Photoemission study of the poly(3-hexylthiophene)/Au interface

The interface between the conjugated polymer poly(3-hexylthiophene) (P3HT) and Au was investigated using photoemission spectroscopy. Electrospray thin film deposition was used to deposit P3HT on a polycrystalline Au thin film in several steps without breaking the vacuum. In between deposition steps, x-ray photoemission spectroscopy and ultraviolet photoemission spectroscopy measurements were carried out. The resulting series of spectra allowed the determination of the orbital lineup at the interface. The results indicate that the P3HT interface has a smaller hole injection barrier (0.59eV) than comparably structured oligothiophene contacts.