Luminescence properties of Eu3+ ions doped in novel host materials Sr9R(PO4)7 (R = In, Ga)

Novel Sr 9 R(PO 4 ) 7 (R = In, Ga) host materials for Eu 3+ - doped phosphors were synthesized by a high-temperature solid-state reaction method. The crystal structure, luminescence properties and thermal stability of the phosphors were explored. The phase analysis indicated that the phosphors crystallized in monoclinic structure, the emission spectra of both In and Ga containing phosphors were mainly composed of two sharp peaks centered at about 591 and 617 nm, corresponding to the 5 D 0 → 7 F 1 and 5 D 0 → 7 F 2 transitions of Eu 3+ ions. While, the relative emission and excitation intensities of Sr 9 In(PO 4 ) 7 : Eu 3+ were weaker than Sr 9 Ga(PO 4 ) 7 : Eu 3+ . Moreover, the energy transfer mechanism among Eu 3+ ions in the phosphors depended upon energy transfer among the nearest-neighbor ions described by the Dexter theory. The selected Sr 9 In(PO 4 ) 7 : 0.06Eu 3+ and Sr 9 Ga(PO 4 ) 7 : 0.06Eu 3+ exhibited high thermal stability and the chromaticity coordinate of the phosphors were located in the red-orange light region.