Expanding the Photosensitive Area via Electrode-Geometry Design in Anisotropic Semimetal TaCoTe 2

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 TaCoTe 2, 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.