1 research outputs found
Graphene-Based Thermopile for Thermal Imaging Applications
In
this work, we leverage grapheneās 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 ā¼7ā9 V/W
(at Ī» = 10.6 Ī¼m), with a time constant of ā¼23 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 (300ā500 K). By comparing the fundamental
achievable performance of these graphene-based thermopiles with standard
thermocouple materials, we extrapolate that grapheneās high
carrier mobility can enable improved performances with respect to
two main figures of merit for infrared detectors: detectivity (>8
Ć 10<sup>8</sup> cm Hz<sup>1/2</sup> W<sup>ā1</sup>) and
noise equivalent temperature difference (<100 mK). Furthermore,
even average graphene carrier mobility (<1000 cm<sup>2</sup> V<sup>ā1</sup> s<sup>ā1</sup>) is still sufficient to detect
the emitted thermal radiation from a human target