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Monitoring the Effects of Illumination on the Structure of Conjugated Polymer Gels Using Neutron Scattering
Published on: December 21, 2017
Factors controlling hole injection in single conjugated polymer molecules
Leonid Fradkin1, Rodrigo E Palacios, Joshua C Bolinger
1Center for Nano and Molecular Science and Technology, University of Texas, Austin, Texas 78712, USA.
The Journal of Physical Chemistry. A
|March 6, 2009
Summary
Charge injection into conjugated polymers is complex. Good electrical contact is essential for light-assisted positive charge transfer in single polymer chains, as shown by fluorescence-voltage single molecule spectroscopy.
Area of Science:
- Organic electronics
- Materials science
- Nanoscale science
Background:
- Conjugated polymers are key materials in organic electronics.
- Understanding charge injection mechanisms at the molecular level is crucial for device performance.
- Previous studies explored bias scan rate and optical intensity effects on charge injection.
Purpose of the Study:
- To elucidate molecular-level details of light-assisted positive charge injection into single conjugated polymer chains.
- To investigate the influence of device atmosphere and molecular environment on charge transfer.
- To determine the necessity of electrical contact for efficient charge injection.
Main Methods:
- Extensive fluorescence-voltage single molecule spectroscopy (FV-SMS) measurements.
- Utilizing a vacuum microscope for precise control of the device atmosphere.
- Employing thicker supporting matrices and insulating polymer blocking layers.
Main Results:
- Triplet states in MEH-PPV influence FV-SMS modulation.
- Charge injection rate and yield show minimal molecule-to-molecule variation under identical conditions.
- Good electrical contact between hole transport layers and single molecules is essential for charge injection.
Conclusions:
- Charge transfer at organic semiconductor interfaces is complex.
- Single molecule methods are powerful tools for nanoscale process understanding.
- Optimizing electrical contact is critical for efficient charge injection in organic electronic devices.
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