Regensburg 2007 – wissenschaftliches Programm
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SYOE: Symposium Organic Thin Film Electronics: From Molecular Contacts to Devices
SYOE 8: Poster Session SYOE
SYOE 8.105: Poster
Dienstag, 27. März 2007, 18:00–20:00, Poster B
Nonlinear I-V Characteristics of Nanoparticle Compacts and Nanocomposites — •Simone Herth1,2, Xiaoping Wang1, Teresa Hugener1, Henrik Hillborg3, Tommaso Auletta3, Linda Schadler1, and Richard Siegel1 — 1Rensselaer Polytechnic Institute, Troy, NY, USA — 2Bielefeld University, Bielefeld, Germany — 3ABB AB, Corporate Research, Schweden
Materials with nonlinear I - V characteristics are commonly used as field grading materials. In many cases, the non-linearity is achieved through the addition of equiaxed fillers to a polymer matrix. These composite field grading materials are optimized in terms of non-linearity, conductivity, and breakdown strength. One limitation in designing new field grading materials is a robust understanding of the relationship between powder morphology, composition and electrical characteristics of the powder, as well as a robust understanding of the relationship between powder conductivity and non-linearity and composite non-linearity. In this work, treatment of ZnO powder with a SnF2 solution resulted in a powder that yielded highly non-linear behavior. The highest non-linearity was achieved for powders with at least two different phases and a rough surface, as indicated by transmission electron micrographs. In contrast, the non-linearity of the nanocomposite conductivity is mainly determined by the conductivity of the nanofiller. The electrical behavior of the non-linear powder can be understood by a polarization of the nanoparticles at the interfaces, whereas the nonlinearity of the nanocomposites can be explained by a tunnelling mechanism between two particles.