Prediction Of Two-Dimensional Silicon Phosphides New Structure

Since the discovery of graphene in 2004,the research on the exploration of structures and properties of new two-dimensional?2D?materials has aroused a wide interest.In recent years,in addition to graphene,two-dimensional materials such as two-dimensional hexagonal boron nitride?h-BN?,transition metal sulfide,oxide and black phosphorene have also been prepared,greatly expanding the properties and applications of two-dimensional materials.The continuous discovery of new two-dimensional materials has opened up an increasingly bright road for the fields of microelectronics,optoelectronics,optical engineering and new energy.In this paper,a new two-dimensional SiP structure is proposed based on the two-dimensional CP structure and the two-dimensional SiP structure studied previously,since Si and C are from same group with similar properties.This research is mainly divided into three parts:?1?several types two-dimensional silicon phosphides with silicon forming three bonds and two-dimensional SiP similar to 2D?-?compound tetragonal structure are investigated.In the process of study,we first optimized these structures and then calculated their stability and electronic property.The results show that in the two-dimensional compounds of SiP,Si atoms can not only form the sp³hybridization structure with four bonds,but also form the structure with three bonds.Based on our calculation,only three two-dimensional SiP??₁-SiP,?₁-SiP and tetragonal SiP?are stable.In addition,molecular dynamic?MD?simulation shows that?₁-SiP,?₁-SiP and tetragonal SiP have good thermal stability at room temperature.We also explored their electronic properties and the effects of in-layer strain on electronic properties.With the increase of tensile and compressive strain,?₁-SiP,?₁-SiP and tetragonal SiP,the binding energy of the three kinds of structure decreases.?₁-SiP exhibits a semiconducting property,and its band gap will transform from a semiconductor to a metal with the increase of tensile and compressive strain.These structures are new structures and will have some new properties,which have guiding significance for material preparation.At the same time,the two dimensional SiP compound system is also more perfect.?2?We studied the bulk phase structure of SiP,judged whether the bulk structure of two-dimensional SiP new structure is a layered structure,and explored the stability and properties of bulk SiP.The results show that bulk SiP structure is not a layered structure.As a result they can't mechanical stripping from the bulk structure,but may be obtained by epitaxial growth on a suitable substrate.The electronic band structure of SiP shows that all the calculated bulk SiP are metallic.?3?We studied the extension of the two-dimensional SiP new structure.The two-dimensional tetragonal SiP structure is stable.Moreover,its binding energy is the highest among the seven SiP structures,and the structure is special.Thus,we studied several tetragonal SiP isoelectronic counterparts??-?compounds and?-?compounds?by using isoelectronic counterparts methods.The first principle density functional theory was used to optimize the structures,and caculated their stability and electronic properties.The research shows that nearly none of?-?compounds and?-?compounds are dynamically stable,and most of them don't like such structure.