Dresden 2026 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 50: Electronic structure theory II
O 50.4: Vortrag
Dienstag, 10. März 2026, 15:15–15:30, TRE/PHYS
Quantum-mechanical analysis of the 4H-SiC surface — •Kateřina Dočkalová1,2, Martin Friák2, and Jana Pavlů1 — 1Dept. Chem., Masaryk Uni., Brno, Czech Rep. — 2Inst. Phys. Mater., Czech Acad. Sci., Brno, Czech Rep.
Silicon carbide (SiC) is a key wide-bandgap semiconductor employed in high-power and high-voltage electronic devices. Among its polytypes, 4H-SiC is particularly promising for next-generation power electronics. We investigated the atomic and electronic structure of the 4H-SiC (0001) surface with a specific focus on the challenges of modelling polar orientations. To accurately capture the intrinsic surface properties, we evaluate the planar-averaged electrostatic potential and the electron localisation function (ELF) using various models (differing in bottom-surface termination, passivation with pseudohydrogens, and vacuum thickness) and applying electrostatic corrections. These strategies suppress artificial dipole moments and eliminate spurious internal electric fields that often compromise surface calculations. We find that either carbon termination at the bottom surface or pseudohydrogen passivation can individually introduce a spurious internal electric field manifested in the vacuum potential. Interestingly, applying electrostatic corrections does not improve the electrostatic-potential profile for models in which the vacuum region is already sufficiently thick. Financial support from the Czech Academy of Sciences (Praemium Academiae, M.F.) and Masaryk University (MUNI/A/1691/2024) is acknowledged. Computational resources were provided via e-INFRA CZ (ID:90254).
Keywords: 4H-SiC; DFT; ab initio calculations; surface; electrostatic potential