Graphene/Ge Photoconductive Position-Sensitive Detectors Based on the Charge Injection Effect

Area of Science:

• Materials Science
• Optoelectronics
• Nanotechnology

Background:

• Position-sensitive detectors (PSDs) are crucial for applications like optical communication and automatic alignment.
• Detecting invisible infrared light spots requires specialized high-precision sensors.

Purpose of the Study:

• To propose and demonstrate a new graphene/germanium (Ge) heterojunction architecture for position-sensitive detectors.
• To leverage the charge injection effect for amplified signals and high-efficiency photodetection.

Main Methods:

• Fabrication of a graphene/Ge heterojunction device.
• Characterization of the device's photoresponse to infrared light.
• Evaluation of performance metrics including response speed, responsivity, and detection distance.

Main Results:

• The graphene/Ge heterojunction PSD demonstrated a fast response speed of 3 μs.
• Achieved a high responsivity of approximately 40 A/W at the 1550 nm band.
• Exhibited a significant detection distance of 3000 μm.

Conclusions:

• The graphene/Ge heterojunction serves as an effective platform for near-infrared light spot position sensing.
• The charge injection effect within the heterojunction significantly enhances the device's performance.
• This technology holds potential for advanced optical communication and alignment applications.