Nickel adsorption and incorporation on a 2 × 2-T4 GaN(0 0 0 1) surface: A DFT study

► Adsorption, diffusion and incorporation of nickel atoms on the 2 × 2-T4 GaN(0 0 0 1) surface were theoretically studied. ► Ni adsorption process is energetically more favorable that the Ni incorporation in interstitial and Ga-substitutional sites. ► Ni surface adsorption is more favorable in moderate and extreme Ga-rich conditions. ► Our DFT calculations predict the interface formation of NiGax/GaN layer growth, before the Ni film formation on GaN.