Carrier mobility of one-dimensional vanadium selenide (V 2 Se 9 ) monolayer and nanoribbon systems: DFT study.

Vanadium selenide (V 2 Se 9 ) 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 V 2 Se 9 . In this study, we predicted the electronic and transport properties of V 2 Se 9 through computational analyses. We calculated the intrinsic carrier mobility of V 2 Se 9 monolayers (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 V 2 Se 9 is highly anisotropic, reachingμ2D,ze=1327cm 2 V -1 s -1 across the chain direction. The electron mobility of 1D NR systems in a (010)-plane ML of V 2 Se 9 along 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=775cm 2 V -1 s -1 ) was higher than that of a 2D (010)-plane ML (μ2D,xe=567cm 2 V -1 s -1 ). These results demonstrate the potential of vdW-1D crystal V 2 Se 9 as a new nanomaterial for ultranarrow (sub-3 nm width) optoelectronic devices with high electron mobility.