title: NaYF4:Pr3+ nanocrystals displaying photon cascade emission.
abstract: The quantum-cutting process is observed in nanocrystalline fluoride (NaYF(4)) doped with Pr(3+). The thermal decomposition synthesis method was used to synthesize the NaYF(4) nanocrystals with an average size of 42 nm. The morphological high resolution transmission electron microscopy (HRTEM), structural X-ray diffraction (XRD) and spectroscopy, with the use of synchrotron radiation, have been employed to characterize the material. The different excitation energies created different luminescence response of the NaYF(4):Pr(3+) nanocrystals. The quantum-cutting phenomenon has been observed under the direct excitation of the 4f5d bands of praseodymium. After excitation of the NaYF(4) matrix this process is quenched and part of the energy is released through the self-trapped excitons emission. The origin of the different types of emission transitions has been analyzed in detail.
authors: Department of Physics, University of the Free State, Nelson Mandela Drive, (IB 51) PO Box 339, Bloemfontein, 9300, South Africa. marek.gusowski@wp.pl
authors: Marek A
authors: MA
authors: Gusowski
authors: Hendrik C
authors: HC
authors: Swart
authors: Lisa S
authors: LS
authors: Karlsson
authors: Monika
authors: M
authors: Trzebiatowska-Gusowska
mesh_terms: D003460:Crystallization / Q000379:methods*; D005459:Fluorides / Q000138:chemical synthesis*; D008027:Light; D049449:Luminescence; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D017785:Photons; D013499:Surface Properties; D015019:Yttrium
chemical_list: D046911:Macromolecular Substances; C525362:sodium yttriumtetrafluoride; D015019:Yttrium; D005459:Fluorides