Open AccessEvidence of new 2D material: Cu2Te
Author(s) -
Yongfeng Tong,
Meryem Bouaziz,
Wei Zhang,
Baydaa Obeid,
Antoine Loncle,
Hamid Oughaddou,
Hanna Enriquez,
Karine Chaouchi,
Vladimir A. Esaulov,
ZheSheng Chen,
Heqi Xiong,
Yingchun Cheng,
Azzedine Bendounan
Publication year - 2020
Publication title -
2d materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.702
H-Index - 72
ISSN - 2053-1583
DOI - 10.1088/2053-1583/ab8918
Subject(s) - scanning tunneling microscope , brillouin zone , x ray photoelectron spectroscopy , angle resolved photoemission spectroscopy , materials science , fermi level , photoemission spectroscopy , monolayer , superstructure , band gap , alloy , condensed matter physics , low energy electron diffraction , electronic structure , crystallography , electronic band structure , electron diffraction , nanotechnology , electron , chemistry , diffraction , physics , optics , nuclear magnetic resonance , optoelectronics , quantum mechanics , composite material , thermodynamics
The number of two-dimensional (2D) materials has grown steadily since the discovery of graphene. Each new 2D material demonstrated unusual physical properties offering a large flexibility in their tailoring for high-tech applications. Here, we report on the formation and characterization of an uncharted 2D material: ‘Cu 2 Te alloy monolayer on Cu(111) surface’. We have successfully grown a 2D binary Te-Cu alloy using a straightforward approach based on chemical deposition method. Low electron energy diffraction (LEED) and scanning tunneling microscopy (STM) results reveal the existence of a well-ordered alloy monolayer characterized by (√3 × √3)R30° superstructure, while the x-ray photoemission spectroscopy (XPS) measurements indicate the presence of single chemical environment of the Te atoms associated with the Te-Cu bonding. Analysis of the valence band properties by angle resolved photoemission spectroscopy (ARPES); in particular the electronic states close to the Fermi level suggests a strong hybridization between Te and Cu electronic states leading to an appearance of new dispersive bands localized at the surface alloy, which is confirmed by first-principles calculations. These bands are strongly influenced by the surface reconstruction and undergo a back-folding at the boundaries of the reduced surface Brillouin zone (SBZ). More interesting, a band gap of about 0.91 eV and a Rashba splitting in the conduction band are obtained. These findings taken together clearly prove the presence of 2D-type electron system within the Cu 2 Te alloy layer, which is promising for spintronic application.