Photoluminescence from ultrathin Ge-rich multiple quantum wells observed up to room temperature: Experiments and modeling

Wendav T, Fischer IA, Virgilio M, Capellini G, Oliveira F, Cerqueira MF, Benedetti A, Chiussi S, Zaumseil P, Schwartz B, Busch K, Schulze J (2016)

Publication Type: Journal article

Publication year: 2016

Journal

Physical Review B American Physical Society

Book Volume: 94

Article Number: 245304

Journal Issue: 24

DOI: 10.1103/PhysRevB.94.245304

Abstract

Employing a low-temperature growth mode, we fabricated ultrathin Si1-xGex/Si multiple quantum well structures with a well thickness of less than 1.5 nm and a Ge concentration above 60% directly on a Si substrate. We identified an unusual temperature-dependent blueshift of the photoluminescence (PL) and exceptionally low thermal quenching. We find that this behavior is related to the relative intensities of the no-phonon (NP) peak and a phonon-assisted replica that are the main contributors to the total PL signal. To investigate these aspects in more detail, we developed a strategy to calculate the PL spectrum employing a self-consistent multivalley effective mass model, in combination with second-order perturbation theory. Through our investigation, we find that while the phonon-assisted feature decreases with temperature, the NP feature shows a strong increase in the recombination rate. Besides leading to the observed robustness against thermal quenching, this causes the observed blueshift of the total PL signal.

Authors with CRIS profile

Jörg Schulze

Involved external institutions

Humboldt-Universität zu Berlin DE Germany (DE) Università degli Studi Roma Tre IT Italy (IT) University of Vigo / Universidade de Vigo ES Spain (ES) Universidade do Minho PT Portugal (PT) Universität Stuttgart DE Germany (DE) University of Pisa / Università di Pisa (UniPi) IT Italy (IT) Brandenburgische Technische Universität Cottbus-Senftenberg (BTU) DE Germany (DE)

How to cite

APA:

Wendav, T., Fischer, I.A., Virgilio, M., Capellini, G., Oliveira, F., Cerqueira, M.F.,... Schulze, J. (2016). Photoluminescence from ultrathin Ge-rich multiple quantum wells observed up to room temperature: Experiments and modeling. Physical Review B, 94(24). https://doi.org/10.1103/PhysRevB.94.245304

MLA:

Wendav, T., et al. "Photoluminescence from ultrathin Ge-rich multiple quantum wells observed up to room temperature: Experiments and modeling." Physical Review B 94.24 (2016).

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