%0 Journal Article
%T Strategies for Fabricating Nanogap Single-Crystal Organic Transistors
%A S. Alborghetti
%A P. Stamenov
%A G. Fois
%A J. M. D. Coey
%J ISRN Nanotechnology
%D 2012
%R 10.5402/2012/253246
%X Nanotechnology is an emerging technology for fabricating nanostructures where at least one dimension is smaller than 100£¿nm. This paper explains how single-crystal organic transistors of channel length down to just 7£¿nm can be fabricated without damaging the organic material. Single crystals of C60, rubrene, and pentacene have been chosen in our structures, but the same process can be used for a wide variety of organics. The method combines high-resolution electron-beam lithography and vacuum device assembly with piezo manipulators. As modern devices are typically designed with short semiconducting channel length, this type of fabrication methods allows downscaling of organic electronic devices for research purposes. 1. Introduction Conjugated organic semiconductors as electronic materials have been the subject of intense research, because they have some processing and performance advantages over conventional semiconductors for low-cost and large-area device applications. The two most widely studied types of devices employing organic semiconductors are organic field effect transistors (OFET) [1] and organic light emitting diodes (OLED) [2]. These devices are currently incorporated into a variety of prototypes for displays and display drivers [3] and, beyond this, have a wide range of other potential applications. In the very recent years, organic materials attracted attention for spin electronics, because of the prospect that the spin relaxation times could be much longer than in inorganic materials [4], primarily as a consequence of the smaller spin-orbit coupling and diminished hyperfine interactions. Due to the intrinsically low mobility of organic compounds, the organic electronic devices cannot readily rival the performance of those based on crystalline inorganic semiconductors; nevertheless, the processing properties and the observed electrical characteristics demonstrated that they can be competitive for applications requiring large-area coverage, structural flexibility, chemical tenability, and low-cost processing. The most widely used organic semiconductors can be broadly classified into two categories: small molecules or oligomers (usually processed in vacuum) and polymers (usually processed by wet chemical techniques). The most representative small molecule compounds employed in this field, having the highest reported mobility, are pentacene and rubrene [5, 6]. On the other hand, among the most studied polymers are the polyphenylene derivatives, of interest mainly for their luminescence (a property required for light emitting diodes) [7] and
%U http://www.hindawi.com/journals/isrn.nanotechnology/2012/253246/