High-performance graphene/n-Si hybrid photodetector toward self-driven optical communications

High-speed optical communication systems are built for real-time, massive, and remote information exchange; however, it is strongly reliant on the applied power. Herein, we developed a self-driven optical communication system based on a high-performance graphene/n-Si (Gr/n-Si) hybrid photodetector. Under zero bias, the Gr/n-Si device presents good performance at a wavelength of 520 nm, including the photoresponsivity of 0.27 A W−1, specific detectivity of 9.39 × 1011 Jones, and on/off ratio of 104 with a rise and fall time of 128 and 131 ns, respectively. This hybrid device also exhibits 3 dB bandwidth of 2.18 MHz as well as a small noise equivalent power of 1.68 × 10−17 W Hz−1/2. Furthermore, an optical communication system was constructed based on this hybrid photodetector, through which the audio and text signals were steadily and accurately transmitted under zero bias. Our work lays a solid foundation to demonstrate a promising application of Gr/n-Si hybrid devices toward self-driven optical communications.