An in-plane photoelectric effect in two-dimensional electron systems for terahertz detection
Authors
Wallis, Robert
Degl'Innocenti, Riccardo
Publication Date
2022-04-15Journal Title
Science Advances
ISSN
2375-2548
Publisher
American Association for the Advancement of Science
Type
Article
This Version
VoR
Metadata
Show full item recordCitation
Michailow, W., Spencer, P., Almond, N. W., Kindness, S. J., Wallis, R., Mitchell, T. A., Degl'Innocenti, R., et al. (2022). An in-plane photoelectric effect in two-dimensional electron systems for terahertz detection. Science Advances https://doi.org/10.1126/sciadv.abi8398
Abstract
Many mid and far infrared semiconductor photodetectors rely on a photonic response, when the photon energy is large enough to excite and extract electrons due to optical transitions. Towards the terahertz range with photon energies of a few meV, classical mechanisms are employed instead. This is the case in two-dimensional electron systems, where terahertz detection is dominated by plasmonic mixing and by scattering-based thermal phenomena.
Here, we report on the observation of a quantum, collision-free phenomenon which yields a giant photoresponse at terahertz frequencies (1.9 THz), more than ten-fold as large as expected from plasmonic mixing. We artificially create an electrically tunable potential step within a degenerate two-dimensional electron gas. When exposed to terahertz radiation, electrons absorb photons and generate a large photocurrent under zero source-drain bias. The observed phenomenon, which we call the "in-plane photoelectric effect", provides an opportunity for efficient direct detection across the entire terahertz range.
Relationships
Is supplemented by: https://doi.org/10.17863/CAM.58046
Sponsorship
George and Lilian Schiff Studentship, Schiff Foundation, University of Cambridge
Honorary Vice-Chancellor’s Award, Cambridge Trust, University of Cambridge
Funder references
Engineering and Physical Sciences Research Council (EP/P021859/1)
European Commission Horizon 2020 (H2020) Future and Emerging Technologies (FET) (881603)
Identifiers
External DOI: https://doi.org/10.1126/sciadv.abi8398
This record's URL: https://www.repository.cam.ac.uk/handle/1810/334799
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