Explaining the temperature-induced shift of the V-O charge transfer band experimentally and design of single-excitation ratiometric optical thermometry

Temperature-induced redshift of the V-O charge transfer band (CTB) is promising for designing high performance optical thermometry. The shift mechanism is considered as the thermal populations of high vibrational energy levels of the VO₄ ^3- ground state. Direct experimental evidence for this, however, is still lacking. In this work, Tm³⁺-doped YVO₄ with various doping concentrations was studied to achieve strong ¹D₂ emission of Tm³⁺. The temperature dependent CTB was studied at low temperatures to give direct evidence experimentally for the shift mechanism of the CTB using YVO₄:20% Tm³⁺. It was found that the V-O CTB does not shift when the temperature is lower than a certain temperature (60 K), verifying the proposed shift mechanism experimentally. In addition, based on the temperature quenching of ¹D₂ emission of Tm³⁺ and the redshift of the CTB, single-excitation ratiometric thermometry was carried out using YVO₄:30% Tm³⁺,6% Sm³⁺. High relative sensitivity was achieved with a maximal value reaching up to 3.86% K^-1 at approximately 355 K.

The explanation of abnormal thermal quenching of the charge transfer band based on thermally coupled levels and applications as temperature sensing probes

TATQ and EATQ abnormal thermal quenching phenomena are observed and explained. Sr based on abnormal thermal quenching of CTB is four times of that derived from TCLs in the same phosphor.

TemperatureDependent Luminescence of RedEmitting Ba2Y5B5O17: Eu3+ Phosphors with Efficiencies Close to Unity for NearUV LEDs

Solid state white light sources based on a near-UV LED chip are gaining more and more attention. This is due to the increasing efficiency of near-UV-emitting LED chips and wider phosphors selection if compared to devices based on blue LED chips. Here, a brief overview is given of the concepts of generating white light employing near-UV LED and some optical properties of the available phosphors are discussed. Finally, the synthesis and optical properties of very efficient red-emitting Ba₂Y₅B₅O₁₇:Eu³⁺ phosphor powder and ceramics is reported and discussed in terms of possible application as a red component in near-UV LED-based white light sources.

Realizing emission color tuning, ratiometric optical thermometry and temperature-induced redshift investigation in novel Eu3+-doped Ba3La(VO4)3 phosphors

Eu³⁺ doped Ba₃La(VO₄)₃ phosphors with tunable emitting colors were firstly explored and their photoluminescence properties were investigated.

Sr1.7Zn0.3CeO4F0.2:Eu3+: novel dual-emission temperature sensors for remote, noncontact thermometric application

A novel dual-emitting temperature sensor Sr_1.7Zn_0.3CeO₄F_0.2:Eu³⁺ was synthesized. The intensity ratio shows superior linearity as a function of the temperature, indicating the potential application in the thermometry field.

Investigation into the temperature sensing behavior of Yb3+ sensitized Er3+ doped Y2O3, YAG and LaAlO3 phosphors

The sensitivities (S) of Y₂O₃ (YAG/LaAlO₃):Yb³⁺/Er³⁺ phosphors increased with increasing average bond covalency and the calculated values were basically in good agreement with our experimental results.

Synthesis and photoluminescence properties of a novel Sr2CeO4:Dy3+ nanophosphor with enhanced brightness by Li+ co-doping

A series of Dy³⁺ (0.005–0.09 mol%) and Li⁺ (0.005–0.03 mol%) co-doped strontium cerate (Sr₂CeO₄) nanopowders are synthesized by low temperature solution combustion synthesis.