# Research Progress and Applications of 2D Antimonene
## 2 Theoretical Research and Experimental Methods
### Epitaxial Growth
#### 2.4.2 Preparation of Single-Layer Antimonene  
In 2016, [PERSON] et al. [53] first reported the preparation of single-layer antimonene on Bi\({}_{2}\)Te\({}_{3}\) and Sb\({}_{2}\)Te\({}_{3}\) substrates with lattice mismatch of 1.9% and 0.8%, respectively, by molecular beam epitaxy. Subsequently, the preparation of single-layer antimonene on Bi\({}_{2}\)Se\({}_{3}\), PdTe\({}_{2}\), Ge, Ag and Cu substrates has been reported by [PERSON] et al., who deposited Sb on the substrate at room temperature and precisely controlled its growth rate. In order to study the chemical environment of Sb film, XPS (X-ray photoelectron Spectroscopy) measurements were conducted before and after the deposition of antimony on Sb\({}_{2}\)Te\({}_{3}\) and Bi\({}_{2}\)Te\({}_{3}\) substrates. The results show that Sb film is not coupled with the substrate, and the binding energy of Sb film in Sb/Bi\({}_{2}\)Te\({}_{3}\) is less than 0.09 eV compared with Sb/Sb\({}_{2}\)Te\({}_{3}\). It has a relatively weak van der Waals force or relatively small charge transfer. The electronic structure of antimonene was measured by ARPES (Angle resolved photoemission spectroscopy). The results show that lattice distortion and charge transfer effect lead to the change in surface state band dispersion. The results show that the antimonene prepared by the method has high crystallinity, but its area is small. In 2018, [PERSON] et al. [54] prepared antimonene on Bi\({}_{2}\)Se\({}_{3}\) substrate and grew antimonene films at room temperature by controlling the rate of 0.53 A/min in a temperature-controlled Knudsen cell. The deposition of 0.15 ML (ML denoted as single-layer antimonene) and 2 ML of antimony on the substrate was observed with STM. Islands formed at a lower coverage and they reached coalescence at slightly higher than 2 ML. STM test showed that the coverage rate of antimonene was low, the uniformity was poor and the film size was small. At the same time, STM showed the existence of honeycomb surface structure of antimonene. PdTe\({}_{2}\) was selected as the substrate for the epitaxy growth of antimonene for the following reasons: its lattice mismatch with the substrate is only 0.4%, and it has a chemically stable surface. Compared with the absence of lattice mismatch, the compressive strain will make the film grow prematurely from nucleation into the transition zone, while the tensile strain is the opposite. When the lattice mismatch is too large, the film will be subjected to a large stress, which may tear the film and transform the two-dimensional growth into three-dimensional growth. [PERSON] et al. [55] prepared single-layer antimonene on PdTe\({}_{2}\) substrate. At the same time, the first-principles calculation was carried out based on density functional theory (DFT), and the experimental results were clarified. In an ultra-high vacuum (UHV) chamber with a pressure of 2 \(\times\) 10\({}^{-10}\) mbar, antimony atoms were vaporized in the Knudsen cells and deposited on a PdTe\({}_{2}\) substrate at a substrate temperature of 400 K, as described in Figure 9a. STM, LEED and XPS were used to characterise the film. As shown in Figure 9b, there are only six diffraction spots in this LEED pattern. These diffraction spots come from the lattice of antimony thin film and PdTe\({}_{2}\) substrate, indicating that antimony has a lattice almost consistent with the surface of PdTe\({}_{2}\), and the adsorption layer of antimony is an ordered lattice. As shown in STM Figure 9b, the antimony atomic layer on the surface of PdTe\({}_{2}\) is smooth and homogeneous with no obvious defects. The height of the atomic layer is 2.8 A, as shown in Figure 9e. Figure 9c shows a high-resolution STM image of single-layer antimonene, which is a graphene-like honeycomb lattice. Figure 9f shows the height profile of the flexed honeycomb lattice along the blue line in Figure 9c, which indicates that the periodicity of the graphene-like honeycomb lattice is 4.13 \(\pm\) 0.02 A. XPS measurements were used to study the interaction between antimonene and substrate.