Enhanced thermal stability and charge transfer band redshift induced ratiometric thermometry of Sr2Al2SiO7:Sm3+/K+ phosphors

作者：Xiuying Tian, Shiyi Zhang, Qian Zhou, Jin Wen, Changyan Ji, Zhi Huang, Ling Zhu, Fei Luo, Xin Liu, Jing Li, Hongxia Peng, Shuying Zhou, Guowen Li, Hua‐Tay Lin · 发表于：Journal of Alloys and Compounds · 年份：2025 · DOI：10.1016/j.jallcom.2025.182656 · 被引用次数：6 · 研究领域：Luminescence Properties of Advanced Materials、Optical properties and cooling technologies in crystalline materials、Perovskite Materials and Applications

In this study, Sr 2 Al 2 SiO 7 : Sm 3+ and Sr 2 Al 2 SiO 7 : Sm 3+ /K + phosphors were synthesized via a high-temperature processing for remote temperature sensing applications. X-ray diffraction (XRD) analysis confirmed the tetragonal gehlenite structure of Sr 2 Al 2 SiO 7 with space group P 4 ̅ 2 1 m and the presence of impurity phases, which also confirmed the effective replacement of Sr 2+ by Sm 3+ in the crystal structure. Scanning electron microscopy (SEM) observations showed irregular grain morphology and severe particle agglomeration. The particle size distribution of the sample ranges from 5 to 95 μm, with the particles mainly concentrated around 22.54 μm. EDS mappings verified the presence of Sm 3+ and K + ions within the crystal structure. UV–vis diffuse reflection spectra and bandgap calculations indicated a reduced bandgap due to doping. PL and PLE spectra demonstrated concentration-dependent characteristics, with optimal concentrations of 0.03 for Sm 3+ and 0.04 for K + . Temperature-dependent PL and PLE measurements revealed enhanced the thermal stability and temperature sensitivity upon K + doping, with thermal stability improving from 86.015 % to 90.86 % at 423 K. The observed redshift in PLE spectra with increasing temperature was explained. Furthermore, the temperature-dependent redshift of CTB and the 6 H 5/2 → 4 F 7/2 transition were then effectively utilized for thermometry. The relative sensitivity reached 0.472 % K −1 at 473 K, showing competitive perf...