Negative differential resistance effect and current rectification in WS2 nanotubes: A density functional theory study

Electronic properties of (n,0) zigzag tungsten disulfide WS2 nanotubes and transport properties of (7,0) zigzag nanotube heterojunction are investigated by utilizing non-equilibrium Green's function formalism (NEGF). The results reveal that inclusion of the spin-orbit (SO) coupling significantly reduces the value of the band gap about 15.52\%. Additionally, strong negative differential resistances take place in voltage regions between-0.2 and-0.4 V as well as between-0.5 and-0.6 V. Moreover, temperature dependent transport properties are elab-orately investigated in this work. The results show that, as the temperature increases to 600 K the stronger negative differential resistance occurs in both positive and negative bias voltages. Finally, a reasonably large degree of rectification ratio can be established. Our analysis can provide a comprehensive perspective on the NDR effect and current rectification in WS2 nanotubes and can be used as a beneficial guide for future designing of novel logical and nanoelectronic and spintronic devices.

Automated summary

Non-equilibrium Green's function formalism (NEGF) was used to investigate the electronic properties of (n,0) zigzag tungsten disulfide WS2 nanotubes and the transport properties of (7,0) zigzag nanotube heterojunction. The results showed that the spin-orbit (SO) coupling significantly reduced the band gap by about 15.52%. Moreover, strong negative differential resistances were observed in voltage regions between -0.2 and -0.4 V as well as between -0.5 and -0.6 V. Temperature dependent transport properties were also elaborately studied, revealing a stronger negative differential resistance at both positive and negative bias voltages as the temperature increased to 600 K. Lastly, a reasonably large degree of rectification ratio was established. The findings of this study provide a comprehensive perspective on the NDR effect and current rectification in WS2 nanotubes and serve as a beneficial guide for future design of novel logical, nanoelectronic, and spintronic devices.