Analytical model for charge transport in organic thin-film transistors: application to polythiophene

Laboratoire de physique des matériaux: structure et propriétés, groupe Physique des Composants et Dispositifs Nanométriques, Faculté des sciences de Bizerte, 7021 Jarzouna-Bizerte, Tunisia

^a e-mail: zoraisana@yahoo.fr

Received: 10 November 2011
Revised: 26 April 2012
Accepted: 16 July 2012
Published online: 3 September 2012

Abstract

The electronic charge transport in active layer of organic thin-film transistor (OTFT) based on conductor polythiophene (sexithiophene (6T) and octithiophene (8T)) was studied. A mathematical model is presented based on the variable range hopping (VRH) transport theory. Using the VRH model the expression of source-drain current is established for two regimes: linear regime for drain bias V_D = −2 V and saturation regime for V_D = −30 V at low temperature and at room temperature. All electrical key parameters of OTFTs based on polythiophene have been extracted. A good agreement between theoretical model and experimental measurement of electrical characteristics is obtained for both temperature ranges: low temperature and room temperature.