Tuesday, February 17, 2015

Scientists Create First Nanowire FET Detectors

Novel solid-state nanomaterial platform enables terahertz photonics
A team of scientists in Italy and France has created a novel solid-state technology that opens the door to the use of terahertz (THz) photonics in a wide range of applications. The reported their findings in the journal APL Materials.
By using an approach that exploits the excitation of plasma waves in the channel of field-effect transistors (FET), they were able to create the first FET detectors based on semiconductor nanowires, designed in a plethora of architectures - including tapers, heterostructures and metamaterial-antenna coupled. They also developed the first THz detectors made of mono- or bi-layer graphene.
"Our work shows that nanowire FET technology is versatile enough to enable 'design' via lithography of the detector's parameters and its main functionalities," explained Miriam Serena Vitiello, lead author of the paper as well as research scientist and group leader of Terahertz Photonics Group in the Nanoscience Institute at CNR and Scuola Normale Superiore in Pisa, Italy.
The nanowire detector offers "a concrete perspective of application-oriented use, since it operates at room temperature - reaching detection frequencies greater than 3 THz, with maximum modulation speed in the MHz range, and noise equivalent powers that are already competitive with the best commercially available technologies," Vitiello said.
Because the nanodetectors can be tapped for large-area fast imaging across both the THz and the sub-terahertz spectral ranges, their commercial potential lies in a variety of spectroscopic and real-time imaging applications - possibly in the form of fast multi-pixel THz cameras.
Next, the scientists' goals are to "push the device's performance in the ultrafast detection realm, explore the feasibility of single photon detection by using novel architectures and material choices, develop compact focal plane arrays, and to integrate on-chip the nanowire detectors with THz quantum cascade microlasers," noted Vitiello. "This will allow us to take THz photonics to a whole new level of 'compactness' and versatility, where it can finally begin to address many killer applications."
'One dimensional semiconductor nanostructures: an effective active-material for TeraHertz detection' by Miriam S. Vitiello et al,  APL Materials  2015 (DOI: 10.1063/1.4906878).

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