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New Ordering-Induced Optical Transitions in Strained Sige Superlattices

Published online by Cambridge University Press:  28 February 2011

Sverre Froyen ,
D. M. Wood  and
Alex Zunger
Sverre Froyen
Affiliation:
Solar Energy Research Institute,Golden,CO 80401
D. M. Wood
Affiliation:
Solar Energy Research Institute,Golden,CO 80401
Alex Zunger
Affiliation:
Solar Energy Research Institute,Golden,CO 80401
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Abstract

First principles total energy and electronic structure calculations for SinGen superlattices grown epitaxially on a Si (001) substrate reveal a nearly direct band gap despite the pronounced indirectness of the Si0.5Ge0.5alloy. While the new direct superlattice transitions have their origin in folded indirect transitions of the random alloy, their transition matrix elements are considerably enhanced by superlattice atomic relaxation and the superlattice ordering potential. For a superlattice grown on a substrate with an lager lattice contant than we predict a nearly direct band gap.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 91: Symposium A – Heteroepitaxy on Silicon II , 1987 , 293
Copyright
Copyright © Materials Research Society 1987

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References

REFERENCES

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