Electronic Properties Of Phosphorene-like Homo-and Heterostructures: A First Principles Study

Phosphorene is an excellent candidate for semiconductor materials in the post-silicon era owing to its high carrier mobility(¹0⁴ cm²V^-1s^-1)and visible light responsive band gap?¹ eV?.The phosphorene-like homo-and heterostructures usual inherit the electronic structural properties as well as some fantastic properties beyond their parent materials.It is an effective means for the performance manipulation of phosphorene based devices.Thus,the investigations on the phosphorene-like homo-and heterostructures are promising for semiconductor applications.In this paper,three typicalphosphine-likehomo-andheterostructures werestudied:phosphorene/hexagonal boron nitride?P/h-BN?heterostructure,90°twisted bilayered phosphorene homostructure,and chromium iodide/tungsten-selenide?CrI₃/WSe₂?heterostructure.The first-principles calculations were used to investigate the electronic structure properties of these three homo-and heterostructures,including carrier mobility,carrier effective mass anisotropy,and valley electron properties.In addition,in the viewpoint of application,strain and electric field are effective means for property modification.We also made a detailed discussion on the response of the electronic structure properties of the three materials under strain and electric field.The main conclusions are as follows:1.The h-BN substrate in P/h-BN heterostructure can induces large two-dimensional elastic modulus,and the increase value is more than 160 J/m².Meanwhile,due to wide band gap feature of h-BN,the electronic bands near Fermi level of P are well preserved in heterostructure,including the carrier effective mass and the deformation potential.Thus,the carrier mobility in P/h-BN heterostructure increases nearly 10 times compared to that of P.2.The 90° twisted angle induces isotropic atomic structure to the bilayer phosphorene homostructure due to the complementary structures along the armchair and zigzag directions of P.The electronic structure of 90?twisted bilayer phosphorene also exhibits an isotropic feature.And uniaxial strain can tune the electronic anisotropy,namely,the ratio of the effective mass along the?–X direction to that along the?–Y direction.Typically,the hole anisotropy reaches as high as 6under a small strain of 1%.While the high anisotropy only for hole carriers owes to that the conduction band is insensitive to strain.3.The WSe₂/CrI₃ heterostructure is type-II semiconductor,where the WSe₂ contributes the VBM while the CrI₃ offers the CBM.It means the transitions of electron and hole are easier to distinguish.More interestingly,the energy degenerated valleys of WSe₂ at two K points are well preserved in heterostructure.And the valleys split 10.3 me V under electric field pointing from WSe₂to CrI₃,which results from the interaction between the magnetic CrI₃ and the pseudospin of WSe₂.Moreover,due to the giant Stark effect of electric field,the the heterostructure transfers from the semiconductor to the metal at the critical field of 0.06 V/?.And the critical field for the evolution from Type-II to Type-I is-0.03 V/?.