InvestigationoftheelectronicpropertiesofRubis-PhthalocyanineMoleculesonMgO/Ag(100)

When magnesium oxide (MgO) thin films are prepared in the close vicinity of a metal surface, its properties are not so different from the bulk one. In this study, we prepared magnesium oxide (MgO) thin film on silver-Ag(100) surface using a reactive oxidation method and investigated the effect of this thin insulating film on the charge transfer properties for ruthenium phthalocyanine (RuPc) molecules on the silver substrate. From the investigation, carried out by low energy electron diffraction, scanning tunneling electron microscopy and spectroscopy (STM/S), it was revealed that MgO was grown epitaxially on Ag(100) and the MgO islands approximately 50-70 nm were formed on the surface for less than 1 ML coverage. STS confirmed the presence of uncovered Ag in-between MgO islands. The bandgap of thin MgO film was just like bulk MgO. Deposition of 1ML of RuPc on MgO/Ag(100) has formed well ordered pattern on clean Ag patches and less ordered structure on MgO islands. A shift in molecular orbital is observed for RuPc at MgO/Ag(100) as compared to RuPc on clean Ag(100). After annealing, we er able to observe single RuPc molecules on MgO islands. Preparing a well ordered surface with molecules on MgO/Ag(100) is useful for many spin-based devices, sensing, catalysis and magnetic applications.