Gd on GaN(0001) surface: Growth, interaction, and Fermi level movement

The growth, interfacial reaction, and Fermi level movement of Gd on n-type GaN(0001)-(1×1) surface were studied by using x-ray photoelectron spectroscopy. It was observed that the annealing promotes further diffusion and an interfacial Gd-Ga exchange reaction which reduces the Schottky barrier height. It was found that the Gd grows in a layer-by-layer-like mode and reacts with the substrate at the interface which lead to the formation of metallic Ga at room temperature.