Highly Sensitive Dual Self‐Referencing Temperature Readout from the Mn⁴⁺/Ho³⁺ Binary Luminescence Thermometry Probe

Abstract

of luminescence signal in comparison to other methods, relatively fast response, and a good spatial resolution. Temperature can be determined from different features of luminescence, such as excitation and emission band positions and bandwidths, emission band intensities, luminescence intensity ratio (LIR; the ratio of intensities of two emission bands), anisotropy, emission decay-or rise-times, etc. [2] Temperature readouts from LIR and emission lifetime are by far the most exploited luminescence thermometry methods. Both readouts are self-referencing and are not affected by fluctuations in the excitation and signal detection. Luminescence of any substance is strongly affected by temperature, and, thus, variety of materials may be utilized as a luminescence thermometry probe. The choice is commonly made on quantum dots, organic dyes, metal-organic complexes and frameworks, and lanthanide or transition metal ion based phosphors, the last of which are the most exploited ones. When screening materials for the suitable luminescence thermometry probe for the specific application, attention is given to material's structural, chemical, luminescent, and thermographic properties. Most of all, luminescence of material should notably change with temperature to provide sensitive measurement with adequate temperature resolution. Also, a probe should provide repeatable and reproducible temperature determination. Furthermore, for the practical realization of thermometer, some other materials properties are of interest, such as excitation and emission wavelengths and bandwidths, which should facilitate production of cost-effective and simple measurement devices.Regarding structural and chemical properties, lanthanide and transition metal ion based materials and material's systems meet most of above mentioned conditions. They are thermally and chemically stable, provide sufficient brightness, and exceptional photostability. They also facilitate thermometry with excellent repeatability and reproducibility. However, they generally lack sensitivity and, consequently, temperature resolution. LIR readout scheme with trivalent lanthanide ion activated phosphors exploits emissions from two closely separated and thermally coupled excited states (either in the upconversion or downshifting processes). [3] In such case, the relative sensitivity is limited by the energy difference between these excitedThe binary luminescence thermometry probe is prepared from Y 2 O 3 :Ho 3+ and Mg 2 TiO 4 :Mn 4+ powders. This probe facilitates self-referencing temperature readouts with excellent repeatability from both emission intensity ratio and excited state lifetimes. The ratio of intensities of Mn 4+ deep red emission from 2 E, 4 T 2 → 4 A 2 electronic transitions, and Ho 3+ green emission from 5 F 4 , 5 S 2 → 5 I 8 electronic transitions provides temperature measurements over the room temperature to 100 °C temperature range with a superior relative sensitivity of 4.6% °C −1 and temperature resolution of 0.1 °C. Over the same temperature range, the tem...

A Ho3+‐Based Luminescent Thermometer for Sensitive Sensing over a Wide Temperature Range

“…[ 1,2 ] Remote temperature sensing based on luminescence thermometry offers an alternative that is capable of measuring heat generation and diffusion on the microscopic scale. [ 3 ] Among the various choices of luminescent systems, [ 4–9 ] crystals doped with lanthanide (Ln 3+ ) ions represent a particularly promising class of luminescent thermometers, because their dimensions can be tuned from a few nanometers to several micrometers and their photoluminescence spectrum is sensitive to temperature. A characteristic feature of Ln 3+ ions is their rich energy level structure, which results in emission spectra with well‐separated lines.…”

Self‐Trapped Exciton to Dopant Energy Transfer in Rare Earth Doped Lead‐Free Double Perovskite

“…We further measured the photoluminescence (PL) of CNAIC:Ho 3+ (Figure b). Besides the main emission derived from STEs, the sharp emission peaks, located at around 490, 550, and 650 nm, correspond to the transition of Ho 3+ 5 F 3 → 5 I 8 , 5 F 4 → 5 I 8 , and 5 F 8 → 5 I 8 , respectively . In addition to the abundant characteristic emission spectra in the visible region, rare earth ions usually have rich emissions in infrared region.…”

Smartphone‐Based Luminescent Thermometry via Temperature‐Sensitive Delayed Fluorescence from Gd2O2S:Eu3+

“…To date, phosphors for lifetime‐based thermometry have had lifetimes typically much less than 10 ms, making it impossible to measure the lifetime with a 30‐fps camera. A broad range of luminescent materials—such as lanthanides, [ 2d ] organic‐inorganic compounds, [ 10 ] carbon dots, [ 11 ] organic molecules, [ 12 ] nitrogen‐vacancy centers in diamond, [ 13 ] and dual emitter systems [ 14 ] —have already been explored for thermometry based on either PL intensity ratio or lifetime parameters. Indeed, commercial products have been available since the 1980s that use the luminescence from phosphor‐coated fiber tips to determine temperature.…”