Electronic structure of long-range ordered pentacene structures on the stepped Cu(1 1 9) surface

The formation of long-range ordered molecular structures can be achieved by depositing pentacene molecules (C22H14) in ultra-high-vacuum (UHV) conditions on copper vicinal surfaces. The growth morphology of pentacene on the Cu(1 1 9) surface and the induced electronic states have been singled out and compared with the corresponding flat Cu(0 0 1) surface. Low energy electron diffraction (LEED) reveals the presence of a single domain long-range ordered phase for pentacene grown on Cu(1 1 9), and multi-phase domains when deposited on Cu(0 0 1). We identify similar hybrid molecule/substrate electronic states for both systems and we follow the molecular orbitals evolution as a function of pentacene deposition, by means of high-energy-resolution UV photoelectron spectroscopy (HR-UPS). The electronic spectral density evolution indicates the dominance of pentacene π extended orbitals interaction with the copper d bands for both systems.