Effects of Li co-doping on the luminescence properties of Lu0.8Sc0.2BO3:Ce polycrystals

In this paper, monovalent cation Li1+ co-doped Lu0.79−xSc0.2Ce0.01LixBO3 (x = 0, 0.005, 0.01, 0.03, 0.05) polycrystal samples were prepared and a series of methods (such as X-ray excited luminescence, diffuse reflectance, fluorescence decay, X-ray Absorption Near Edge Structure (XANES), thermoluminescence, photoluminescence emission and excitation spectra) was used to comprehensively investigate its co-doping effects. It was found that Li co-doping may play a negative role: introducing more point defects and additional color centers (such as Ce4+ and oxygen vacancy). Furthermore, the increase in the number of traps in the vicinity of luminescence center Ce3+ ions will induce the competition absorption of excitation energy with the luminescence centers, and hence deteriorate the luminescence properties.

► Li1+ co-doping does not change the luminescence mechanism of Lu0.79Sc0.2Ce0.01BO3.
► Part of Ce3+ in Li1+ co-doping Lu0.79Sc0.2Ce0.01BO3 samples has been converted to higher valance ion Ce4+.
► Li1+ co-doping deteriorates the luminescence properties of Lu0.79Sc0.2Ce0.01BO3.