Dual-emission center ratiometric optical thermometer based on Bi(3+) and Mn(4+) co-doped SrGd(2)Al(2)O(7) phosphor

In recent years, more and more attention has been paid to optical temperature sensing, and how to improve its accuracy is the most important issue. Herein, a new temperature sensing material, SrGd(2)Al(2)O(7):Bi(3+),Mn(4+), based on fluorescence intensity ratio was designed in this work. It has both blue-purple and red luminescence under 300 nm excitation, and the dual-emitting centers with distinct colors, the different thermal sensitivities of Bi(3+) and Mn(4+), and the energy transfer between Bi(3+) and Mn(4+) give it excellent signal resolution and accurate temperature detection. The S(a) of SrGd(2)Al(2)O(7):0.04Bi(3+),0.003Mn(4+) phosphor reaches a maximum value of 8.573% K(−1) at 473 K, and the corresponding S(r) is 1.927% K(−1), both of which are significantly better than those of most other reported optical temperature sensing materials. Taking all the results into account, the SrGd(2)Al(2)O(7):0.04Bi(3+),0.003Mn(4+) phosphor can be regarded as a prominent FIR-type temperature sensing material.