Modification of the Cu(110) Shockley surface state by an adsorbed pentacene monolayer

Abstract

The modification of the Cu͑110͒ Shockley-type surface state by an adsorbed pentacene layer was determined using high-resolution angle-resolved photoelectron spectroscopy. It was found that the surface state is shifted by 80-120 meV to higher binding energies, depending on the pentacene coverage. In addition, an increase in the surface-state population is measured for the sample adsorbed with one monolayer of pentacene. The modification of the surface state by the adsorption of pentacene is put into relation to a complex interplay of different phenomena such as the hybridization and mixing of electronic states, the polarization of the adsorbate in the surface dipole, and the Pauli repulsion. Thus, this observation of a molecular adlayer shifting a surface state away from the Fermi energy sheds more light on the adsorbate-adsorbent interactions.

Multimorphism in molecular monolayers: Pentacene on Cu(110)

“…This shows that the molecules interact more strongly with the Cu-substrate than in the case of weakly physisorbed systems. This stronger interaction is also observed in angle-resolved photoelectron spectroscopy measurements of pentacene on Cu(110) 34 . The bending of the molecules is also confirmed in some of the here presented STM images like in Figure 3 where the ends of the molecules are The (7 x 2)-structure reported here is quite similar to the p(6.5 x 2) and c(13 x 2) structures reported by Söhnchen et al 12 .…”

“…Nevertheless, we demonstrated in a previous study that the stronger inter-molecular interaction for 1 ML coverage of pentacene along the [ 0 1 1 ]-direction can lead to an increase of the anisotropy of the Cu(110) Shockley surface state. This observation has been attributed to a 1-dimensional band formation 34 .…”

Monitoring the formation of interface-confined mixture by photoelectron spectroscopy

“…Such effects are commonly analyzed by photoemission, either by probing core-level states or by measuring the evolution of the valence band, including the behavior of the surface state. 12 The latter is strongly sensitive to different types of adsorbates [13][14][15][16] and can even track the formation of, e.g., faulted stacking at the interface, which results in general from a relaxation of strains in the system through a creation of dislocation loops. 17 In this contest, we have recently found a partially occupied Shockley-type surface resonance on a Ag/Pt(111) system with a binding energy and a RSO splitting amplitude, both depending on the thickness of the Ag layer.…”

Transformation of the Ag(111) surface state due to molecule-surface interaction with ordered organic molecular monolayers

“…In this regard, the Shockley surface state (SS) transformed by substrate-adsorbate interaction is of particular significance. [4][5][6] Among organic molecules, particular interest has been attracted to those which are able to form strictly ordered commensurate structures on the surfaces of some substrates. The organic molecules perylene-3,4,9,10-tetracarboxylic acid dianhydride (PTCDA) and naphthalene-1,4,5,8-tetracarboxylic acid dianhydride (NTCDA) are typical representatives which can form such structures and therefore are widely used in investigation of molecular adsorption processes and phase transitions on noble metal surfaces.…”