Sub‐Millimeter‐Scale Monolayer p‐Type H‐Phase VS2

Abstract 2D H‐phase vanadium disulfide (VS 2 ) is expected to exhibit tunable semiconductor properties as compared with its metallic T‐phase structure, and thus is of promise for future electronic applications. However, to date such 2D H‐phase VS 2 nanostructures have not been realized in experiment likely due to the polymorphs of vanadium sulfides and thermodynamic instability of H‐phase VS 2 . Preparation of H‐phase VS 2 monolayer with lateral size up to 250 µm, as a new member in the 2D transition metal dichalcogenides (TMDs) family, is reported. A unique growth environment is built by introducing the molten salt‐mediated precursor system as well as the epitaxial mica growth platform, which successfully overcomes the aforementioned growth challenges and enables the evolution of 2D H‐phase structure of VS 2 . The honeycomb‐like structure of H‐phase VS 2 with broken inversion symmetry is confirmed by spherical aberration‐corrected scanning transmission electron microscopy and second harmonic generation characterization. The phase structure is found to be ultra‐stable up to 500 K. The field‐effect device study further demonstrates the p‐type semiconducting nature of the 2D H‐phase VS 2 . The study introduces a new phase‐stable 2D TMDs materials with potential features for future electronic devices.