Coming up next
2026-03-26 - 13:30 @ BW 0.06 Gorleaus building
SLAM seminar: Serge Lemay
Title Internal dynamics of random-coil semiconducting polymers probed by coupled electronic/ionic transport
Abstract Semiconducting polymer chains are fascinating materials with a broad range of applications spanning printed electronics, photovoltaics and display technology. They are mostly utilized in the form of thin films and, as a result, their electrical characteristics at the single-molecule level have received little attention. Using microfabricated electrodes and electrochemical gating, we were able to measure the current through single polymer chains of polythiophene derivatives. The molecules reversibly adsorb on the surface of the measurement device, forming transient contacts with electrodes separated by ≈10 nm. Fluctuations between internal conformations of the individual polymers are resolved as abrupt, multilevel switches in the electrical current. This behavior is qualitatively consistent with simple simulations based on the worm-like-chain model for semiflexible polymers. In addition to probing the intrinsic properties of single semiconducting polymer chains, the results provide a new window into the dynamics of random-coil polymers and enable the use of semiconducting polymers as electrical labels for single-molecule (bio)sensing assays.