Photoexcitation of coupled plasmon-LO phonon modes in AlxGa1-xAs
| Autor: | Manor R, D. Fekete, O. Brafman, R. F. Kopf |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
Condensed matter physics
Phonon Scattering Chemistry Plasma Condensed Matter Physics Molecular physics Electronic Optical and Magnetic Materials Photoexcitation Condensed Matter::Materials Science symbols.namesake Ion implantation Dispersion relation Materials Chemistry symbols Condensed Matter::Strongly Correlated Electrons Electrical and Electronic Engineering Raman spectroscopy Plasmon |
| Zdroj: | Semiconductor Science and Technology. 9:1659-1665 |
| ISSN: | 1361-6641 0268-1242 |
| Popis: | We report the micro-Raman scattering by a photoexcited plasma coupled to LO phonon modes in AlxGa1-xAs at power densities as high as 1.3*106 W cm-2. There are two polar modes, so three branches of the coupled plasmon-LO phonon dispersion are expected, but two of those are experimentally observed and only for phonon-like characteristics. This means that the inhomogeneous photoexcited plasma hardly affects the line frequencies, unlike the behaviour of the homogeneous plasma produced by doping. Still, altering the high power photoexcitation modifies the various line intensity ratios significantly. We show that by varying the free carrier concentration, either by restricting the probe to high densities produced in the central part of the beam or by reducing the free carrier concentration due to traps created by ion implantation, the intensities and the widths of the Raman lines could be controlled. |
| Databáze: | OpenAIRE |
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