Energy band structure of Bi-Bi1-xSbxcompositional superlattices
| Autor: | N B Mustafaev |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
Condensed Matter::Quantum Gases
Condensed matter physics Chemistry Superlattice Fermi surface Fermi energy Condensed Matter::Mesoscopic Systems and Quantum Hall Effect Condensed Matter Physics Brillouin zone Condensed Matter::Materials Science Effective mass (solid-state physics) Dispersion relation General Materials Science Wave vector Electronic band structure |
| Zdroj: | Journal of Physics: Condensed Matter. 6:2039-2046 |
| ISSN: | 1361-648X 0953-8984 |
| DOI: | 10.1088/0953-8984/6/10/021 |
| Popis: | Within the McClure model a dispersion equation for the energy spectrum of the Bi-Bi1-xSbx superlattices in the envelope function approximation is derived. The effective mass of minibands, the Fermi energy and the concentration of free carriers in a superlattice with X=0.1 and the period d=10 nm are determined. The dependence of the miniband energy upon the ratio r=dI/dII is obtained (dI is the thickness of the Bi layers and dII is the thickness of the alloy layers). It is shown that there is a transition from the semiconducting state (r 0.31) in the superlattice with X=0.1 and d=10 nm due to an energy overlap between the minibands at the L and T points of the Brillouin zone. For dI=4 nm and dII=6 nm the Fermi surface of electrons is closed whereas the Fermi surface of holes is open in the direction of the superlattice wavevector q. In the superlattice with X=0.12 and dI=dII=60 nm the transverse components of the effective-mass tensor change signs at a certain value of q=qo. As a result, at q>q0 the dependence of the miniband energy on the wavevector k in the plane of layers has a shape like a 'camel's back'. |
| Databáze: | OpenAIRE |
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