关键词: Ca₂Sn_1-xCe_xO₄, Ce⁴⁺-O^2-, charge transfer, luminescent property

Abstract: Ce⁴⁺-doped Ca₂SnO$_{4}$ with a one-dimensional structure, which emits bright blue light, is prepared by using a solid-state reaction method. The x-ray diffraction results show that the Ce⁴⁺ ions doped in Ca$_{2}$SnO$_{4}$ occupy the Sn⁴⁺ sites. The excitation and emission spectra of Ca$_{2}$Sn$_{1-x}$Ce$_{x}$O$_{4}$ appear to have broad bands with peaks at $\sim$ 268 nm and $\sim$ 442 nm, respectively. A long excited-state lifetime ($\sim$ 83 $\mu$s) for the emission from Ca$_{2}$Sn$_{1-x}$Ce$_{x}$O$_{4}$ suggests that the luminescence originates from a ligand-to-metal Ce⁴⁺ charge transfer (CT). The luminescent properties of Ca$_{2}$Sn$_{1 - x}$Ce$_{x}$O$_{4}$ have been compared with those of Sr$_{2}$CeO$_{4}$, which is the only material reported so far to show Ce$^{4 + }$ CT luminescence. More interestingly, it is observed that the emission intensity of Ca$_{2}$Sn$_{1 - x}$Ce$_{x}$O$_{4}$ with a small doping concentration (x $\sim$ 0.03) is comparable to that of Sr$_{2}$CeO$_{4}$ in which the concentration of active centre is 100%.

Key words: Ca₂Sn_1-xCe_xO₄, Ce⁴⁺-O^2-, charge transfer, luminescent property