Optical Antenna Effect in Semiconducting Nanowires

• Published in: Nano letters Vol. 8; no. 5; pp. 1341 - 1346
• Main Authors: Chen, G, Wu, Jian, Lu, Qiujie, Gutierrez, H. R, Xiong, Qihua, Pellen, M. E, Petko, J. S, Werner, D. H, Eklund, P. C
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01-05-2008
• Subjects: Applied sciences; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Crystallization - methods; Electric Conductivity; Electronics; Exact sciences and technology; Gallium - chemistry; Light; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; Macromolecular Substances - chemistry; Materials science; Materials Testing; Molecular Conformation; Molecular electronics, nanoelectronics; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Nanotechnology - methods; Nanotubes - chemistry; Nanotubes - ultrastructure; Particle Size; Phosphines - chemistry; Physics; Scattering, Radiation; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Semiconductors; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Confinement; Semiconductor materials; Light matter interaction; Nanostructures; Raman spectroscopy; Standing waves; Selection rules; Nanometer scale; Raman scattering; Nanowire device; Nanowires; Nanostructured materials; Antenna radiation patterns
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl080007v

We report on investigations of the interaction of light with nanoscale antennae made from crystalline GaP nanowires (NWs). Using Raman scattering, we have observed strong optical antenna effects which we identify with internal standing wave photon modes of the wire. The antenna effects were probed in individual NWs whose diameters are in the range 40 < d < 300 nm. The data and our calculations show that the nature of the backscattered light is critically dependent on the interplay between a photon confinement effect and bulk Raman scattering. At small diameter, d < 65 nm, the NWs are found to act like a nearly perfect dipole antenna and the bulk Raman selection rules are masked leading to a polarized scattering intensity function I R ∼ cos4 θ. Underscoring the importance of this work is the realization that a fundamental understanding of the “optical antenna effect” in semiconducting NWs is essential to the analysis of all electro-optic effects in small diameter filaments.