Strain-controlled thermoelectric properties of phosphorene hetero-bilayers

TL;DR

This paper explores how uniaxial strain can reversibly control the thermoelectric and electronic properties of phosphorene hetero-bilayers, enabling potential applications in novel device design.

Contribution

It introduces a strain-controlled method to selectively manipulate electronic and thermal conductivities in phosphorene hetero-bilayers based on first-principles calculations.

Findings

Reversible semiconductor-metal transition induced by strain.

Selective control of electronic and thermal conduction in hetero-bilayers.

Potential for designing strain-tunable thermoelectric devices.

Abstract

The application of strain to 2D materials allows manipulating the electronic, magnetic, and thermoelectric properties. These physical properties are sensitive to slight variations induced by tensile and compressive strain and to the uniaxial strain direction. Herein, we take advantage of the reversible semiconductor-metal transition observed in certain monolayers to propose a hetero-bilayer device. We propose to pill up phosphorene (layered black phosphorus) and carbon monosulfide monolayers. In the first, such transition appears for positive strain, while the second appears for negative strain. Our first-principle calculations show that depending on the direction of the applied uniaxial strain; it is possible to achieve reversible control in the layer that behaves as an electronic conductor while the other layer remains as a thermal conductor. The described strain-controlled selectivity could be used in the design of novel devices.