Electronic properties of strained antimonene and graphene/antimonene heterostructures – SAGA

To achieve our objectives, we employ a combination of cutting-edge experimental and theoretical techniques:

Angle-Resolved Photoemission Spectroscopy (ARPES): Enables direct mapping of the electronic band structure of strained and unstrained antimonene.

Scanning Tunneling Microscopy (STM) and Spectroscopy (STS): Provides an atomic-scale understanding of the local electronic properties of antimonene and its interfaces with graphene.

Density Functional Theory (DFT) Calculations: Complement experimental data and predict modifications in the electronic band structure under different strain conditions.

Our research has revealed several major findings regarding antimonene and its interactions with metallic surfaces:

Strong hybridization with metallic surfaces: Our spectroscopic studies have demonstrated significant electronic hybridization between antimonene and the metallic surfaces on which it is deposited. This interaction considerably alters the band structure of antimonene and must be taken into account for its integration into electronic devices.

Enhanced spin-orbit interaction at the Sb/metal interface: The intrinsic spin-orbit interaction of antimonene is significantly amplified upon contact with a metallic substrate. This phenomenon could play a key role in the emergence of topological effects and opens new perspectives for applications in spintronics and quantum electronics.

Modification of the gold surface layer structure: The adsorption of antimony on a gold surface induces a notable reorganization of the metal’s atomic surface layer, leading to a rectangular symmetry instead of its initial hexagonal symmetry. This observation suggests potential implications for the growth of 2D materials and the modification of the electronic properties of metallic surfaces.

These results highlight the importance of substrate-material interactions in controlling the electronic properties of antimonene. They open new perspectives for its use in advanced electronic devices, particularly in spintronics and flexible electronics.

The results obtained within the SAGA project open several avenues for research and potential applications:

Control of the Sb-metal interaction for interface engineering

The strong interaction between antimonene and the metallic substrate, as revealed by our studies, suggests that controlled modification of interfaces could enable fine-tuning of the system’s electronic properties. Exploring other metallic surfaces and alloys will be essential to better understand and leverage this effect in functional devices.

Exploitation of the enhanced spin-orbit interaction

The electronic hybridization between antimonene and the metallic substrate induces a particularly strong spin-orbit interaction. This property could be harnessed for the development of advanced spintronic devices, particularly in quantum logic and spin electronics applications. Further studies on the spin electronic states and their dynamics are needed to confirm these prospects.

Structural modification of metallic surfaces and new electronic states

The formation of a rectangular unit cell on gold in the presence of antimonene is a key finding, indicating a deep reorganization of the metallic surface. This discovery could have important implications for the controlled growth of other 2D materials on metals, as well as for the design of new catalytic surfaces with tunable electronic properties.

The research on two dimensional (2D) materials is experiencing, nowadays, an extraordinary rise. Two are the main objectives that drives this scientific field: the fabrication and characterization of novel 2D materials and the vertical stacking of different 2D crystals (van der Walls heterostructures) with the desired properties. In this respect antimonene is attracting an increasing attention. Antimonene is a trivial semiconductor which is expected to be tuned to a 2D topoloigical insulator by strain. Moreover the antimonene/graphene interface has been proposed for energy applications such as in batteries, in electrocatalisis, and supercapacitors. In this project we will first investigate experimentally, for the first time, the electronic band structure of antimonene under tensile strain probing the existance of the topological phase. Once realized, strained antimonene will be a very promising candidate material for the observation of quantum spin Hall effect at room temperatures, which is a step forward toward the use of 2D topological insulators in electronic devices with low power consumption.
Secondly we will produce and address the electronic structure of a graphene/antimonene van der Waals heterostructure. With our sample growth method, we will be able to fabricate an heterostructure where the graphene and the strained antimonene band structure are located in the same region of reciprocal space. After the electronic hybridization of the two constituen, we will probe the trasfer of the antimonene topological protection on the graphene electronic properties by proximity effects. If the transfer will be efficient, we will than have a novel van der Waals heterostructure in which both the graphene outstaing electrons mobility and the antimonene topological protection are present and coupled toghether. Moreover the graphene will act as a protective membrane against oxidation making the system suitable for device fabrication.