A Comparative Study on Luminescence Properties of Y₂O₃: Pr³⁺ Nanocrystals Prepared by Different Synthesis Methods

Pr³⁺-doped Y₂O₃ nanocrystals (NCs) have been obtained via five wet-chemistry synthesis methods which were optimized in order to achieve superior optical properties. To this end, a systematic study on the influence of different reaction parameters was performed for each procedure. Specifically, precursor concentration, reaction temperature, calcination temperature, and time, among others, were analyzed. The synthesized Y₂O₃: Pr³⁺ NCs were characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), and reflectance and Raman spectroscopy. In addition, the optical properties of such NCs were investigated by excitation, emission, and luminescence decay measurements. Concretely, emission from the ¹D₂ level was detected in all samples, while emission from ³P_J was absent. Finally, the effect of the synthesis methods and the reaction conditions on the luminescence decay has been discussed, and a comparative study of the different methods using the fluorescence lifetime of so-obtained Y₂O₃: Pr³⁺ NCs as a figure of merit has been carried out.