Stochastic Electrical Detection of Single Ion‐Gated Semiconducting Polymers

Abstract

AbstractSemiconducting polymer chains constitute the building blocks for a wide range of electronic materials and devices. However, most of their electrical characteristics at the single‐molecule level have received little attention. Elucidating these properties can help understanding performance limits and enable new applications. Here, coupled ionic–electronic charge transport is exploited to measure the quasi‐1D electrical current through long single conjugated polymer chains as they form 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 consistent with the theoretical simulations based on the worm‐like‐chain (WLC) model for semiflexible polymers. In addition to probing the intrinsic properties of single semiconducting polymer chains, the results provide an unprecedented window into the dynamics of random‐coil polymers and enable the use of semiconducting polymers as electrical labels for single‐molecule (bio)sensing assays.