High-performance thermoelectric properties of strained two-dimensional tellurium

Abstract

Elemental two-dimensional (2D) materials in monolayer form are attractive due to their simplicity and indigenous properties. In the present study, we investigate the influence of biaxial strain on group VI elemental 2D material of tellurium, which has been discussed for its potential in various applications. Considering realistic estimates of strain that may be imposed to monolayer Te through van der Waals heterostructing with other known 2D materials, we demonstrate that the structural, electrical, and thermal transport properties can get strongly influenced by strain. Importantly, through strain engineering, the thermoelectric performance of elemental 2D Te in $p$-type doping can be made comparable to that of the known binary or ternary layered compound at room temperature, and can outperform the known binary or ternary layered compounds at high to moderate temperature. The $ZT$ of monolayer Te is found to reach a value of 6.07 at 800 K under tensile strain, being larger than 2 for temperature greater than 400 K. Our study provides a way to tune the thermoelectric properties of 2D Te for future applications.