The Study Of Electrionic And Thermal Transport Properties Of Bilayer Borophene

With the advent of graphene in the 2004,people continue to design and prepare new two-dimensional materials,but only a very small number of single two-dimensional materials,and most of the structure has off-surface buckling,at present only Boride has the same pure plane structure as graphene.With the successful preparation of boron,it is found that the material has excellent properties in mechanics,electricity,optics,heat transport and so on.Boron in mechanical properties of a firm,soft,toughness in one of the two-dimensional materials;Boride is currently the lightest and thinnest metal;Dirac cones near Fermi energy levels have been found in the?₁₂2 structure and?₃ structure of boride;High temperature superconductivity with phonon regulation due to strong electro-acoustic coupling,high energy storage capacity and plasma excitation in the near visible light band,boron can be widely used in flexible electronic devices,optical control devices,lithium-ion and sodium ion batteries and composite design.Based on the first principle and the non-equilibrium green function method,this paper first gets the new structure of double-layer boron,analyzes the thermal transport and electrical transport of the structure,and designs the non-knot transistor based on the semiconductor boron.The main contents are as follows:?1?A new structure of double-layer boron was obtained.Based on the single-layer structure of boron?₁₂ prepared experimentally,we found that the double-layer boron was unstable by adhere,and there was a virtual frequency in the dispersion spectrum,which reduced the double distance and found a stable double-layer boron combined with B-B covalent bond,which had AA/AB two kinds of stacking methods,Analyzing AB structure from energy angle is more stable than AA structure.In addition,we constructed a two-layer AA and AB structure by adhere binding body structure,after calculation found that they are also stable.?2?The electrical transport and thermal transport properties of double-layer boron were studied.The study of the properties of electrical transport found that the I-V curves of AB and AA structures composed of?₁₂ have ohm characteristics,show good metal properties,and have a strong anisotropy,in addition,because the electronic distribution of AB structure is more local,so that when the bias phase at the same time the current is relatively small.The study of thermal transport properties found that the thermal conductivity of AB structure and AA structure is equivalent,although AB and AA structures have good thermal conductivity,but it is much smaller than the thermal conductivity of single-layer?₁₂,mainly due to the decrease of the phonon spectrum in the low frequency band.?3?Based on the electrical transport properties of semiconductor boride non-junction transistors.We take the semiconductor boron system as the research object,by doping to form N-type and P-type non-junction transistors,the I-V curve shows that P-type non-junction transistor transmission along the?direction of the best performance,switch ratio to reach 1.2*10⁴,and can improve its performance by increasing the length of the gate voltage,We are mainly based on the analysis of the density distribution and electron transmittance of the electron local state.