Gomes Djardiel da S, Ribeiro Luiz A, Pereira Marcelo L
Faculty UnB Planaltina, Materials Science Postgraduate Program, University of Brasília, Brasília, Federal District 73345-010, Brazil.
Institute of Physics, University of Brasília, Brasília, Federal District 04455, Brazil.
ACS Omega. 2024 Dec 10;9(51):50570-50578. doi: 10.1021/acsomega.4c08395. eCollection 2024 Dec 24.
Two-dimensional (2D) silicon-based materials have garnered significant attention for their promising properties, making them suitable for various advanced technological applications. Here, we present Irida-Silicene (ISi), a novel 2D silicon allotrope inspired by Irida-Graphene (IG), which was recently proposed and is entirely composed of carbon atoms. ISi exhibits a buckled structure composed of 3-6-8 membered rings, unlike its planar carbon counterpart. Using density functional theory (DFT) calculations, we discuss its stability, structural, electronic, optical, and mechanical properties. Our results indicate that ISi exhibits bond lengths ranging from 2.27 to 2.32 Å, with buckling of 0.78 Å, the latter significantly larger than that reported for silicene. The nanomaterial demonstrates good dynamical and thermal stability at room temperature, without phonon dispersion with imaginary frequencies, and a cohesive energy of -4.98 eV/atom. ISi is a metallic monolayer with a Dirac cone above the Fermi level in the center of the band, and it is also a nonmagnetic material. Furthermore, the system displays anisotropic electronic properties, showing semiconducting behavior depending on the direction, with a region devoid of electronic states between -0.2 and -0.8 eV. The optical activity of ISi is primarily observed in the infrared and ultraviolet regions, with a peak for photons with an energy of 5.5 eV in the latter case. Finally, regarding mechanical properties, we report estimated elastic and bulk moduli of approximately 34 and 41 N/m, respectively. The system can withstand up to 15% of strain, depending on the direction and type of deformation. These findings suggest that ISi holds potential for various technological applications, expanding the potential uses of 2D silicon-based materials beyond silicene.
二维（2D）硅基材料因其具有的优异性能而备受关注，使其适用于各种先进技术应用。在此，我们展示了铱硅烯（ISi），这是一种受铱石墨烯（IG，最近被提出且完全由碳原子组成）启发的新型二维硅同素异形体。与平面碳对应物不同，ISi呈现出由3 - 6 - 8元环组成的褶皱结构。使用密度泛函理论（DFT）计算，我们讨论了其稳定性、结构、电子、光学和机械性能。我们的结果表明，ISi的键长范围为2.27至2.32 Å，褶皱为0.78 Å，后者明显大于硅烯报道的值。这种纳米材料在室温下表现出良好的动力学和热稳定性，不存在虚频声子色散，内聚能为 - 4.98 eV/原子。ISi是一种金属单层，在能带中心的费米能级上方有一个狄拉克锥，并且它也是一种非磁性材料。此外，该系统表现出各向异性的电子特性，根据方向显示出半导体行为，在 - 0.2至 - 0.8 eV之间存在一个无电子态区域。ISi的光学活性主要在红外和紫外区域观察到，在后一种情况下，能量为5.5 eV的光子有一个峰值。最后，关于机械性能，我们报告估计的弹性模量和体模量分别约为34和41 N/m。根据变形方向和类型，该系统可承受高达15%的应变。这些发现表明，ISi在各种技术应用中具有潜力，扩展了二维硅基材料除硅烯之外的潜在用途。
