Boron-based 2D monolayers have attracted tremendous interest due to their unique physical and chemical properties. In this paper, we report novel pentagonal monolayers, B₂S and B₂Se, which are predicted to be energetically, dynamically, and thermally stable based on density functional theory. At the HSE06 level of theory, they exhibit a moderate indirect bandgap of (e.g., 1.82 eV for Penta-B₂S and 1.94 eV for Penta-B₂Se). Strain-induced indirect-to-direct bandgap transition, high hole mobility ($~{10}^3$ ${\mathit{Cm}}^2{V}^{-1}{S}^{-1}$) and strong optical absorption (α $~{10}^5$ ${\mathit{Cm}}^{-1}$) in the visible region are observed for these monolayers. Moreover, the electronic band structures and optical spectra are tunable by mechanical strains suggesting their visible light-harvesting capabilities for optoelectronic applications. In this way, the pentagonal family of 2D materials is now expanded to include boron-containing photocatalytic materials for water splitting applications.

硼基二维单层膜由于其独特的物理和化学性质而引起了极大的兴趣。在本文中，我们报告了新型五边形单分子层 B ₂ S 和 B ₂ Se，基于密度泛函理论预测它们在能量、动态和热方面是稳定的。在 HSE06 理论水平，它们表现出中等的间接带隙（例如，Penta-B _{2 S 为 1.82 eV，Penta-B 2} Se为 1.94 eV ）。应变诱导的间接到直接带隙跃迁，高空穴迁移率（$~{10}^3$ ${\mathit{厘米}}^2{五}^{-1}{\mathrm{小号}}^{-1}$）和强光吸收（α$~{10}^5$ ${\mathit{厘米}}^{-1}$) 在可见区域观察到这些单层。此外，电子能带结构和光谱可通过机械应变进行调节，表明它们在光电应用中具有可见光捕获能力。通过这种方式，二维材料的五边形家族现在扩展到包括用于水分解应用的含硼光催化材料。