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Title: Electronic, structural, and substrate effect properties of single-layer covalent organic frameworks

Recently synthesized two-dimensional covalent organic frameworks (COFs) exhibit high surface area, large pore size, and unique structural architectures, making them promising materials for various energy applications. Here, a total of nine COFs structures, including two deposited on a hexagonal boron nitride substrate, are investigated using density functional theory, quasi-particle many-body theory within the GW approximation, and an image charge model. The structures considered belong to two major families (thiophene-based COF-n (T-COF-n) and tetrakis (4-aminophenyl) porphyrin-x (TAPP-x)) differing from the presence of B—O or C=N linkers. While T-COF-n structures are shown to constitute planar networks, TAPP-x systems can display non-negligible corrugation due to the out-of-plane rotation of phenyl rings. We find that the electronic properties do not differ significantly when altering the chain molecules within each family. Many-body effects are shown to lead to large band-gap increase while the presence of the substrate yields appreciable reductions of the gaps, due to substrate polarization effects.
Authors:
;  [1] ;  [1] ;  [2]
  1. Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)
  2. (United States)
Publication Date:
OSTI Identifier:
22415778
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 142; 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:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; BORON NITRIDES; COVALENCE; DENSITY FUNCTIONAL METHOD; MANY-BODY PROBLEM; MOLECULES; POLARIZATION; POLYCYCLIC SULFUR HETEROCYCLES; PORPHYRINS; QUASI PARTICLES; REDUCTION; SUBSTRATES; SURFACE AREA; THIOPHENE; TWO-DIMENSIONAL SYSTEMS; YIELDS