Surface band-gap narrowing in quantized electron accumulation layers

An energy gap between the valence and the conduction band is the defining property of a semiconductor, and the gap size plays a crucial role in the design of semiconductor devices. We show that the presence of a two-dimensional electron gas near to the surface of a semiconductor can significantly al...

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Veröffentlicht in:Physical review letters 2010-06, Vol.104 (25), p.256803-256803, Article 256803
Hauptverfasser: King, P D C, Veal, T D, McConville, C F, Zúñiga-Pérez, J, Muñoz-Sanjosé, V, Hopkinson, M, Rienks, E D L, Jensen, M Fuglsang, Hofmann, Ph
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Sprache:eng
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Zusammenfassung:An energy gap between the valence and the conduction band is the defining property of a semiconductor, and the gap size plays a crucial role in the design of semiconductor devices. We show that the presence of a two-dimensional electron gas near to the surface of a semiconductor can significantly alter the size of its band gap through many-body effects caused by its high electron density, resulting in a surface band gap that is much smaller than that in the bulk. Apart from reconciling a number of disparate previous experimental findings, the results suggest an entirely new route to spatially inhomogeneous band-gap engineering.
ISSN:0031-9007
1079-7114
DOI:10.1103/physrevlett.104.256803