Graphene Nanogap Interdigitated Asymmetric Electrodes for Photodetection
Rabiaa Elkarous,
Afrah Bardaoui,
Jérôme Borme,
Nabil Sghaier,
Pedro Alpuim,
Diogo M. F. Santos,
Radhouane Chtourou
Affiliations
Rabiaa Elkarous
Laboratory of Nanomaterials and Systems for Renewable Energies (LaNSER), Research and Technology Centre of Energy (CRTEn), Borj Cedria Science and Technology Park, Hammam-Lif 2050, Tunisia
Afrah Bardaoui
Laboratory of Nanomaterials and Systems for Renewable Energies (LaNSER), Research and Technology Centre of Energy (CRTEn), Borj Cedria Science and Technology Park, Hammam-Lif 2050, Tunisia
Jérôme Borme
2D Materials and Devices Group, International Iberian Nanotechnology Laboratory, 4715-330 Braga, Portugal
Nabil Sghaier
Laboratory of Nanomaterials and Systems for Renewable Energies (LaNSER), Research and Technology Centre of Energy (CRTEn), Borj Cedria Science and Technology Park, Hammam-Lif 2050, Tunisia
Pedro Alpuim
2D Materials and Devices Group, International Iberian Nanotechnology Laboratory, 4715-330 Braga, Portugal
Diogo M. F. Santos
Center of Physics and Engineering of Advanced Materials, Laboratory for Physics of Materials and Emerging Technologies, Chemical Engineering Department, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal
Radhouane Chtourou
Laboratory of Nanomaterials and Systems for Renewable Energies (LaNSER), Research and Technology Centre of Energy (CRTEn), Borj Cedria Science and Technology Park, Hammam-Lif 2050, Tunisia
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 µm) are fabricated, and their photoresponsivities are evaluated at different wavelengths. The 100 µm 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.
