Optically-Thin Broadband Graphene-Membrane Photodetector

A broadband graphene-on-Si3N4-membrane photodetector for the visible-IR spectral range is realised by simple lithography and deposition techniques. Photo-current is produced upon illumination due to presence of the build-in potential between dissimilar metal electrodes on graphene as a result of cha...

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Bibliographic Details
Main Authors: Tania Moein, Darius Gailevičius, Tomas Katkus, Soon Hock Ng, Stefan Lundgaard, David J. Moss, Hamza Kurt, Vygantas Mizeikis, Kȩstutis Staliūnas, Mangirdas Malinauskas, Saulius Juodkazis
Format: Article
Language:English
Published: MDPI AG 2020-02-01
Series:Nanomaterials
Subjects:
Online Access:https://www.mdpi.com/2079-4991/10/3/407
Description
Summary:A broadband graphene-on-Si3N4-membrane photodetector for the visible-IR spectral range is realised by simple lithography and deposition techniques. Photo-current is produced upon illumination due to presence of the build-in potential between dissimilar metal electrodes on graphene as a result of charge transfer. The sensitivity of the photo-detector is <inline-formula> <math display="inline"> <semantics> <mrow> <mo>&#8764;</mo> <mn>1</mn> <mo>.</mo> <mn>1</mn> </mrow> </semantics> </math> </inline-formula><inline-formula> <math display="inline"> <semantics> <mi mathvariant="sans-serif">&#956;</mi> </semantics> </math> </inline-formula>A/W when irradiated with 515 and 1030 nm wavelengths; a smaller separation between the metal contacts favors gradient formation of the built-in electric field and increases the efficiency of charge separation. This optically-thin graphene-on-membrane photodetector and its interdigitated counterpart has the potential to be used within 3D optical elements, such as photonic crystals, sensors, and wearable electronics applications where there is a need to minimise optical losses introduced by the detector.
ISSN:2079-4991