Ultrafast, Broadband Photodetector Based on MoSe2/Silicon Heterojunction with Vertically Standing Layered Structure Using Graphene as Transparent Electrode

A MoSe₂/Si heterojunction photodetector is constructed by depositing MoSe₂ film with vertically standing layered structure on Si substrate. Graphene transparent electrode is utilized to further enhance the separation and transport of photogenerated carriers. The device shows excellent performance in terms of wide response spectrum of UV-visible-NIR, high detectivity of 7.13 × 10¹⁰ Jones, and ultrafast response speed of ≈270 ns, unveiling the great potential for the heterojunction for high-performance optoelectronic devices.