Improving Accuracy and Sensitivity of Lanthanide-Based Luminescent Manometers by Augmented Spectral Shift Method

Abstract

Luminescence manometry is most often realized by a spectral shift of luminescence bands. Typically, the shift of spectrally narrow-band emission is quantified, which is highly precise but not very sensitive to pressure variations. Alternatively, the spectral shift of a broadband emission may be exploited, which is more sensitive but less precise, due to the difficulty in accurate determination of the band centroid. In this work, a mixed approach is presented, combining the shift in broadband chromium emission from the 4T2 → 4A2 level with a narrow-band neodymium emission (4F3/2 → 4I11/2 transition), observed in the La3Ga5GeO14 spectrum. The resulting optical Nd3+-based manometer demonstrates an absolute sensitivity of 2.92 cm–1/GPa for the 4F3/2 → 4I11/2 electronic transition. An additional advantage of using this material is its negligible spectral shift with temperature, determined in the T range of 77–343 K, making the pressure readouts independent of this parameter (i.e., temperature variations).

Energy Transfer in Mixed Lanthanides Complexes: Toward High‐Performance Pressure Sensors Based on the Luminescence Intensity Ratio

“…Depending on the physicochemical characteristics of the materials, their photoluminescence can be sensitive to various physical variables. Among various PL sensors, [5,6,[7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] those related to pressure sensing are a hot topic in many fields of basic science, DOI: 10.1002/adom.202301800 technology, and engineering, such as biology, [23] tribology, [24,25] , and optics. [26] Rare-earth based compounds are among the most interesting and reliable materials to develop thanks to their long emission lifetime, sharp emission peak, low toxicity, and high functionalizability.…”

A highly sensitive lifetime-based luminescent manometer and bi-functional pressure–temperature sensor based on a spectral shift of the R-line of Mn4+ in K2Ge4O9

“…1,10,[13][14][15] However, despite its attractiveness, this approach is modestly employed in luminescence manometry. [16][17][18][19][20] Pressure applied to the phosphor can induce various effects altering the luminescence kinetics of the emitting state, such as (I) phase transitions, resulting in a significant change in the energy level structure of the system; (II) formation of crystal defects, which may result in energy migration to traps and defect states; and (III) shortening the interionic distances, leading to increased probabilities of interionic energy transfer, which may induce nonradiative depopulation of emitting levels due to cross-relaxation processes. [21][22][23][24] A key example is SrF 2 :Yb 3+ ,Er 3+ where growing pressure activates cross-relaxation, shortening the lifetimes of the 2 H 11/2 and 4 S 3/2 levels of Er 3+ ions.…”

“…As a response to this demand lifetime-based luminescent manometers based on materials doped with transition metal (TM) ions have been recently proposed. 18,19,[29][30][31][32] Due to the unique electronic configuration of TM ions, their spectroscopic properties exhibit high sensitivity to the changes in the local environment of the ions. In general, the compression of the phosphor induces a change in the strength of the crystal field acting on these ions.…”

Temperature invariant lifetime based luminescent manometer on Mn4+ ions

“…[7][8][9][10][11] Among the luminescent manometers described so far, the most common way to readout the pressure values in a given system is through spectral band shift analysis. [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] This strategy applies both to luminophores with a narrow emission band headed by ruby and also to broadband luminophores. In this case, the pressure reading involves either an analysis of the position of the emission band centroid or a ratiometric reading of the ratio of luminescence intensities occurring in the two spectral bands.…”

“…In this case, the pressure reading involves either an analysis of the position of the emission band centroid or a ratiometric reading of the ratio of luminescence intensities occurring in the two spectral bands. 9,11,[19][20][21][22] However, in the case of applications of luminescent manometers in environments where the medium is characterized by a dispersive dependence of the extinction coefficient, a reading based on analysis of the spectral response, including ratiometric approach and the band shift of the luminophore can lead to reduced reliability owing to the interactions of the emitted light with the medium in the form of absorption and/or scattering. 23,24 Hence, in such applications, luminescent manometers using pressure-induced changes in luminescence kinetics are advantageous.…”