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Noninvasive sensing of temperature and pressure offers new and exciting opportunities to investigate and monitor the variation of physicochemical and spectroscopic properties of materials under extreme conditions. In this work, Tm2+‐doped SrB4O7 phosphor material—a novel, contactless bifunctional, and multimodal optical sensor for pressure and temperature is reported. A series of SrB4O7: xTm2+ samples are synthesized via a high‐temperature solid‐state method in air. The impact of high pressure (up to ≈13 GPa) and temperature (from 10 to 400 K) on spectroscopic properties of SrB4O7:Tm2+ is investigated. The emission band of Tm2+ demonstrates a significant spectral shift and a band broadening as a function of both pressure and temperature. Such a result is a consequence of a significant change of vibronic components of the Tm2+ 4f125d ↔ 4f13 zero‐phonon line. The emission bandwidth and its spectral position exhibit excellent sensitivities to pressure, that is, ≈23.17 and ≈−11.85 cm−1 GPa−1, respectively. Furthermore, for the first time, it is shown that temperature sensing can be realized via four different pathways in a single material: i) bandwidth, ii) band shift, iii) band intensity ratio, and iv) luminescence lifetime, with maximal sensitivities of ≈3.85 cm−1 K−1, 1.44 cm−1 K−1, 1.48% K−1 and 4.16% K−1, respectively. [ABSTRACT FROM AUTHOR]

Abstract: In this study, it is shown how the temperature range of luminescent thermometers can be widened in an unprecedented way by combining the intra‐ and interconfigurational transitions of the Pr3+ ion in a single material. Using Sr2GeO4:Pr3+ crystalline powders as an illustrative example, the implementation of luminescence thermometry is reported in the broadest temperature range up to now (17–600 K) with a remarkable performance: maximum relative sensitivity values of 9.0% · K−1 (at 22 K, cryogenic range), 0.6% · K−1 (at 300 K, physiological range), and 0.5% · K−1 (at 600 K, high‐temperature range) and minimum temperature uncertainty of 0.1 K. [ABSTRACT FROM AUTHOR]

Having proven that the temperature range of luminescent thermometers can be greatly widened by combining the intra‐ and interconfigurational transitions of the Pr3+, the possibility to manage important thermometric parameters by bandgap engineering and variation of energy of excitation photons are examined. Partial replacement of Ge with Si to form Sr2(Ge,Si)O4:Pr is very useful to manage these luminescence thermometer properties. This allows control of the range of temperatures within which the 5d1→4f Pr3+ luminescence can be detected. Also, excitation energy appears to affect the thermometer's performance. These allow adjustment of the range of temperatures that can be measured with the highest accuracy, reaching the spectacular value of Sr = 9.2% K−1 at 65 K for a Sr2(Ge0.75,Si0.25)O4:0.05%Pr3+ thermometer upon 244 nm excitation. For the first time, it has been proven that excitation energy may significantly affect the performance of luminescence thermometers. In Sr2(Ge0.75,Si0.25)O4:0.05%Pr3+ the highest relative sensitivity shifts from 65 K upon 244 nm excitation (Sr = 9.2% K−1) to 191 K upon 253 nm excitation (Sr = 3.97% K−1). This occurs despite both excitation wavelengths fitting within the 4f→5d1 excitation band. This paper shows that bandgap management is useful to effectively design new luminescent thermometers. [ABSTRACT FROM AUTHOR]

