Bi3+-based luminescent thermometry in perovskite-type CaZrO3 phosphor

Based on the luminescence of Bi3+, novel temperature sensing materials CaZrO3:Bi3+ and CaZrO3:Bi3+/Sm3+ were successfully synthesized by solid-state reaction. The XRD patterns show that the synthesized materials have a pure phase of CaZrO3. The XPS results show that the Bi3+ and Sm3+ can be detected in CaZrO3:Bi3+/Sm3+. With the excitation of 318 nm, the CaZrO3:Bi3+ material shows intense temperature-dependent luminescence. The maximum relative sensitivity can be obtained at 440 K (1.78% K−1). Under the excitation of 408 nm, the CaZrO3:Sm3+ material shows the characteristic emission peaks of Sm3+. The spectral overlap between the emission spectrum of Bi3+ and the excitation spectrum of Sm3+ leads to an energy transfer from Bi3+ to Sm3+ in CaZrO3:Bi3+/Sm3+ phosphor. With the excitation of 318 nm, the emission spectrum of CaZrO3:Bi3+/Sm3+ material shows the characteristic peaks of Bi3+ and Sm3+. The fluorescence decay curves also show the evidence of the energy transfer from Bi3+ to Sm3+. The luminescence intensity ratio of Sm3+ and Bi3+ in CaZrO3:Bi3+/Sm3+ shows obvious temperature dependence. Based on the luminescence intensity ratio, a large relative sensitivity is obtained at 443 K (1.15% K−1).