▎ 摘　　要

Two-dimensional graphene (2-D graphene) has limited application potential in optoelectronics because of its low light absorptivity and gapless property. This work presents photodetectors with increased light absorption efficiency, which couple 3-D graphene with the optical cavity structure of germanium-on-insulator (GeOI). Multiple reflections are generated at the 3-D graphene/GeOI heterojunction due to the unique plasmonic nanoresonator and optical cavity structures. The photodetectors exhibit excellent responsivity (R = 0.9 x 10(4) mA W-1) and specific detectivity (D* = 3.96 x 10(10) cmHz(1/2)W(-1)) under 1550-nm illumination with fast response rates, excellent reproducibility, and long-term stability. The technique paves the way for creating novel high-performance graphene-based photodetectors with hybrid architectures.