Distribution and mobility of structural defects in Czochralski-grown β-Ga2O3 crystals

• Applicants: Dr. Merve Pinar Kabukcuoglu; Dr. Carsten Richter
• Subject Area: Thermodynamics and Kinetics as well as Properties of Phases and Microstructure of Materials ; Synthesis and Properties of Functional Materials
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 562785033

The proposed research project aims to gain a deep understanding of sources, formation mechanisms and evolution of structural defects in single crystals of gallium oxide (ß-Ga2O3) grown by the Czochralski method. This material is currently subject to extensive research owing to its outstanding electrical properties, which give ß-Ga2O3 the potential to become a superior platform for high-power electronics enabling more efficient energy conversion. We will employ a set of state-of-the-art techniques for 3D imaging of structural defects, mostly based on ex situ and in situ diffraction of synchrotron radiation, as a function of applied thermo-mechanical stresses. We believe that this study has the potential to close two knowledge gaps that are a) the types and distribution of defects in Cz grown ß-Ga2O3 crystals in general and b) the microscopic structural processes and kinetic parameters behind plastic deformation of this material. The latter particularly concerns the nucleation and mobility of dislocations. We will track the evolution of individual dislocations and compare it against dynamics simulations to extract the fundamental material parameters of plasticity. This information will, in turn, allow to refine models of stress-induced degradation in Ga2O3 at high temperatures thus providing a basis for a future optimization of the growth procedures.

• DFG Programme: Research Grants