A family of LixBy monolayers with a wide spectrum of potential applications

Abstract

Using first-principles calculations and evolutionary structure search, we predict a series of kinetically and thermodynamically stable LixBy monolayers. While the Li2B2 monolayer (metallic) is found to be isotropic, the Li4B8 (metallic), Li2B6 (indirect bandgap semiconductor with a gap size similar to that of bulk Si), and Li2B12 (metallic) monolayers are anisotropic. Notably, the Li2B2 monolayer has a small Poisson’s ratio, the Li2B6 monolayer achieves a high hole mobility of 6.8 × 103 cm2·V−1·s−1 (as required for high-speed electronic devices), and the Li2B12 monolayer is auxetic.