Eur. Phys. J. B 72, 385-395 (2009)
https://doi.org/10.1140/epjb/e2009-00368-y

Charge carrier mobility in sulphonated and non-sulphonated Ni phthalocyanines: experiment and quantum chemical calculations

¹ Institute of Macromolecular Chemistry, AS CR, v. v. i., Heyrovský Sq. 2, 162 06 Prague, Czech Republic
² J. Heyrovský Institute of Physical Chemistry, AS CR, v. v. i., Dolejškova 3, 182 23 Prague, Czech Republic
³ Faculty of Chemistry, Brno University of Technology, Purkyňova 118, 612 00 Brno, Czech Republic
⁴ Institute of Physics, AS CR, v. v. i., Na Slovance 2, 182 21 Prague, Czech Republic
⁵ Institute of Microelectronics, NCSR Demokritos, 15310 Aghia Paraskevi, Attiki, Greece

Corresponding authors: ^a krat@fzu.cz - ^b zalis@jh-inst.cas.cz

Received: 22 June 2009
Revised: 1 October 2009
Published online: 31 October 2009

Abstract

The objective of this interdisciplinary paper was to study theoretically and experimentally the electronic part of charge carrier transport in the class of sodium salts of sulphonated Ni phthalocyanine as candidates for p-type channels in organic field-effect transistors. These materials were selected because of their enhanced solubility as compared to their non-sulphonated counterparts. The values of the field-effect charge carrier mobility determined on the OFET structures using NiPc(SO₃Na)_x films were much higher than the charge carrier mobility obtained on the respective device prepared from non-substituted phthalocyanine. In order to explain differences between charge carrier mobility of sulphonated and non-sulphonated Ni phthalocyanines, quantum chemistry studies of molecular aggregates were performed. Quantum chemistry modeling of the semiconductive molecular systems is new and progressive – we highlighted factors at the molecular level which led to the enhancement of the charge carrier mobility in systems containing SO₃Na groups.