Polarization-Sensitive Photothermoelectric Response Based on In-Plane Anisotropic Antiferromagnetic Semiconductor CrSBr

Two-dimensional (2D) magnetic materials are driving plenty of attention due to their scientific and technological significance. In-plane anisotropy in such a system further broadens their application areas especially in various angle-resolved functional devices. Here, we report an air-stable 2D antiferromagnetic semiconductor (CrSBr) with a strong intrinsic optical and optoelectronic in-plane anisotropy. First, the results of polarization absorption spectra demonstrate the presence of a linear dichroism (LD) transition in CrSBr, which shows consistency with our density functional theory (DFT) calculations. Besides, representative angle-resolved reflection and refraction in CrSBr flakes have been further characterized, indicating their anisotropic light–matter interactions. Moreover, a polarized photodetector based on the photothermoelectric (PTE) effect mechanism is fabricated successfully, with the dichroic ratio of I_p-max/I_p-min as measured up to 2.26 under 850 nm excitation. These results indicate a promising potential to advance the application of 2D van der Waals magnetic materials in polarization-sensitive optics, optoelectronic devices, and opto-spintronics.