Down-conversion luminescence and its temperature-sensing properties from Er~(3+)-doped sodium bismuth titanate ferroelectric thin films

摘要

Here, we demonstrate outstanding temperature-sensing properties from Na_(0.5)Bi_(0.49)Er_(0.01)TiO_3 (NBT:Er) thin films. The perovskite phase for them is stable in the temperature range from 80 to 440 K. Interestingly, the Er doping enhances the ferroelectric polarization and introduces local dipolar, which are positive for temperature sensing. Pumped by a 488-nm laser, the NBT:Er thin films show strong green luminescence with two bands around 525 and 548 nm. The intensity ratio Ⅰ_(525)/Ⅰ_(548) can be used for temperature sensing, and the maximum sensitivity is about 2.3 × 10~(-3) K~(-1) higher than that from Er-doped silicon oxide. These suggest NBT:Er thin film is a promising candidate for temperature sensor.