Resumo

RUDA, Harry E.  e  SHIK, Alexander. Polarization-sensitive optical properties of metallic and semiconducting nanowires. Superf. vacío [online]. 2006, vol.19, n.3, pp.1-11. ISSN 1665-3521.

Polarization phenomena in the optical absorption and emission of metallic, semiconducting or composite nanowires and nanorods are considered theoretically. Most nanowire-based structures are characterized by a dramatic difference in dielectric constant ε between their material and environment. Due to image forces caused by such ε mismatch, coefficients of optical absorption and emission become essentially different for light polarized parallel or perpendicular to the nanowire axis. As a result, the intensity and spectra of absorption, luminescence, luminescence excitation, and photoconductivity in single nanowires or arrays of parallel nanowires are strongly polarization-sensitive. In light-emitting nanowire core-shell structures, the re-distribution of a.c. electric field caused by the image forces may result in essential enhancing of core luminescence in frequency regions corresponding to luminescence from the semiconducting core or when the frequency of optical excitation coincides to the frequency of the plasmon resonance in the metallic shell. In random nanowire arrays, the effects described above may result in ''polarization memory'', where polarization of luminescence is determined by the polarization of the exciting light. Recent experimental data on ''polarization memory'' in CdSe/ZnS nanorods are presented.

Palavras-chave : Manowires; Optical properties; Semiconductor.