Self‐Calibrated Thermometer and Dynamic Anti‐Counterfeiting Based on YNbO₄:Pr³⁺ Luminescent Material

Abstract Phosphors with multifunctional applications have attracted extensive research, especially in thermometer and anti‐counterfeiting fields. Herein, a series of Pr³⁺‐doped YNbO₄ (YNO) phosphors with adjustable photoluminescence and red persistent luminescence (PersL) performances are developed. YNO host exhibits the blue self‐activated luminescence, and the different Pr³⁺ emission peaks possess various thermal stability properties due to the thermal quenching channel generated by the intervalence charge transfer state between Pr³⁺ and Nb⁵⁺ ions. Two kinds of fluorescence intensity ratio models with high absolute and relative sensitivities are realized to measure the temperature under dual‐wavelength excitation. Moreover, YNO:Pr³⁺ exhibits the red PersL with a duration of about 120 s upon ceasing the UV excitation light source. The fabricated YNO:Pr³⁺‐polydimethylsiloxane films display different luminescence patterns with the passage of time after turning off UV light, which can cleverly achieve dynamic conversion. These results demonstrate that YNO:Pr³⁺ phosphor has potential applications in dual‐wavelength excited thermometry and dynamic anti‐counterfeiting fields.