Hexagonal boron phosphide monolayer exfoliation induced by arsenic incorporation in the BP (111) surface: A DFT study

• Published in: Applied surface science 2021-02, Vol.538, p.148163, Article 148163
• Main Authors: Munive Hernández, Onam, Guerrero-Sánchez, J., Ponce-Pérez, R., García Díaz, Reyes, Fernandez-Escamilla, H.N., Cocoletzi, Gregorio H.
• Format: Article
• Language: English
• Subjects: 2D materials; Boron phosphide; DFT; Hexagonal BP
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2020.148163

[Display omitted] •DFT results for As deposition on BP (111) suggest generation of atomic wires.•As incorporation promotes h-BP 2D monolayer, positive phonons suggest stability.•PDOS show substrate effect on h-BP such as gap reduction from 0.9 to 0.5 eV.•h-BP desorption energy of 0.26 eV/1x1 suggest exfoliation is possible. Density functional theory (DFT) calculations have been performed to investigate adsorption and incorporation of arsenic on the boron phosphide (111) surface. We considered different arsenic coverages. Dimers (1/2 ML), trimers (¾ ML), and atomic wires (1 ML) are formed upon increasing As coverage. However, at full monolayer, the most relevant result is the hexagonal boron phosphide (h-BP) monolayer formation, a 2D graphene-like structure. The h-BP monolayer phonon dispersion shows only positive frequencies indicating dynamical stability. At the same time, this suggests the possible h-BP monolayer exfoliation (desorption energy of only 0.26 eV/1x1) because it is weakly attached to the substrate by van der Waals interactions, as demonstrated by the non-covalent interaction index analysis. Electronic band structures indicate that this 2D layer may support direct transitions, making it useful for applications in electronic devices. The density of states and projected density of states complement the electronic properties analysis. We encourage the experimental realization of h-BP by As incorporation on BP surfaces.