Helicity Dependent Photocurrent in Eshelby Twisted GeS Nanowires

Helicity dependent photocurrent (HDPC) has been extensively studied for its potential applications in spintronics and quantum information sensing. The effect has been primarily observed, often at low temperatures, in materials such as topological insulators or Weyl semimetals, where surface symmetry breaking has resulted in a helical spin texture. HDPC may also arise from structural chirality in nanostructures. One such example is Eshelby twisted van der Waals GeS nanowires, where the in-plane crystal axes of each layer rotate along the nanowire axis forming a helical wire and representing a 3D moiré structure. Here, we report these twisted GeS nanowires exhibit clear HDPC at ambient conditions. The left and right circularly polarized light produces a photocurrent difference of up to 10%, when the light is propagated with a large incident angle (around 70 degrees) such that the wavevector is nearly parallel to the nanowire axis. This highlights the potential for developing optoelectronic devices capable of selectively responding to light of a given handedness, without requiring costly cooling systems.