Synergistic luminescent thermometer and indoor plant growth lighting utilizing Mg2LaSbO6:Eu3+/Mn4+ phosphor

The development of non-contact temperature sensors has attracted much attention, and high sensitivity is the difficulty to overcome. A new type of red phosphor, Mg2LaSbO6:Eu3+,Mn4+ (MLSO:Eu3+,Mn4+), was synthesized by the solid phase reaction method. The effect of different Eu3+ concentrations on its luminescence was discussed, and its temperature-sensitive properties were studied. The results indicate that Eu3+ and Mn4+ successfully entered the matrix lattice, causing slight distortion of the crystal structure of the phosphor MLSO:Eu3+,Mn4+. The emission spectrum of the phosphor MLSO:Eu3+,Mn4+ consists of sharp emission peaks of Eu3+ (560-640 nm) and broadband emission peaks of Mn4+ (640-800 nm). The experimental results show that the red light emission (612 nm) intensity of Eu3+ and the deep red light emission (695 nm) intensity of Mn4+ in the phosphor MLSO:Eu3+,Mn4+ are temperature dependent. Therefore, using the Fluorescence Intensity Ratio (FIR) technique, temperature fluorescence testing was conducted on the phosphor MLSO:0.02Eu3+,0.002Mn4+ to achieve visible light temperature measurement. The maximum relative sensitivity (Sr) was calculated to be 3.97% K-1 (@440 K), and the maximum sensitivity (Sa) was 0.17 K-1 (@400 K). Meanwhile, the electroluminescence spectra of LED devices prepared using the phosphor MLSO:0.06Eu3+,0.002Mn4+ were consistent with the absorption spectra of chlorophyll (A and B) and photosensitizers (Pr and Pfr) required for plant growth. It shows that the phosphor MLSO:Eu3+,Mn4+ can be used in the field of optical temperature measurement and indoor plant growth lighting.