Abstract
We describe physical measurements on a unique class of pentacene-based compounds [e.g., 6,13-bis(triisopropylsilylethynyl)pentacene] where additional symmetric side groups have been added to enhance their solubility in common organic solvents. Single crystals of these materials formed from precipitation consist of various π stacking configurations (columnar) of the pentacene molecules which are different from the herringbone motif of unsubstituted pentacene. Here we report the anisotoropic resistivity of single crystals of these materials, including the determination of activation gaps (of order 1 eV) obtained from Arrhenius analysis of the temperature dependent resistivity. We find that the resistivity at room temperature lies in the range 10+5-10+10Ωcm, depending on crystallographic direction and side-group placement and composition. We further describe the response of the conductivity to optical excitation, and present preliminary studies of the dependence of the conductivity on Iodine doping and hydrostatic pressure.
Original language | English |
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Pages (from-to) | 301-306 |
Number of pages | 6 |
Journal | Current Applied Physics |
Volume | 1 |
Issue number | 4-5 |
DOIs | |
State | Published - Nov 2001 |
Bibliographical note
Funding Information:JEA thanks the Office of Naval Research (N00014-99-1-0859) and the National Science Foundation (CAREER award CHE-9875123) for generous support of this research. We thank Prof. Carolyn Brock for the helpful discussions and Mr. Matt Krepps for performing the combustion analysis. JSB thanks NSF-DMR 99-71474, and is grateful to the Department of Physics and Astronomy at the University of Kentucky for sabbatical leave support where this work has been carried out.
Keywords
- 72.20.-i
- 78.90.+t
- Acenes
- Optical excitation
- Organic semiconductor
- Resistivity
ASJC Scopus subject areas
- General Materials Science
- General Physics and Astronomy