Fig. 4: Theoretical analysis of the open-core TSDs of GaN.
From: Dislocation-assisted electron and hole transport in GaN epitaxial layers
a Schematic plot of the relaxed open-core structure threading screw dislocation of GaN, where the big green and small grey balls represent Ga and N atoms, and the yellow and blue surface represent the isosurface of the differential electronic state distribution in the open-core TSD supercell. The charge isosurface is set to 1e-4 e/Bohr3. b Comparison of the electronic band structures for bulk GaN and open-core type TSD supercell, obtained by PBE functional from first-principles calculation, a shallow energy level at 47.97 meV below the bulk GaN CBM was identified. This calculation result is consistent with the ETSD found in PL (including thermal quenching and level fitting); c Summary of TSD induced ETSD detection; d Calculation of the electrostatic potential along the core of TSD, the induced potential φTSD is about 1 eV.
