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arXiv · 0710.1686

Electronic functionalization of the surface of organic semiconductors with self-assembled monolayers

M. F. Calhoun·J. Sanchez·D. Olaya·M. E. Gershenson·V. Podzorov*
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Abstract

Molecular self-assembly has been extensively used for surface modification of metals and oxides for a variety of applications, including molecular and organic electronics. One of the goals of this research is to learn how the electronic properties of these surfaces can be modified by self-assembled monolayers (SAM). Here, we demonstrate a new type of molecular self-assembly: the growth of organosilane SAMs at the surface of organic semiconductors, which results in a dramatic increase of the surface conductivity of organic materials. For organosilane molecules with a large dipole moment, SAM-induced surface conductivity of organic molecular crystals approaches 10^-5 S per square, which is comparable to the highest conductivity realized in organic field-effect transistors (OFETs) at ultra-high densities of charge carriers. SAM-functionalized organic surfaces are fully accessible to the environment which makes them very attractive for sensing applications. We have observed that the interaction of vapors of polar molecules with SAM-functionalized organic semiconductors results in a fast and reversible change of the conductivity, proportional to the pressure of an analyte vapor.

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M. F. Calhoun, J. Sanchez, D. Olaya, M. E. Gershenson, V. Podzorov*. 2007-10-09. Electronic functionalization of the surface of organic semiconductors with self-assembled monolayers. https://doi.org/10.1038/nmat2059

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