title: Tunable luminescence properties and energy transfer in LaAl₁₁O₁₈:Eu,Tb phosphor.
abstract: Eu(2+) and Tb(3+) singly doped and co-doped LaAl11O18 phosphors were prepared by a combustion method using urea as a fuel. The phase structure and photoluminescence (PL) properties of the prepared phosphors were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence excitation and emission spectra. When the content of Eu(2+) was fixed at 0.01, the emission chromaticity coordinates could be adjusted from blue to green region by tuning the contents of Tb(3+) ions from 0.01 to 0.03 through an energy transfer (ET) process. The fluorescence data collected from the samples with different contents of Tb(3+) into LaAl11O18: Eu, show the enhanced green emission at 545 nm associated with (5)D(4)-(7)F(5) transitions of Tb(3+). The enhancement was attributed to ET from Eu(2+) to Tb(3+), and therefore Eu(2+) ion acts as a sensitizer (an energy donor) while Tb(3+) ion as an activator. The ET from Eu(2+) to Tb(3+) is performed through dipole-dipole interaction. The ET efficiency and critical distance were also calculated. The present Eu(2+)-Tb(3+) co-doped LaAl11O18 phosphor will have potential application for UV convertible white light-emitting diodes.
authors.affiliation: Department of Physics, Kamla Nehru Mahavidyalaya, Nagpur, 440009, India.
authors.forename: M S
authors.initials: MS
authors.lastname: Mendhe
authors.affiliation: Department of Physics, Kamla Nehru Mahavidyalaya, Nagpur, 440009, India.
authors.forename: S P
authors.initials: SP
authors.lastname: Puppalwar
authors.affiliation: Department of Physics, RTM Nagpur University, Nagpur, 440033, India.
authors.forename: S J
authors.initials: SJ
authors.lastname: Dhoble
mesh_terms: D000535:Aluminum / Q000737:chemistry*; D004735:Energy Transfer; D005063:Europium / Q000737:chemistry*; D007811:Lanthanum / Q000737:chemistry*; D049449:Luminescence; D010100:Oxygen / Q000737:chemistry*; D013725:Terbium / Q000737:chemistry*
chemical_list: D013725:Terbium; D005063:Europium; D007811:Lanthanum; D000535:Aluminum; D010100:Oxygen
keywords: LaAl11O18: Eu2+, Tb3+; SEM; XRD; energy transfer; photoluminescence