Study Results from Technical University Broaden Understanding of Biological Pigments (Morphology and local transport characteristics of metalloporphyrin thin films)
By a News Reporter-Staff News Editor at Life Science Weekly -- Data detailed on Biological Factors have been presented. According to news originating from Chemnitz, Germany, by NewsRx correspondents, research stated, "Organic systems such as porphyrin-based molecules stand as a promising alternative for molecular devices. These systems have important photophysical and electrochemical properties and can be easily prepared by well-established synthesis and deposition techniques."
Our news journalists obtained a quote from the research from Technical University, "Nevertheless, not very much is known about their electrical properties and charge transport mechanisms. In this work, the local electrical properties of [5,10,15,20-tetra(p-methoxyphenyl) porphyrin] copper(II) (Cu-TMPP) thin films deposited on nickel substrates are investigated. The implementation of current-sensing atomic force microscopy (cs-AFM) allows the detection of local variations of the topographic and transport properties of Cu-TMPP thin films with nanometric spatial resolution. In particular, the electric current mapping approach adopted here allows the quantification of the local charge transfer through the organic structures in a reliable and controlled manner. The formation of organic dendrites with heights between 2 and 5 nm and lengths in the micrometric scale is observed. On thicker organic films, a layered filamentary-like growth is observed. These dendrites behave as a semiconducting matrix structure over a conducting metallic substrate and could be used for tuning transport properties on a device scale by reducing the contact area at the organic film-metal electrode interface. In addition, a detailed investigation of the electrical evolution of the conducting sites in the organic thin films is presented as a function of the thickness and applied electric field. For the majority of the conducting sites (>70-80%), a field dependent transition from a linear-like to an exponential transport regime is identified. We relate the non-homogeneous electrical response to the formation of molecular dendrites and interface defects."
According to the news editors, the research concluded: "This electrical analysis and the understanding of the underlying transport mechanism become important for future implementation of porphyrin-based devices."
For more information on this research see: Morphology and local transport characteristics of metalloporphyrin thin films. Organic Electronics, 2014;15(7):1432-1439. Organic Electronics can be contacted at: Elsevier Science Bv, PO Box 211, 1000 Ae Amsterdam, Netherlands. (Elsevier - www.elsevier.com; Organic Electronics - www.elsevier.com/wps/product/cws_home/620806)
The news correspondents report that additional information may be obtained from P.F. Siles, Technical Univ Chemnitz, Fac Mech Engn, Cluster Excellence MERGE, D-09107 Chemnitz, Germany. Additional authors for this research include C.C.B. Bufon, D. Grimm, A.R. Jalil, C. Mende, F. Lungwitz, G. Salvan, D.R.T. Zahn, H. Lang and O.G. Schmidt (see also Biological Factors).
Keywords for this news article include: Europe, Germany, Chemnitz, Metalloporphyrins, Biological Factors, Biological Pigments
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