The employment of phosphors in luminescence thermometry is deemed one of the pivotal developments in the field. Besides the convenience of remote readings, phosphors may offer a plethora of other alluring benefits in this field. At present, one of the most paramount predicaments in this field involves developing an optical thermometer capable of functioning across an extensive temperature range encompassing hundreds of degrees while simultaneously delivering reasonable thermal sensitivity. As recently proven by us, the range of temperature readout can be significantly enhanced by the combination of intra- and interconfigurational transitions of Pr3+ while maintaining S r > 0.5 %/K across the whole temperature range. In this work, the idea has been extended using the combination of two dopants, Pr3+ and Tb3+, which exhibit minimal interference and instead demonstrate a combined impact of their respective temperature-dependent attributes across a range of almost 850 degrees (17–888 K) with relative thermal sensitivity up to 3.5 %/K at 405 K. Additionally, an impressive value of S r = 1.17 %/K at elevated temperature (738 K) was obtained. Temperature sensing was possible by utilizing both Pr3+ and Tb3+ emissions, showing different thermal quenching properties. That was key for broadening the temperature operating range compared to the singly-doped Y 2 SiO 5 :Pr3+ phosphors. [Display omitted] • Co-substitution of inorganic host structure to broaden temperature operating range. • Y 2 SiO 5 :Pr, Tb as a highly efficient and sensitive luminescence thermometer in the 17–888 K range. • Multiphonon relaxation utilized as a tool to extend the operating range of the luminescence thermometer. [ABSTRACT FROM AUTHOR]

Abstract: In this study, it is shown how the temperature range of luminescent thermometers can be widened in an unprecedented way by combining the intra‐ and interconfigurational transitions of the Pr3+ ion in a single material. Using Sr2GeO4:Pr3+ crystalline powders as an illustrative example, the implementation of luminescence thermometry is reported in the broadest temperature range up to now (17–600 K) with a remarkable performance: maximum relative sensitivity values of 9.0% · K−1 (at 22 K, cryogenic range), 0.6% · K−1 (at 300 K, physiological range), and 0.5% · K−1 (at 600 K, high‐temperature range) and minimum temperature uncertainty of 0.1 K. [ABSTRACT FROM AUTHOR]

Using luminescent materials for temperature measuring is considered the perspective remote technique nowadays. Designing new materials which combine a wide operating range with satisfying relative thermal sensitivity (S r) and temperature uncertainty values is still a challenge. In this paper, we study the luminescence properties and thermometric performance of a mixture of two phosphors. These are Ga-modified garnets - Y 3 (Al 3 Ga 2)O 12 :0.1%Pr and Y 3 (Al 1 Ga 4)O 12 :0.1%Pr - already reported as dual-mode luminescent thermometers. We show a new concept to improve important thermometric parameters of luminescence thermometers. We prove that such a mixture offers a significantly flatter course of the relative thermal sensitivity vs. temperature with S r around 1%K−1 over a broad temperature interval. Independently of which of the thermometric parameter is used, temperature measurement may be easily executed in the broad range of temperatures, 15–675 K. At the core of our concept is the use of two phosphors of the same crystal structure. This allows for the equally effective excitation of the two components of the mixture, while both use the same activator. [Display omitted] • Dual-mode thermometry is executed over 15–675 K range mixing two phosphors. • The Mixed phosphors belong to the same crystal structure of Pr activated garnets. • The same crystal structure allowed efficient excitation with the same energy. • The Mixed phosphors allowed to improve the accuracy of temperature measuring. [ABSTRACT FROM AUTHOR]

Having proven that the temperature range of luminescent thermometers can be greatly widened by combining the intra‐ and interconfigurational transitions of the Pr3+, the possibility to manage important thermometric parameters by bandgap engineering and variation of energy of excitation photons are examined. Partial replacement of Ge with Si to form Sr2(Ge,Si)O4:Pr is very useful to manage these luminescence thermometer properties. This allows control of the range of temperatures within which the 5d1→4f Pr3+ luminescence can be detected. Also, excitation energy appears to affect the thermometer's performance. These allow adjustment of the range of temperatures that can be measured with the highest accuracy, reaching the spectacular value of Sr = 9.2% K−1 at 65 K for a Sr2(Ge0.75,Si0.25)O4:0.05%Pr3+ thermometer upon 244 nm excitation. For the first time, it has been proven that excitation energy may significantly affect the performance of luminescence thermometers. In Sr2(Ge0.75,Si0.25)O4:0.05%Pr3+ the highest relative sensitivity shifts from 65 K upon 244 nm excitation (Sr = 9.2% K−1) to 191 K upon 253 nm excitation (Sr = 3.97% K−1). This occurs despite both excitation wavelengths fitting within the 4f→5d1 excitation band. This paper shows that bandgap management is useful to effectively design new luminescent thermometers. [ABSTRACT FROM AUTHOR]