AVS 45th International Symposium
    Organic Electronic Materials Topical Conference Monday Sessions
       Session OE+EM-MoA

Invited Paper OE+EM-MoA3
Fast Electronic Transport in Organic Molecular Solids?

Monday, November 2, 1998, 2:40 pm, Room 327

Session: Organic Thin Film Devices II: Transitors and Transport
Presenter: N. Karl, Universität Stuttgart, Germany
Correspondent: Click to Email
The fundamental aspects of electronic charge transport in organic solids will be reviewed and some specific features of this class of materials highlighted. Examples of appropriate measurement techniques - such as time-of-flight (TOF), field effect transistor (FET), and surface acoustoelectric travelling wave (SAW) techniques - as well as of characteristic results - such as magnitude, temperature dependence and anisotropy of intrinsic charge carrier mobilities - will be presented. While ample basic knowledge has been gained from well-defined ultrahigh purity single crystals, where mobilities of several hundred cm@super 2@/Vs could be reached (see e.g. ref. 1), understanding of the electronic properties of organic thin films is often unsatisfactory. Different kinds and degrees of structural disorder, residual foreign molecules, and a sensitivity to accidental doping by ambient donor or acceptor molecules (such as e.g. O@sub 2@) frequently not only lead to ill-defined irreproducible or nonstationary properties but also to slow transport. Sample preparation under well-controlled conditions and careful sample characterization by sensitive methods of structural and trace impurity chemical analysis are the prime prerequisite not only for further progress in fundamental research, but also for the development of innovative applications. Needless to say that proper selection of material parameters, such as sufficient stability and specific molecular architecture-based functions, is necessary for designing promising molecular-electronic systems, but the complementary aspect of efficient charge carrier transport, which is a superordinated consideration in most applications, may necessitate optimization compromises. @FootnoteText@ @footnote 1@ "Organic Semiconductors" in: Landolt-Börnstein (New Series) Group III, Vol.17i, pp 106-218 (Springer-Verlag, Berlin, New York 1985).