NIR luminescence thermometers based on Yb-Nd coordination compounds for the 83-393 K temperature range

Multimetallic neodymium-ytterbium-gadolinium compounds with 9-anthracenate and 9-acridinate anions were tested in order to create the first luminescent thermometer for elevated temperatures. High luminescence intensity and high signal resolution were reached thanks to the concentration quenching elimination due to the partial substitution of the emitting ions with Gd³⁺. As a result, NIR emitting materials for luminescence thermometry in the wide temperature range (83-393 K) based on lanthanide coordination compounds (CCs) were obtained. The best thermometric properties among the studied systems were demonstrated by Yb_0.02Nd_0.12Gd_0.86(ant)₃, and its temperature sensitivity reached 1.8% K^-1 in the temperature range of 293-393 K.