Impact of diameter and temperature on domain suppression by hot electrons in zigzag carbon nanotubes under constant electric field

The impact of the diameter of zigzag carbon nanotubes (CNTs) and temperature on domain suppression by injection of hot electrons at a strong rate along the axis of the tubes are investigated. The semiclassical Boltzmann kinetic equation was utilized in the theoretical work to derive the current density when hot electrons are available. First, the study was carried on by changing the value of the zigzag carbon nanotube's diameter at a fixed temperature. Second, we vary the temperature while keeping the diameter constant. For the semiconducting zigzag CNTs, increasing both the diameter and temperature enhances the suppression of the electric field domain required for a higher potential of terahertz radiation generation. However, in the metallic zigzag CNTs, we observed an enhancement of domain suppression when the diameter and temperature were decreased. These observations suggest that larger-diameter semiconducting zigzag CNTs at higher temperatures and smaller-diameter metallic zigzag CNTs at lower temperatures are better candidates for the generation of terahertz radiation.