CNR ExploRA

Articolo in rivista, 2011, ENG, 10.1021/jp2090704

Correlation among Morphology, Crystallinity, and Charge Mobility in OFETs Made of Quaterthiophene Alkyl Derivatives on a Transparent Substrate Platform

Generali Gianluca [ 1 ] ; Dinelli Franco [ 2 ] ; Capelli Raffaella [ 1 ] ; Toffanin Stefano [ 1 ] ; di Maria Francesca [ 3 ] ; Gazzano Massimo [ 3 ] ; Barbarella Giovanna [ 3 ] ; Muccini Michele [ 1, 4 ]

[ 1 ] CNR, ISMN, I-40129 Bologna, Italy [ 2 ] CNR, INO UOS A Gozzini, Area Ric Pisa S Cataldo, I-56124 Pisa, Italy [ 3 ] CNR, ISOF, I-40129 Bologna, Italy [ 4 ] ETC Srl, I-40129 Bologna, Italy

In this Article, we present a comprehensive study of organic field-effect transistors (OFETs) made of thin films of methyl, n-butyl, and n-hexyl end-substituted quaterthiophenes on a transparent substrate platform. This particular platform has been already used for organic light-emitting diodes (OLEDs) but rarely employed for OFETs. In perspective, this is a very promising route for the development of field-effect photonic applications such as organic light-emitting transistors (OLETs). A systematic characterization of the organic films has been made by means of atomic force microscopy (AFM) and X-ray diffraction (XRD) to correlate morphology, crystallinity and charge mobility to the alkyl chain length. In particular, a charge mobility value of 0.09 cm(2)/(V s) has been obtained in transparent OFETs with a large area channel for DH4T grown at room temperature. This mobility exceeds the one obtained on silicon-oxide substrates and is likely due to a more favorable interaction of the DH4T molecules with the PMMA layer employed as gate dielectric.

Journal of physical chemistry. C 115 (46), pp. 23164–23169