(Invited) Exploiting Luminescence for Measurements of Temperature

Abstract

Temperature is by far the most-measured physical quantity, and temperature sensors are used by a large extent in daily life, industry, military, medicine, etc., with a market share of about 75%–80% of all sensors. Demands for temperature measurements of moving or contact sensitive objects, difficult to access bodies, objects in hazardous locations, at the nanoscale, in living organisms and cells, have stimulated research on the development of new temperature measurement concepts and temperature probes. Luminescence thermometry is among aspiring concepts capable of meeting aforementioned demands in the future. The changes of luminescence properties of materials with temperature allows some materials to act as sensitive thermometers. The phenomenon become the basis of a new arm in the field of luminescence spectroscopy commonly termed as a luminescence thermometry. This lecture will present a brief introduction into the concept of temperature measurements via luminescence, with the description of the temperature quenching of emission. Then, an overview of different concept modalities of luminescence thermometry will be given including: the steady-state luminescence concepts (use of the emission band shapes and positions, emission intensity and intensity ratios, use of the materials with a single- or multi- emission centers) and concepts based on the temporal changes in emission (emission decay- and rise-times). The most important quantities used to characterize the performance of a measurements (such as temperature sensitivities, temperature and spatial resolution, measurement ranges) will be explained and compared between different measurements modalities as well as between different classes of materials utilized as temperature probes. Finally, several designs of temperature sensing by luminescence in a different application fields will be highlighted.