Regulation of the electronic properties of GaN(0001) surface by metal atoms

On the basis of first-principles calculation, we investigate the control of the electronic properties of the GaN(0001) surface by metal atoms. The results show that all the metal-atom-adsorbed GaN(0001) surfaces are direct-band-gap semiconductors, and their band gaps could be reduced considerably. The results of the density of states indicate that the orbital hybridization of the electronic states near the Fermi level took place between adatoms and the GaN(0001) surface, and electrons were mainly transferred from the adatoms to the GaN. Furthermore, the work function of the GaN(0001) surface becomes smaller with the adsorption of metal atoms, while the effect of metallic activity becomes more pronounced. (C) 2018 The Japan Society of Applied Physics