Atomic scale localization of Kohn–Sham wavefunction at SiO2/4H–SiC interface under electric field, deviating from envelope function by effective mass approximation

To clarify the cause of the low channel conductivity at the SiO2/4H–SiC interface, the wavefunction at the SiC conduction band minimum was calculated using density functional theory under an applied electric field. We found that the wavefunction for a 4H–SiC (0001) slab tends to be localized at the cubic site closest to the interface. Importantly, because the conduction electrons are distributed closer to the interface (