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Title: A van der Waals pn heterojunction with organic/inorganic semiconductors

van der Waals (vdW) heterojunctions formed by two-dimensional (2D) materials have attracted tremendous attention due to their excellent electrical/optical properties and device applications. However, current 2D heterojunctions are largely limited to atomic crystals, and hybrid organic/inorganic structures are rarely explored. Here, we fabricate the hybrid 2D heterostructures with p-type dioctylbenzothienobenzothiophene (C{sub 8}-BTBT) and n-type MoS{sub 2}. We find that few-layer C{sub 8}-BTBT molecular crystals can be grown on monolayer MoS{sub 2} by vdW epitaxy, with pristine interface and controllable thickness down to monolayer. The operation of the C{sub 8}-BTBT/MoS{sub 2} vertical heterojunction devices is highly tunable by bias and gate voltages between three different regimes: interfacial recombination, tunneling, and blocking. The pn junction shows diode-like behavior with rectifying ratio up to 10{sup 5} at the room temperature. Our devices also exhibit photovoltaic responses with a power conversion efficiency of 0.31% and a photoresponsivity of 22 mA/W. With wide material combinations, such hybrid 2D structures will offer possibilities for opto-electronic devices that are not possible from individual constituents.
Authors:
; ; ; ; ; ; ;  [1] ; ;  [2] ; ; ;  [3] ; ;  [4] ;  [5]
  1. National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China)
  2. National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing 210093 (China)
  3. Department of Physics, Southeast University, Nanjing 211189 (China)
  4. College of Engineering and Applied Science, Nanjing University, Nanjing 210093 (China)
  5. Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong)
Publication Date:
OSTI Identifier:
22486011
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 107; 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:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CHANNELING; EFFICIENCY; ELECTRIC POTENTIAL; EPITAXY; HETEROJUNCTIONS; HYBRIDIZATION; INTERFACES; MOLECULAR CRYSTALS; MOLYBDENUM SULFIDES; OPTICAL PROPERTIES; PHOTOVOLTAIC EFFECT; RECOMBINATION; SEMICONDUCTOR MATERIALS; TUNNEL EFFECT; TWO-DIMENSIONAL SYSTEMS; VAN DER WAALS FORCES