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Title: Enhanced absorption in two-dimensional materials via Fano-resonant photonic crystals

The use of two-dimensional (2D) materials in optoelectronics has attracted much attention due to their fascinating optical and electrical properties. However, the low optical absorption of 2D materials arising from their atomic thickness limits the maximum attainable external quantum efficiency. For example, in the visible and near-infrared regimes monolayer MoS{sub 2} and graphene absorb only ∼10% and 2.3% of incoming light, respectively. Here, we experimentally demonstrate the use of Fano-resonant photonic crystals to significantly boost absorption in atomically thin materials. Using graphene as a test bed, we demonstrate that absorption in the monolayer thick material can be enhanced to 77% within the telecommunications band, the highest value reported to date. We also show that the absorption in the Fano-resonant structure is non-local, with light propagating up to 16 μm within the structure. This property is particularly beneficial in harvesting light from large areas in field-effect-transistor based graphene photodetectors in which separation of photo-generated carriers only occurs ∼0.2 μm adjacent to the graphene/electrode interface.
Authors:
 [1] ; ;  [2] ;  [3] ; ;  [4] ; ;  [5]
  1. Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, Tennessee 37212 (United States)
  2. Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37240 (United States)
  3. Interdisciplinary Materials Science Program, Vanderbilt University, Nashville, Tennessee 37212 (United States)
  4. Department of Mechanical Engineering, Vanderbilt University, Nashville, Tennessee 37212 (United States)
  5. Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)
Publication Date:
OSTI Identifier:
22398987
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 106; Journal Issue: 18; Other Information: (c) 2015 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; CRYSTALS; ELECTRICAL PROPERTIES; ELECTRODES; FIELD EFFECT TRANSISTORS; GRAPHENE; INTERFACES; LIGHT TRANSMISSION; MOLYBDENUM SULFIDES; OPTICAL PROPERTIES; PHOTODETECTORS; QUANTUM EFFICIENCY; TWO-DIMENSIONAL CALCULATIONS; TWO-DIMENSIONAL SYSTEMS; VISIBLE RADIATION