Berlin 2024 – wissenschaftliches Programm
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DS: Fachverband Dünne Schichten
DS 8: Thin Film Properties II
DS 8.1: Vortrag
Mittwoch, 20. März 2024, 09:30–09:45, A 060
Vacancy like defects in Cd3As2 — •Maciej Oskar Liedke1, Anthony Rice2, Maik Butterling1, Eric Hirschmann1, Nancy M. Haegel2, Kirstin Alberi2, and Andreas Wagner1 — 1Institute of Radiation Physics, Helmholtz-Zentrum Dresden - Rossendorf, Bautzner Landstr. 400, Dresden 01328, Germany — 2National Renewable Energy Laboratory, Golden, Colorado 80401, USA
Cd3As2 is a three-dimensional topological semimetal which can be transformed into exotic phases, e.g., Weyl semimetals, topological superconductors, or axion insulators. Using epitaxy provides an avenue for varying and controlling point defects during Cd3As2 growth. The knowledge of vacancy defects is essential for interpretation of electron transport behavior and guides growth efforts to develop materials with low defect concentrations. Point defects in Cd3As2 epilayers grown by molecular beam epitaxy with varying As/Cd flux ratios are probed by positron annihilation spectroscopy. We show that lower As/Cd flux ratios produce higher concentrations of point defects. Remarkably, the measurements indicate that the average defect size is larger than a monovacancy and vacancy complexes dominate [Rice et al. APL Mater 11, 061109 (2023)]. The evolution of defect microstructure as a function of temperature will be discussed as well.
Keywords: Cd3As2; topological semimetal; defects; positron annihilation spectroscopy