Lanthanide‐Based Thermometers: At the Cutting‐Edge of Luminescence Thermometry

Abstract

Present technological demands in disparate areas, such as microfluidics and nanofluidics, microelectronics and nanoelectronics, photonics and biomedicine, among others, have reached to a development such that conventional contact thermal probes are not accomplished anymore to perform accurate measurements with submicrometric spatial resolution. The development of novel noncontact thermal probes is, then, mandatory, contributing to an expansionary epoch of luminescence thermometry. Luminescence thermometry based on trivalent lanthanide ions has become very popular since 2010 due to the unique versatility, stability, and narrow emission band profiles of the ions that cover the entire electromagnetic spectrum with relatively high emission quantum yields. Here, a perspective overview on the field is given from the beginnings in the 1950s until the most recent cutting‐edge examples. The current movement toward usage of the technique as a new tool for thermal imaging, early tumor detection, and as a tool for unveiling the properties of the thermometers themselves or of their local neighborhoods is also summarized.

One Ion, Many Facets: Efficient, Structurally and Thermally Sensitive Luminescence of Eu2+ in Binary and Ternary Strontium Borohydride Chlorides

“…In fact, they are even competitive with convential ratiometric thermometers (Sr ≥ 1 % · K -1 ) using two emission transitions from thermally coupled excited states. [88][89][90][91][92][93] In that sense, the presented compounds are also promising single-band luminescent thermometers.…”

Triplet‐State Position and Crystal‐Field Tuning in Opto‐Magnetic Lanthanide Complexes: Two Sides of the Same Coin

“…Nevertheless, Tb-tfac outperformed the other complexes with am aximum sensitivity of 5.7 %K À1 at 300 K-amongst the highest valuesr eported for lanthanide complex-based luminescent thermometers. [56] Tb-acac was apt for al ower-temperature operation, whereas Tb-hfac showedamore limited usabilityd ue to the constraints imposed in terms of maximum operating temperature (i.e.,3 23 K) by the labile water molecule in the Tb 3 + coordinations phere.…”

Physical Manipulation of Lanthanide‐Activated Photoluminescence

“…Based on this, they realized temperature measurement in a wide range of 100-700°C and achieved a high sensitivity of up to 4 × 10 −3 K −1 at 330 K. Moreover, since both excitation and emission wavelengths are located within the "optical window" of biological tissues, this luminescent nanothermometer may be used for biological temperature sensing. [111] Louika et al [112] reported a mixed Eu-Tb metal organic framework, [Tb 0.9 Eu 0.1 (1,3-bdc) 3 (H 2 O) 2 ]·H 2 O, as a luminescent thermometer, in which the luminescence intensity ratio of Tb 3+ to Eu 3+ presented the classical Mott-Seitz model temperature dependence in the 12-230 K range. [60] Lanthanide organic frameworks have also been investigated as a fascinating class of luminescent thermometers with excellent performance in the past few years.…”