2. 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.html2
http://www.sigmaaldrich.com/materials-
science/organic-electronics/opv-tutorial.html
http://solarenergygroupe.com/
4. 4
Purpose
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.
Objectives
Develop a redox ladder using pulse radiolysis results from various
donor-acceptor solutions in THF
Test a fit function for the change in electron transfer equilibrium
Test several polymers studies by the OPV community for redox values
6. 5
[TBAPF6]
CoCp2 0/+
p-NBz
My experiment: Fill in the redox
ladder from 1,4-Dinitrobenzene
(p-NBz) to the solvated electron.
Nick’s 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 experiment
Creating the Ladder
PCPDTBT
12. Results
10
F8BT
Phthalic
Anhydride (PA)
Nitrobenzene (NBz)
IDTBT
2-Ethyl-anthra
quinone (EtAQ)
Tetramethyl
Benzoquinone (DQ)
E(-)
Pyromellitic
Dianhydride (PMDA)
We can start to expand our ladder by
determining the ΔEredox between different
compounds until we connect the ladder
to 1,4-Dinitrobenzene and Nick’s
experiment.
Donor Acceptor ΔG (meV)
F8BT PA 69
PA NBz 46
NBz IDTBT 50
NBz EtAQ 113
EtAQ DQ 87
DQ PMDA 145
13. Conclusions
11
This ladder is getting extensive but still requires
more molecules and conjugate polymers to fill in
gaps between p-NBz and the solvated electron
This method will help narrow down where a
polymer’s 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
14. Acknowledgements
12
This 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.