Emission Enhancement and Energy Transfers in YV 0.5 P 0.5 O 4 Nanoparticles Codoped with Eu 3+ and Bi 3+ Ions.

In this study, solid-state solutions of yttrium orthovanadate-phosphate with varying concentrations of codopants (Eu 3+ , Bi 3+ ) have been obtained via coprecipitation. An ionic radii mismatch between V 5+ and P 5+ substituents is manifested in broad XRD lines. The sharpening of the XRD lines is observed with increasing bismuth ions concentration in the Eu 3+ codoped YV 0.5 P 0.5 O 4 matrix. The difference in the number of the Stark components for the 5 D 0 → 7 F J transitions indicates changes in the lattice and a number of possible Eu 3+ sites. A thorough, systematic spectroscopic analysis of YV 0.5 P 0.5 O 4 : x mol % Eu 3+ , y mol % Bi 3+ was conducted at room temperature and 5 K. Metal-to-metal energy transfers occurring between Eu 3+ , V 5+ , and Bi 3+ optically active ions have been investigated. Additionally, efficiency of the Bi 3+ -Eu 3+ energy transfer (ET) was calculated.