Hopping transport and the Hall effect near the insulator-metal transition in electrochemically gated poly(3-hexylthiophene) transistors

Shun Wang, Mingjing Ha, Michael Manno, C. Daniel Frisbie, C. Leighton

Research output: Contribution to journalArticlepeer-review

106 Scopus citations

Abstract

Despite 35 years of investigation, much remains to be understood regarding charge transport in semiconducting polymers, including the ultimate limits on their conductivity. Recently developed ion gel gating techniques provide a unique opportunity to study such issues at very high charge carrier density. Here we have probed the benchmark polymer semiconductor poly(3-hexylthiophene) at electrochemically induced three-dimensional hole densities approaching 1021 cm-3 (up to 0.2 holes per monomer). Analysis of the hopping conduction reveals a remarkable phenomenon where wavefunction delocalization and Coulomb gap collapse are disrupted by doping-induced disorder, suppressing the insulator-metal transition, even at these extreme charge densities. Nevertheless, at the highest dopings, we observe, for the first time in a polymer transistor, a clear Hall effect with the expected field, temperature and gate voltage dependencies. The data indicate that at such mobilities (∼0.8cm2 V-1 s-1), despite the extensive disorder, these polymers lie close to a regime of truly diffusive band-like transport.

Original languageEnglish (US)
Article number1210
JournalNature communications
Volume3
DOIs
StatePublished - 2012

Fingerprint Dive into the research topics of 'Hopping transport and the Hall effect near the insulator-metal transition in electrochemically gated poly(3-hexylthiophene) transistors'. Together they form a unique fingerprint.

Cite this