Realization of High Thermoelectric Performance Of Black Phosphorus / Black Arsenic Hybrid Heterojunction Nanoscale Devices by Interface Engineering

Abstract

Thermoelectric properties of two different black phosphorus and black arsenic hybrid lateral heterostructure (LHS) and vertical van der Waals heterostructure (vdWHS) nanodevices are investigated based on first-principle density functional theory combined with non-equilibrium Green's function method. Results show that thermoelectric properties are significantly enhanced by constructing vertical van der Waals heterostructures, and high ZT values are derived from energy filtering effect of the interface for low and medium frequency phonons when a weak coupling contact is adopted. Due to the decrease of phonon transmittance and the spectrum range of effective phonon transmission, the vertical van der Waals heterostructure with smaller contact area and slightly lower phonon thermal conductance finally shows better thermoelectric performance, and optimal ZT value is close to 3.5 when T is 350 K. Our theoretical work provides a new approach and theoretical guidance for achieving high performance of high-density integrated circuits in microelectronics industry.

Keywords: thermoelectric properties, Hybrid heterostructure nanodevice, Interface scattering, Density Functional Theory, Non-equilibrium Green's function method