Giant anisotropic photocurrent modulated by strain in type-II Weyl semimetal Td-MoTe2

TL;DR

This study demonstrates how strain can significantly modulate the anisotropic photocurrent in a monolayer Td-MoTe2 Weyl semimetal, revealing potential for strain-engineered optoelectronic devices.

Contribution

It provides first-principles insights into strain effects on transport and photocurrent in Td-MoTe2, highlighting strain as a tool for tuning Weyl semimetal properties.

Findings

Strain along different directions drastically alters photocurrent magnitude.

Photocurrent can be suppressed or enhanced by applying strain along specific axes.

Strain modifies the energy band structure, including Weyl points.

Abstract

We build a Cu-MoTe2-Cu device model and use first-principles density functional theory to study the transport properties of single-layer Td-MoTe2. We obtained the effect of strain on the energy band structure, transport properties, and photocurrent. The strain-induced photocurrent shows an anisotropy that reflects the modulation of the energy bands, including the Weyl point, by strain. The photocurrent can be suppressed to almost zero when the strain is applied along the vacuum direction. In contrast, the photocurrent can be significantly increased when the strain is applied along the transport direction. The transport properties and magnitude of the photocurrent in the MoTe2-based device can be effectively modulated by adjusting the strength and direction of the strain.