Calculated natural band offsets of all II–VI and III–V semiconductors: Chemical trends and the role of cation d orbitals

Using first-principles all-electron band structure method, we have systematically calculated the natural band offsets ΔEv between all II–VI and separately between III–V semiconductor compounds. Fundamental regularities are uncovered: for common-cation systems ΔEv decreases when the cation atomic number increases, while for common-anion systems ΔEv decreases when the anion atomic number increases. We find that coupling between anion p and cation d states plays a decisive role in determining the absolute position of the valence band maximum and thus the observed chemical trends.