Si-Based NIR Tunneling Heterojunction Photodetector With Interfacial Engineering and 3D-Graphene Integration

Here, we have fabricated high-performance near-infrared (NIR) tunnelling heterojunction photodetectors (THPDs) by in-situ synthesizing three-dimensional (3D) graphene on Si with the insertion of a high- $\kappa $ tunnelling layer. Combining the high light-harvesting ability of 3D-graphene and the effective dark current suppression of the high- $\kappa $ tunnelling layer, the trade-off between the ultrafast response and ultra-sensitivity in graphene-based PDs is successfully bridged. Our device exhibits ultra-high responsivity (11.2 A/W), excellent specific detectivity ( ${5}.{9} \times {10}~^{{10}}$ Jones), and ultra-fast response ( $168~\mu \text{s}$ ) at the communication wavelength (1550 nm). This work provides a universal strategy to fabricate high-performance and low-cost graphene/silicon PDs in the communication wavelength.