Construction of Novel Luminescent Thermometers Using Single-Doped Phosphors with Color-Tuning Properties

Optical thermometry based on fluorescence intensity ratio (FIR) technology has several advantages such as remote signaling, non-invasiveness, and excellent spatial resolution. These qualities are needed in industrial and medical applications. Here, we prepared luminescent thermometers by single doping of rare earth (RE) elements (e.g., samarium (Sm3+) or europium (Eu3+)) into Ca2Y0.97Bi0.03SbO6 (CYBS) phosphors via high-temperature solid-state reactions. Tuning of the CYBS:Eu3+ and CYBS:Sm3+ ratios in the phosphors provided a wide range of color changes from purplish blue to red and from purplish blue to pink, respectively. The higher values of absolute sensitivity (Sa) and relative sensitivity (Sr) resulted in better optical thermometry performance. Both phosphors exhibit excellent temperature sensing with Sa/Sr values (at 483 K) of 4.945×10-2/0.968×10-2 K-1 (CYBS:0.05Eu3+) and 2.964×10-2/0.864×10-2 K-1 (CYBS:0.05Sm3+). Thus, RE doped CYBS materials with color tuning properties and superior temperature sensing performance are recommended for the construction of novel luminescent optical thermometers