Unveiling a novel silicene-like material: A DFT study on pentahexoctite-silicon and its optoelectronic characteristics

Abstract

Silicon-based two-dimensional (2D) materials, including well-known silicene, have garnered considerable attention due to their potential in advanced optoelectronic applications. Here, we introduce a novel 2D silicon variant, pentahexoctite silicon (PH-Si), inspired by the unique structural attributes of pentahexoctite carbon. By using state-of-the-art density functional theory (DFT) calculations and ab initio molecular dynamics (AIMD) simulations, we investigated the fundamental optoelectronic and structural traits of PH-Si. Our findings reveal that PH-Si boasts promising electronic properties characterized by anisotropic conductance and metallic behavior along specific directions. We also examine its structural and dynamic stability through phonon calculations and AIMD simulations. PH-Si structural stability was also confirmed by its low formation energy of −3.62 eV and dynamical stability at 1000 K. The material exhibits optical absorption in visible (Vis) and ultraviolet (UV) spectral regions, positioning it as a potential Vis-UV detector and absorber. Additionally, we assess its crucial mechanical attributes, encompassing elastic stiffness constants, Young’s modulus (ranging from 5 to 40 GPa), and a Poisson ratio of 0.8, collectively offering valuable insights into its mechanical performance. The comprehensive exploration of PH-Si’s properties is a step towards diversifying silicon-based 2D materials, opening channels for innovative applications in the rapidly evolving field of flat electronics.