| The electrical properties of single-material-gate and triple-material-gate carbon nanotubesfield-effect transistors(CNTFETs) are cacluated based on the non-equilibrium Green’s function ofCNTFETs. The results show that the electrical properties of carbon nanotubes are similar to that ofthe silicon MOSFET in the output characteristic curve; carbon nanotubes exhibit different electricalproperties with different chiral values N. In particular, the nanotubes possess the highest on/offcurrent ratio when N=3p+1. Compared with the single-material-gate carbon nanotubes,triple-material-gate carbon nanotubes have a higher on/off current ratio, a better control ability ofthe gate and a more shorter channel effect.It proposes two new structures of CNTFETs which are triple-material-gate HALO dopingcarbon nanotubes and triple-material-gate linear doping carbon nanotubes. The results show thatlinear doping can improve the frequency characteristics of carbon nanotubes. With the increase ofthe linear doping length, it will lead to larger cutoff frequency. The reasonable length can make thecutoff frequency of the heterogeneous gate carbon nanotubes reach up to THz, while has an idealon/off current ratios. By comparing the static and high-frequency characteristics between carbonnanotubes and graphene, it can be found that the carbon nanotubes possess higher on/off currentratios, larger cutoff frequency and suppress the short channel effect effectively.The paper discusses the high-frequency characteristics of CNTFETs based on plasma fluidmodel. Shortening field effect transistor channel length can improve the response amplitude. Thereare two kinds of modes of terahertz detection response: resonance and non-resonance mode. Inresonance mode when ωτ>>1, the detection curve has an obvious peak value, when the signalfrequency is equal to the eigen frequency or harmonic frequency of the plasma wave. Innon-resonance mode when ωτ <<1, the curve is smooth in the whole frequency range. |
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