Highly-efficient double perovskite Mn4+-activated Gd2ZnTiO6 phosphors: A bifunctional optical sensing platform for luminescence thermometry and manometry

Energy Gap Linear Superposition of Thermally Coupled Levels toward Enhanced Relative Sensitivity of Ratiometric Thermometry

“…An accurate temperature measurement is of great significance and triggers a great demand for versatile thermometers. − Thereinto, ratiometric luminescence thermometry (RLT) has attracted considerable attention by virtues of non-invasive, fast response, high precision, and substantial electromagnetic interference resistance. , Generally, conventional RLT is performed by decoding the functional relationship between the temperature and fluorescence intensity ratio (FIR) of two emission bands detonated by thermally coupled levels (TCLs) of the luminescence centers . To evaluate the performance of optical thermometry, the relative sensitivity ( S R ) is proposed and expressed as a percentage change per temperature, reflecting the thermally induced relative change of FIR .…”

“…Thus, three pairs of TCLs with respective emissions are declared in the model. The photoluminescence intensity I i for the transition from the excited state |i⟩ to the ground state |0⟩ can be expressed as 21(1) where A i , N i , ℏ, and ω i represent the spontaneous emission probability, population in the |i⟩ state, reduced Planck constant, and photon angular frequency of the radiation, respectively. Notably, when the energy levels |i⟩ and nearby level |j⟩ are thermally coupled, the populations of |i⟩ and |j⟩ act under Boltzmann distribution and satisfy the following relationship:22…”

Modulating A site compositions of europium(iii)-doped double-perovskite niobate phosphors

“…The calculated lifetime results of the CINO:0.35Eu 3+ phosphor are listed in Table S7 †. It is evident that the lifetime decreases from 0.543 ms@318 K to 0.48 ms@598 K, which can be well fitted by the Struck and Fonger model: 61 where τ 0 is the lifetime at 318 K, Δ E is the vibration energy, and A is a constant. Therefore, the A and Δ E / k values of the CINO:0.35Eu 3+ phosphor were fitted to be about 504 442.12 and 9090.35, respectively.…”

Influence of the Synthesis Conditions on the Morphology and Thermometric Properties of the Lifetime-Based Luminescent Thermometers in YPO4:Yb3+,Nd3+ Nanocrystals

“…Therefore, an important alternative to the ratiometric technique is the lifetime-based approach. ,− In the case of luminescence kinetics, the absorption of the emitted radiation by the medium does not significantly affect the lifetimes of excited states and thus does not modify the calibration curve of the thermometer. To increase the sensitivity of a thermometer based on luminescence kinetics, physical processes are sought that will significantly affect the thermal dynamics of the emission level depopulation in a predictable way.…”