A Study Of Electrical Transport Properties Of Stanene Nanoribbons

As the graphene was discovered,IV group such as silicene,germanene,and stanene of two-dimensional materials have become hot topics in condensed matter physics.In particular,stanene has quantum spin hall effect at room temperature,and topological superconductivity,which applied in electronic,spintronics and quantum computers fields.Based on the first-principle calculations and non-equilibrium Green's function,the electronical structure and electrical transportaton of stanene nanoribbons were nont only investigated by doping,hydrogenating surface modification and straining,but stanene junctionless transistor with the high on/off ratio was designed.Furthermore,the quantum size effect on the transport properties of nanoribbons was further analyzed,providing a theoretical base for the future application of nanoscale stanene nanoribbons in nanoelectronics.The main research of this paper include the following two aspects:1.N-type and P-type doping of armchair stanene nanoribbons.Based on the first-principle calculation and non-equilibrium Green's functions,it is found that with the hydrogen passivation the armchair-type stanene nanoribbons(ASnNRs)doped with B-and Al-atoms becomes P-type semiconductors.While doping with N,P,F,and Cl atoms,it becomes N-type semiconductors and still direct semiconductors with the reducing energy gap.Doping with N atom,the energy band at the Fermi level is strongly localized.The peak at the Fermi level in the electron transmission spectrum shows the decrease of the conductance.Based on the calculation results of the stability and conductance,we believe that the Al-doped and Cl-doped ASnNRs can be the better performance of P-type and N-type semiconductors,respectively.2.The study of the junctionless transistors electrical transport properties of stanene and stanane.Firstly,the effect of width on stanene nanoribbon transistor was studied,and the performance of the width of 18.72?(N=9)was worse than that of 11.47?(N=6),so the research object of SnNR was N=6.Secondly,the variation of energy gap was researched under different strain on stanene nanoribbons and on the hydrogenated stanane nanoribbons,and it was found that their variation trend were almost opposite.Finally,the on/off ratio based on stanene nanoribbons and stanane nanoribbons junctionless transistors is given,for stanene nanoribbons,the on/off ratio increases with the tensile strain and decreases with compressive strain,but for stanane nanoribbons,it was found that the hydrogenating can increase the on/off ratio greatly,and the compressive strain can also increase the on/off ratio.When the strain reaches-8.0%,the on/off ratio achieves2.44×10~5 which is about 20 times than none strain,we explain the phenomenon precisely by the relationship between the electrostatic potential of the potential barrier height and with the strain.