Effects of perfluorination on the electronic, optical, and transport properties of polyaromatic hydrocarbons: pentaceneand pyrene in the molecular and solid phase

We report a comparative study on pentacene and pyrene polyaromatic hydrocarbons (PAHs) and their perfluorinated counterparts. The study has been performed for both the isolated molecule and their molecular solid phases. The former are investigated, performing all-electron calculations, using Density Functional Theory (DFT) and Time Dependent DFT with localized gaussian basis set and hybrid B3LYP exchange correlation functional, in order to quantify the effects of morphology and chemical modifications on their electronic, optical, and transport properties: in particular electron affinity, ionization energy, fundamental gap, optical absorption, exciton binding energy, and reorganization energies for holes and electrons. The molecular solids using DFT-LDA with plane-waves basis set and ionic pseudopotentials in order to determine and compare ground state properties. In contrast, different exchange-correlation functionals (LDA, PBE0) are considered.