Synthesis of Sm3+ doped SrAl2Si2O8 phosphors and improved emission intensity by Li+ doping

Sr0.95Al2Si2O8:0.05Sm(3+) and Sr0.95-xAl2Si2O8:0.05Sm(3+)/xLi(+) phosphors were synthesized by a solid-state reaction. The phase, crystal structure and luminescent properties of the synthesized phosphors were investigated. All of the synthesized phosphors have a single phase, indicating that Sm3+ and Li+ ions have doped into the SrAl2Si2O8 hosts and formed solid solutions. Under the excitation at 405 nm, Sr0.95Al2Si2O8:0.05Sm(3+) and Sr0.95-xAl2Si2O8:0.05Sm(3+)/xLi(+) phosphors show emission bands resulting from the (4)G(5/2) -> H-6(5/2), (4)G(5/2) -> H-6(7/2), (4)G(5/2) -> H-6(9/2) and (4)G(5/2) -> H-6(11/2) transitions of Sm3+. The codoped Li+ ions could enhance the emission intensity of Sm3+. Sr0.9Al2Si2O8:0.05Sm(3+)/0.05Li(+) phosphor has a good thermal stability. The integral intensity at 225 A degrees C is about 65% of the initial intensity at 25 A degrees C.