Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Thermal and Photochemical Electrocyclic Reactions: Overview01:26

Thermal and Photochemical Electrocyclic Reactions: Overview

Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
Carrier Transport01:21

Carrier Transport

The generation of electrical current in semiconductors is fundamentally driven by two mechanisms: drift and diffusion. These processes are essential for the functionality and performance of semiconductor-based devices.
Drift Current:
The drift of charge carriers is started by an external electric field (E). Charged particles, such as electrons and holes, experience an acceleration between collisions with lattice atoms. For electrons, this results in a drift velocity (vd) given by:
Protein Diffusion in the Membrane01:24

Protein Diffusion in the Membrane

Proteins show rotational as well as lateral diffusion across the membrane. The lateral diffusion of proteins was confirmed through the cell fusion experiment where mouse and human cells were fused, resulting in hybrid cells. When the human and mouse cells fused, the specific membrane proteins on human and mouse cells were marked with the red and green-fluorescent markers, respectively. Initially, the red and green fluorescence was located on the respective hemisphere of the cell. As time...
Photochemical Electrocyclic Reactions: Stereochemistry01:26

Photochemical Electrocyclic Reactions: Stereochemistry

The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Dynamic Equilibrium02:20

Dynamic Equilibrium

A reversible chemical reaction represents a chemical process that proceeds in both forward (left to right) and reverse (right to left) directions. When the rates of the forward and reverse reactions are equal, the concentrations of the reactant and product species remain constant over time and the system is at equilibrium. A special double arrow is used to emphasize the reversible nature of the reaction. The relative concentrations of reactants and products in equilibrium systems vary greatly;...
Photoluminescence: Fluorescence and Phosphorescence01:23

Photoluminescence: Fluorescence and Phosphorescence

Photoluminescence is a process where a molecule absorbs light energy and re-emits it in the form of light. This phenomenon occurs when a substance absorbs photons, promoting its electrons to higher energy level excited states, followed by a relaxation process in which the electrons return to their original ground state energy levels and emit light. Photoluminescence is widely observed in various materials, including semiconductors, and organic and inorganic compounds.
A pair of electrons in a...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Triplet-pair character of the 2<sup>1</sup>A<sub>g</sub> dark state of polyenes.

Physical chemistry chemical physics : PCCP·2026
Same author

Geometric thermodynamics in open quantum systems: Coherence, curvature, and work.

The Journal of chemical physics·2026
Same author

A Vibronic Coupling Model to Study the Nonadiabatic Dynamics of Polyenes.

The journal of physical chemistry. A·2026
Same author

Noise-induced decoherence-free zones for anyons.

Chaos (Woodbury, N.Y.)·2026
Same author

Temperature-dependence of charge and exciton transport in one-dimensional systems subject to static and dynamic disorder.

The Journal of chemical physics·2026
Same author

Tensorial spin-phonon relaxation reveals mode-selective relaxation pathways in a single-molecule qubit.

The Journal of chemical physics·2025

Related Experiment Video

Updated: May 18, 2026

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level
06:55

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level

Published on: September 26, 2016

Exciton dynamics in disordered poly(p-phenylenevinylene). 2. Exciton diffusion.

William Barford1, Eric R Bittner, Alec Ward

  • 1Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom. william.barford@chem.ox.ac.uk

The Journal of Physical Chemistry. A
|October 4, 2012
PubMed
Summary

We developed a theory for exciton diffusion in disordered polymers, showing how structural defects impact exciton movement and light emission. This helps understand polymer optoelectronics.

More Related Videos

Recombination Dynamics in Thin-film Photovoltaic Materials via Time-resolved Microwave Conductivity
11:30

Recombination Dynamics in Thin-film Photovoltaic Materials via Time-resolved Microwave Conductivity

Published on: March 6, 2017

Ultrafast Time-resolved Near-IR Stimulated Raman Measurements of Functional &#960;-conjugate Systems
09:57

Ultrafast Time-resolved Near-IR Stimulated Raman Measurements of Functional π-conjugate Systems

Published on: February 10, 2020

Related Experiment Videos

Last Updated: May 18, 2026

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level
06:55

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level

Published on: September 26, 2016

Recombination Dynamics in Thin-film Photovoltaic Materials via Time-resolved Microwave Conductivity
11:30

Recombination Dynamics in Thin-film Photovoltaic Materials via Time-resolved Microwave Conductivity

Published on: March 6, 2017

Ultrafast Time-resolved Near-IR Stimulated Raman Measurements of Functional &#960;-conjugate Systems
09:57

Ultrafast Time-resolved Near-IR Stimulated Raman Measurements of Functional π-conjugate Systems

Published on: February 10, 2020

Area of Science:

  • Materials Science
  • Polymer Physics
  • Organic Electronics

Background:

  • Exciton diffusion is crucial for organic electronic devices.
  • Conformational disorder in conjugated polymers significantly affects exciton behavior.
  • Understanding exciton transfer mechanisms is key to optimizing material properties.

Purpose of the Study:

  • To present a first-principles theory for exciton diffusion in conformationally disordered conjugated polymers.
  • To investigate the influence of static and dynamic disorder on exciton localization and transfer.
  • To elucidate the relationship between polymer structure, exciton dynamics, and photophysical properties.

Main Methods:

  • Developed a theory based on exciton transfer from vibrationally relaxed states (VRSs) to local exciton ground states (LEGSs).
  • Implemented the Frenkel-Holstein model to compute wave functions and energies of LEGSs and VRSs.
  • Applied a kinetic Monte Carlo algorithm to an ensemble of poly(p-phenylenevinylene) chains.

Main Results:

  • Torsional disorder and trans-cis defects were found to reduce exciton diffusion length.
  • Radiative recombination occurs from VRSs in the tail of their density of states.
  • Torsional disorder increases band gap, density of states line width, and Stokes shift, causing blue absorption and red emission shifts.

Conclusions:

  • The developed theory accurately predicts exciton diffusion lengths (~8-11 nm) in agreement with experimental data.
  • Structural disorder, particularly torsional fluctuations, plays a critical role in determining exciton diffusion and optical properties.
  • The findings provide a theoretical framework for designing conjugated polymers with tailored optoelectronic characteristics.