Highly Sensitive Optical Thermometry of Yb3+-Er3+ Codoped AgLa(MoO4)2 Green Upconversion Phosphor

Er3+-Yb3+ codoped AgLa(MoO4)(2) phosphors with intense green emission from H-2(11/2)/S-4(3/2) I-4(15/2) transitions and negligible red emission from F-4(9/2) I-4(15/2) transition of Er3+ were synthesized by sol-gel process. Its temperature sensing performance was evaluated based on the temperature dependence of fluorescence intensity ratio (FIR) of two green emission bands in the range 300-510K. The maximum sensitivity of AgLa(MoO4)(2): 0.02Er(3+)/0.4Yb(3+) is approximately 0.018K(-1) at 480K, which is much higher than those of reported samples based on green emissions of Er3+. Result suggests that AgLa(MoO4)(2): Er3+/Yb3+ has a great potential application in optical temperature sensors.