Theoretical Study On Electronic Structure And Optical Properties Of New Two-Dimensional Materials

Two-dimensional materials have potential applications in electronic devices,gas storage and separation,catalysts,high-performance sensors and other fields for their unique physical properties.In this paper,the antimonene-based heterostructures are constructed,and the influences of biaxial strain on the electrical properties are studied by using the first-principles method.In addition,two-dimensional structures of iodide BiI3 and YI3 are predicted by CALYPSO software,and their mechanical properties,electronic structure and optical properties are discussed.The main conclusions are as follows:1.The properties at ground state and electronic structures under biaxial strains of the three heterostructures(G/Sb,h-BN/Sb,As/Sb)based on antimony were studied.The results show that the h-BN/Sb van der Waals heterostructure can achieve the transition from indirect bandgap to direct one under stress,and the bandgap value increases from 0.13 eV to 1 eV and then gradually decreases.At the same time,As/Sb heterostructure changes from semiconducting to semi-metal,realizing the continuous bandgap modulation from 1eV-0 eV under the condition of biaxial strain,which corresponding to the near-infrared and far-infrared spectral ranges.2.The two-dimensional layered materials YI3 and BiI3 were predicted by CALYPSO software.The phonon spectra show that the BiI3 was stable and YI3 was unstable.The optical absorption properties of BiI3 were calculated by HSE06 + SOC method,and the results indicate that BiI3 has good optical response in the visible range and also has a higher light absorption coefficient.