DFT study of co- and homo-oligo(fluoro-substituted aniline)s as ambipolar materials

Abstract

In this work, a series of co- and homo-oligomers consisting 2-fluoroaniline (FA) and aniline (A) were studied as active p/n-conducting materials for use in the charge storage applications using the density functional theory (DFT) approach. The calculations were performed on the di-, tetra-, hexa-, and octamer derivatives of co-oligo(FA-A), oligo(FA), and oligo(A) in their undoped and both the p- and n-doped phases. The calculated results were used to evaluate the extent of the π-conjugation length, band gap energy, charge carrier injection rate, ionization potential, and electron affinity of co-oligomers with respect to the parent oligomers. A further characterization of the oligomers was performed through the UV–vis spectral characteristics computed by the time-dependent DFT. The results obtained were extrapolated to the infinite chain length to investigate the influence of fluorine substitution on the observed behavior of the corresponding polymers. More satisfactory properties were obtained for the co-polymers in both the p- and n-doped species with respect to poly(FA), reflecting their hole and electron transport facilities for conductivity.