Related Experiment Video
Updated: May 24, 2026

Monitoring the Effects of Illumination on the Structure of Conjugated Polymer Gels Using Neutron Scattering
Published on: December 21, 2017
Visualization and manipulation of individual dopant states in single conjugated oligomers
Shiyong Wang1, Weihua Wang, Nian Lin
1Department of Physics, The Hong Kong University of Science and Technology, Hong Kong, China.
Abstract:
Nonlinear excitations associated with dopant states play fundamental roles for charge transport in conjugated polymers. Here we report on real-space visualization of individual dopant states in single conjugated oligomers of poly-para-phenylene using cryogenic scanning tunneling microscopy and spectroscopy. We have found that these states exhibit a typical spatial extension of 4 nm along the oligomers. In particular, these states create a shallow level inside the band gap of the parent oligomers. The origin of these states is traced to a novel doping mechanism of dehydrogenation of the phenylene moiety. Furthermore, we use a scanning tunneling microscope tip to charge/discharge the dopant states and measure their lifetimes. The present results demonstrate a strategy to characterize and manipulate individual dopant states in conjugated polymers with subnanometer resolution.
More Related Videos
Related Concept Videos
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
Structure of Conjugated Dienes
Conjugated dienes are compounds characterized by the presence of alternating double and single bonds. In a conjugated system like 1,3-butadiene, the unhybridized 2p orbital on each carbon overlaps continuously, allowing the π electrons to be delocalized across the entire molecule. In contrast, this type of overlap does not occur in cumulated and isolated dienes, such as 2,3-pentadiene and 1,4-pentadiene, respectively. Instead, the π electrons remain localized between the double...
Photochemical Electrocyclic Reactions: Stereochemistry
Selection Rules: Photochemical Activation
Cationic Chain-Growth Polymerization: Mechanism
Ziegler–Natta Chain-Growth Polymerization: Overview
UV–Vis Spectroscopy of Conjugated Systems
One of the factors influencing λmax is the extent of conjugation in the...

