Abstract:

The chemical bonding and band edge line-up of several gate insulators on monoclinic (M1) phase VO2arestudied based on hybrid density functional calculations. High dielectric constant HfO2and ZrO2, wide band gapoxide Al2O3, and narrower band gap oxide TiO2are considered. The insulating interface supercells with a cleanbandgap are built and adapted to analysis the band alignment. All the gate insulators show the type-I bandalignment with VO2. The valence band offsets are all larger than 1 eV. The calculated conduction band offsets forHfO2, ZrO2and Al2O3are all larger than 2 eV. In terms of the band alignment, these three insulators can work assuitable gate dielectrics for VO2-based device application, but more accurate line-up analysis on TiO2/VO2in-terface is still needed.

More infos on the article homepage -Aug 2019