Study On The Electronic Transport Properties Of Graphene And Its Nitride Structure

With the semiconductor industry's demand for device miniaturization and the flourishing development of nano-science and technology,graphene and the emerging two-dimensional graphene-like materials have attracted people's extensive research interest.These two-dimensional materials have only one atomic layer thickness,exhibiting different physical properties from bulk materials,and have brought new development opportunities to the semiconductor industry.The underlying physical mechanism has also been excavated by people.In this paper,the electronic structure and transport properties of graphene and its nitride materials are studied by using density functional theory and non-equilibrium Green's function.The effective regulation of electronic structure and interesting electron transport phenomena are discovered,then the hidden physical mechanisms are explained.This study provides a good alternative for the design and application of nanoelectronic devices.Taking advantage of the edge sensitivity of the zigzag graphene nanoribbon,unlike the reported regulations of edge modification with heteroatoms or the edge carbon ring reconstruction,for the first time,the linear carbon chain is vertically grown on the edge of the nanoribbon,so that the carbon chain does not follow the direction of electron transport,but is perpendicular to the direction of electron transport,constructing a new nanoelectronic device.It is found that the electronic transport properties are closely related to the number of atoms in the carbon chain and have parity.This is mainly due to two kinds of carbon-carbon bond length,i.e.,double bond structure and single triple bond structure,and the former destroys the?operation symmetry of the nanoribbons,allowing the energy bands near the Fermi level to couple with each other and increasing the current.The purpose to effectively regulate the transport of electrons through the number of carbon atoms in the carbon chain is achieved.Utilizing the structural characteristics of the distribution of C,N heteroatoms and holes in two-dimensional C₂N-h2D material,it is cut into zigzag and armchair nanoribbons with various edge morphology.The effective regulation of the electronic structure of C₂N nanoribbons is achieved through the structure's own edge morphology and edge heteroatom modification,and nanoelectronic devices composed of C₂N nanoribbons with various width or different electronic properties are constructed.The transition between the metal and the insulator controlled by the bias is realized,and interesting electronic transport phenomena such as a negative differential resistance effect,a multiple negative differential resistance effect,and rectification are found,and the rectification ratio is as high as 10¹⁰.In addition,due to the uniform distribution of holes,the C₂N structure is more suitable for functionalization,doping of transition metal atoms in the center of the hole achieves effective control of the electronic structure and magnetic properties of the C₂N nanoribbon,and increases the spin polarization rate to 100%,providing a basis theoretical guidance for future C₂N device applications.Similar to C₂N material,two-dimensional C₃N material also has C and N heteroatoms but no large holes,so the edge morphology after two-dimensional C₃N tailoring into nanoribbons depends on the type of edge atoms.The paper focuses on the study of the regulation of the electronic structure of C₃N nanoribbons by the edge atomic species.It is found that whether the C₃N nanoribbons are semiconductors depends on whether the nitrogen atoms appear at the top and bottom edges at the same time.By constructing nanoribbons of different edge types into step-like bipolar devices,the effects of edge types,step sizes,and interface barriers on the electron transport phenomena are studied,and interesting physics phenomenon such as rectifier diode behavior and negative differential resistance effects are discovered.The simple cutting method and abundant electron transport properties of C₃N materials are beneficial to its application in nanoelectronic devices.