CuTe chains on Cu(111) by deposition of 1/3 ML Te: atomic and electronic structure

Abstract

The surface atomic and electronic structure after deposition of 1 /3 monolayer (ML) Te on Cu(111) was determined using a combination of low-energy electron diffraction (LEED), scanning tunneling microscopy and spectroscopy (STM/STS), angle-resolved single and two-photon photoelectron spectroscopy (ARPES /AR-2PPE) and density functional theory (DFT) calculations. Contrary to the current state in literature Te does not create a two-dimensional surface alloy but forms Cu2Te2 adsorbate chains in a 2 √ 3 × √ 3 R30 • superstructure. We establish this by a high-precision LEED-IV structural analysis with Pendry R factor of R = 0.099 and corroborating DFT and STM results. The electronic structure of the surface phase is dominated by an anisotropic downward dispersing state at the Fermi energy EF and a more isotropic upward dispersing unoccupied state at E − EF = +1.43 eV. Both states coexist with bulk states of the projected band structure and are therefore surface resonances.