title: Quantum effect on the energy levels of Eu2+ doped K2Ca2(SO4)3 nanoparticles.
abstract: Quantum confinement effect on the energy levels of Eu(2+) doped K(2)Ca(2)(SO(4))(3) nanoparticles has been observed. The broad photoluminescence (PL) emission band of Eu(2+) doped K(2)Ca(2)(SO(4))(3) microcrystalline sample observed at ∼436 nm is found to split into two narrow well resolved bands, located at 422 and 445 nm in the nanostructure form of this material. This has been attributed to the reduction in the crystal field strength of the nanomaterials, which results in widening the energy band gap and splitting the broad 4f(6)5d energy level of Eu(2+). Energy band gap values of the micro and nanocrystalline K(2)Ca(2)(SO(4))(3) samples were also determined by measuring the UV-visible absorption spectra. These values are 3.34 and 3.44 eV for the micro and nanocrystalline samples, respectively. These remarkable results suggest that activators having wide emission bands might be subjected to weak crystal strength via nanostructure materials to modify their electronic transitions. This might prove a powerful technique for producing new-advanced materials for use in the fields of solid state lasers and optoelectronic devises.
authors.affiliation: Center of Nanotechnology, King Abdulaziz University, Jeddah, 21589, Saudi Arabia. nsalah@kau.edu.sa
authors.forename: Numan
authors.initials: N
authors.lastname: Salah
authors.forename: Sami S
authors.initials: SS
authors.lastname: Habib
authors.forename: Zishan H
authors.initials: ZH
authors.lastname: Khan
mesh_terms: D005063:Europium / Q000737:chemistry*; D007477:Ions / Q000737:chemistry*; D049449:Luminescence; D008422:Materials Testing; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D049329:Nanostructures / Q000737:chemistry; D010316:Particle Size; D011789:Quantum Theory; D013053:Spectrophotometry / Q000379:methods; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D014961:X-Ray Diffraction
chemical_list: D007477:Ions; D005063:Europium
references.citation: Immunol Lett. 2003 Dec 15;90(2-3):67-70
references.pmid: 14687705