Giant anisotropic photocurrent modulated by strain in Weyl semimetal T_d-MoTe₂

We built a Cu-MoTe₂-Cu device model and used first-principles density functional theory to study the transport properties of the T_d-MoTe₂ heterojunction. We obtained the effect of strain on the energy band structure of the bulk T_d-MoTe₂, the transport properties, and photocurrent of the Cu-MoTe₂-Cu device. 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.