Engineering the band structures of few-layer black phosphorus by adsorbed metal atoms

• Published in: Chemical physics letters 2020-02, Vol.740, p.137075, Article 137075
• Main Authors: Ge, X., Zhou, X.H., Ye, X., Chen, X.S.
• Format: Article
• Language: English
• Subjects: Band structures; Black phosphorus; First-principles calculations; Stark effect
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2019.137075

[Display omitted] •Charge transfer between adsorbed metals and BP builds an internal electric field.•Electronic structures of few-layer BP can be modulated by the Stark effect.•Phase transition of semiconductor-Dirac metal was found in few-layer BP. Few-layer black phosphorus (BP) is an important member in a family of two-dimensional materials because of its unique physical properties. But, for future applications, further tuning its electronic structure is necessary. Here we investigate, using ab initio density-function theory, the band structures of few-layer BP after the adsorption of the alkali metal atoms. It is shown that such adsorption can modify the band structures of few-layer BP in terms of the Stark effect. The charge transfer between the adsorbed atoms and few-layer BP is responsible for the internal electric field. Both the effects of the layer thickness and the concentration of adsorbed atoms on the band structures of few-layer BP are also quantitatively studied. The calculated results show that the band gap decreases with increasing the concentration of the adsorbed atoms. Further increasing the thickness of few-layer BP will close its band gap and induce the phase transition of semiconductor - Dirac metal. These findings imply that the electronic properties of few-layer BP can be modulated by adsorbing the alkali metal atoms.