Initial growth of lutetium(III) bis-phthalocyanine on Ag(111) surface

Marius Toader; Martin Knupfer; Dietrich R T Zahn; Michael Hietschold

doi:10.1021/ja200168a

Initial growth of lutetium(III) bis-phthalocyanine on Ag(111) surface

J Am Chem Soc. 2011 Apr 13;133(14):5538-44. doi: 10.1021/ja200168a. Epub 2011 Mar 18.

Authors

Marius Toader¹, Martin Knupfer, Dietrich R T Zahn, Michael Hietschold

Affiliation

¹ Institute of Physics, Solid Surfaces Analysis Group, Chemnitz University of Technology, D-09107 Chemnitz, Germany.

PMID: 21417330
DOI: 10.1021/ja200168a

Abstract

The adsorption of lutetium(III) bis-phthalocyanine (LuPc(2)) on Ag(111) was investigated using scanning tunneling microscopy and spectroscopy (STM/STS). A comprehensive study was carried out toward understanding the driving mechanism responsible for the formation of the first and second monolayers (MLs). In both MLs, the adsorbed molecules are found to exhibit different in-plane orientations arranged according to a "chess-board" like pattern. Highly resolved STM images allowed an exact determination of the corresponding angle mismatch, which differs for the first and second MLs. The tunneling transport through individual molecules reveals a negative differential resistance (NDR) effect detectable within the current-voltage curves. The corresponding density of states (DOS) representation is consistent with a resonant tunneling mechanism sustained by the valence band (VB) states close to the Fermi energy (E(F)) recorded via highly resolved ultraviolet photoemission spectroscopy (UPS).