Graphene-based plasmonic photodetector for photonic integrated circuits

Area of Science:

• Photonics and optoelectronics
• Materials science and engineering
• Nanotechnology

Background:

• Photonic-integrated-circuits (PICs) are crucial for optical communication and computing.
• Graphene's unique electronic and optical properties make it a promising material for PICs.
• Existing photodetectors often require complex integration with other photonic components.

Purpose of the Study:

• To develop a planar-type graphene-based plasmonic photodetector (PD).
• To enable the creation of all-graphene photonic-integrated-circuits (PICs).
• To investigate the light detection mechanism and performance of the proposed graphene PD.

Main Methods:

• Fabrication of a monolithic graphene plasmonic waveguide and PD structure.
• Characterization of the photodetector's response to horizontally incident light.
• Analysis of the photocurrent profile and its dependence on graphene-metal interface length.
• Measurement of the time response constants.

Main Results:

• The graphene PD successfully detected horizontally incident light.
• A Schottky-like barrier effect at the graphene-electrode interface resulted in photocurrents of opposite polarity.
• Photocurrent amplitude increased with increasing graphene-metal interface length.
• Time constants of less than 39.7 ms were obtained for the time response.

Conclusions:

• The developed planar graphene plasmonic PD is suitable for integration into all-graphene PICs.
• The device's performance is influenced by the Schottky-like barrier and interface length.
• The fast response time indicates potential for high-speed optical applications.