1. Controlling photothermoelectric directional photocurrents in graphene with over 400 GHz bandwidth
- Author
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Stefan M. Koepfli, Michael Baumann, Robin Gadola, Shadi Nashashibi, Yesim Koyaz, Daniel Rieben, Arif Can Güngör, Michael Doderer, Killian Keller, Yuriy Fedoryshyn, and Juerg Leuthold
- Subjects
Science - Abstract
Abstract Photodetection in the near- and mid-infrared spectrum requires a suitable absorbing material able to meet the respective targets while ideally being cost-effective. Graphene, with its extraordinary optoelectronic properties, could provide a material basis simultaneously serving both regimes. The zero-band gap offers almost wavelength independent absorption which lead to photodetectors operating in the infrared spectrum. However, to keep noise low, a detection mechanism with fast and zero bias operation would be needed. Here, we show a self-powered graphene photodetector with a > 400 GHz frequency response. The device combines a metamaterial perfect absorber architecture with graphene, where asymmetric resonators induce photothermoelectric directional photocurrents within the graphene channel. A quasi-instantaneous response linked to the photothermoelectric effect is found. Typical drift/diffusion times optimization are not needed for a high-speed response. Our results demonstrate that these photothermoelectric directional photocurrents have the potential to outperform the bandwidth of many other graphene photodetectors and most conventional technologies.
- Published
- 2024
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