LAUSR

Abstract Using density functional theory and ultra-soft pseudopotential method based on first principles calculations, the adsorption energies, work functions, dipole moments, partial density of states, Mulliken population and charge differential densities of Cs adsorbed Al0.5Ga0.5N(0001) surfaces were calculated at the coverage of 0.25 ML. After Cs adsorption, the charges of Cs atom transfer to the Al and Ga atoms in the first molecular layer of the surface, the surface dipole moments increase, the density of states move to low energy, and the work functions decrease. The electron cloud increased after Cs adsorption, when Cs at BAl site, Ga and Cs form ionic bond, Al and Cs form covalent bond. The calculations indicate that the BAl site is the most stable adsorption site.