High-efficiency energy transfer in the strong orange-red-emitting phosphor CeO(2):Sm(3+), Eu(3+)

High-efficiency energy transfer (ET) from Sm(3+) to Eu(3+) leads to dominant red emission in Sm(3+), Eu(3+) co-doped single-phase cubic CeO(2) phosphors. In this work, a series of Sm(3+) singly and Sm(3+)/Eu(3+) co-doped CeO(2) cubic phosphors was successfully synthesized by solution combustion followed by heat treatment at 800 °C in air. The crystal structure, morphology, chemical element composition, and luminescence properties of the obtained phosphors were investigated using X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and photoluminescence analysis. Under 360 nm excitation, the Sm(3+) singly doped CeO(2) phosphor emitted strong yellow-red light at 573 nm ((4)G(5/2)–(6)H(5/2)) and 615 nm ((4)G(5/2)–(6)H(7/2)). Meanwhile, the CeO(2):Sm(3+), Eu(3+) phosphors showed the emission characteristic of both Sm(3+) and Eu(3+), with the highest emission intensity at 631 nm. The emission intensity of Sm(3+) decreased with increasing Eu(3+) content, suggesting the ET from Sm(3+) to Eu(3+) in the CeO(2):Sm(3+), Eu(3+) phosphors. The decay kinetics of the (4)G(5/2)–(6)H(5/2) transition of Sm(3+) in the CeO(2):Sm(3+), Eu(3+) phosphors were investigated, confirming the high-efficiency ET from Sm(3+) to Eu(3+) (reached 84%). The critical distance of energy transfer (R(C) = 13.7 Å) and the Dexter theory analysis confirmed the ET mechanism corresponding to the quadrupole–quadrupole interaction. These results indicate that the high-efficiency ET from Sm(3+) to Eu(3+) in CeO(2):Sm(3+), Eu(3+) phosphors is an excellent strategy to improve the emission efficiency of Eu(3+).