title: Graphene-Based Thermopile for Thermal Imaging Applications.
abstract: In this work, we leverage graphene's unique tunable Seebeck coefficient for the demonstration of a graphene-based thermal imaging system. By integrating graphene based photothermo-electric detectors with micromachined silicon nitride membranes, we are able to achieve room temperature responsivities on the order of ~7-9 V/W (at λ = 10.6 μm), with a time constant of ~23 ms. The large responsivities, due to the combination of thermal isolation and broadband infrared absorption from the underlying SiN membrane, have enabled detection as well as stand-off imaging of an incoherent blackbody target (300-500 K). By comparing the fundamental achievable performance of these graphene-based thermopiles with standard thermocouple materials, we extrapolate that graphene's high carrier mobility can enable improved performances with respect to two main figures of merit for infrared detectors: detectivity (>8 × 10(8) cm Hz(1/2) W(-1)) and noise equivalent temperature difference (<100 mK). Furthermore, even average graphene carrier mobility (<1000 cm(2) V(-1) s(-1)) is still sufficient to detect the emitted thermal radiation from a human target.
authors.affiliation: Department of Electrical Engineering and Computer Science, ‡Department of Physics, and §Department of Materials Science and Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
authors.forename: Allen L
authors.initials: AL
authors.lastname: Hsu
authors.affiliation: Department of Physics, Harvard University , Cambridge, Massachusetts 02138, United States.
authors.forename: Patrick K
authors.initials: PK
authors.lastname: Herring
authors.affiliation: Department of Physics and Astronomy, University of California, Riverside , Riverside, California 92521, United States.
authors.forename: Nathaniel M
authors.initials: NM
authors.lastname: Gabor
authors.affiliation: Department of Electrical Engineering and Computer Science, ‡Department of Physics, and §Department of Materials Science and Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
authors.forename: Sungjae
authors.initials: S
authors.lastname: Ha
authors.forename: Yong Cheol
authors.initials: YC
authors.lastname: Shin
authors.affiliation: Department of Electrical Engineering and Computer Science, ‡Department of Physics, and §Department of Materials Science and Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
authors.forename: Yi
authors.initials: Y
authors.lastname: Song
authors.affiliation: Army Research Laboratory , 2800 Powder Mill Road, Adelphi, Maryland 20783, United States.
authors.forename: Matthew
authors.initials: M
authors.lastname: Chin
authors.affiliation: Army Research Laboratory , 2800 Powder Mill Road, Adelphi, Maryland 20783, United States.
authors.forename: Madan
authors.initials: M
authors.lastname: Dubey
authors.affiliation: Department of Electrical Engineering and Computer Science, ‡Department of Physics, and §Department of Materials Science and Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
authors.forename: Anantha P
authors.initials: AP
authors.lastname: Chandrakasan
authors.affiliation: Department of Electrical Engineering and Computer Science, ‡Department of Physics, and §Department of Materials Science and Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
authors.forename: Jing
authors.initials: J
authors.lastname: Kong
authors.forename: Pablo
authors.initials: P
authors.lastname: Jarillo-Herrero
authors.affiliation: Department of Electrical Engineering and Computer Science, ‡Department of Physics, and §Department of Materials Science and Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
authors.forename: Tomás
authors.initials: T
authors.lastname: Palacios
keywords: Graphene; detectors; infrared; microelectromechanical Systems; thermal imaging; thermopile