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Spin-dependent recombination probed through the dielectric polarizability
Sam L Bayliss1, Neil C Greenham1, Richard H Friend1
1Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE, UK.
Nature Communications
|October 7, 2015
Summary
Spin-selective recombination in organic semiconductors is crucial for optoelectronic devices. We developed a method to measure this spin-selectivity by observing changes in dielectric polarizability under magnetic resonance.
Area of Science:
- Organic electronics
- Quantum mechanics
- Materials science
Background:
- Spin degree of freedom is robust in organic semiconductors due to weak spin-orbit coupling.
- Spin-selective recombination is vital in optoelectronic devices, influencing charge-transfer states in photovoltaic blends.
- Understanding spin dynamics is key to advancing organic semiconductor performance.
Purpose of the Study:
- To implement a novel detection scheme for probing spin-selective recombination.
- To investigate spin-selective recombination in organic semiconductors under suppressed hyperfine field mixing.
- To quantitatively model and estimate spin-dependent recombination rates.
Main Methods:
- Utilizing changes in dielectric polarizability under magnetic resonance to detect spin-selective recombination.
- Employing microwave driving to suppress spin-singlet and spin-triplet state mixing.
- Developing a quantitative model to analyze experimental observations.
Main Results:
- Successfully implemented a detection scheme to probe spin-selective recombination.
- Observed spin-selective recombination in a regime where hyperfine field mixing is suppressed.
- Quantitatively estimated the spin-dependent recombination rate.
Conclusions:
- The developed technique provides a new pathway to study spin dynamics in organic semiconductors.
- The findings offer insights into the fundamental processes governing charge recombination in these materials.
- Parallels drawn with Majorana-Brossel resonances suggest broader applicability of the observed phenomena.
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