Growth and electronic structure of CuFPc on Si(1 0 0)

The stability of hexadecafluoro copper phthalocyanine ultrathin films after the deposition onto clean Si(1 0 0)2×1 substrate has been studied by means of X-ray and ultraviolet photoemission spectroscopies. In particular the nature of a strong metallic Cu 2p component in the monolayer regime film has been investigated. These data have been compared with the results acquired on a thick film deposited on SiO2 substrate before and after an in situ thermal annealing. The valence band features indicate that the bulk-like molecular electronic structure is already present even at monolayer stage. Instead, when the annealed film presents the metallic Cu 2p structure, the molecular structure is completely destroyed. This indicates that the metallic component in the Cu 2p spectrum is not due to the loss of the Cu atom during the deposition but can be attributed to the screening of the Cu 2p core hole by the high density of electrons at the Si(1 0 0)2×1 surface.