Polarization-Sensitive Photodetectors Based on Anisotropic 2D Selenium and Its Multifunctional Applications

Polarization-based communication and on-chip imaging devices are crucial for the next generation of multifunctional devices. Due to their thickness-dependent properties and polarization detection capabilities, single-element two-dimensional (2D) materials have emerged as promising candidates. However, achieving devices with low static power consumption, tunable polarization-sensitive photodetection, and a broadband photoresponse remains challenging. Herein, we report high-performance polarization-sensitive photodetectors based on 2D selenium (Se), photodetectors that exhibit an excellent polarization ratio of 3.09, an ultralow dark current (∼10–12 A), a fast response time (∼3 ms), as well as air stability exceeding two months without encapsulation. Its unique intrinsically anisotropic atomic chain structure enables a polarization-sensitive photoresponse, which can be effectively modulated by gate voltage and power density. The polarized light-encrypted communication and polarization imaging based on a 2D-Se photodetector are further demonstrated. This study opens up a promising pathway for next-generation high-performance and multifunctional photodetectors.