Anti-Counterfeiting Application and Temperature Sensing Characteristics of SrBi 4 Ti 4 O 15 :Yb 3+ /Er 3+ Phosphor Designed by Solid State Method For Dual-Mode Upconversion Luminescence

Rare earth ion-doped upconversion luminescent materials have found extensive utility in anti-counterfeiting applications. However, in practice, single-mode photoluminescence falls short of addressing increasingly intricate demands of contemporary anti-counterfeiting measures. This work presents successfully synthesized dual-mode excited SrBi 4 Ti 4 O 15 upconversion phosphor doped with Yb 3+ /Er 3+ , designed to emit two distinctive colors, green and red under excitation at either 980 or 1550 nm. Introduction of the multi-color emission significantly enhances the security of anti-counterfeiting strategies in a variety of modes. A comprehensive investigation is conducted into potential upconversion mechanisms driven by different excitation sources, examining both 980 and 1550 nm wavelengths. Anti-counterfeiting properties are evaluated for synthesized phosphor by gauging the luminous intensity ratio between red and green light. Research findings unequivocally point to the immense potential of SrBi 4 Ti 4 O 15 upconversion phosphor doped with Yb 3+ /Er 3+ for robust multimode anti-counterfeiting applications, representing a promising development in this field.