title: Structural and luminescence properties of Y(2-x)GeMoO8:REx (RE = Eu, Tb) phosphors.
abstract: Y(2-x)GeMoO8:REx (RE = Eu, Tb) phosphors were synthesized using a facile sol-gel method. The morphology and structure of the phosphors were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD); while their luminescent properties were investigated by photoluminescence (PL) spectrometry. Our results reveal that all of these Y(2-x)GeMoO8:REx (RE = Eu, Tb) phosphors adopted the tetragonal phase, belonging to Scheelite (CaWO4 ) structure. The obtained YGeMoO8:Eu phosphors exhibit a strong emission in the red light range which can be assigned to the (5)D0  → (7)F2 transition of Eu(3+) when it is excited at 459 nm. Under 392 and 489 nm excitation, the YGeMoO8:Tb phosphors present predominant green emission ((5)D4  → (7)F5) at 540 nm. The highest emission of the phosphors can be achieved by adjusting the doping concentration to be 0.25 for Eu(3+) and 0.15 for Tb(3+), respectively. The promising luminescence properties of these materials indicate that they can be potentially applied to white-light-emitting diodes.
authors.affiliation: School of Chemistry and Chemical Engineering, Southeast University, Nanjing, Jiangsu, 211189, People's Republic of China.
authors.forename: Naixu
authors.initials: N
authors.lastname: Li
authors.forename: Jiancheng
authors.initials: J
authors.lastname: Zhou
authors.forename: Yueming
authors.initials: Y
authors.lastname: Sun
mesh_terms: D005063:Europium / Q000737:chemistry; D049449:Luminescence; D049408:Luminescent Agents / Q000138:chemical synthesis / Q000737:chemistry*; D008163:Luminescent Measurements; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D013050:Spectrometry, Fluorescence; D013725:Terbium / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D049408:Luminescent Agents; D013725:Terbium; D005063:Europium
keywords: optical properties; phosphor; photoluminescence