Graphene Nanogap Interdigitated Asymmetric Electrodes for Photodetection

This work proposes a high-performance asymmetric gold/graphene/platinum photodetector. The new photodetector, operating without bias, integrates interdigitated 100 nm spaced metallic contacts that induce a built-in potential and a short carrier path, allowing an improvement in the separation and collection of the photocarriers. A chemical vapor deposition graphene layer is transferred onto the interdigitated electrodes elaborated using high-resolution electron-beam lithography. Three devices with different side dimensions (100, 1000, and 3000 mu m) are fabricated, and their photoresponsivities are evaluated at different wavelengths. The 100 mu m device shows the highest photoresponsivity of 358 A/W at a 400 nm illumination. These promising results confirm the proposed design's ability to increase the photodetector's active area, improve light absorption, and achieve high separation and collection of photogenerated carriers. This makes it of great interest for optoelectronic applications.

Automated summary

This study proposes a high-performance asymmetric gold/graphene/platinum photodetector that operates without bias. It incorporates interdigitated metallic contacts to enhance the separation and collection of photocarriers. By utilizing chemical vapor deposition and electron-beam lithography, three devices with different dimensions were fabricated and evaluated for their photoresponsivities at different wavelengths. The 100 μm device exhibited the highest photoresponsivity of 358 A/W at 400 nm illumination. These findings demonstrate the potential of the proposed design to increase the active area, improve light absorption, and achieve efficient separation and collection of photogenerated carriers, making it highly relevant for optoelectronic applications.