Tunable Frtzhlich polarons in organic single-crystal transistors

Year: 2006

Authors: Hulea I. N., Fratini S., Xie H., Mulder C. L., Iossad N.N., Rastelli G., Ciuchi S., Morpurgo A.F.

Autors Affiliation: Delft Univ Technol, Kavli Inst Nanosci, NL-2628 CJ Delft, Netherlands; CNRS, Lab Etud Proprietes Elect Solides, F-38042 Grenoble 9, France; Univ Aquila, Dipartimento Fis, I-67010 Coppito, Italy; Univ Aquila, CNR, INFM, SMC, I-67010 Coppito, Italy

Abstract: In organic field-effect transistors (FETs), charges move near the surface of an organic semiconductor, at the interface with a dielectric. In the past, the nature of the microscopic motion of charge carrierswhich determines the device performancehas been related to the quality of the organic semiconductor. Recently, it was discovered that the nearby dielectric also has an unexpectedly strong influence. The mechanisms responsible for this influence are not understood. To investigate these mechanisms, we have studied transport through organic single-crystal FETs with different gate insulators. We find that the temperature dependence of the mobility evolves from metallic-like to insulating-like with increasing dielectric constant of the insulator. The phenomenon is accounted for by a two-dimensional Frtzhlich polaron model that quantitatively describes our observations and shows that increasing the dielectric polarizability results in a crossover from the weak to the strong polaronic coupling regime. This represents a considerable step forward in our understanding of transport through organic transistors, and identifies a microscopic physical process with a large influence on device performance. (c) 2006 Nature Publishing Group.

Journal/Review: NATURE MATERIALS

Volume: 5 (12)      Pages from: 982  to: 986

KeyWords: polarons, organic semiconductor transistors
DOI: 10.1038/nmat1774

Citations: 503
data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2024-11-17
References taken from IsiWeb of Knowledge: (subscribers only)
Connecting to view paper tab on IsiWeb: Click here
Connecting to view citations from IsiWeb: Click here