Band lineup at hexagonal SixGe1-x/SiyGe1-y alloy interfaces

Belabbes A, Botti S, Bechstedt F (2022)

Publication Type: Journal article

Publication year: 2022

Journal

Physical Review B American Physical Society

Book Volume: 106

Article Number: 085303

Journal Issue: 8

DOI: 10.1103/PhysRevB.106.085303

Abstract

The natural and true band profiles at heterojunctions formed by hexagonal SixGe1-x alloys are investigated by a variety of methods: density-functional theory for atomic geometries, approximate quasiparticle treatments for electronic structures, different band-edge alignment procedures, and construction of various hexagonal unit cells to model alloys and heterojunctions. We demonstrate that the natural band offsets are rather unaffected by the choice to align the vacuum level or the branch point energy, as well as by the use of a hybrid or the Tran-Blaha functional. At interfaces between Ge-rich alloys we observe a type-I heterocharacter with direct band gaps, while Si-rich junctions are type-I but with an indirect band gap. The true band lineups at pseudomorphically grown heterostructures are strongly influenced by the generated biaxial strain of opposite sign in the two adjacent alloys. Our calculations show that the type-I character of the interface is reduced by strain. To prepare alloy heterojunctions suitable for active optoelectronic applications, we discuss how to decrease the compressive biaxial strain at Ge-rich alloys.

Involved external institutions

Friedrich-Schiller-Universität Jena DE Germany (DE) Sultan Qaboos University / جامعة السلطان قابوس OM Oman (OM)

How to cite

APA:

Belabbes, A., Botti, S., & Bechstedt, F. (2022). Band lineup at hexagonal SixGe1-x/SiyGe1-y alloy interfaces. Physical Review B, 106(8). https://doi.org/10.1103/PhysRevB.106.085303

MLA:

Belabbes, Abderrezak, Silvana Botti, and Friedhelm Bechstedt. "Band lineup at hexagonal SixGe1-x/SiyGe1-y alloy interfaces." Physical Review B 106.8 (2022).

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