First-principles Investigation Of Doping And Biaxial Strain Effect On Antimonene

The discovery of graphene has attracted much attention to two-dimensional materials.Among them,the antimonene-based materials are highly sought after by researchers because of their good stability,non-toxicity and superior properties.In recent years,researchers have conducted a series of studies on antimonene,but the research on its magnetic and optical properties is still in the initial stage,and the research on the effect of strain on the properties of the material is very scarce.More importantly,the synergistic effect of doping and strain will has a significant impact on the electronic,magnetic and optical properties of materials,which requires researchers to pay a lot of attention.In this paper,the doped elements were selected as Cr and Fe,and the physical properties of the two doping systems are systematically explored.In addition,the effect of strain on the doping systems is also studied.The main contents include the following three aspects:(1)Cr-doped antimonene is a narrow indirect band gap semiconductor material.Although the doped system presents a magnetic ground state,it presents an anti-ferromagnetic state when considering the coupling effect between local magnetic moments.In addition,the introduction of Cr atoms can effectively improve the absorption efficiency of the antimonene-based materials in the visible region,especially in the low energy region.More importantly,the optimal doping concentration value is about 5.56%.(2)Fe-doped antimonene systems have a band gap value of about 0 e V and achieve room-temperature ferromagnetism.The(0,1)configuration of Fe doping not only has the lowest formation energy,but also the Curie temperature is higher than room temperature and the temperature is suitable.Therefore,adjacent sites should be selected as far as possible in the experimental fabrication.In addition,the absorption capacity of Fe-doped antimonene material in the near-infrared region was gradually enhanced with the increase of doping concentration,which greatly improved the light utilization efficiency of Fe-doped antimonene material in the low-energy region.However,from the absorption spectrum corresponding to the energy range of the visible light region,we found that Fe doping and the change of doping concentration did not effectively improve the light absorption capacity in this region.(3)In the Cr-doped antimonene systems under the biaxial strain,the band gaps of these doped systems undergo a process from gradually closing to re-opening,whether in biaxial compression and biaxial tensile strain.For Fe-doped antimonene,the doped system is a direct band gap semiconductor material at 8% tensile strain.As the compression strain strength continues to increase,the doping system gradually transforms from a metal into a half-metal material.In terms of optical properties,for the two doping systems regulated by biaxial compression strain,the absorption coefficient of visible light increases with the increase of compression intensity,which greatly improves the utilization efficiency of Cr and Fe doping systems in the visible region.