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Title: Ultraviolet-enhanced photodetection in a graphene/SiO{sub 2}/Si capacitor structure with a vacuum channel

We report photodetection properties of a graphene/oxide/silicon capacitor structure with a nanoscale vacuum channel. The photogenerated two-dimensional electron gas (2DEG) inversion charges at SiO{sub 2}/Si interface are extracted out to air and transported along the void channel at low bias voltage (<5 V). A monolayer graphene, placed on top of SiO{sub 2} and suspended on the void channel, is utilized as a photon-transparent counter-electrode to the 2DEG layer and a collector electrode for the out-of-plane transported electrons, respectively. The photocurrent extracted through a void channel reveals high responsivity (1.0 A/W at 633 nm) as measured in a broad spectral range (325–1064 nm), especially demonstrating a UV-enhanced performance (0.43 A/W responsivity and 384% internal quantum efficiency at 325 nm). The mechanisms underlying photocarrier generation, emission, and transport in a suspended-graphene/SiO{sub 2}/Si structure are proposed.
Authors:
;  [1]
  1. Department of Electrical and Computer Engineering and Petersen Institute of NanoScience and Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261 (United States)
Publication Date:
OSTI Identifier:
22489467
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 118; Journal Issue: 10; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; AIR; CAPACITORS; ELECTRIC POTENTIAL; ELECTRODES; ELECTRON GAS; ELECTRONS; GRAPHENE; INTERFACES; LAYERS; NANOSTRUCTURES; PERFORMANCE; PHOTONS; QUANTUM EFFICIENCY; SILICON; SILICON OXIDES; TWO-DIMENSIONAL SYSTEMS; ULTRAVIOLET RADIATION; VOIDS