Bai Xue, Song Hongwei, Yu Lixin, Yang Linmei, Liu Zhongxin, Pan Guohui, Lu Shaozhe, Ren Xingguang, Lei Yanqiang, Fan Libo
Key Laboratory of Excited State Physics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 16 Eastern Nan-Hu Road, Changchun 130033, P.R. China.
J Phys Chem B. 2005 Aug 18;109(32):15236-42. doi: 10.1021/jp050652f.
One-dimensional pure cubic Y(2)O(3)/Eu(3+) nanocrystals (NCs) were synthesized by a hydrothermal method at various temperatures. The NCs prepared at 130 degrees C yielded nanotubes (NTs) with wall thickness of 5-10 nm and outer diameter of 20-40 nm. The NCs prepared at 170 and 180 degrees C yielded nanowires (NWs) with diameters of approximately 100 and approximately 300 nm, respectively. Their luminescent properties, including electronic transition processes, local environments surrounding Eu(3+) ions, electron-phonon coupling, and UV light irradiation induced spectral changes have been systematically studied and compared. The results indicate that the Y(2)O(3)/Eu(3+) NTs and NWs have strong red (5)D(0)-(7)F(2) transitions. The fluorescence lifetime of (5)D(1)-(7)F(1) hardly changes in different samples, while that of (5)D(0)-(7)F(2) decreases a small amount in Y(2)O(3)/Eu(3+) NTs. The (5)D(0)-(7)F(2) lines originate from the emissions of Eu(3+) ions occupying one C(2) site, like that in the bulk powders. The phonon sideline with a frequency shift of 40-50 cm(-1) appears at the low-energy side of the (7)F(0)-(5)D(0) zero phonon line. The relative intensity of the sideline to zero phonon line increases by varying from NTs to NWs, and the spectral position of the phonon sideline shifts red. The UV light irradiation induced spectral change in the charge-transfer band was studied. The results indicate that the spectral change is dependent on sample size and is wavelength selective. A detailed model was proposed to explain the light-induced spectral change.
通过水热法在不同温度下合成了一维纯立方Y(2)O(3)/Eu(3+)纳米晶体（NCs）。在130℃制备的NCs生成了壁厚为5-10nm、外径为20-40nm的纳米管（NTs）。在170℃和180℃制备的NCs分别生成了直径约为100nm和约300nm的纳米线（NWs）。对它们的发光特性进行了系统研究和比较，包括电子跃迁过程、Eu(3+)离子周围的局部环境、电子-声子耦合以及紫外光照射引起的光谱变化。结果表明，Y(2)O(3)/Eu(3+)NTs和NWs具有强烈的红色(5)D(0)-(7)F(2)跃迁。(5)D(1)-(7)F(1)的荧光寿命在不同样品中几乎不变，而(5)D(0)-(7)F(2)的荧光寿命在Y(2)O(3)/Eu(3+)NTs中略有下降。(5)D(0)-(7)F(2)谱线源于占据一个C(2)位点的Eu(3+)离子的发射，与体相粉末中的情况类似。在(7)F(0)-(5)D(0)零声子线的低能侧出现了频率偏移为40-50cm(-1)的声子伴线。伴线与零声子线的相对强度从NTs到NWs逐渐增加，且声子伴线的光谱位置向红移。研究了紫外光照射引起的电荷转移带光谱变化。结果表明，光谱变化取决于样品尺寸且具有波长选择性。提出了一个详细的模型来解释光致光谱变化。
