## 3 Results
When the growth temperature is below T\({}_{\text{critical}}\), the surface energy cannot break the chemical bond of Sb\({}_{4}\), so they will deposit as the tetrahedral form. Hence, it tends to grow more randomly, which can be proven by the XRD spectrum (Figure 1d). For A-1, it is amorphous, but, for B-1, it has a clear Sb (003) peak, which indicates the crystal structure. As for A-2, it has a stronger Sb (003) peak and other Sb peaks, which indicates it is polycrystalline feature. From Figure 1d, we can see when we use Sb\({}_{4}\) molecules, the Sb (012) peak can be observed, and, from literature, we know that the Sb (012) peak may be a feature of antimonene [28; 31]. Accordingly, we chose Sb\({}_{4}\) molecules to grow more antimonene samples. We tried to grow several samples with different growth temperatures, as shown in Figure 2b-h. Figure 2a is the sapphire substrate that is used in this study. Before each growth, we undertook pretreatment on the c-plane sapphire substrate, so that terraces were formed on the surface. After annealing, Sb\({}_{4}\) molecules were used to grow antimonene at different growth temperatures in the MBE chamber. Table 2 shows the details. From A-1 and A-2, we can see that the antimony covers the entire sapphire surface. However, when the growth temperature rises, the surface energy is getting higher, so the grown antimony will change to a triangular prism structure and cannot cover the entire surface. When the growth temperature rises to 265 \({}^{\circ}\)C, fewer antimony structure can be seen, but when the growth temperature rises to 270 \({}^{\circ}\)C, it is hard to find the grown antimony by atomic force microscope(AFM) scan. Hence, we are convinced that 270 \({}^{\circ}\)C is too high for antimony molecules to stick and nucleate. A similar trend is observed by Raman spectroscopy measurements. Raman data (Figure 2i) show that Raman peaks can be seen at 110 cm\({}^{-1}\) and 150 cm\({}^{-1}\), which indicate the antimony structure [28]. Besides, under 265 \({}^{\circ}\)C, we can still see antimony Raman peaks and triangle column structure, but under 270 \({}^{\circ}\)C, it shows no antimony. Accordingly, the highest nucleation temperature on an annealed sapphire substrate in our study is between 265 \({}^{\circ}\)C and 270 \({}^{\circ}\)C, which is similar to the value that was reported by [PERSON] et al. [34; 35]. In addition, we studied the stability of the grown samples. As we can see in Figure 2j,k, the AFM images on the same sample show that similar surface morphology is observed one year later, which means no apparent change occurred. Hence, we believe the antimonene samples are stable in the air for at least one year [18]. Figure 3a shows the XRD data that were measured from group A samples. It can be seen that, when the growth temperature is between 200 \({}^{\circ}\)C-250 \({}^{\circ}\)C, the grown antimony has preferentially crystalized signals such as Sb (003) peak at 23.7\({}^{\circ}\)and Sb (012) peak at 28.7\({}^{\circ}\). Figure 3b shows the zoomed-in diffractogram in that region. We can calculate the integrated area of each peak and easily obtain the ratio of Sb (012)/Sb (003) as a function of the growth temperature. Since Sb (012) peak is the indicator of antimonene formation, this ratio can be used to find the preferred growth condition for antimonene. We define a term to represent the total crystalline content, which is calculated as the sum of the integrated areas of antimony (003) and (012) peaks, based on Figure 3b. As shown in Figure 3c,d