Solvent induced shape change in CePO4:Dy3+ nanophosphors and effect of metal ions: A photoluminescence study

The influence of different solvents and metal ions (Li+, Ba2+, Bi3+) on the crystallization behaviour, morphology and enhancement in photoluminescence intensity of Dy3+ doped CePO4 were investigated. Highly crystalline luminescent nanophosphors of CePO4:Dy3+ re-dispersible in polar solvents were successfully prepared via a simple polyol route at 140 °C. As-prepared Dy3+ doped CePO4 nanophosphors prepared in EG and DMF appeared to have crystalline monoclinic phase but exhibited hexagonal phase when prepared in water and water mixed solvents. The hexagonal phase transformed to monoclinic phase after heating at 900 °C. TEM study revealed different shapes of the synthesized nanophosphors with change of solvents. The luminescence intensity of 4F9/2→6H15/2 at 478 nm (blue) was found to be more prominent than 4F9/2→6H13/2 at 572 nm (yellow). The introduction of metal ions (Li+, Ba2+ and Bi3+) in CePO4:Dy3+ led to considerable luminescent enhancement. The nanophosphors were subsequently incorporated in polymer films of PVA which showed the characteristic emissions of Dy3+. It also served as an effective method to improve the performance of polymer materials and brought about novel properties in them.