# Research Progress and Applications of 2D Antimonene
## 2 Theoretical Research and Experimental Methods
### Epitaxial Growth
#### 2.4.1 Preparation of Multilayer Antimonene  
In 2016, [PERSON] et al. [9] grew antimonene with thickness of 1-50 nm and transverse size of 5-10 \(\upmu\)m on fluorophlogopite substrate by van der Waals epitaxy. It is also pointed out that the antimonene polygon has a conductivity of up to 10\({}^{4}\) S\(\cdot\)m\({}^{-1}\) and good optical transparency. The sample synthesis process is shown in Figure 7a, using a two-zone tubular furnace with separate temperature control. The antimony powder placed in the source area was heated to 660 \({}^{\circ}\)C to vaporize the antimony vapor. The fluorophlogopite substrate was placed in the downstream area at 380 \({}^{\circ}\)C. The synthesis process was kept for 60 min, then the furnace was cooled to room temperature. Figure 7b shows the growth pattern of antimonene on mica sheet. Figure 7c-f shows typical optical microscope image of several layers of antimonene sheets synthesized on a substrate with a scale of 5 \(\upmu\)m. These antimonenes exhibit several polygonal shapes, including triangles, hexagons, diamonds, and trapezoids. As shown in Figure 7g, the thickness of antimonene polygons as low as 4 nm(approximately 10 atomic layers) was observed with an atomic force microscope, and in fact, very small sheets of antimonene with transverse dimensions of approximately 100 nm and thickness as low as 1 nm (Figure 7h) were obtained. Microscopic study on HRTEM (High Resolution Transmission Electron Microscopy) and Raman spectroscopy showed that the obtained antimonene was a curved hexagonal structure \(\beta\) phase. Based on first principles and molecular dynamics calculations, the thermodynamic and kinetic stability of antimonene was illustrated. The air stability of antimonene and the thermodynamic stability of antimonene were demonstrated by the non-easy reaction between antimonene and oxygen. At the same time, the semiconductor parameter analyzer was used to characterize the electrical characteristics of antimony transistor. The surface antimony has good conductivity and current-voltage (Ids-Vds) characteristics at zero gate bias, and the I-V curve shows good ohmic performance. The resistance of 30 nm thick antimony device is 600 \(\Omega\), and the conductivity is 1.6 \(\times\) 10\({}^{4}\) Sm\({}^{-1}\). The conductivity change in antimonene device after 100 consecutive bendings was measured, and the conductivity decreased by only 4%, which proves its application potential as flexible transparent conductive electrode. In addition to van der Waals epitaxy, there is also molecular beam epitaxy. [PERSON] et al. [50] grew antimonene of 1-5 BL (BL is double layer) on Bi\({}_{2}\)Te\({}_{2}\)Se substrate, while antimonene of 1 BL is rare; most of them are 2-5 BL antimonene, and the area of antimonene is tens of nanometers. STM (Scanning Tunneling Microscope) was used to observe the formation of 2, 3, 4, 5 BL layers of antimonene on Bi\({}_{2}\)Te\({}_{2}\)Se substrate, with the area proportion of approximately 18%, 18%, 8%, 2%. To investigate the electronic structure of antimonene thin films, STS measurements were conducted. dI/dV curves were plotted along the lines  
Figure 7: Synthesis of antimonene polygons on mica substrate by van der Waals epitaxy: (**a**) Schematic diagram of synthesis in tubular furnace; (**b**) schematic diagram of van der Waals epitaxial; (**c**–**f**) optical images of typical anti–monad polygons with triangular, hexagonal, rhombus and trapezoidal shapes, respectively. The scale is 5 μm; (**g**) AFM images of typical triangular anti–monoene slices. The thickness is 4 nm. The scale is 1 mm; (**h**) atomic force microscope image of microantimonene sheet. The thickness is approximately 1 nm. The scale is 50 nm. Reprinted with permission from Ref. [9]. Copyright 2016, Springer Nature. crossing the two adjacent edges. The results show that the charge transfer between the film and the substrate depends on the thickness of the film. For two-dimensional materials with layered structure, it can also be used as a substrate for the growth of antimonene.