Multidirectional strain-induced thermoelectric figure of merit enhancement of zigzag bilayer phosphorene nanoribbons

Abstract

Abstract We have theoretically investigated strain-induced thermoelectric power generation properties of zigzag bilayer phosphorene nanoribbon. Since energy bandgap size and edge state dispersion play a significant role in the thermoelectric properties of such a structure, we have investigated the effect of strain in different directions on these two quantities. We have shown that by applying both tensile and compressive strains in different directions, it is possible to properly tune the energy bandgap size and adjust the edge state dispersion. We have also selected strain combinations in different directions that simultaneously increase the size of the energy bandgap and decrease the dispersion of the edge state. It has shown that with such combinations of strains, the maximal figure of merit has been improved by about two times compared to the pristine case.