Enhanced spin injection efficiency in ferromagnet/semiconductor tunnel junctions

Wang, J., Xing, D. Y. and Sun, H. B. (2003) Enhanced spin injection efficiency in ferromagnet/semiconductor tunnel junctions. Journal of Physics Condensed Matter, 15 27: 4841-4850. doi:10.1088/0953-8984/15/27/315

Author Wang, J.
Xing, D. Y.
Sun, H. B.
Title Enhanced spin injection efficiency in ferromagnet/semiconductor tunnel junctions
Journal name Journal of Physics Condensed Matter   Check publisher's open access policy
ISSN 0953-8984
Publication date 2003-07-01
Sub-type Article (original research)
DOI 10.1088/0953-8984/15/27/315
Volume 15
Issue 27
Start page 4841
End page 4850
Total pages 10
Place of publication United Kingdom
Publisher Institute of Physics Publishing
Language eng
Subject C1
240204 Condensed Matter Physics - Other
780102 Physical sciences
0299 Other Physical Sciences
Abstract Within the ballistic transport picture, we have investigated the spin-polarized transport properties of a ferromagnetic metal/two-dimensional semiconductor (FM/SM) hybrid junction and an FM/FM/SM structure using quantum tunnelling theory. Our calculations indicate explicitly that the low spin injection efficiency (SIE) from an FM into an SM, compared with a ferromagnet/normal metal junction, originates from the mismatch of electron densities in the FM and SM. To enhance the SIE from an FM into an SM, we introduce another FM film between them to form FM/FM/SM double tunnel junctions, in which the quantum interference effect will lead to the current polarization exhibiting periodically oscillating behaviour, with a variation according to the thickness of the middle FM film and/or its exchange energy strength. Our results show that, for some suitable values of these parameters, the SIE can reach a very high level, which can also be affected by the electron density in the SM electrode.
Keyword Physics, Condensed Matter
Ferromagnet-semiconductor Interface
Q-Index Code C1

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Mathematics and Physics
2004 Higher Education Research Data Collection
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Citation counts: TR Web of Science Citation Count  Cited 7 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 7 times in Scopus Article | Citations
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Created: Wed, 15 Aug 2007, 12:03:49 EST