Research On The Application And Synergistic Manipulation Of Ionic Liquids Gel Based On Two-dimensional Material Micro-nanodevices

With the rapid development of information technology,traditional semiconductor technology has faced severe challenges in performance and power consumption at advanced nodes.Therefore,it is an urgent scientific problem to seek solutions to break through the performance bottleneck of traditional transistors from the material level,device level,and system level.With the failure of Moore’s Law,researchers have turned their attention to two-dimensional material systems with richer physical properties,in order to develop new high speed and low power information electronic devices.The atomic level thickness of two-dimensional materials can effectively reduce the short channel effects of transistors while maintaining high carrier mobility,and exhibit novel physical properties in electricity,mechanics,optics,etc.,and have electric field manipulable characteristics.One of the main parameters in electric field manipulate is carrier concentration,and effective manipulate of this parameter is crucial for the preparation of high-performance transistors.However,in traditional transistors,the controllability is often limited by the dielectric material.The rapidly developing ionic liquid brings new hope for electric field manipulate.Using an ionic liquid as the gate dielectric can create an electric double layer with only nanometer scale gaps,enabling greater field effect manipulation of physical properties compared to traditional transistors.However,the liquid properties of ionic liquids largely limit their applications.To improve the practicality of ionic liquids,this research has prepared thickness manipulated ionic liquid gel films with strict stoichiometric ratios,which retain the high ionic conductivity and high capacitance of the ionic liquid and can be directly applied in solid state devices,greatly expanding the application scope of ionic liquids.Based on two dimensional nanodevices,this paper characterizes and measures the ionic liquid gel films,and innovatively studies the photoelectric synergy manipulate of two-dimensional materials by the ionic liquid gel films,as well as the electrical transport measurement of magnetic ionic liquid gel film gate field effect transistors.The main research work is as follows:（1）A manipulable thickness ionic liquid gel film was prepared by strict stoichiometric ratio,and its capacitance frequency characteristics were tested as a capacitor based on the ionic liquid gel film.The capacitance at low frequency was 30μF/cm²,exhibiting super-capacitive properties almost identical to those of ionic liquids.Field effect devices were fabricated based on two-dimensional materials such as graphene,and compared with traditional Si O₂ gate dielectrics,the ionic liquid gel film gate dielectric devices exhibited significantly improved electrical characteristics such as transconductance and switching ratio,indicating the significant modulation ability of the gel film.In addition,using the ionic liquid gel film,graphene devices on flexible substrates were also fabricated,and the data showed that the film could be well adapted to flexible devices.（2）Due to their thickness dependent bandgap,most two-dimensional materials are sensitive to light,and the combination of optical and ionic modulation enables the synergistic manipulate of the optoelectronic properties of two-dimensional materials.This approach facilitates the research and exploration of various quantum phenomena in two-dimensional materials,and demonstrates the application prospects of novel two-dimensional optoelectronic devices.Firstly,ionic liquid gel films with different thicknesses were prepared and their transparency was measured.The films exhibited100%transmittance in the wavelength range of 390～800 nm.Then,field effect devices based on molybdenum disulfide were fabricated,and the transfer characteristics of the devices were measured by applying varying gate voltages.With increasing incident light power,the threshold voltage and subthreshold swing of the device significantly decreased,indicating that the device was more easily turned on under the synergistic effect of light and electric fields,and its switching rate between on and off states was faster.（3）Currently,most ionic liquids are composed of non-magnetic cations and anions.[BMIM]Fe Cl₄,as a paramagnetic ionic liquid,provides an additional degree of freedom magnetic ordering besides the strong regulation ability of ionic liquids.It is expected to induce rich transport phenomena at gate interfaces.We prepared manipulable thickness magnetic ionic liquid gel films through strict stoichiometric ratios.The films retained the properties of the magnetic ionic liquid while solving the problem of liquid spillage and expanding the application range of magnetic ionic liquids.Finally,we measured the electrical properties of graphene field effect transistors based on magnetic ionic liquid gel gate dielectric films.The resistance dependence on gate voltage showed the electrostatic field effect of ionic gating,and the transfer characteristics indicated that the magnetic ionic liquid gel films can effectively manipulate the carrier concentration of graphene and exhibit significant bipolar behavior,laying a foundation for subsequent multi-field manipulate of electric and magnetic fields.