5d Transition-metal Atom/Dimer Adsorption Tailored Electronic Structure Of Two-Dimensional Materials

Nowadays,there are more and more micro-or nano-electronic devices electronic devices based on two-dimensional(2D)materials,and their practical applications are also developing continuously,because 2D materials have many excellent physical properties.Transition metal dichalcogenides(TMDC),monolayer carbonitride and other materials have unique electronic,optical and catalytic properties,and have a good prospect in many applications such as electronic devices and other fields.In addition,researchers often tailored the electronic structure and physical properties of two-dimensional materials by methods like atom adsorption,atom doping,biaxial strain and so on,which provides theoretical basis for their research and practical application of materials.Based on density functional theory,this dissertation mainly investigated the electronic structure and magnetic properties of the two-dimensional WSe₂ monolayer adsorbed by transition metal atoms Os,Ir and their dimers,transition metal atoms Os,Ir and their dimer adsorbs two-dimensional g-C₃N₄ can adjusts its electronic structure through strain,the electronic structure of the transition metal atoms Os,Ir and their dimers adsorb two-dimensional VI₃ monolayer can be changed by applying strain.By calculating the electronic structure of WSe₂ monolayer and the adsorption of atoms and dimers,it is found that adsorption changes the band structure of WSe₂monolayer.Among them,Ir–Co dimer adsorbed WSe₂ monolayer with-22.9 me V valley splitting,and the perpendicular magnetic anisotropy(PMA)can be obtained in some adsorption situations.The adsorption structure can be tuned by applying biaxial strain.For example,when Ir-Co dimer is adsorbed,a larger PMA and changes of properties such as electronic structure can be obtained.The electronic structure and magnetic properties of the transition metal atom dimers adsorbed g-C₃N₄ monolayer are calculated.It is found that the adsorption of Ir atoms,Os-Ir,Ir-Os,Os-Os and Ir-Ir dimers adsorb g-C₃N₄monolayers can obviously introduces magnetism,and the band gap of g-C₃N₄ monolayer also has a certain range of changes under the atoms adsorption.The Os atom and Ir-Ir dimer adsorption will show a PMA when strains are applied,which has potential application at room temperature.The electronic structure of the VI₃ monolayer adsorbed by 5d transition metal atoms and their dimers are calculated.The atomic adsorption changes the band structure of the VI₃ monolayer.During the adsorption of atoms and its dimers,Os,Ir atoms and Ir-Co dimers adsorb VI₃ monolayer show PMA,which has good application prospects in spintronics devices.