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

Abstract

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 NaLu2F7:xYb3+, 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 (SRmax) 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.