Afterglow enhancement with In3 + codoping in CaTiO3:Pr3 + red phosphor

CaTiO3:Pr3 + phosphor with a single red emission peak of around 613 nm was co-doped with In3 + to charge compensate in the lattice sites where a trivalent ion Pr3 + substitutes a divalent Ca2 + ion. This phosphor was prepared via the solid state reaction process. The concentration of In3 + was varied from 0.05 to 0.3 mol% and it was found that the In3 + incorporation enhanced the intensity of the red emission and the afterglow decay time of the CaTiO3:Pr3 + phosphor considerably. It is most likely that the incorporated In3 + charge compensators enhanced the luminescence intensity of the phosphor by neutralizing the additional positive charge generated by the Pr3 + ions when substituting in the Ca2 + ions site. The orthorhombic CaTiO3 phase was identified by X-ray diffraction. Scanning electron microscopy images showed agglomerated particles with different shapes and sizes. A single red emission of Pr3 + of around 613 nm and phosphorescence decay time of 6 min were measured using photoluminescence (PL) spectroscopy and afterglow measurements, respectively. Diffuse reflectance spectroscopy was used to determine the absorbing centres of the phosphor.