Voltage-induced metal-insulator transition in polythiophene field-effect transistors.
We have extensively studied the carrier transport in regio-regular polythiophene field-effect transistors (FETs) from room temperature to 4.2 K. At low temperatures, Zabrodskii plots (dlnsigma/dlnT) demonstrate that the gate voltage and source-drain voltage combine to induce the insulator-to-metal transition at a carrier density of 5x10(12) cm-2. The carrier transport in the insulating regime is well described by phonon assisted hopping in a disordered Fermi glass with Coulomb interaction between the hopping charge carrier and the opposite charge left behind, as described by Efros and Shklovskii.
Dhoot
A S
AS
Center for Polymers and Organic Solids and Mitsubishi Chemical Center for Advanced Materials, University of California, Santa Barbara, California 93106, USA.
Wang
G M
GM
Moses
D
D
Heeger
A J
AJ