Work

Hexagonal Ge / Si 0.25 Ge 0.75 quantum wells: Prediction of quantization and light-emission strength

Year: 2025

Type: article

Abstract: We investigate heterostructures composed of hexagonal Ge quantum wells embedded within hexagonal Si 0.25 Ge 0.75 alloy layers, systematically considering variations in crystallographic orientation, well thickness, and external biaxial strain. This study employs density functional theory together with accurate functionals for calculations of the quasiparticle electronic structure. Overall, the heterostructures exhibit type-I band alignment, with the localization of electron and hole wave functions predominantly within the hexagonal Ge regions. The quantum confinement of both charge carrier types is determined by the orientation and thickness of the Ge layer for three different external strains. The results obtained can be interpreted within a rectangular potential-well model, with characteristic parameters derived from band structures of hexagonal Ge and Si 0.25 Ge 0.75 , as well as their strained multiquantum well structures, properly aligned via the branch point energies. Besides confinement energies and subbands, optical transition strengths are also discussed.

Source: Physical review. B./Physical review. B

DOI: 10.1103/3l5b-b8ry

Authors: Abderrezak Belabbes, Martin Keller, Jürgen Furthmüller, Silvana Botti, Friedhelm Bechstedt

Institutions: Sultan Qaboos University, Friedrich Schiller University Jena, Ruhr University Bochum

Language: English

Topic: Semiconductor Quantum Structures and Devices

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Funder: Horizon 2020 Framework Programme

Award: G6033118824