Self-calibrated optical thermometer based on luminescence from SrLu 2 O 4 :Bi 3+ ,Eu 3+ phosphors.

Bi 3+ ,Eu 3+ co-doped SrLu 2 O 4 phosphors were synthesized by a solid state reaction method. Their structural, luminescent and temperature sensing properties have been systematically investigated. The color-tunable emissions from violet to red were detected with the increase of Eu 3+ concentration. Relying on energy transfer process from Bi 3+ to Eu 3+ and thermal quenching behaviour, the fluorescence intensity ratio (FIR) presents excellent temperature sensing performance. The maximum absolute and relative sensitivities reach 1.10% K -1 and 0.87% K -1 , respectively. These meaningful results indicate that SrLu 2 O 4 :Bi 3+ ,Eu 3+ is a promising material for optical temperature sensing.