Graphene Readout Silicon-Based Microtube Photodetectors for Encrypted Visible Light Communication.

The implementation of an advanced light receiver is imperative for the widespread application of visible light communication. However, the integration of multifunctional and high-performance visible light receivers is still limited by device structure and system complexity. Herein, a graphene-readout silicon-based microtube photodetector is proposed as the receiver for omnidirectional Mbps-level visible light communication. The integration of graphene-semiconductor material systems simultaneously ensures the effective absorption of incident light and rapid readout of photogenerated carriers, and the device exhibits an ultrafast response speed of 75 ns and high responsivity of 6803 A W. In addition, the microtube photodetector realizes the omnidirectional light-trapping and enhanced polarization photodetection. As the receiving end of the visible light communication system, the microtube photodetector achieves a data rate of up to 778 Mbps, a field of view of 140°, and the encrypted visible light communication of polarized light, providing a new possibility for the future development of the internet of things and information security.