Carrier mobility of one-dimensional vanadium selenide (V₂Se₉) monolayer and nanoribbon systems: DFT study

Vanadium selenide (V₂Se₉) 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 V₂Se₉. In this study, we predicted the electronic and transport properties of V₂Se₉through computational analyses. We calculated the intrinsic carrier mobility of V₂Se₉monolayers (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 V₂Se₉is highly anisotropic, reachingμ2D,ze=1327cm²V^-1s^-1across the chain direction. The electron mobility of 1D NR systems in a (010)-plane ML of V₂Se₉along 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=775cm²V^-1s^-1) was higher than that of a 2D (010)-plane ML (μ2D,xe=567cm²V^-1s^-1). These results demonstrate the potential of vdW-1D crystal V₂Se₉as a new nanomaterial for ultranarrow (sub-3 nm width) optoelectronic devices with high electron mobility.