Effects of annealing on device parameters of organic field effect transistors using liquid-crystalline tetrasubstituted zinc phthalocyanine

¹ The Wolfson Centre for Materials Processing, Brunel University - Uxbridge, Middlesex UB8 3PH, UK
² Nikolaev Institute of Inorganic Chemistry - Lavrentiev pr., 3, Novosibirsk 630090, Russia
³ Novosibirsk State University - Pirogova Str. 2, Novosibirsk 630090, Russia
⁴ Department of Physics, University of Pune - Ganeshkhind, Pune 411007, India
⁵ Space Vehicles Directorate, Air Force Research Laboratory - 3550 Aberdeen Avenue, SE Kirtland AFB, NM 87117, USA
⁶ Gebze Institute of Technology, Department of Chemistry - P.O. Box: 141, 41400, Gebze, Kocaeli, Turkey

^(a) asim.ray@brunel.ac.uk

Received: 17 February 2014
Accepted: 13 May 2014

Abstract

The device performance of organic thin-film transistors (OTFTs) employing the solution processed films of room temperature liquid-crystalline tetrasubstituted zinc phthalocyanine derivative was found to depend upon the film morphology. Atomic force microscopic and X-Ray diffraction studies show that the annealing at produced a preferentially unidirectional void-free film with improved surface smoothness. The OTFTs with the annealed films exhibited enhanced conductivity, threefold reduction in threshold voltage, a nearly one order of magnitude increase in the on/off ratio and more than one-third reduction of hysteresis in the transfer characteristics.