CaSnO3: Pr3+ phosphor for new application in temperature sensing

Synthesis and photoluminescent characterization of ceramic phosphors Li2MgGeO4:Ln3+ (Ln3+ = Pr3+ or Tm3+) under different excitation wavelengths

In the current work, germanate phosphors Li₂MgGeO₄:Ln³⁺ (Ln = Pr, Tm) have been synthesized and then investigated using luminescence spectroscopy. The X-ray diffraction analysis demonstrate that ceramic compounds Li₂MgGeO₄ containing Pr³⁺ and Tm³⁺ ions crystallize in a monoclinic crystal lattice. Luminescence properties of Pr³⁺ and Tm³⁺ ions have been examined under different excitation wavelengths. The most intense blue emission band related to the ¹D₂ → ³F₄ transition of Tm³⁺ is overlaps well with broad band located near 500 nm, which is assigned to F-type centers. These effects are not evident for Pr³⁺ ions. Ceramic phosphors Li₂MgGeO₄:Ln³⁺ (Ln = Pr, Tm) are characterized based on measurements of the excitation/emission spectra and their decays. The experimental results indicate that germanate ceramics Li₂MgGeO₄ doped with trivalent rare earth ions can be applied as inorganic phosphors emitting orange (Pr³⁺) or blue (Tm³⁺) light.

A colorimetric optical thermometry of host-sensitized Pr3+-doped niobate phosphors based on electronic-rich-site strategy

Most praseodymium-doped red-emitting phosphors need high-temperature synthesis conditions with a reducing atmosphere. The niobate matrix selected in this work provides a sufficient electron-rich-site environment for praseodymium through charge migration, and praseodymium can be self-reduced in air atmosphere, which is safe and environmentally friendly. By building the [NbO₆] group → Pr³⁺ energy transfer and finely modifying the doping concentration of Pr³⁺ ions, we constructed a dual-luminescence-system of the [NbO₆] group and Pr³⁺. Thereby, optical temperature measurement based on fluorescence intensity ratio (FIR) technology of Pr³⁺ ions and [NbO₆] groups was carried out using non-thermal coupling pairs, through the Boltzmann fitting and integral calculation, the maximum S_r and S_a values were 2.25% K^-1 and 0.0049 K^-1 at 403 K and 443 K, respectively, the S_r value is four times that obtained from the thermal coupling of Pr³⁺ ions, which exceeded most values previously reported for the fluorescence powder. Accordingly, we also studied the thermal sensitivity of Er³⁺ ions and Eu³⁺ ions mono-doped CaNb₂O₆ substrates. Results reveal that CaNb₂O₆:Pr³⁺/Er³⁺/Eu³⁺ phosphors have splendid temperature sensitivity and have far-reaching application prospects in the field of temperature measurements.

Development of a cyan blue-emitting Ba3La2(BO3)4:Ce3+,Tb3+ phosphor for use in dental glazing materials: color tunable emission and energy transfer

Herein, we demonstrated the possibility of using Ba₃La₂(BO₃)₄:Ce³⁺,Tb³⁺ phosphors in dental glazing paste.