Near-field two-photon-induced photoluminescence from single gold nanorods and imaging of plasmon modes
Near-field two-photon-induced photoluminescence from single gold nanorods and imaging of plasmon modes
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DOI：
10.1021/jp051631o
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发表时间：
2005-07-14
影响因子：
3.3
通讯作者：
Okamoto, H
中科院分区：
文献类型：
--
作者：
Imura, K;Nagahara, T;Okamoto, H
利用扫描近场光谱研究了单根金纳米棒的双光子诱导光致发光特性。该过程被发现是由一个连续的单光子吸收，在sp和d带中产生一对电子和空穴。当费米面附近的电子与X和L对称点附近的空穴复合时，就会发出光致发光。从X和L区域发射的光子的偏振特性被发现是不同的。这些特性可以通过金纳米棒的晶体结构和能带结构来理解。我们发现特征空间振荡功能沿着长轴的纳米棒的光致发光激发图像。用绿色的并矢方法计算的纳米棒的态密度图很好地再现了图像，并归因于纳米棒内部等离子体激元模式的波函数的空间特性。
We investigated the two-photon-induced photoluminescence properties of single gold nanorods by scanning near-field spectroscopy. The process was found to be initiated by a sequential one-photon absorption for creating a pair of an electron and a hole in the sp and d bands. Photoluminescence is then radiated when the electron near the Fermi surface recombines with the hole near the X and L symmetry points. The polarization characteristics of emitted photons from the X and L regions were found to be different. These characteristics can be understood by the crystalline structure and the band structure of the gold nanorod. We found characteristic spatial oscillatory features along the long axis of the nanorods in photoluminescence excitation images. The images were well reproduced by density-of-states maps of the nanorods calculated with Green's dyadic method and were attributed to the spatial characteristics of the wave functions of the plasmon modes inside the nanorods.