Physical Chemistry Chemical Physics 2014-10-01

Phonon dynamics and electron-phonon coupling in pristine picene.

Sarah J Hill, Allison P Clark, Daniel P Silver, David M Livingston

Index: Phys. Chem. Chem. Phys. 14(5) , 1694-9, (2012)

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Abstract

The paper reports a complete analysis of the phonon structure of crystalline picene, a recently announced organic semiconductor. Both lattice and intramolecular vibrations are investigated. An exhaustive assignment of lattice phonons is obtained through polarized Raman spectra assisted by lattice dynamics calculations based on a well tested atom-atom potential model. Raman, infrared spectra and density functional (DFT) calculations are used for the characterization of intramolecular modes. Coupling between low-frequency molecular vibrations and lattice phonons is accounted for. Molecule-to-molecule transfer integrals, as well as the Peierls and Holstein (non-local and local) coupling constants, are evaluated through the semiempirical method INDO/S (Intermediate Neglect of Differential Overlap with Spectroscopic parametrization).