2017-786 Infrared Detectors And Heat Recycling Cells Based On Metallo-Graphene Nanocomposites

SUMMARY

UCLA researchers in the Department of Electrical Engineering have developed a high-responsivity photodetector that utilizes metallo-graphene nanocomposites for superior detection of infrared wavelengths.

BACKGROUND

Infrared photodetectors are key tools used in multiple applications ranging from medical thermography (detecting irregular blood flow) to building inspections (determining efficiency of heat insulation). Continuous improvements are being made to device detection bandwidths, sensitivity, and responsivity. Currently, graphene is becoming an appealing candidate for the development of infrared photodetectors due to its low-cost nature and ability to generate photocarriers across a broad spectral range. However, their use has been limited by tradeoffs among responsivity, operation speed, and broadband.

INNOVATION

UCLA researchers have developed a novel photodetection system using gold-patched graphene nanoribbons. This system, unlike previous graphene photodetectors, does not utilize quantum dots and defect states, effectively bypassing limitations on bandwidth and responsivity, increasing response time by seven orders of magnitude and bandwidths by one order of magnitude. This novel photodetector is capable of ultrabroad operation bandwidth from the visible (800nm wavelength) to infrared (20μm wavelength) while maintaining a high responsivity level (0.6-8 A/W). In addition, the specific design of the gold-patched graphene nanoribbons allows for ultrafast photodetection.

POTENTIAL APPLICATIONS

• Night vision
• Hyperspectral imaging and sensing
• Heat recycling cells
• Thermal imaging cameras
• Medicinal thermal imaging (detection of bloodflow)

ADVANTAGES

• Higher responsivity levels compared to previously reported graphene photodetectors
• Faster response times (more than seven orders of magnitude) compared to photodetectors based on quantum dots and tunneling barriers
• Broader bandwidths, despite high speed
• Lower cost compared to current state of the art
• Can be applied universally to various metallic nanostructure geometries

RELATED MATERIALS

• Cakmakyapan, S., Lu, P.K., Navabi, A. et al. Gold-patched graphene nano-stripes for high-responsivity and ultrafast photodetection from the visible to infrared regime. Light Sci Appl 7, 20 (2018). https://doi.org/10.1038/s41377-018-0020-2

STATE OF DEVELOPMENT

The researchers have developed a proof-of-concept device.