Multifunctional Optical Thermometry Based on La2MgSnO6:Mn4+, M (M=Bi3+, Sm3+) double perovskite phosphors

To develop novel luminescent materials for optical thermometry, a series of La 2 MgSnO 6 :Mn 4+ , M (M=Bi 3+ , Sm 3+ ) phosphors were prepared by the solid-state method. Upon UV excitation, the La 2 MgSnO 6 : Mn 4+ sample demonstrates strong red emission originating from the 2 E g → 4 A 2g transition of Mn 4+ . By co-doping with Bi 3+ or Sm 3+ , it becomes possible to achieve tunable emission in La 2 MgSnO 6 phosphors. Due to the different thermal quenching behavior between the Mn 4+ and Bi 3+ or Sm 3+ , a high-sensitivity thermometric was developed using the fluorescence intensity ratio mode. The maximum sensitivity was obtained to 1.5%K -1 at 473K. The emission spectra of La 2 MgSnO 6 : Mn 4+ , M (M=Bi 3+ , Sm 3+ ) phosphor significantly coincide with the absorption spectra of plant pigments in the blue and red regions. These findings indicate that the as-prepared La 2 MgSnO 6 : Mn 4+ , M (M=Bi 3+ , Sm 3+ ) phosphors are promising candidate materials for plant cultivation and high-temperature optical thermometry.