纳米Gd_2O_3中两种格位Eu^(3+)的电荷迁移态激发跃迁

Charge Transfer Excitation of Eu^(3+) with Two-sites in Nanocrystal Gd_2O_3: Eu^(3+)

观测了粒径分别为15,23,135 nm的立方相Gd_2O_3:Eu^(3+)的选择激发光谱、发射光谱和激发光谱。受强量子限域效应的影响,纳米Gd_2O_3:Eu^(3+)的激发光谱的强度表现出对颗粒尺寸的明显依赖性。用Jorgensen公式计算电荷迁移带的位置,与实验测得激发光谱中位置相一致。通过电荷迁移带不同位置的选择激发光谱可以分辨出立方相Gd_2O_3:Eu^(3+)中C_2和S_6格位Eu^(3+)的发光,从选择激发的发射光谱和激发光谱结果计算出C_2和S_6格位电荷迁移带的激发光谱,与实验结果相符合。

This paper reports the site-selective excited emission, fluorescence and photoluminescence excitation spectroscopy of cubic Gd_2O_3: Eu^(3+) nanocrystals with diameters of 15, 23, 135 nm. The intensity distribution of pho- toluminescence spectra of Gd_2O_3: Eu^(3+) nanocrystal depends on the size of nanocrystal, as a result of strong quantum confinement effect. The position of charge transfer band (CTB) calculated by Jorgensen formula is consistent with the experiment results. The emission peaks of C_2 and S_6 sites Eu^(3+) in cubic Gd_2O_3: Eu^(3+) are dissolved by the site- selective spectra excited with wavelengths in the CTB. The photoluminescence excitation spectra of C_2 and S_6 sites Eu^(3+) CTB are worked out through the site-selective excitation spectra and photoluminescence excitation spectra. It agrees well with the experiment results.