Efficient Resonant Energy Transfer in (Ce3+, Tb3+)-Codoped CaCO3 Green Phosphor

作者：Nara Jun ichi^*; Adachi Sadao

来源：ECS Journal of Solid State Science and Technology, 2013, 2(7): R135-R141.

DOI：10.1149/2.016307jss

Ce3+, Tb3+)-codoped CaCO3 phosphor was synthesized by the coprecipitation method. The synthesized phosphor was investigated using scanning electron microscopy, X-ray diffraction analysis, photoluminescence (PL) analysis, PL excitation spectroscopy, diffuse reflectance, and luminescent decay measurements. The singly doped CaCO3:Tb3+ phosphor showed seven emission peaks at similar to 489-679 nm among which the green emission peak at similar to 543 nm was the strongest. The CaCO3: Ce3+, Tb3+ codoped phosphor also showed seven emission peaks, but at about 200 times larger intensities. This enhancement in the PL intensities of the codoped sample was attributed to an efficient resonant energy transfer from Ce3+ to Tb3+. The luminescent decay times were also determined to be similar to 30 ns (Ce3+ emission) and similar to 1 - 2 ms (Tb3+ emission), independent of the Ce3+ concentration from 0 to 10 mol% with Tb3+ of 0.17 mol%. The temperature dependence of the Tb3+ emission intensities yielded quenching energies of similar to 40 meV and similar to 0.35 eV in the lower and higher temperature regions, respectively. The proposed electronic energy-level diagrams for Ce3+ and Tb3+ in the CaCO3 host may help a better understanding of the photoluminescent properties of this phosphor.

• 出版日期2013