Tunable and highly sensitive fluorescent thermometers from La₂CaZrO₆:Cr³⁺ with a time-resolved technology

Non-contact optical temperature measurement can effectively avoid the disadvantages of traditional contact thermometry and thus, become a hot research topic. Herein, a fluorescence intensity ratio (FIR) thermometry using a time-resolved technique based on La₂CaZrO₆:Cr³⁺ (LCZO) is proposed, with a maximum relative sensitivity (Sr - FIR) of 2.56% K^-1 at 473 K and a minimum temperature resolution of 0.099 K. Moreover, the relative sensitivity and temperature resolution can be effectively controlled by adjusting the width of the time gate based on the time-resolved technique. Our work provides, to our knowledge, new viewpoints into the development of novel optical thermometers with adjustable relative sensitivity and temperature resolution on an as-needed basis.