Broken Structural Symmetry in Terahertz Detectors: Physical Mechanisms, Device Design, and Recent Advances

Breaking the structural symmetry of devices is a crucial design strategy that endows terahertz (THz) detectors with novel operating mechanisms and unique characteristics. This approach enhances their advantages in polarization detection, flexible electronics, self‐powered operation, broadband detection, and high‐speed sensing. Herein, this study reviews the working principles, device design strategies, and recent research progress of THz detectors with broken structural symmetry. The detection of THz radiation can be achieved through electronic and photonic techniques. The fundamental principles underpinning electronic and photonic techniques are based on symmetry breaking are rectification and the creation of a nonequilibrium state. Building on this foundation, this study further explores the design strategies and key challenges of asymmetric detectors from two perspectives: the channel and the electrodes (antennas). Specifically, it provides an in‐depth discussion on symmetry‐breaking‐induced phenomena, novel asymmetric structures, and dominant detection mechanisms. In addition, it offers systematic recommendations for material selection and structural optimization of detector channels and electrodes. Finally, it summarizes the key application scenarios of asymmetric THz detectors and discuss the challenges and opportunities in this field.