Carrier mobility of one-dimensional vanadium selenide (VSe) monolayer and nanoribbon systems: DFT study.

Vanadium selenide (VSe) is a true one-dimensional (1D) crystal composed of atomic nanochains bonded by van der Waals (vdW) interactions. Recent experiments revealed the mechanical exfoliation of newly synthesized VSe. In this study, we predicted the electronic and transport properties of VSethrough computational analyses. We calculated the intrinsic carrier mobility of VSemonolayers (MLs) and nanoribbons (NRs) using density functional theory and deformation potential theory. We found that the electron mobility of the two-dimensional (2D) (010)-plane ML of VSeis highly anisotropic, reachingμ2D,ze=1327cmVsacross the chain direction. The electron mobility of 1D NR systems in a (010)-plane ML of VSealong the chain direction continuously increased as the thickness increased from 1-chain to 4-chain NR (width below 3 nm). Interestingly, the electron mobility of 1D 4-chain NR along the chain direction (μ1D,xe=775cmVs) was higher than that of a 2D (010)-plane ML (μ2D,xe=567cmVs). These results demonstrate the potential of vdW-1D crystal VSeas a new nanomaterial for ultranarrow (sub-3 nm width) optoelectronic devices with high electron mobility.