Transforming Boron Monoxide Monolayer with Light Metal Atoms: Stability and Electronic Properties

Abstract

Using density functional theory (DFT) calculations, we investigated the incorporation of light metal atoms (Li, Na, Be, and Mg) into the pores of a boron monoxide monolayer (p-BO ML), a recently identified member of the small-pore two-dimensional materials family. Our findings revealed that all metal-incorporated BO MLs (BO-M MLs) exhibited excellent dynamical, mechanical, and thermal stabilities. We also assessed their chemical stabilities in the presence of typical atmospheric gases, demonstrating good chemical stability for the BO-Li, BO-Na, and BO-Mg MLs. The electronic structures of BO-M MLs differed significantly from that of the p-BO ML, which has an indirect wide band gap of 3.78 eV. Specifically, BO-Li and BO-Be MLs were nonmagnetic semiconductors with narrow band gaps of 0.44 and 0.19 eV, respectively, while BO-Mg ML was a magnetic semiconductor with a band gap of 0.25 eV. In contrast, BO-Na ML exhibited metallic behavior. Detailed analysis showed that the observed variations in the electronic structures of BO-M MLs, compared to the p-BO ML, arose from a combination of charge transfer from the metal atoms to the BO skeleton and lattice distortion (expansion or shrinkage). The significant changes in the electronic structure of the p-BO ML upon metal incorporation also led to the modulation of its charge carrier mobilities. For instance, while p-BO ML exhibited a high hole mobility of 4522 cm² V^–1 s^–1, the presence of Mg atoms suppressed this hole mobility while significantly enhancing the electron mobility to 5753 cm² V^–1 s^–1. Furthermore, metal incorporation altered the negative curvature energy of the p-BO ML, a rare property with potential implications for mechanical metamaterials and catalysis. These insights provided a deeper understanding of the interplay between metal atoms and BO monolayers, paving the way for future research and technological advancements.