title: Structural and optical properties of Eu3+, Sm3+ co-doped La(OH)3 nano-crystalline red emitting phosphor.
abstract: We report Eu3+, Sm3+ co-doped La(OH)3 nano-crystalline red emitting phosphor prepared following combustion synthesis protocol. The structural and morphological information about the synthesized samples have been explored using X-ray diffraction (XRD) and transmission electron microscopic (TEM) techniques. The optical properties of the samples have been investigated under 355 nm laser excitations. The sample emits intense red emissions at 625 and 707 nm due to 5D0→7F2 and 5D0→7F4 transitions in Eu3+ ion, respectively. The concentrations of both, Eu3+ and Sm3+ in the samples were optimized at 1 mol% to get maximum fluorescence. The presence of Sm3+ in the Eu3+ doped sample enhances the emission intensity up to two times. The samples annealed at higher temperature show significant enhancement in the emission intensity. The life time studies show an efficient energy transfer from Sm3+ to Eu3+ ions and have been discussed with the help of schematic energy level diagram. This enhancement in the emission intensity is discussed in terms of the rare earth ion concentration, annealing temperature and energy transfer.
authors.affiliation: Laser & Spectroscopy Laboratory, Department of Physics, Banaras Hindu University, Varanasi 221 005, India.
authors.forename: R S
authors.initials: RS
authors.lastname: Yadav
authors.affiliation: Department of Physics, National Institute of Technology, Kurukshetra, Haryana 136 119, India.
authors.forename: Y
authors.initials: Y
authors.lastname: Dwivedi
authors.affiliation: Laser & Spectroscopy Laboratory, Department of Physics, Banaras Hindu University, Varanasi 221 005, India. Electronic address: sbrai49@yahoo.co.in.
authors.forename: S B
authors.initials: SB
authors.lastname: Rai
mesh_terms: D005063:Europium / Q000737:chemistry*; D007811:Lanthanum / Q000737:chemistry*; D007834:Lasers; D049449:Luminescence; D053758:Nanoparticles / Q000648:ultrastructure; D055620:Optical Phenomena; D012493:Samarium / Q000737:chemistry*; D013052:Spectrometry, X-Ray Emission; D013816:Thermodynamics; D014961:X-Ray Diffraction
chemical_list: C033562:lanthanum hydroxide; D012493:Samarium; D005063:Europium; D007811:Lanthanum
keywords: Efficient energy transfer; Nano-crystalline phosphor; Rare earth ions; Red emission