Ultrafast, Zero-Bias, Graphene Photodetectors with Polymeric Gate Dielectric on Passive Photonic Waveguides.
American Chemical Society (ACS)
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Mišeikis, V., Marconi, S., Giambra, M. A., Montanaro, A., Martini, L., Fabbri, F., Pezzini, S., et al. (2020). Ultrafast, Zero-Bias, Graphene Photodetectors with Polymeric Gate Dielectric on Passive Photonic Waveguides.. ACS Nano, 14 (9), 11190-11204. https://doi.org/10.1021/acsnano.0c02738
We report compact, scalable, high-performance, waveguide integrated graphene-based photodetectors (GPDs) for telecom and datacom applications, not affected by dark current. To exploit the photothermoelectric (PTE) effect, our devices rely on a graphene/polymer/graphene stack with static top split gates. The polymeric dielectric, poly(vinyl alcohol) (PVA), allows us to preserve graphene quality and to generate a controllable p-n junction. Both graphene layers are fabricated using aligned single-crystal graphene arrays grown by chemical vapor deposition. The use of PVA yields a low charge inhomogeneity ∼8 × 1010 cm-2 at the charge neutrality point, and a large Seebeck coefficient ∼140 μV K-1, enhancing the PTE effect. Our devices are the fastest GPDs operating with zero dark current, showing a flat frequency response up to 67 GHz without roll-off. This performance is achieved on a passive, low-cost, photonic platform, and does not rely on nanoscale plasmonic structures. This, combined with scalability and ease of integration, makes our GPDs a promising building block for next-generation optical communication devices.
Engineering and Physical Sciences Research Council (EP/K01711X/1)
Engineering and Physical Sciences Research Council (EP/K017144/1)
European Research Council (319277)
Engineering and Physical Sciences Research Council (EP/L016087/1)
European Research Council (842251)
European Commission Horizon 2020 (H2020) Future and Emerging Technologies (FET) (785219)
European Commission Horizon 2020 (H2020) Future and Emerging Technologies (FET) (881603)
External DOI: https://doi.org/10.1021/acsnano.0c02738
This record's URL: https://www.repository.cam.ac.uk/handle/1810/313552
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