Transient electrically detected magnetic resonance spectroscopy applied to organic solar cells
- Berlin Joint EPR Lab, Fachbereich Physik, Freie Universität Berlin, D-14195 Berlin (Germany)
The influence of light-induced paramagnetic states on the photocurrent generated by polymer:fullerene solar cells is studied using spin-sensitive techniques in combination with laser-flash excitation. For this purpose, we developed a setup that allows for simultaneous detection of transient electron paramagnetic resonance as well as transient electrically detected magnetic resonance (trEDMR) signals from fully processed and encapsulated solar cells. Combining both techniques provides a direct link between photoinduced triplet excitons, charge transfer states, and free charge carriers as well as their influence on the photocurrent generated by organic photovoltaic devices. Our results obtained from solar cells based on poly(3-hexylthiophene) as electron donor and a fullerene-based electron acceptor show that the resonant signals observed in low-temperature (T = 80 K) trEDMR spectra can be attributed to positive polarons in the polymer as well as negative polarons in the fullerene phase, indicating that both centers are involved in spin-dependent processes that directly influence the photocurrent.
- OSTI ID:
- 22486391
- Journal Information:
- Applied Physics Letters, Vol. 107, Issue 4; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BINDING ENERGY
CHARGE CARRIERS
DETECTION
ELECTRON SPIN RESONANCE
ELECTRONS
EXCITATION
EXCITONS
FULLERENES
LASERS
ORGANIC SOLAR CELLS
PARAMAGNETISM
PHOTOCURRENTS
PHOTOVOLTAIC EFFECT
POLARONS
POLYMERS
SPECTRA
SPECTROSCOPY
SPIN
TEMPERATURE RANGE 0065-0273 K
VISIBLE RADIATION