Flexible Multi-Element Photothermoelectric Detectors Based on Spray-Coated Graphene/Polyethylenimine Composites for...

Area of Science:

• Materials Science
• Nanotechnology
• Infrared Detection

Background:

• Photothermoelectric (PTE) detectors offer self-powered, non-bias operation ideal for various applications.
• Existing PTE materials suffer from oxidation instability, complex fabrication, and scalability issues, limiting industrial adoption.

Purpose of the Study:

• To develop a stable, flexible, and scalable PTE detector using graphene and polyethylenimine.
• To optimize fabrication using spray-coating for enhanced performance and diverse surface compatibility.

Main Methods:

• Fabrication of a vertical graphene/polyethylenimine composite PTE detector via an optimized spray-coating technique.
• Characterization of photovoltage detectivity and responsivity under 973 K blackbody radiation (2.98 μm peak wavelength).
• Evaluation of long-term stability and mechanical flexibility (concave and convex bending).

Main Results:

• Achieved high photovoltage detectivity of 6.05 × 10^7 cm Hz^1/2 W^-1 and responsivity of 2.7 V W^-1.
• Demonstrated long-term material stability and robust flexibility on various surfaces.
• Successfully established and verified a nondestructive testing system using the developed detector.

Conclusions:

• The spray-coated, flexible graphene/polyethylenimine PTE detectors offer stable, broadband infrared absorption and energy conversion.
• These detectors are promising for future health monitoring, wearable electronics, and industrial inspection applications.