Asymmetric Silver 鈥淣anocarrot鈥?Structures: Solution Synthesis and Their Asymmetric Plasmonic Resonances
详细信息 查看全文
- 作者：Hongyan Liang ; David Rossouw ; Haiguang Zhao ; Scott K. Cushing ; Honglong Shi ; Andreas Korinek ; Hongxing Xu ; Federico Rosei ; Wenzhong Wang ; Nianqiang Wu ; Gianluigi A. Botton ; Dongling Ma
- 刊名：The Journal of the American Chemical Society
- 出版年：2013
- 出版时间：July 3, 2013
- 年：2013
- 卷：135
- 期：26
- 页码：9616-9619
- 全文大小：254K
- 年卷期：v.135,no.26(July 3, 2013)
- ISSN：1520-5126
文摘
Here we report the wet-chemical synthesis of asymmetric one-dimensional (1D) silver 鈥渘anocarrot鈥?structures that exhibit mixed twins and stacking fault domains along the 111 direction. Oriented attachment is the dominant mechanism for anisotropic growth. Multipolar plasmon resonances up to fourth order were measured by optical extinction spectroscopy and electron energy-loss spectroscopy (EELS) and are in agreement with theoretical calculations. Compared with those of symmetric 1D nanostructures of similar length, the dipole modes of the nanocarrots show a clear red shift, and the EELS maps show an asymmetric distribution of the resonant plasmonic fields and a compression of the resonance node spacing toward the tail. In addition, increasing the length of the nanocarrots causes an increase in the intensity and a steady red shift of the longitudinal surface plasmon resonance peaks. The silver nanocarrots also show very high sensitivity to the refractive index of their environment (890 卤 87 nm per refractive index unit).