Dresden 2026 – wissenschaftliches Programm

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FM: Fachverband Funktionsmaterialien

FM 7: Crystal Defects and Real Structure Physics in Diamond and Functional Materials I

FM 7.8: Vortrag

Dienstag, 10. März 2026, 11:30–11:45, BEY/0E40

Distortion tensor around dislocations in GaN studied by electron backscatter diffraction and cathodoluminescence spectroscopy — •Domenik Spallek, Vladimir Kaganer, Oliver Brandt, Thomas Auzelle, and Jonas Lähnemann — Paul-Drude-Institut für Festkörperelektronik, Berlin, Germany

The effect of elastic distortion in the vicinity of a threading dislocation (TD) in GaN on its luminescence has been shown previously [1]. However, quantifying this distortion and its components remains a challenge. Therefore, we investigate individual TDs by correlated high-resolution electron backscatter diffraction (HR-EBSD) and cathodoluminescence (CL) spectroscopy. The sample is a high-purity, homoepitaxial GaN layer grown by molecular beam epitaxy with a low TD density.

A cross-correlation analysis with the software CrossCourt from BLG Vantage is used to determine the spatially-resolved components of the distortion tensor from the HR-EBSD results [2]. Signatures of the TDs are resolved in the elastic strain and rotation components. Through reference measurements, we explore the resolution limit of this analysis and its dependence on the material and measurement conditions. Hyperspectral CL maps show a reduced intensity as well as a shifted emission wavelength around the TD. With additional modeling of the distortion around a TD, these correlated measurements are related to the Burger’s vector of the dislocation, determining its type.

[1] Kaganer et al., Phys. Rev. Appl. 12, 054038 (2019).

[2] Wilkinson et al., Ultramicroscopy 106, 307 (2006).

Keywords: GaN threading dislocations; Electron backscatter diffraction; Cathodoluminescence; Deformation matrix