Computational Modeling, Simulation and Tight–Binding Analysis of Electronic Characteristics of Defective Germanene Nanoribbons for Future Applications of High Sensitivity Ge-Based Nanosensors

Abstract

In this research, the electronic characteristics of germanene sheet and nanoribbons using the computational modeling, simulation and tight binding approximation are investigated. Our analysis is focused on the pristine sheet of germanene as well as defective monolayer. The obtained results show that applying the Stone–Wales defect into the germanene monolayer changes the energy band structure. The E-k curves around the Dirac point are no longer linear, in which a band gap is opened, and the Fermi velocity is reduced. Furthermore, the main parameters such as density of states, carrier concentration in degenerate and non-degenerate limits, carrier effective mass, conductance and AC conductivity of germanene are analytically modeled with the inclusion of the spin–orbit coupling effect, temperature and ribbon width. Obtained results demonstrate that the inclusion of the spin–orbit coupling makes a small splitting of the energy levels and creating a small band gap. Finally, the Tight binding and computational values are compared with our simulation results and available data, and a rational agreement is reported in terms of trend and value. The findings of this study provide theoretical reference for the design of germanene-based nanosensors and optoelectronic devices.