Effect of interdiffusion and quantum confinement on Raman spectra of the Ge/Si(100) heterostructures with quantum dots
| Autor: | Kucherenko, I. V., Vinogradov, V. S., Melnik, N. N., Arapkina, L. V., Chapnin, V. A., Chizh, K. V., Yuryev, V. A. |
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| Rok vydání: | 2009 |
| Předmět: | |
| Zdroj: | Proc. 16th Int. Symp. "Nanostructures: Physics and Technology", Vladivostok, Russia, July 14-18, 2008 |
| Druh dokumentu: | Working Paper |
| Popis: | We used Raman scattering for study the phonon modes of self-organized Ge/Si quantum dots, grown by a molecular-beam epitaxy method. It is revealed, that Ge-Ge and Si-Ge vibrational modes considerably intensify at excitation of exciton between the {Lambda}3 valence and {Lanbda}1 conduction bands (transitions E1 and E1+{Delta}1), that allows to observe Raman scattering spectrum from extremely small volumes of Ge, even from one layer of quantum dots with the layer thickness of ~ 10 A. It is shown that Si diffuses into the Ge quantum dots from the Si spacer layers forming Ge_xSi_{1-x} solid solution, and Si concentration was estimated. It is revealed, that the frequency of Ge-Ge mode decreases in 10 1/cm at decreasing of the Ge layer thickness from 10 up to 6 A as a result of phonon size confinement effect. Comment: Reported at the 16th Int. Symp. "Nanostructures: Physics and Technology", Vladivostok, Russia, July 14-18, 2008 |
| Databáze: | arXiv |
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