Internal field induced enhancement and effect of resonance in Raman scattering of InAs nanowires

Abstract

An internal field induced resonant intensity enhancement of Raman scattering of phonon excitations in InAs nanowires is reported. The experimental observation is in good agreement with the simulated results for the scattering of light under varying incident wavelengths, originating from the enhanced internal electric field in an infinite dielectric cylinder. Our analysis demonstrates the combined effect of the first higher lying direct band gap energy (E 1 ) and the refractive index of the InAs nanowires in the internal field induced resonant Raman scattering. Furthermore, the difference in the relative contribution of electro-optic effect and deformation potential in Raman scattering of nanowires and bulk InAs over a range of excitation energies is discussed by comparing the intensity ratio of their LO and TO phonon modes.

Manipulation of polarization anisotropy in bare InAs and InAs/GaSb core-shell nanowires

“…S2 in the supplementary material). A similar enhancement in scattering intensity has been reported earlier for InAs NWs 19 and Si nanocones. 14 In summary, we have investigated the effect of the shell in governing the non-linear polarization anisotropy of the Raman scattering intensity in InAs/GaSb core-shell NWs with respect to bare InAs NWs.…”

Enhanced Raman Scattering with Dielectrics

“…233 Other possibilities for SERS could be opened by direct exploitation of the strong internal fields originating from the efficient coupling of light with high-refractive-index InAs NWs. 234 In the case of sulfides and selenides, most published works have been related to the peculiarities resulting from their size reduction to form quantum-dot structures. Lombardi and coworkers investigated the Raman responses of ZnS 235 and CdS 236 in the detection of 4-MPY solutions.…”

“…For example, numerical simulations demonstrated that InAs antennas, formed by triangular or dot dimers, can exploit plasmons in the terahertz range to concentrate the electromagnetic field within the antenna gap, giving rise to exceptional enhancement (up to 10 11 ) . Other possibilities for SERS could be opened by direct exploitation of the strong internal fields originating from the efficient coupling of light with high-refractive-index InAs NWs …”

Resonant enhancement of Raman scattering by surface phonon polaritons in GaAs nanowires

“…To the best of our knowledge, theoretical studies predicting conditions for the amplification of the Raman signal from surface phonons at photonic (Mie and other) resonances are not available yet. Nevertheless, experimental evidence of Raman amplification on Mie resonances has already been demonstrated in InAs [45], silicon [46][47][48] and germanium NWs [49,50], but only for the bulk phonon modes.…”