Study On The Band Structure Of Monolayer MoS₂ And MoS₂/Graphene Heterojunction

With the development of science and technology,the preparation conditions of the traditional semiconductor field is becoming more and more mature,the technology is more and more advanced,and the electronic components become more and more sophisticated.Now the most advanced 14-10 nanometer transistor size has been reached,in recent years the size is expected to reach 6-4 nm.In this case the energy consumption of microelectronic devices has become a limiting factor in the further development of microelectronics industry.With 3D?3-Dimensional?chip technology potential is exhausted,the shackles of development of microelectronics chip industry need to truly innovative breakthrough.A new research area--the two-dimensional atomic structure of the material attracted much attention.The two-dimensional atomic structure material is different from other materials in the electronic structure and magnetic properties.Because of the characteristics of the geometric structure,the thickness of the electronic devices can be greatly reduced,so it becomes a hot material to manufacture integrated and miniaturized electronic devices.In this paper,the electronic structures of graphene-MoS₂ heterojunction and molybdenum disulfide under tension and external electric field were examined on the basis of the first principles density-functional theory.This paper is divided into five chapters.In chapter 1,we have briefly introduced the current semiconductor electronic chip industry development status and the popular 2D graphene materials,molybdenum disulfide and MoS₂/graphene heterojunction.The second chapter introduces the theoretical research of this paper: the method of density functional theory,energy band theory,projection augmented plane wave?PAW?pseudo potential method and the first principle calculation software package VASP.In chapter 3,we investigated the electronic structures of graphene-MoS₂ heterojunction under tension and external electric field.The charge transfer,the Schottky barrier,and the work function can also be controlled by external electric field.The fourth chapter studies the dependence of the band gap on the lattice constant and the spacing between S-S in a single layer of molybdenum disulfide.The fifth chapter summarizes the full text.