Enhanced photoluminescence due to Bi³⁺ → Eu³⁺ energy transfer and re-precipitation of RE doped homogeneous sized Y₂O₃ nanophosphors

Precipitation and re-precipitation of metal ions has been carried out from original and supernatant solution producing Bi³⁺ - Eu³⁺ doped Y₂O₃:Eu³⁺ and Eu³⁺/Tb³⁺ doped Y₂O₃, respectively. Shorter reaction time is unable to consume all metal ions present in the solution which can be utilized through re-precipitation process. The doping of Bi³⁺ - Eu³⁺ in Y₂O₃ helps to absorb maximum UV light. The activation of Y₂O₃ matrix by Bi³⁺ and Eu³⁺ ions, together and separately, were studied considering the excitation energy transfer to the luminescence centers. The successful replacement of Y³⁺ by RE³⁺ ions can help for fine tuning of emission wavelength. Re-precipitation of supernatant solution by adding terbium precursor can successively produce uniform sized Tb³⁺ doped Y₂O₃:Eu³⁺. The re-precipitation of the supernatant solution ensures maximum consumption of metal ions for higher product yield and possible fine tuning of emission wavelengths.