Regensburg 2025 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 15: Quantum Dots and Wires: Growth and Properties

HL 15.6: Vortrag

Dienstag, 18. März 2025, 10:45–11:00, H13

Photoluminescence from SiGe and Ge quantum dots on Si nanotips: role of composition and capping — •Diana Ryzhak¹, Johannes Aberl², Enrique Prado-Navarrete², Lada Vukušić², Agnieszka Anna Corley-Wiciak¹, Oliver Skibitzki¹, Marvin Hartwig Zoellner¹, Markus Andreas Schubert¹, Michele Virgilio³, Moritz Brehm², Giovanni Capellini^1,4, and Davide Spirito¹ — ¹IHP Leibniz-Institut für innovative Mikroelektronik, Im Technologiepark 25, 15236 Frankfurt (Oder), Germany — ²Institute of Semiconductor and Solid State Physics, Johannes Kepler University Linz, Altenberger Strasse 69, 4040, Linz, Austria — ³Dipartimento di Fisica E. Fermi, Università di Pisa, Largo Pontecorvo 3, 56127, Pisa, Italy — ⁴Dipartimento di Scienze, Università Roma Tre, V.le G. Marconi 446, 00146 Roma, Italy

Quantum dots (QDs) have been studied for their unique optical properties, which are essential for LEDs and lasers. The main challenge remains to control the fabrication processes of QDs. Therefore, we have used a nanoheteroepitaxy (NHE) approach and fabricated nearly strain-free SiGe and Ge QDs on Si(001) nanotip (NT) patterned substrates. The QDs were deposited by molecular beam epitaxy at 850°C, yielding defect-free structures selectively on the NTs as observed by transmission electron microscopy. Upon tuning the Si content, the photoluminescence (PL) peak emission shifted from 0.78 to 0.9 eV. The PL emission can be remarkably enhanced by capping the QDs with Al2O3 or Si3N4 for reduction of the surface recombination processes.

Keywords: Quantum Dots (QDs); Nanoheteroepitaxy; SiGe, Ge; Molecular beam epitaxy (MBE); Photoluminescence (PL)