PowerPoint Presentation
Stephanie HernandezDr. Matthew BirdNick BonuraPlotting Relative
Redox Potentials in THF without Electrolyte
Organic Photovoltaic Cells Advantages Organic polymers used in
the cell are solution-processable, cheap, and in abundance supply
Constructed utilizing Roll to Roll processing Applied to various
substrates for a wider range of applications compared to silicon
solar cells.Potential to retrofit buildings to supply a secondary
power source.
Source:
http://www.sigmaaldrich.com/materials-science/organic-electronics/opv-tutorial.html
2http://www.sigmaaldrich.com/materials-science/organic-electronics/opv-tutorial.htmlhttp://solarenergygroupe.com/
Source:
http://www.sigmaaldrich.com/materials-science/organic-electronics/opv-tutorial.htmlOrganic
Photovoltaic Cells
3http://www.sigmaaldrich.com/materials-science/organic-electronics/opv-tutorial.htmlhttp://solarenergygroupe.com/Challenges
Low efficiencies reported compared to silicon solar cellsLack of
understanding of charge separationExtending lifetime of
devicesDifficulty estimating HOMO and LUMO levels of materials
4Purpose To avoid propagation uncertainties in results and
further aid investigation into OPV devices by providing redox
potentials of polymers and small molecules in THF without
electrolyte.
ObjectivesDevelop a redox ladder using pulse radiolysis results
from various donor-acceptor solutions in THF Test a fit function
for the change in electron transfer equilibriumTest several
polymers studies by the OPV community for redox values
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5
PCPDTBT[TBAPF6]
CoCp2 0/+
*Information on the reduction potentials in 0.1M [TBAPF6] in THF
was taken from another experimentCreating the Ladderp-NBz
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[TBAPF6]
CoCp2 0/+p-NBzMy experiment: Fill in the redoxladder from
1,4-Dinitrobenzene (p-NBz) to the solvated electron.
Nicks experiment:Test the fit function against Cobaltocenium
(CoCp2) and p-NBz, while determining the oxidation/reduction
values. *Information on the reduction potentials in 0.1M [TBAPF6]
in THF was taken from another experimentCreating the
LadderPCPDTBT
6Effect of ion-pairing and ionic environment on reduction
potential
Might be defined as formal potential in presence of salt
Methods70.5cmAcceptorDonorElectron pulseLight source
FilterDetector
The Experiment
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9
The Experiment
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Results 9
Results10
F8BTPhthalic Anhydride (PA)Nitrobenzene (NBz)IDTBT2-Ethyl-anthra
quinone (EtAQ)Tetramethyl Benzoquinone (DQ) E(-)Pyromellitic
Dianhydride (PMDA)We can start to expand our ladder by determining
the Eredox between different compounds until we connect the ladder
to 1,4-Dinitrobenzene and Nicks experiment.DonorAcceptorG
(meV)F8BTPA69PANBz46NBzIDTBT50NBzEtAQ113EtAQDQ87DQPMDA145
Conclusions11This ladder is getting extensive but still requires
more molecules and conjugate polymers to fill in gaps between p-NBz
and the solvated electronThis method will help narrow down where a
polymers reduction potential lies relative to other molecules in
THF This will aid in rational designs of OPV cells as new
combinations of donor an acceptor molecules are tested
Acknowledgements12This project was supported by the U.S.
Department of Energy, Science Undergraduate Laboratory Internships
Program (SULI). The author also thanks John Miller for his
expertise and useful advice without whom this project would not
have been possible. Thanks to Brookhaven National Laboratory and
the Office of Educational Programs for hosting and granting access
to the Laser Electron Accelerator Facility (LEAF)for this
project.
