X-ray photoemission spectroscopy of nonmetallic materials: Electronic structures of boron and B_xO_y

The electronic structure of boron (B) and BxOywas studied using x-ray photoelectron spectroscopy (XPS). These are nonmetallic materials which possess extreme hardness, and intriguing solid-state structures constructed by a building block of twelve boron atoms in an icosahedron. An XPS shift in non-metallic materials was caused by a change in occupancy of electronic states of impurities and charge trapping defects. The results show that the β-rhombohedral boron have a surface Fermi level located at 0.7±0.1 eV from its valence band maximum (VBM) and a binding energy for its B 1s core level at 187.2 eV from VBM.