In-situ grown 1D Te/2D Bi2O2Se van der Waals heterostructure for high-performance self-powered polarization-sensitive photodetection
Low-dimensional semiconductors have attracted widespread attention in next-generation broadband infrared photodetectors due to their tunable band structures, strong light-matter interactions, and compatibility with mixed-dimensional integration. Among them, tellurium (Te) and bismuth selenide (Bi2O2Se) are ideal candidates for high-performance detection owing to their inherent anisotropy, high carrier mobility, and broad spectral response. Constructing heterojunction photodetectors based on these materials enables self-powered operation and suppresses dark current. Heterojunction interface engineering and band structure design are crucial for high-performance Te/Bi2O2Se heterojunction photodetectors. Here, we in-situ construct a one-dimensional (1D) Te/two-dimensional (2D) Bi2O2Se heterojunction via a two-step chemical vapor deposition method, achieving a clear interface and type-II band alignment. The photodetector based on the Te/Bi2O2Se heterojunction, operating in self-driven mode, exhibits high performance: a responsivity of ~0.89 A·W−1 and a fast response time of ~29/41 μs under 1550 nm light irradiation. Furthermore, owing to the optical absorption anisotropy of tellurium, the device demonstrates a high polarization ratio of 2.8 and successfully enables polarization optical communication and polarization imaging applications. This work provides new insights into the in-situ construction strategy for high-quality mixed-dimensional van der Waals heterojunctions and advances high-performance photodetectors and their applications.