Near‐Infrared, Self‐Powered and Polarization‐Sensitive Photodetector Based on GeSe–MoTe2 p–n Heterojunction

Abstract Near‐infrared polarization‐sensitive photodetectors hold the advantages of capturing light signals with high performance while shielding stray light, endowing them the potential applications in target tracking, remote sensing, and computer vision. Here, a 2D polarization‐sensitive, self‐powered, and near‐infrared photodetector is constructed by vertically stacking multilayer p‐type GeSe on n‐type MoTe 2 . The type‐II energy band alignment and anisotropic crystalline structure of GeSe components allow an effective separation and transmission of polarized light excited carriers, enabling the capability of polarization‐sensitive and self‐powered photodetections. The device exhibits broadband spectral coverage from visible (405 nm) to near‐infrared (1310 nm) wavelength range. At zero bias and 808 nm light, the responsivity ( R ) and detectivity ( D *) can reach 52 mA W –1 and 4.1 × 10 11 Jones, respectively. Due to the extremely low dark current of several tens of fA, the photoswitching ratio can reach close to 10 6 . More importantly, because of the strong in‐plane anisotropic orthogonal structure of GeSe, the polarization sensitivity can reach 5.4 under 635 nm polarized light illumination, outperforming the polarization‐sensitive photodetectors based on 2D anisotropic materials and heterostructures. This work provides an effective strategy of using anisotropic/isotropic GeSe/MoTe 2 heterojunctions to realize self‐powered, near‐infrared, and polarization‐sensitive photodetectors with integrated angle‐resolved optoelectronic devices.