Photoluminescence origin and non-contact thermometric properties in Pb2+-activated CaZrO3 perovskite phosphor

Based on high temperature solid state technique, a series of Pb2+/Sm3+ doped CaZrO3 perovskite phosphors have been successfully synthesized. Comparing with CaZrO3 host, the absorption edge of CaZrO3:x%Pb2+ samples exhibits a red shift with the increase of Pb2+ ions doping concentration. Analysis shows that the red shift of absorption edge can be attributed to the 1P1 level of Pb2+ ions which is just below the bottom of conduction band. By comparing the absorption and excitation spectra of CaZrO3:x%Pb2+ samples, it is found that the excitation band at 286 nm should be composed of two parts, MMCT and 1S0→3P1 transitions, respectively. The normalized excitation and emission spectra of CaZrO3:x%Pb2+ samples also confirm that the excitation band at 286 nm should be composed of MMCT and 1S0→3P1 transitions, and the emission band at 370 nm should come from the 3P1→1S0 transition. Based on the analysis of the absorption and excitation spectrum of CaZrO3:Sm3+, it indicates that the excitation band of CaZrO3:Sm3+ sample at 231 nm should be the O2--Sm3+ charge transfer state. In addition, the characterization of the temperature sensing properties demonstrates that the relative sensitivities of CaZrO3:Pb2+ and CaZrO3:Pb2+/Sm3+ samples have high stability. In the temperature range of 303–443 K, the relative sensitivity for CaZrO3:Pb2+ and CaZrO3:Pb2+/Sm3+ materials is in the range of 1.03%−1.32% K−1 and 0.89%−1.13% K−1, respectively. Therefore, the CaZrO3:Pb2+/Sm3+ material has great potential and application value in temperature sensing.