Expanding the Photosensitive Area via Electrode-Geometry Design in Anisotropic Semimetal TaCoTe₂

Two-dimensional materials exhibit strong light-matter interactions, rendering them ideal candidates for photodetectors. The key issue for photodetection is the separation of photogenerated electron-hole pairs, which are usually confined at the interfacial junctions. This confinement limits the active area in photodetectors based on two-dimensional materials. In this work, we demonstrate that through the codesign of electrode configuration and device geometry, a significantly expanded photoresponse area can be achieved in the anisotropic semimetal TaCoTe₂, thereby overcoming the limitation of line-shaped junction area in the traditional lateral structure. This large-area photocurrent exhibits polarization independence, stable spatial distribution against variations in temperature, and robustness across a wide range of wavelengths (500-2000 nm). This approach could be extended to other in-plane anisotropic semimetals, providing a viable pathway for developing broadband polarization-insensitive photodetectors.