Novel transparent glass-ceramics of NaLu2F7:Yb3+, Er3+ for accurate temperature sensing and anti-counterfeiting.

The development of up-conversion materials with strong emission and low thermal effect is crucial for achieving higher temperature sensing accuracy. In this work, novel transparent NaLu 2 F 7 : x Yb3+, 0.02Er3+ (x = 0, 0.2, 0.4, 0.6, 0.8, 1) glass-ceramics (GCs) were manufactured by melt-quenching technique. The temperature sensing capabilities of GC20 based on thermally coupled energy levels (TCELs) and non-thermally coupled energy levels (nTCELs) were studied, which enable self-calibration. Our findings reveal that the maximum relative sensitivity (S Rmax) of TCELs and nTCELs are 1.19% K−1 and 0.89% K−1 at 313 K, respectively. More importantly, the UC luminescence color of GC20 varies from yellow to green as the excitation power increases. The unique phenomenon can be utilized for anti-counterfeiting purposes without any background interference. Overall, our results demonstrate that these novel GCs possess significant potential in accurate temperature sensing and anti-counterfeiting fields. • The transparent NaLu 2 F 7 :Yb3+, Er3+ glass-ceramics are successfully elaborated. • The self-calibration temperature sensing based on TCELs and nTCELs is achieved. • Heating effect is erased by optimizing concentration of Yb3+ and excitation power. • By varying excitation power of 980 nm laser, tunable emission can be achieved. [ABSTRACT FROM AUTHOR]