Impact of Defects on Thermal Transport in Germanene/Stanene Heterobilayers: An RNEMD Analysis

Germanene and stanene are two-dimensional allotropes of group - IV substrates which have recently attracted a vast attention in nanostructure device fabrication purpose. Stanene and germanene are graphene-like honeycomb structure materials except for its buckled structure. In this study, we generated defective structures with a variety of vacancies, such as point vacancy and bi-vacancy on the 2D germanene/stanene heterobilayer structure and afterwards characterized its thermal propagation by using reverse non-equilibrium molecular dynamics (RNEMD) simulation. We also varied the length of the bilayer to characterize the variation of thermal conductivity. Furthermore, we have investigated phonon density of state for better understanding. The bilayer nanostructures thermal conductivity decreases by $40-55 \%$ to a concentration of vacancy of $2 \%$. The germanene/stanene nanosheet studied in our investigation provides valuable insights for optimizing thermal transport in thermoelectric applications and enhancing control in low-dimensional germanene/stanene nanostructure-based nanoelectronics.