First principles research on electronic structure of Zn-doped Ga0.5Al0.5As (001) β2 (2×4) surface

Using the plane-wave ultrasoft pseudopotential method based on the first-principles density functional theory (DFT), the geometric and electronic structures of Zn doped Ga0.5Al0.5As (001) β2 (2×4) reconstruction surface are researched. Twelve doped sites at different atomic layers are chosen; the influence of Zn atom on geometric structure, formation energy, ionicity, band structure, density of states (DOS) and work function of Ga0.5Al0.5As (001) β2 (2×4) surface is researched. Geometric structure change caused by replacing Al to Zn is more obvious than replacing Ga to Zn. The doped surface models formed by replacing Ga to Zn are more stable than that by replacing Al to Zn. Doping at Al sites is more beneficial for photoemission.