Structural and luminescence properties of persistent Sm(III) activated Ba3MgSi2O8 phosphors for lighting application
摘要
In this communications, Ba3MgSi2O8:xSm3+ (x = 0.5, 1.0, 2.0, 3.0 and 4.0 mol%) phosphors were prepared by solid phase reaction technique. Examined and discussed their structural phases, luminescence characteristics, and the mechanics of energy transfer via X-ray diffraction (XRD) and fluorescence spectroscopy. Notably, the sample with a 2.0% concentration of Sm doping showcased the highest emission intensity in PL measurements. This particular sample exhibited PL emission in the yellow-orange-red spectrum, escorted by peaks specifically as to at 565 nm, 601 nm, and 647 nm, each linked with distinct transitions among Sm3+ ion energy levels. The 565 nm emission peak is tied to the transition 4G5/2 → 6H5/2, span of the 601 nm and 647 nm peaks rebus the result of transitions 4G5/2 → 6H7/2 and 4G5/2 → 6H9/2, respectively. These have being observed under various excitation wavelengths ranging from the UV to the visible spectrum at 345 nm, 364 nm, 376 nm, 406 nm, 420 nm, 439 nm, 470 nm, and 557 nm, corresponding to sequential transitions in Sm3+ ions such as from 4G5/2 to various excited states. Additionally, the investigation into thermoluminescence (TL) revealed that the Sm3+ doped phosphors exhibited two distinct TL intense peaks, with primary one at 71 °C and secondary one at 160 °C. Among these, the sample with 2.0% Sm doping demonstrated the most intense TL response, remaining detectable after 70 min of UV exposure.