Assessing thermometric performance of Sr2CeO4 and Sr2CeO4:Ln3+ (Ln3+ = Sm3+, Ho3+, Nd3+, Yb3+) nanocrystals in spectral and temporal domain

Abstract

Luminescent thermometry is rapidly growing experimental technique of thermal sensing, which provides the temperature detection in real time and contactless way. To address existing challenges of accurate temperature measurement, we developed and investigated new Sr2CeO4 nanocrystalline inorganic dual luminescence temperature sensors and optimized their temperature sensitivity and temperature operating range by introducing lanthanide co-dopants (Ln3+ = Ho3+, Yb3+, Nd3+, Sm3+) to luminescent Ce3+ ions in . Both, spectral and temporal temperature susceptibility of newly developed sensors, have been demonstrated and evaluated. In general, lanthanide doping leads to the shortening of luminescent decay time owing to enhanced thermal quenching rate. Among all Ln3+ ions studied here, the employment of Yb3+ ions provides the widest temperature range and highest relative temperature sensitivities, both, based on luminescence lifetime and ratiometric luminescence operating principles (2.80%/oC at −45 °C). However, for temperatures above 50 °C, the Sr2CeO4:Ho3+ ratiometric luminescent thermometer is proven to perform better, which exhibited relative sensitivities above 1%/oC. The advantage of using Ho3+ and Sm3+ doped Sr2CeO4 nanocrystalline luminescent thermometers is the fact, their visible emission colour is responsive to temperature changes, which enables naked-eye qualitative evaluation as well. It is worth noticing, to the best of our knowledge this works reports the highest relative sensitivity for Ln4+ based luminescent thermometers.