High‐Performance Polarization‐Sensitive Photodetectors Based on Fully Depleted T‐MoS ₂ /MoTe ₂ /B‐MoS ₂ Heterojunction

Abstract With the development of emerging technologies, polarized photodetectors play an irreplaceable role in many fields, including communication and defense. However, the simultaneous optimization of photodetector parameters, including sensitivity, quantum efficiency, response speed, and polarization resolving capability, is still a great challenge. To address the challenge, a sandwiched Top‐MoS ₂ /1T′‐MoTe ₂ /Bottom‐MoS ₂ heterostructure photodetector is proposed. The device features two opposing built‐in electric fields, significantly improving the efficiency of separating and collecting photogenerated carriers and reducing their travel distance. When operated in self‐powered mode, the device demonstrates exceptional responsivity of 331 mA W ⁻¹ , detectivity of 2.48 × 10 ¹² Jones, and a rapid response time of 35/98 µs at 638 nm. Compared with the MoS ₂ /1T′‐MoTe ₂ device, the responsivity is increased by nearly 3‐fold, and the detectivity is increased by nearly 22 times. In addition, the device displays competitive polarization sensitivity with polarization ratio values of 8 under 638 nm. Leveraging these outstanding performance metrics, high‐resolution polarization imaging capabilities have been successfully demonstrated using this device. The T‐MoS ₂ /1T′‐MoTe ₂ /B‐MoS ₂ device improves the Degree of Linear Polarization (DOLP) from 0.5 to 0.79 compared to conventional the MoS ₂ /1T′‐MoTe ₂ devices. This work opens new avenues for improving the performance of anisotropic semi‐metallic heterojunction photodetectors, thereby providing new directions for the design of high‐performance and multifunctional photodetectors.