Electronic excitations of oligoacenes: A time dependent density functional theory study

Oligoacenes in their crystalline state are increasingly used in the field of electronics and photonics. Following a recent systematic theoretical study of the five smallest oligoacene molecules (naphthalene, anthracene, tetracene, pentacene, and hexacene), we evaluate their one- and two-particle properties (electron affinities, ionisation energies, quasiparticle correction to the highest occupied molecular orbital-lowest unoccupied molecular orbital gap, exciton binding energy, electronic absorption), using different exchange-correlation functionals in the framework of Density Functional Theory (DFT) and Time Dependent DFT. The hybrid functional B3LYP is found to yield the best agreement with the available experimental data.