The Investigation On Fabrication And Property Of Two-Dimensional Van Der Waals Heterostructure Transistors Based On Molybdenum Disulphide

In recent years,the scaling of conventional silicon(Si)-based semiconductor devices has been critically hindered by quantum effects,heat effects and etc.,which means the conventional route to improve the device performance by simply miniaturizing the size of components is facing increasing challenge.Novel low-dimensional semiconductor nanomaterials and their van der Waals(vd Ws)heterostructures have been attracting a lot of attention owing to their intriguing physical properties such as atomic-level thickness,absence of dangling bonds,ultra-high carrier mobility and on/off ratio,holding great promises in enabling advanced next-generation information devices.Given their good potential,it is important to explore low-dimensional semiconductor nanomaterials and their vd Ws heterostructures as well as their diverse properties.This thesis focuses on the fabrication and property investigation of several novel low-dimensional semiconductor nanomaterials and their information devices.Through a customized facile all-dry transfer technique,low-dimensional devices have been fabricated without any post-transfer lithographical and chemical processes,preserving the pristine material properties,which could help improve device performance.The main research efforts in this thesis are:1.High performance tunable Schottky barrier field-effect transistor(FET).Using the all-dry transfer technique,a high-quality graphene/molybdenum disulphide(MoS₂)heterostructure FET is fabricated,in which a Schottky barrier junction likely forms at the interface of the heterojunction.By tuning this device using gate voltage,the transistor exhibit clear field effect with reasonable on/off ratio.2.2D vd Ws heterostructure devices with improved contact and performance.Developed from the graphene/MoS₂ Schottky junction,a graphene/MoS₂/graphene heterostructure is designed as the channel material of an FET.Graphene and h-BN structures are used as the gate electrode and dielectric layer respectively.The device shows reasonable contact as well as device performance such as good on/off ratio.We further show that this 2D vd Ws heterostructure-based FET can also work well on flexible subtract.