| Recently,arsenene and antimonene have been found to have moderate band gaps and mobility,indicating that these materials have potential applications in nano-electronic devices,photodetectors,and integrated circuits.Therefore,based on the first-principles calculation method,the cut one-dimensional antimonene nanoribbons were doped with magnetic atoms,the magneto-electronic properties and spin transport properties were studied,and the arsenene/SnS2 van der Waals(vdW)heterojunction,through the external electric field and vertical strain to tune its band gap and light absorption performance,in order to provide a reference for the practical application of new nanomaterials in photovoltaic devices,and finally studied the gas-sensitive properties of six kinds of toxic gas molecules adsorbed on the zigzag antimonene nanoribbons(ZSbNR).First,how to induce magnetism have become one of research hot topics.Here,we study geometrical stability and magneto-electronic properties for antimonene nanoribbons doped with low concentration transition metal(TM)atom(Mn,Fe,Cr and Co).It is found that these structures are stable by the formation energy calculation and molecular dynamics simulation.In particular,results show that these doped nanoribbons possess interesting magnetic phases,such as magnetic half-metal,magnetic half-semiconductor,and bipolar magnetic semiconductor,depending on the type of TM atoms.Furthermore,Mn-doped ribbon based magnetic device is constructed and the spin transport behaviors are investigated in details.The perfect double spin-filtering effect,excellent dual spin diode performance and giant magnetoresistance up to 109%are observed in this device.These findings might make a significant contribution for designing multi-function spintronic devices.Subsequently,we consider 2D Arsenene and SnS2 to construct vdW heterostructures of 6 possible ways of stacking.And based on first principles calculation,by comparing the different way of stacking heterostructures' binding energy,found that A3 stacking structure is the most stable in energy.So we detailed research on the electronic structure,band alignment,optical properties and vertical strain and electric field control for this structure.The calculation results show that the intrinsic band gap of the Arsenene/SnS2 heterostructures is much smaller than Arsenene monolayer.The bilayer heterostructure is type II band alignment,which can effectively promote separation of electron-hole pairs.Its light absorption range covers visible light to ultraviolet light,and the light absorption intensity is up to 105 orders of magnitude.Meanwhile,the vertical strain and electric field between the layers can tune the band gap of the heterostructures,in which the electric field can realize the transition from semiconductor to metal.The research results show that heterostructures has great potential for application in the future of optoelectronic devices and the photovoltaic field.Finally,we have studied the adsorption capacity of the six toxic gas molecules of PH3,H2S,SO2,NH3,NO and NO2 on ZSbNR.The calculation results that for the two gas molecules PH3 and H2S,they have a weak adsorption effect on ZSbNR.However,NO2 has formed a chemical bond with ZSbNR,which is not considered here.The remaining three gas molecules of SO2,NO and NH3 have strong adsorption energy and obvious charge transfer.We believe that ZSbNR has strong adsorption capacity for them.ZSbNR can be used to detect these three gas molecules.Finally,we calculated the transport characteristics of these adsorption systems.For the three molecules of SO2,NO,and NH3,the currents have obvious changes compare before adsorption,of which NO system changes the most,with a sensitivity of 245%.Based on the above results,we believe that ZSbNR can be used as a detection material for SO2,NO and NH3 gas sensing equipment. |
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