Open AccessInvestigation of the charge-transfer spectra of Ce4+-doped Ca2SnO4 with one-dimensional structure
Author(s) -
Fu Shi-Liu,
Fei Chai,
Jie Chen,
Zhang Han-Yan
Publication year - 2008
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
ISSN - 1000-3290
DOI - 10.7498/aps.57.3254
Subject(s) - phosphor , excitation , ion , octahedron , doping , materials science , luminescence , spectral line , analytical chemistry (journal) , x ray photoelectron spectroscopy , atomic physics , physics , chemistry , nuclear magnetic resonance , optoelectronics , chromatography , quantum mechanics , astronomy
Ca2Sn1-xCexO4 and Ca2-ySrySn1-xCexO4 with one-dimensional structures were prepared by the solid-state reaction method. The X-ray photoelectron spectra of Ce4+-doped Ca2SnO4 showed the existence of two oxidation states of O2- ions with binding energy peaks at 5277 eV and 5293 eV. The former corresponds to the terminal O2- ions in the SnO6 octahedra while the latter corresponds to the equatorial O2- ions of the octahedra. The luminescence from Sr2CeO4 and Ca2Sn1-xCexO4 phosphors with one-dimensional structures originates from a ligand-to-metal Ce4+ charge transfer (CT) and it is generally accepted that there exist two excitation peaks in the ultraviolet excitation band. However, it was found from the Ca2-ySrySn1-xCexO4 sample that the excitation band of Ca2Sn1-xCexO4 was actually comprised of three excitation peaks which were centered at about 31000, 34500 and 37400cm-1. When Sr2+ ions were doped in Ca2Sn1-xCexO4, three excitation components peaking at about 31200, 34700 and 38400cm-1 were observed apparently, whose locations exhibited a blue shift as compared with those of Ca2Sn1-xCexO4. However, the substitution of Ca2+ by Sr2+ had no influence on the shape of the emission spectrum. The excitation spectrum of Sr2CeO4 can also be deconvoluted into three Gassian components which are centered at about 29300, 33400 and 37000cm-1, respectively.