Adsorption of barium on surface of GaN(0001)

Abstract

For the first time, the adsorption of barium atoms on the surface of the (0001) face of GaN was calculated using the density functional method. The 2D GaN layer was modeled using a GaN(0001) 2×2 supercell containing 10 GaN bilayers. The electron density of state and the adsorption energy of the Ba atom were calculated for five adsorption sites of the Ba atom: in the hollow position, in the bridge position between the surface Ga (N) atoms, and above the surface Ga (N) atom. There was one Ba atom per 4 surface Ga atoms in the first GaN bilayer. The adsorption of the barium atom above the surface N atom was most preferable. The adsorption energy was 2,96 eV. The adsorption of Ba atoms resulted in an insignificant reconstruction of the GaN surface: the maximum shift of the Ga (N) atoms did not exceed 0,11 Å. The adsorption of Ba resulted in the formation of a surface band below the Fermi level.

Keywords

• density functional method
• electronic structure
• interface
• surface
• adsorption
• barium
• gan