Modeling And Simulation Of Graphene And TMDs Negative Differential Resistance Device

The new type of resonant tunneling diode(RTD)has low power consumption,high speed,and special I-V curve characteristics,so that it has broad prospects in the fields of oscillator circuits,logic devices,wireless communications and neural networks.At the same time,with the rapid development of integrated circuit field,the size of devices is constantly approaching the limit of"Moore's Law".The development of existing silicon-based technologies has encountered bottlenecks.In this situation,the need for a material that can replace silicon in the field of integrated circuits is imminent,because two-dimensional materials have a series of excellent properties such as higher carrier mobility,good stability,and easy preparation.More and more researchers are turning their attention to the emerging two-dimensional materials.This article is mainly based on theoretical calculations and simulations,using different two-dimensional materials,based on the principle of quantum tunneling,to achieve the NDR effect of two-dimensional devices.Firstly,the band gap of GNR is related to its width.Starting from graphene,the wide and narrow bands of GNR are used to build devices.The GNR at both ends of the device are n-type doped,and the graphene narrow band connected to the graphene broadband in the scattering region is p-type doped to build a potential barrier.Discrete energy levels are formed locally.The quantum well of the scattering region is used to realize the NDR effect of the GNRFET.In order to extend the quantum well based on the negative resistance effect on graphene to other two-dimensional materials,this paper constructs a Mo S₂ field effect tube.Mo S₂ was chosen because it has different phases,and among these different phases,there are both a 1T phase that exhibits metallicity and a 2H phase that exhibits semiconductors.In this paper,1T-type Mo S₂ is used as the electrode,and the scattering region of the device is composed of 2H,1T,and 2H Mo S₂ heterostructures.Due to the large band gap of 2H-type Mo S₂ in the scattering region,a potential barrier is formed at both ends of the 1T-type Mo S₂.Under the local effect of this barrier,the 1T-type Mo S₂ forms a discrete energy level.In the role of this quantum well,Mo S₂devices also show NDR characteristic.The innovation of this subject is the design of new two-dimensional material NDR devices based on the quantum well mechanism,including GNR NDR devices and Mo S₂NDR devices.First,a wide-narrow band of graphene with different widths is used to form a quantum well.Based on the quantum well,free electrons in the source region of the device pass through the quantum well through resonant tunneling to form a multiple NDR effect.Then,the design method of designing NDR devices based on the quantum well mechanism is extended to other new two-dimensional material devices.Through this design method,the NDR effect is also observed on the output characteristic curve of the Mo S₂ device.Simultaneously,the devices composed of different TMDs were simulated,and it was found that when the atoms constituting the TMDs were"heavy",there was no obvious discrete energy level in the quantum well.Therefore,when designing TMDs NDR devices,it is necessary to prefer the“lighter”atoms.This mechanism of designing NDR devices through the quantum well mechanism provides guidance for the design of other two-dimensional material NDR devices.Based on two-dimensional NDR devices,this article explores various aspects of two-dimensional NDR devices from device design principles to device modeling and simulation.It provides a basis for further research on this subject and design of new two-dimensional material NDR devices.