Asymmetric Silver “Nanocarrot” Structures: Solution Synthesis and Their Asymmetric Plasmonic Resonances Academic Article uri icon

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abstract

  • Here we report the wet-chemical synthesis of asymmetric one-dimensional (1D) silver "nanocarrot" 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 ± 87 nm per refractive index unit).

authors

  • Liang, Hongyan
  • Rossouw, David
  • Zhao, Haiguang
  • Cushing, Scott K
  • Shi, Honglong
  • Korinek, Andreas
  • Xu, Hongxing
  • Rosei, Federico
  • Wang, Wenzhong
  • Wu, Nianqiang
  • Botton, Gianluigi
  • Ma, Dongling

publication date

  • July 3, 2013