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Title: Highly tunable quantum Hall far-infrared photodetector by use of GaAs/Al{sub x}Ga{sub 1−x}As-graphene composite material

We have developed a highly tunable, narrow band far-infrared (FIR) photodetector which utilizes the characteristic merits of graphene and two-dimensional electron gas (2DEG) in GaAs/Al{sub x}Ga{sub 1−x}As heterostructure in the Quantum Hall states (QHS). The heterostructure surface is covered with chemical vapor-deposited graphene, which functions as a transparent top-gate to vary the electron density of the 2DEG. FIR response observed in the vicinity of integer QH regime can be effectively tuned in a wide range of 27–102 cm{sup −1} with a bias voltage less than −1 V. In addition, we have found that the presence of graphene can genuinely modulate the photoresponse. Our results demonstrate a promising direction for realizing a tunable long-wavelength FIR detector using QHS in GaAs 2DEG/ graphene composite material.
Authors:
 [1] ;  [2] ; ;  [1] ;  [3]
  1. Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China)
  2. Department of Physics, Tamkang University, Tamsui Dist., New Taipei City 25137, Taiwan (China)
  3. (China)
Publication Date:
OSTI Identifier:
22310695
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 18; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ABSORPTION SPECTROSCOPY; ALUMINIUM COMPOUNDS; CHEMICAL VAPOR DEPOSITION; COMPOSITE MATERIALS; ELECTRIC POTENTIAL; ELECTRON DENSITY; ELECTRON GAS; FAR INFRARED RADIATION; GALLIUM ARSENIDES; GRAPHENE; PHOTODETECTORS; SURFACES; TWO-DIMENSIONAL CALCULATIONS; WAVELENGTHS; X-RAY SPECTROSCOPY