Super high-performance 7-atomic-layer thermoelectric material ZrGe2N4.

ABSTRACT

7-Atomic-layer materials have attracted much attention recently because of their rich structures and more-abundant properties than 3- and 5-atomic-layer materials. However, the thermoelectric properties of the new monolayer materials have not been explored yet. Here, we investigate the thermoelectric conversion efficiency of a 7-atomic-layer structure ZrGe2N4, which is selected from a series of 7-atomic-layer structures according to their stabilities and thermoelectric properties. The results indicate that this material is an excellent candidate for high-performance thermoelectric materials. Its figure of merit ZT value is close to 4.0 at high temperature. The high efficiency originates from two factors one is the lower thermal conductivity of ZrGe2N4 and the other is the decoupling of electron and phonon transport in the 7-atomic-layer structures.