The topological order and its correlation to self-atom transport in amorphous materials: silicon and germanium as model systems

• Applicants: Professor Dr. Hartmut Bracht, since 4/2023; Dr. Matthias Posselt
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2020 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 438446155

In the framework of this research project the topological order and dynamic structural evolution during annealing of high purity amorphous silicon and germanium prepared by single and multiple self-ion implants will be investigated by fluctuation electron microscopy (FEM) and electron correlation microscopy (ECM). The temperature dependence of local structural changes determined by ECM will be compared to results of macroscopic self- diffusion experiments that are performed by means of isotopically controlled high purity amorphous silicon and germanium structures. Variance profiles obtained from FEM analyses and ECM data recorded on the amorphous material systems will be simulated by molecular dynamics calculations. The calculations will be based on empirical potentials and optimized to describe not only general structural properties but also experimental data on self-diffusion and epitaxial recrystallization in these amorphous systems obtained in this work and published in the literature. Our approach to combine microscopic and macroscopic studies on the local structure and dynamic evolution of ion-implanted amorphous silicon and germanium with atomistic simulations of the short and medium range order is expected to provide valuable information not only about the intrinsic atomic transport properties of these high purity amorphous materials but also about their local structure and dynamic structural evolution under heat treatments.

• DFG Programme: Research Grants
• Ehemaliger Antragsteller: Dr. Martin Peterlechner, until 4/2023