Anisotropic PdSe ₂ /GeAs Heterostructures with Switchable Photocurrent Polarity for Polarization Imaging and Programmable Logic Gates

The stacking of different 2D materials provides an extraordinary platform for multifunctional optoelectronic devices. However, for 2D anisotropic materials, which offer an additional degree of freedom for controlling in-plane photoelectric performance, their stacking for multifunctional device applications remains limited. Here, as an example, we fabricated an anisotropic PdSe₂/GeAs heterojunction and achieved multifunctional operations. First, the device exhibits self-driven performance with a responsivity of up to 680 mA/W, a detectivity of 1.1 × 10¹¹ Jones, and an external quantum efficiency as high as 158%. In addition, the device demonstrates excellent capabilities in high-resolution polarization imaging and image convolution processing. Furthermore, the polarity of photocurrent in the device can be switched as a function of gate voltage. By combining multi-modal control strategies through both electrical and optical regulation, the device achieves multi-state logic outputs and programmable photonic logic gate functions. This work provides new insights into the development of highly integrated and multifunctional optoelectronic systems based on anisotropic heterostructures, paving the way toward intelligent optical sensing and high-speed optical communication applications.