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Title: Derivatization and diffusive motion of molecular fullerenes: Ab initio and atomistic simulations

Journal Article · · Journal of Applied Physics
DOI:https://doi.org/10.1063/1.4923352· OSTI ID:22490781
 [1];  [2]; ;  [3];  [4];  [5];  [6]
  1. Qatar Environment and Energy Research Institute (QEERI), Hamad Ben Khalifa University (HBKU), Qatar Foundation, P.O. Box 5825, Doha (Qatar)
  2. Department of Physics, King Fahd University of Petroleum and Minerals, 31261 Dhahran (Saudi Arabia)
  3. Department of Chemical Engineering, King Fahd University of Petroleum and Minerals, 31261 Dharan (Saudi Arabia)
  4. Departement Fysica, Universiteit Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen (Belgium)
  5. Department of Materials and London Centre for Nanotechnology, Imperial College London, SW7 2AZ London (United Kingdom)
  6. Department of Materials and Centre for Plastic Electronics, Imperial College London, SW7 2AZ London (United Kingdom)

Using first principles density functional theory in combination with the nonequilibrium Green's function formalism, we study the effect of derivatization on the electronic and transport properties of C{sub 60} fullerene. As a typical example, we consider [6,6]-phenyl-C{sub 61}-butyric acid methyl ester (PCBM), which forms one of the most efficient organic photovoltaic materials in combination with electron donating polymers. Extra peaks are observed in the density of states (DOS) due to the formation of new electronic states localized at/near the attached molecule. Despite such peculiar behavior in the DOS of an isolated molecule, derivatization does not have a pronounced effect on the electronic transport properties of the fullerene molecular junctions. Both C{sub 60} and PCBM show the same response to finite voltage biasing with new features in the transmission spectrum due to voltage induced delocalization of some electronic states. We also study the diffusive motion of molecular fullerenes in ethanol solvent and inside poly(3-hexylthiophene) lamella using reactive molecular dynamics simulations. We found that the mobility of the fullerene reduces considerably due to derivatization; the diffusion coefficient of C{sub 60} is an order of magnitude larger than the one for PCBM.

OSTI ID:
22490781
Journal Information:
Journal of Applied Physics, Vol. 118, Issue 2; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
Country of Publication:
United States
Language:
English