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

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.