# Research Progress and Applications of 2D Antimonene
## 2 Theoretical Research and Experimental Methods
### Epitaxial Growth
#### 2.4.2 Preparation of Single-Layer Antimonene
High-quality antimony was evaporated from standard Knudsen cell with pressure of 1 \(\times\) 10\({}^{-10}\) mbar and beam source of 0.3 ML/min to prepare antimonene. At the same time, the difference of electronic structure on MoTe\({}_{2}\) substrate shows that different electronic structures will be caused by inconsistent electron transfer between different substrates. It proves that interface engineering can be used to adjust the interfacial charge transfer, so as to adjust the electronic structure of epitaxial monolayer. The morphologies of substrate and antimonene were detected by in situ monitoring of RHEED (reflection high-energy electron diffraction) patterns. The streaks of exposed SnSe indicated that it had high crystal quality and an atomically flat surface, and the streaks of antimony film indicated that Sb was grown layer by layer on SnSe. STM images showed high quality single-layer antimonene without obvious defects. The electronic structure was measured with STS, revealing band gap changes between 1, 2, and 3 ML layers. dI/dV spectra on both double and triple layers of antimonene showed the density of metallic states, indicating that the semiconductor-semimetallic crossing occurred at 2 ML. [PERSON] et al. [58] also prepared \(\alpha\)-phase antimonene with a thickness of 6.5 A on SnSe. The protection of asymmetric \(\alpha\)-phase antimonene against Dirac state was also studied. The anisotropy of antimonene with Dirac fermion states and Dirac states at high symmetric momentum points has been studied by Angle resolution spectroscopy and first principles. Compared with the spin-free Dirac state of graphene, spin-orbit coupling exists in the Dirac state of \(\alpha\)-phase. As described in Table 1, antimonene has been successfully prepared on substrates of compounds such as Bi\({}_{2}\)Te\({}_{3}\), Sb\({}_{2}\)Te\({}_{3}\) or PdTe\({}_{2}\), on substrates such as pure metal Ge, Ag and Cu, or on two-dimensional substrates. The antimonene generated on the substrate with small lattice mismatches such as Bi\({}_{2}\)Te\({}_{3}\), Sb\({}_{2}\)Te\({}_{3}\), PdTe\({}_{2}\) or Ge has a weak interaction with the substrate. The hexagonal honeycomb structure of antimonene with curved structure was prepared on the substrate with large lattice mismatch such as silver and copper. The antimonene was formed into alloy, and then further growth continued. The tension strain of the substrate could be higher than 20%, and the band gap of antimonene could be changed by this method. On graphene, MoS\({}_{2}\) and other two-dimensional substrates, due to its hexagonal structure similar to antimonene and the van der Waals force between them, antimonene can be grown on such substrates, and it is easy to generate continuous antimonene films. Because of the different charge transfer on different substrates, the electronic structure of antimonene will also be affected differently. For example, in different crystal faces of copper, the lattice constants of single-layer antimonene is not the same, and different substrates will lead to different tensile strains [16]. In addition to the influence of the substrate, the substrate temperature will also affect the adhesion of antimony; generally speaking, the higher the temperature of the substrate, the better the adhesion, but at the temperature above 300 \({}^{\circ}\)C, the adhesion will decline. At the same time, the rate of the beam source also has an effect on the preparation of antimonene. For example, when preparing antimonene on germanium substrate, [PERSON] et al. [12] proposed that the nucleation of the beam source at a high speed is conducive to the nucleation of 2D hexagonal island, while the growth of the beam source at a low speed can grow islands with a large area. Researchers generally use STM, AFM, LEED to study the morphology of antimonene, such as its honeycomb surface structure, size, etc. The interaction and chemical stability between antimonene and substrate were studied by XPS and XRD, while STS was used to study the band gap and electronic structure of antimonene.