Effects of Sr2+ ion-doped on the microstructure and photoluminescence properties of Ca2La0.97Pr0.03TaO6 phosphor

• The intensity of emission peaks can be enhanced by Sr2 + ion doped.
• The amount of oxygen vacancies decrease when the Sr2+ ion doped.
• A greater energy for compressive than for tensile strain for the formation of oxygen vacancies.
• The optimum Sr2+ ion concentration is 3 mol%.

Sr2+ ion-doped Ca2La0.97Pr0.03TaO6 phosphor is synthesized using a vibrating milled solid-state reaction. An initial tensile strain was induced for pure Ca2La0.97Pr0.03TaO6 phosphor during the thermal expansion and shrinkage cooling, and caused oxygen vacancies formed during a calcination process. When the Sr2+ ions are introduced to substitute the Ca2+ ions in the Ca2La0.97Pr0.03TaO6 system, the emission intensities caused by the oxygen vacancies and the f-f transition for the Pr3+ ion increase and then decrease as the Sr2+ ion concentration increases. This is caused by the distinct difference the ion radii of the Ca2+ ion and the Sr2+ ion, which causes the lattice to become distorted and induces an increase in the degree of compressive strain in the vicinity of the Pr3+ ions, which leads to a decrease in the amount of oxygen vacancies to decrease. The optimum Sr2+ ion concentration is 3 mol%.

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