Efficient Large-Area Graphene p-n Junction Terahertz Receivers on an Integrated Optical Platform

Area of Science:

• Optoelectronics
• Terahertz (THz) technology
• Graphene-based devices

Background:

• Graphene p-n junctions offer efficient light guiding and absorption in optoelectronic systems.
• Terahertz (THz) frequencies enable advanced applications in sensing, imaging, communication, and high-speed electronics.
• Existing graphene photodetectors face limitations in performance and scalability.

Purpose of the Study:

• To engineer an antenna-integrated graphene Salisbury screen (AgSS) p-n junction photodetector using industrial-scale graphene.
• To optimize electromagnetic coupling for enhanced THz detection.
• To achieve high performance competitive with established technologies.

Main Methods:

• Utilized large-area, industrially produced graphene.
• Engineered an antenna-integrated graphene Salisbury screen (AgSS) p-n junction.
• Optimized electromagnetic coupling by controlling antenna dimensions and distance to a reflective mirror.

Main Results:

• Achieved room-temperature noise equivalent powers below 300 pWHz⁻¹/².
• Demonstrated response times less than 5 ns.
• Obtained a power dynamic range exceeding four orders of magnitude at 2.86 THz.

Conclusions:

• The AgSS photodetector surpasses exfoliated graphene photodetector performance.
• The device performance is competitive with complementary metal-oxide semiconductor (CMOS) and micro-bolometer technologies at high THz frequencies.
• This advancement paves the way for new THz applications and improved high-speed electronics.