Near-field coupling between plasmonic resonators in Si nanowires

摘要: Nanoscale semiconductors are emerging as promising plasmonic materials for applications in the infrared. Herein, we study the near-field coupling between adjacent plasmonic resonators embedded in Si nanowires with in-situ infrared spectroscopy and discrete dipole approximation calculations. Si nanowires containing multiple phosphorus-doped segments, each with a user-programmable aspect ratio and carrier density, are synthesized via the vapor-liquid- solid technique and support localized surface plasmon resonances (LSPRs) between 5 and 10 μm. Discrete dipole approximation calculations confirm that the observed spectral response results from resonant absorption and free carrier concentrations are on the order of 1020 cm-3. Near-field coupling occurs between neighboring doped segments and the observed trends agree with plasmon hybridization theory. Our results highlight the utility of vapor …