Speaker
Description
Despite advances toward improving the quality of 𝑝-type 4H-SiC substrates and layers, until recently we were still missing a model capable of accounting for the multitude of boron-related optical, junction, and paramagnetic resonance experiments available in the literature. A conspicuous puzzle was the observation of two shallow boron defects with rather distinct axial orientations as found by Electron Spin Resonance (ESR) and Electron Nuclear Double Resonance (ENDOR) data. This feature is not observed in material doped with other group-III elements. Another open issue involved conflicting conclusions from photoluminescence and ESR studies of a deeper boron center, which had been linked to rather distinct models, either based on substitutional or vacancy-related boron defects. We will describe how these problems were recent unlocked by first-principles studies [1], which included the calculation of the electronic activity and the use of the ESPRESSO/GIPAW codes for the evaluation of paramagnetic response of boron defects in 4H-SiC.
References:
1. Theory of shallow and deep boron defects in 4H-SiC, V. J. B. Torres, I. Capan, and J. Coutinho, Physical Review B 106, 224112 (2022); DOI:10.1103/PhysRevB.106.224112
