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Graphene-Insulator-Semiconductor Junction for Hybrid Photodetection Modalities.

ABSTRACT: A sensitive optical detector is presented based on a deeply depleted graphene-insulator-semiconducting (D2GIS) junction, which offers the possibility of simultaneously leveraging the advantages of both charge integration and localized amplification. Direct read-out and built-in amplification are accomplished via photogating of a graphene field-effect transistor (GFET) by carriers generated within a deeply depleted low-doped silicon substrate. Analogous to a depleted metal-oxide-semiconducting junction, photo-generated charge collects in the potential well that forms at the semiconductor/insulator interface and induces charges of opposite polarity within the graphene film modifying its conductivity. This device enables simultaneous photo-induced charge integration with continuous "on detector" readout through use of graphene. The resulting devices exhibit responsivities as high as 2,500?A/W (25,000?S/W) for visible wavelengths and a dynamic range of 30?dB. As both the graphene and device principles are transferrable to arbitrary semiconductor absorbers, D2GIS devices offer a high-performance paradigm for imaging across the electromagnetic spectrum.

SUBMITTER: Howell SW

PROVIDER: S-EPMC5676778 | BioStudies | 2017-01-01

REPOSITORIES: biostudies

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