Control of exciton spin statistics through spin polarization in organic optoelectronic devices.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 23149736.
- Also identified by DOI 10.1038/ncomms2194 and PMC identifier 3514489.
- Licence recorded as CC BY-NC-SA.
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Abstract
Spintronics based on organic semiconductor materials is attractive because of its rich fundamental physics and potential for device applications. Manipulating spins is obviously important for spintronics, and is usually achieved by using magnetic electrodes. Here we show a new approach where spin populations can be controlled primarily by energetics rather than kinetics. We find that exciton spin statistics can be substantially controlled by spin-polarizing carriers after injection using high magnetic fields and low temperatures, where the Zeeman energy is comparable with the thermal energy. By using this method, we demonstrate that singlet exciton formation can be suppressed by up to 53% in organic light-emitting diodes, and the dark conductance of organic photovoltaic devices can be increased by up to 45% due to enhanced formation of triplet charge-transfer states, leading to less recombination to the ground state.