Heterostructures based on small molecules organic compounds

Heterostructures with layers from small molecules organic compounds were deposited on ITO/glass substrate by thermal vacuum evaporation (TVE) technique. Structural, optical and morphological investigations were carried out on the realisedlayers (zinc phthalocyanine - ZnPc, fullerene - C60 and 1,4,5,8-naphthalene - tetracarboxylic dianhydride - NTCDA). The films are polycrystalline keeping the morphological features characteristic to these materials. The prepared hetero structures reveal a large absorption domain in the visible domain. The current-voltage (I-V) characteristics of the investigated structures, recorded in dark, present an improvement in the current value (~one order of magnitude) for the standard structure (ITO/PEDOT:PSS/ZnPc/C60/NTCDA/Al) with a supplimentary layer of poly(3,4 ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS). For the inverted structure (Al/NTCD/C60/ZnPc/ITO) was also noticed an increased curent value in comparasion with that observed for the standard structure

Microscopy and electroanalysis of a first generation copperpoly (propyleneimine) metallodendrimer system

A copper-poly(propyleneimine) (CuPPI) metallodendrimer was physically adsorbed onto the surface of a gold electrode to form an Au|CuPPI electrode system, which was electrochemically characterized by cyclic and square wave voltammetric techniques. The surface morphology of the poly(propyleneimine) dendrimer (PPI) and its copper-functionalized derivative, i.e. CuPPI, were compared using atomic force microscopy (AFM). High resolution transmission electron microscopy (HR-TEM) and high resolution scanning electron microscopy (HR-SEM) data showed that CuPPI has a layered crystalline structure. The metallodendrimer would be a suitable platform for electrochemical biosensing applications since the diffusion coefficient is only very slightly affected by oxygen.