Exploiting intervalence charge-transfer engineering to finely control (Ba, Sr)TiO3:Pr3+ luminescence thermometers

Most recently, it has been demonstrated that the use of 3P0–3H4/1D2-3H4 intensity ratio of Pr3+ transitions is potentially beneficial to luminescence thermometry. In this study, a study is conducted of (Ba1-xSrx)TiO3:0.5%:Pr3+ phosphors following Sr2+ concentrations range (x = 0–0.5) in terms of luminescence thermometry. Besides, an investigation is carried out into thermoluminescence properties, based on which a discussion is conducted about the potential mechanisms behind the experimental results. It is discovered from Pr3+-Ti4+ that the highly efficient thermometric characteristics contribute significantly to the intervalence charge transfer state. Furthermore, through intervalence charge-transfer engineering, the effective management of their thermometric properties is made achievable due to the Ba2+ substitution by Sr2+, which makes the range of the highest relative sensitivity controllable. In the meantime, the maximal relative temperature sensitivity of Pr3+-doped BaTiO3 reaches up to 2.77% K−1 at 371 K as measured. This is expected to shed light on the design of one optical thermometer calibrated itself, exhibiting great performance.