▎ 摘　　要

GeSn materials with tunable bandgaps covering the entire shortwave infrared (SWIR) band present a new paradigm for silicon-based SWIR photodetection. However, crystal quality remains a major limitation for the realization of high-performance photodetectors owing to the large lattice, thermal expansion coefficient mismatching, and Sn segregation. Here, the Sn self-catalyzed growth of lateral GeSn strips on Si(111) substrates by Molecular beam epitaxy (MBE) is investigated. These GeSn strips are defect-free by relaxing the large lattice mismatch and introducing (111)-parallel planar dislocations at the GeSn/Si interface. A graphene-GeSn strip hybrid structure photodetector is fabricated, showing more than 3000 fold increase in photocurrent and an apparent improvement in temporal response compared to the detector without gra-phene. A high responsivity of 1.23 A/W at 1310 nm and 1.08 A/W at 1550 nm is achieved. This work presents a new approach for the integration of microscale but highly crystalline material on a silicon-based platform and shows future applications in the SWIR regime.(c) 2023 Elsevier B.V. All rights reserved.