Electronic and Vibrational Decoupling in Chemically Exfoliated Bilayer Thin Two-Dimensional V₂O₅

Abstract

The synthesis of high-quality two-dimensional (2D) transition metal oxides is challenging compared to 2D transition metal dichalcogenides as a result of the exotic surface changes that can appear during formation. Herein, we report the synthesis of bilayer 2D V 2 O 5 nanosheets with a thickness of ∼1 nm using the chemical exfoliation method and a comprehensive study on the vibrational and optical properties of bilayer 2D V 2 O 5 . We report, for the first time, a thickness-dependent blue shift of 1.33 eV in the optical bandgap, which signifies the emergence of electronic decoupling in bilayer 2D V 2 O 5 . In addition, a thicknessdependent vibrational decoupling of phonon modes observed via Raman spectroscopy fingerprinting was verified by computing the lattice vibrational modes using the density functional perturbation theory. We demonstrate that the manifestation of the electronic and vibrational decoupling can be used as a benchmark to confirm the successful formation of bilayer 2D V 2 O 5 from its bulk counterpart.

First-principles prediction of 1H-Na2Se monolayer: effects of external strain and point defects associated with constituent atoms

“…These studies have aroused tremendous interest in the 2D chalcogenides as MoS 2 [24,25], MoSe 2 [26,27], WS 2 [28,29], WSe 2 [30,31], TaSe 2 [32,33], NiTe 2 [34,35]. Taking the advantages of the advanced synthesis equipment, much more 2D materials families have been experimentally prepared such as layered metal oxides [36,37], layered metal halides [38,39], IIIA nitride [40,41], Mxenes [42,43]. From point of view of application, large-area synthesis of highquality 2D materials is desirable.…”