Electronic band structure of pentacene: An experimental and theoretical study

The intermolecular and intramolecular dispersions of pentacene are measured by angle resolved photoemission spectroscopy using a uniaxially aligned crystalline thin film. The band structure perpendicular to the molecules displays a small dispersion in agreement with density functional theory (DFT). Parallel to the molecules, two pi bands consisting of five and six orbitals are clearly observed. In these intramolecular bands, the orbital emissions are shown to be in agreement with calculations of the photoemission intensities based on DFT both in terms of position and width in momentum space.