Dresden 2017 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 37: III-V Semiconductors
HL 37.5: Talk
Tuesday, March 21, 2017, 10:30–10:45, POT 112
Bond strength inversion in (In,Ga)As — •Stefanie Eckner1, Konrad Ritter1, Philipp Schöppe1, Erik Haubold1, Sven Bauer1, Erich Eckner2, Mark C. Ridgway3, and Claudia S. Schnohr1 — 1Institut für Festkörperphysik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany — 2Institut für Optik und Quantenelektronik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany — 3Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200, Australia
Mixed semiconductors feature different first nearest neighbour pairs whose bond stretching force constants determine fundamental material properties, including their vibrational behaviour and the local atomic arrangements. The latter are particularly crucial for strained thin films and nanostructures and influence other key material properties like the band gap energy. In this study, (In,Ga)As grown by metal organic chemical vapour deposition was studied using extended x-ray absorption fine structure spectroscopy. Measurements were performed at the Ga-K- and In-K-edge at nine different temperatures. The resulting temperature evolution of the bond length variation yields the Ga-As and In-As effective bond stretching force constants. The values obtained for the ternary alloys show a remarkable size inversion with regard to the values in the binary materials, meaning that bond stretching force constants determined for binary III-V-semiconductors are not readily transferable to ternary systems.