Sb Layers on p-GaN: UPS, XPS and LEED Study

The electronic structure of p-type GaN(0001) surfaces and its modification by antimony adsorption, and properties of Sb/GaN(0001) interface, are presented in this report. The studies were carried out in situ by ultraviolet photoelectron spectroscopy, X-ray photoelectron spectroscopy, and low-energy electron diffraction. Thin Sb layers were deposited under ultrahigh vacuum conditions onto the substrate at room temperature. Electron affinity of clean p-GaN surface amounted to 3.0 eV. A small amount of Sb on GaN(0001) surface reduced the electron affinity to 1.9 eV. The work function of the Sb layer was equal to 4.4 eV. For the Schottky barrier height of the Sb/GaN interface, the value of 2.50 eV was obtained.