Model of Local Work Function and PZC for Molecular Self Assembly

Dec 7, 2017 - Jasmin Kaur and Rama Kant. Complex Systems Group, Department of Chemistry, University of Delhi, New Delhi 110007, India. J. Phys. Chem...
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Article Cite This: J. Phys. Chem. C 2018, 122, 911−918

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Model of Local Work Function and PZC for Molecular Self Assembly over Nanostructured Metal Electrode Jasmin Kaur and Rama Kant* Complex Systems Group, Department of Chemistry, University of Delhi, New Delhi 110007, India ABSTRACT: The tuning of metal work function (WF) and potential of zero charge (PZC) through molecular self-assembly and nanostructuring has been trending. We have developed a generic theoretical approach to address the WF and PZC moderations due to organic molecular dipoles at the surface. Theory quantifies the electronic charge redistribution due to polarization through bonding between the metal/adsorbate and dipoles. The amount of charge reorganization at substrate surface is predicted to depend on the effective dipole moment (μN) of the adsorbing molecule. The formula obtained for planar surface is used to elaborate experimental observation for WF of Au electrode covered with various DTC (dithiocarbamate) linked rod shaped organic dipoles (−4.8 to +5.5 D). The charge reorganization is stronger for the molecules with positive end of net dipole toward the metal, i.e., 7−22% of electronic charge whereas for the negative pole toward the metal, it is 0) toward metal δ̃ is