Study On The Device Fabrication And Transport Property Of Novel Two-Dimensional Material And Heterostructures

Since the discovery of graphene,two-dimensional?2D?materials have become the frontier research focus in the field of international materials due to their novel optical,electrical,thermal and mechanical properties.At present,2D materials have covered semiconductors,conductors,insulators and superconductors,penetrating into many existing research fields and expanding some new areas.Especially,the excellent electrical transport properties of 2D materials make it possible to have important application prospects in the fields of new generation nano-electronic devices and optoelectronic devices.Although 2D materials and devices have made great progress recently,there are still many problems to be explored and solved for their practical application.Among them,the device fabrication of 2D materials and heterostructures,and the discovery of new physical properties are the core contents of recent research.In this paper,the fabrication and transport characteristics of new 2D materials and heterostructures devices are studied.The main research contexts are summarized as follows:?1?The effects of different substrates on the electrical characteristics of SnS_0.5Se_1.5devices and the Schottky rectification characteristics are studied.The transfer curves of HfO₂/SnS_0.5Se_1.5 shows hysteresis,while the h-BN/SnS_0.5Se_1.5 device presents intrinsic property of the semiconductor.Moreover,Schottky rectification characteristics are found to be controlled by gate and illumination intensity.This multifunctional Schottky device provides a new option for prospective transistors.?2?BP/SnS_0.5Se_1.5 vdW pn heterostructure are fabricated,and their tunable photoresponse properties are studied.Not only the value of photocurrent can be tuned,its sign?positive or negative?can also be tuned.In addition,the photocurrent response can also be controlled by channel length of each semiconductor in the heterostructure.Moreover,the logical characteristics are also been found to be tuned.This novel device expands the functions of optical detection and logic devices.?3?The tunable polarity behaviour of BP/SnS_0.5Se_1.5 device is studied.It was found that the polarity can be regulated by the source-drain voltage.It can transform from p-type to n-type,showing multiple polarity states.Moreover,the polarity can also be controlled by illumination and channel length.This form of device offers a variety of polarity options and can evolve into a future multifunction device.?4?Low temperature transport properties of Weyl semi-metal WTe₂ thin layers with rich physical properties are studied.It does not exhibit magnetoresistance saturation when subjects to high fields,confirming the compensation of electrons and holes.The lower magnetoresistance values in our samples are demonstrated to be caused by decreased carrier mobility.The dependence of mobility on temperature indicates the main role of optical phonon scattering at high temperature,and competition of different phonon scattering forms at low temperature.In this study,Weyl semi-metal electronic devices are analyzed in depth,and more information is provided for them.