Exciton condensation in the compressively strained SiGe layers of Si/SiGe/Si heterostructures

The photoluminescence spectra of type-I alignment Si/Si 1 − x Ge x /Si heterostructures contained thin Si 1 − x Ge x layers ( d = 25–70 nm) are studied under various temperatures and excitation intensities. It was shown, excitation intensity increase at low temperatures leads to the exciton condensa...

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Bibliographic Details
Published in:	Thin solid films Vol. 517; no. 1; pp. 55 - 56
Main Authors:	Burbaev, T.M., Bagaev, V.S., Bobrik, E.A., Kurbatov, V.A., Novikov, A.V., Rzaev, M.M., Sibeldin, N.N., Schäffler, F., Tsvetkov, V.A., Tarakanov, A.G., Zaitsev, V.V.
Format:	Journal Article
Language:	English
Published:	Elsevier B.V 03-11-2008
Subjects:	Electron–hole liquid Mott transition Photoluminescence Silicon-germanium heterostructure Mott transition Silicon-germanium heterostructure Electron–hole liquid Photoluminescence
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Summary:	The photoluminescence spectra of type-I alignment Si/Si 1 − x Ge x /Si heterostructures contained thin Si 1 − x Ge x layers ( d = 25–70 nm) are studied under various temperatures and excitation intensities. It was shown, excitation intensity increase at low temperatures leads to the exciton condensation resulting electron–hole liquid (EHL) formation in Si 1 − x Ge x layer. Electron–hole pair density n 0 and binding energy of the EHL relative to exciton gas φ decrease noticeably while х increases. The decrease in the binding energy and density of the electron–hole liquid is attributed to splitting of conduction and valance bands due to internal strains in the Si 1 − x Ge x layer. The Mott transition (from the exciton gas to electron–hole plasma) occurs above the critical temperatures for high excitation intensities.
ISSN:	0040-6090 1879-2731
DOI:	10.1016/j.tsf.2008.08.074