Energy Transfer in Sm3+/Eu3+ Doped Li6Gd(BO3)3 Orange-Red Phosphor

Sm3+ and Sm3+/Eu3+ doped Li6Gd(BO3)3 (LGBO) powders were prepared by solid-state reaction. The micro-structure, luminescent characteristics, energy transfer and fluorescence lifetimes were studied. Gd3+ can absorb energy and transfer it to Sm3+ under 278 nm excitation, which increases the luminescent intensity of Sm3+ at 567, 611 and 649 nm. Under 405 nm excitation, the 4G5/2 -6H5/2 transition belonging to Sm3+ and the 5D0 -7F2 transition belonging to Eu3+ appear in the emission spectra of Sm3+/Eu3+ co-doped LGBO phosphors, glowing yellow-orange and red light, respectively. The mechanism behind the energy transfer was analyzed, and the energy transfer efficiency was calculated to be 31.2% when the Sm3+ concentration reached 4mol%. The LGBO: Sm3+/Eu3+ phosphors have prospective applications in solid-state lighting, display devices, bio-imaging, etc.