6533b82bfe1ef96bd128e326
RESEARCH PRODUCT
Influence of the intermediate density-of-states occupancy on open-circuit voltage of bulk heterojunction solar cells with different fullerene acceptors
Martijn LenesAndrea La RosaAndrea La RosaSalvatore FilipponeSalvatore FilipponeHenk J. BolinkGermà Garcia-belmontePablo P. BoixNazario MartínNazario MartínJuan Bisquertsubject
Materials scienceFullereneOrganic solar cellOpen-circuit voltageFermi levelAnalytical chemistryCarrier lifetimeMolecular physicsPolymer solar cellMicrosecondsymbols.namesakeDensity of statessymbolsGeneral Materials SciencePhysical and Theoretical Chemistrydescription
Electron density of states (DOS) and recombination kinetics of bulk heterojunction solar cells consisting of a poly(3-hexylthiophene) (P3HT) donor and two fullerene acceptors, either [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) or 4,4′-dihexyloxydiphenylmethano[60]fullerene (DPM6), have been determined by means of impedance spectroscopy. The observed difference of 125 mV in the output open-circuit voltage is attributed to significant differences of the occupancy of the DOS in both fullerenes. Whereas DPM6 exhibits a full occupation of the electronic band, occupancy is restricted to the tail of the DOS in the case of PCBM-based devices, implying a higher rise of the Fermi level in the DPM6 fullerene. Carrier lifetime describes a negative exponential dependence on the open-circuit voltage, exhibiting values on the microsecond scale at 1 sun illumination.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2010-08-12 |