Polarized and diameter-dependent Raman scattering from individual aluminum nitride nanowires: The antenna and cavity effects

Abstract

Raman scattering of individual aluminum nitride (AlN) nanowires is investigated systematically. The axial direction of single nanowire can be rapidly verified by polarized Raman scattering. The angular dependencies of E-2(high) mode show strongly anisotropic behavior in smaller nanowires, which results from optical antenna effect. Raman enhancement (RE) per unit volume of E-2(high) increases with decreasing diameter of nanowires. Compared to the thin film, similar to 200-fold increase of RE is observed in AlN nanowires having diameter less than 50 nm, which is far beyond the quantum confinement regime. Such a large RE can be attributed to the effects of resonant cavity and stimulated Raman scattering.<p>Funding Agencies|Ministry of Education||National Science Council||Academia Sinica in Taiwan||US AFOSR-AOARD||</p

Vibrational properties of semiconductor nanowires and nanowire heterostructures: ensembles and single nanowires

“…Concerning NWs with wurtzite crystal structure, a detailed analysis of phonon symmetries was performed on GaN NWs by Livneh et al 73, although they did not observe an anisotropy in the Raman intensity linked to the antenna effect. This enhancement was later observed in GaN 70, AlN 74 and InAs 34 NWs with the wurtzite structure.…”

Dynamical properties of AlN nanostructures and heterogeneous interfaces predicted using COMB potentials

“…The charge related parameters are given in Table A1 while the bond-order and pairwise parameters are given in Table A2. 3.10166 6.209731 J (eVe -1 ) 2 3.53243 9.29225 K (eVe -1 ) 3 0.48166 -1.25446 L (eVe -1 ) 4 0.0 0.286350 ξ (Ặ -1 )…”

“…Aluminum nitride (AlN) is an important III-V semiconductor material due to its wide band gap, high thermal conductivity, low thermal expansion, and non-toxicity [1]. Nanostructures of AlN are used for field emitters in flat panel displays [2] and photo-detectors [3,4]. Additionally, thin films of AlN and aluminum oxynitride are important engineering protective coatings [5][6][7][8][9].…”

Raman analysis of gold catalyst vapor liquid solid germanium nanowires

“…Lopez et al [19] performed a finite difference time domain simulation of the same problem, showing again that the electric field inside the NW is distributed in a nonhomogeneous and localized manner which depends on its diameter. In general, these calculations of the effect of substrate type and NW geometry on Raman line intensity are performed assuming a two-dimensional geometry, based on the fact that the NW length can be assumed infinite as compared to their diameter [19,22,[24][25][26]. In addition to this effect of a substrate and of the specific NW diameter, it was also shown that the laser beam wavelength has a strong influence on Raman line intensities measured in semiconductor NWs [19,25,27].…”

“…In addition to this effect of a substrate and of the specific NW diameter, it was also shown that the laser beam wavelength has a strong influence on Raman line intensities measured in semiconductor NWs [19,25,27]. Finally, laser beam polarization is also important, in general the measurements are performed with the electric field of the laser beam polarised along the NW axis [19,22,23,26,28,29].…”