Effect of Stone–Wales defect on the electronic and thermoelectric properties of armchair edge germanene nanoribbons

Abstract

The electronic and thermoelectric properties of germanene armchair-edge nanoribbons (GeNRs) with Stone–Wales (SW) defects are comprehensively investigated. By computing the band structures for nanoribbons of varying widths (N = 5, 6, and 7), I observe that SW defects can modulate the electronic properties, particularly the bandgap, in a width-dependent manner. The density of states (DOS) and transmission function analyses confirm these changes, showing that SW defects introduce scattering centers that affect charge carrier mobility. The voltage-current characteristics reveal a negative differential resistance (NDR) phenomenon in SW-defected GeNRs, indicating potential applications in non-linear electronic devices. Furthermore, the thermoelectric properties, as assessed by the Seebeck coefficient (S) and electronic figure of merit (ZT_e), show that SW defects can significantly enhance the ZT_e value, particularly for the N = 6 width, where ZT_e increases by approximately three times. These findings underscore the potential of SW defects to tailor the electronic and thermoelectric properties of germanene nanoribbons for specific applications.