Infrared dielectric functions and phonon modes of high-quality ZnO films
| Autor: | E. M. Kaidashev, Carsten Bundesmann, Vanya Darakchieva, Marius Grundmann, V. Riede, B. N. Mbenkum, Hans Arwin, Mathias Schubert, Bo Monemar, Daniel Spemann, N. Ashkenov, Horst Neumann, Gerald Wagner, A. Kasic, Michael Lorenz |
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| Rok vydání: | 2003 |
| Předmět: |
Materials science
Condensed matter physics Phonon Analytical chemistry Physics::Optics General Physics and Astronomy Infrared spectroscopy Dielectric Condensed Matter::Materials Science symbols.namesake Ellipsometry Condensed Matter::Superconductivity Vacancy defect symbols Raman spectroscopy Raman scattering Wurtzite crystal structure |
| Zdroj: | Journal of Applied Physics. 93:126-133 |
| ISSN: | 1089-7550 0021-8979 |
| Popis: | Infrared dielectric function spectra and phonon modes of high-quality, single crystalline, and highly resistive wurtzite ZnO films were obtained from infrared (300–1200 cm−1) spectroscopic ellipsometry and Raman scattering studies. The ZnO films were deposited by pulsed-laser deposition on c-plane sapphire substrates and investigated by high-resolution x-ray diffraction, high-resolution transmission electron microscopy, and Rutherford backscattering experiments. The crystal structure, phonon modes, and dielectric functions are compared to those obtained from a single-crystal ZnO bulk sample. The film ZnO phonon mode frequencies are highly consistent with those of the bulk material. A small redshift of the longitudinal optical phonon mode frequencies of the ZnO films with respect to the bulk material is observed. This is tentatively assigned to the existence of vacancy point defects within the films. Accurate long-wavelength dielectric constant limits of ZnO are obtained from the infrared ellipsometry anal... |
| Databáze: | OpenAIRE |
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