Journal ArticleDOI
Near‐band‐gap photoluminescence from pseudomorphic Si1−xGex single layers on silicon
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TLDR
In this article, an analytical expression for the exciton energy gap at 4.2 K valid for x < 0.24 was derived from the no-phonon line energies: ESX(x) = 1.155−0.874x+0.376x2 eV.Abstract:
The systematic study of band‐edge luminescence in pseudomorphic Si/Si1−xGex/Si double‐heterostructure layers is reported for a wide composition range, 0.12<x<0.24, for the first time. An analytical expression for the exciton energy gap at 4.2 K valid for x<0.24 is derived from the no‐phonon line energies: ESX(x) = 1.155−0.874x+0.376x2 eV. Addition of an expression for the exciton binding energy provides an approximation for the energy difference between the alloy valence band and the lowest conduction‐band edge at low temperature. An exciton upshift of 16.9 meV due to quantum confinement is observed in a 6.3‐nm Si0.83Ge0.17 alloy well. This is consistent with either type‐I or type‐II band alignment for which the conduction‐band offset has a magnitude ‖ΔEc‖ ≤ 10 meV. The excitonic hole is closely confined in the alloy but the spectra suggest that the electron density in the silicon barriers is increased for the thin layer.read more
Citations
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Si/SiGe heterostructure parameters for device simulations
L. Yang,Jeremy R. Watling,Richard C W Wilkins,Mirela Boriçi,John R. Barker,Asen Asenov,Scott Roy +6 more
TL;DR: In this paper, the authors present a review of the theoretical models and related empirical expressions to evaluate parameters related to the carrier transport within Si/SiGe heterostructures, such as the band structure of strained or relaxed SiGe, the conduction and valence band offsets in the Si1−xGex/Si1−yGey heterostructure, the effective transport masses and the densities of states, have been calculated and shown to be in good agreement with existing experimental and theoretical results.
Journal ArticleDOI
Onsite matrix elements of the tight-binding Hamiltonian of a strained crystal: Application to silicon, germanium, and their alloys
TL;DR: In this article, a model for the onsite matrix elements of the tight-binding Hamiltonian of a strained diamond or zinc-blende crystal or nanostructure is presented, which is able to reproduce the effects of arbitrary strains on the band energies and effective masses in the full Brillouin zone.
Journal ArticleDOI
Self-Assembly of Aromatic-Functionalized Amphiphiles: The Role and Consequences of Aromatic−Aromatic Noncovalent Interactions in Building Supramolecular Aggregates and Novel Assemblies
TL;DR: In this article, an overview of a study of several different aromatic-functionalized amphiphilesfatty acid and phospholipid derivatives is presented, showing that the aromatics form a small, stable "unit aggregate" characterized by strong edge-to-face interactions among adjacent aromatics.
Journal ArticleDOI
Band‐edge and deep level photoluminescence of pseudomorphic Si1−x−yGexCy alloys
Philippe Boucaud,Clovis Francis,F. H. Julien,J.-M. Lourtioz,Daniel Bouchier,S. Bodnar,B. Lambert,J. L. Regolini +7 more
TL;DR: In this paper, the photoluminescence of strained Si1−x−yGexCy alloys grown by rapid thermal chemical vapor deposition on Si(100) is investigated.
Journal ArticleDOI
Silicon-Germanium Nanostructures for Light Emitters and On-Chip Optical Interconnects
TL;DR: In this article, the authors review the present status of light emitters based on SiGe nanostructures and propose a new route toward CMOS compatible light emitter for on-chip optical interconnects.
References
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Journal ArticleDOI
Theoretical calculations of heterojunction discontinuities in the Si/Ge system.
TL;DR: A theoretical study of the structural and electronic properties of pseudomorphic Si/Ge interfaces, in which the layers are strained such that the lattice spacing parallel to the interface is equal on both sides.
Journal ArticleDOI
Valence-Band Parameters in Cubic Semiconductors
TL;DR: In this article, a semi-empirical model is developed to describe the dependence of the momentum matrix elements on lattice constant, ionicity, and $d$-electron shells in the cores.