Investigating the electronic properties of pentagraphene and pentasilicene and its application in semiconductor devices

Pentasilicene and pentagraphene are two novel two-dimensional allotropes of silicon and carbon, respectively, characterized by a pentagonal lattice structure and semiconducting electronic properties. However, differences in their structures lead to distinct electronic characteristics. In this study, we simulated a field-effect nanotransistor using both materials and analyzed the resulting differences from a physical standpoint. Our simulations employed density functional theory (DFT) in conjunction with the non-equilibrium Green's function (NEGF) method. The results demonstrate that pentasilicene has significant potential for use as a field-effect transistor, while pentagraphene is not suitable for this application due to its relatively large energy band gap. We observed that the pentasilicene field-effect transistor exhibits stable switching behavior with a high on/off current ratio exceeding 10⁴ at room temperature. Additionally, the device's output characteristics reveal negative differential conductance with a favorable peak-to-valley ratio.