%0 Journal Article
%T Electronic Structure of 2H-Tetraphenylporphyrin at Fe/Si (100) Interface
%A Chhagan Lal
%A I. P. Jain
%J ISRN Analytical Chemistry
%D 2013
%R 10.1155/2013/637219
%X Many recent studies have highlighted the possibility to tailor the physical and chemical properties of porphyrin at the molecular level to design novel catalysts, sensors and devices with applications in electronics, opto-electronics, and so forth. In the present work, we study the electronic properties of 2H-Tetraphenylporphyrin (2H-TPP) on iron (Fe) and iron silicide (Fe3Si) onto Si (100) substrate using X-ray and Ultraviolet photoelectron spectroscopy (XPS & UPS). The results revealed that the iron atom is coordinated by TPP molecules on Fe/Si as well as on Fe3Si/Si. XPS results provide evidence of the iron coordination with TPP molecules. The UPS analysis evidenced the fine structure in the electronic spectra related to HOMO states below the Fermi level. 1. Introduction The adsorption of functional molecules on solid substrates has become important in the field of nanoscience and, hence, to exploit the potential of bottom-up strategies the nanostructures are grown in a controlled way. It is known that the position and dimension of the molecular assemblies can be tuned and controlled with high precision down to the atomic level on metals [1¨C3] and semiconductors [4¨C7]. Developing technologically robust families of adsorbed assemblies on semiconductor surfaces is challenging, especially because the electronic skeleton of molecules is slightly altered after the adsorption [8, 9]. Organic/inorganic interfaces are intriguing and challenging because of the wide variety of phenomena they exhibit, and these interfaces have evolved as a potential alternative to conventional electronic devices. The flexibility afforded by organic molecular films in terms of modes of deposition, chemical functionalization, molecular mixing, and doping opens a number of routes to tailor the interface properties, which would not be possible with inorganic materials [10]. Porphyrins are a flexible class of molecules with a square symmetry planar core conformation (macrocycle) and two-dimensional conjugated ¦Ð electron delocalization [11¨C13]. These organic molecules are one of the most studied systems because of their ability to absorb light, to interact with gases, and their involvement in many biological systems. However, they combine a structure-forming element the porphyrin framework with an active site of the porphyrin core. The intrinsic functionality of porphyrins is given by their ability to bind 1st transition row metal atoms at the centre of the macrocycle to form a metalloporphyrin. Many of these molecules are commercially available or can be produced via metalation
%U http://www.hindawi.com/journals/isrn.analytical.chemistry/2013/637219/