The Influence of Defects on the Luminescence of Trivalent Terbium in Nanocrystalline Yttrium Orthovanadate.

Terbium-doped YVO has been considered a nonluminescent solid since the first classic studies on rare-earth-doped phosphors in the 1960s. However, we demonstrate that defect engineering of YVO:Tb nanoparticles overcomes the metal-metal charge transfer (MMCT) process which is responsible for the quenching of the Tb luminescence. Tetragonal (YTb)VO nanoparticles obtained by colloidal precipitation showed expanded unit cells, high defect densities, and intimately mixed carbonates and hydroxides, which contribute to a shift of the MMCT states to higher energies.

A Highly Stable Yttrium Organic Framework as a Host for Optical Thermometry and D O Detection.

The yttrium organic framework (Y Tb Eu ) (BDC) (OH) (H O) (BDC=benzene-1,4-dicarboxylate) is hydrothermally stable up to at least 513 K and thermally stable in air in excess of 673 K. The relative intensities of luminescence of Tb and Eu are governed by Tb -to-Eu phonon-assisted energy transfer and Tb -to-ligand back transfer and are responsible for the differing temperature-dependent luminescence of the two ions. This provides a ratiometric luminescent thermometer in the 288-573 K temperature range, not previously seen for MOF materials, with a high sensitivity, 1.

High-sensitivity dual UV/NIR-excited luminescence thermometry by rare earth vanadate nanoparticles.

High-crystallinity rare earth (RE) vanadate nanoparticles doped with Tm3+, Er3+ or Ho3+ combine multiple emissions in red, green, and blue under dual UV/NIR excitation, promoting high performance self-referenced luminescence thermometry. Due to their very high chemical and thermal stability, these versatile single-phase compositions allow optical thermal sensing from cryogenic (77 K) to moderately high (673 K) temperatures with high reproducibility and low temperature uncertainty. Hence, these nanomaterials operate as optical thermometers in a very broad temperature range (∼600 K), owing to the availability of twelve emission intensity ratios for thermometry.