H4 → 3P2). It goes from a dominant red emission ascribed to the 1D2 → 3H4 transition to a dominant greenish-blue emission ascribed to the 3P0 → 3H4. Finally, the color coordinates associated with the emission for the entire series are plotted in the CIE 1931 color space.