HOPV12 - Blogs

4 th Hybrid and Organic Photovoltaic Conference -Uppsala 2012 200
C77 - Efficient dye regeneration in thick solid state dye-sensitized solar cells
Erik M. J. Johansson a , Lei Yang a , Erik Gabrielsson b , Peter W. Lohse a , Gerrit Boschloo a , Licheng
Sun b , Anders Hagfeldt a
a, Uppsala Universitet, Department of Chemistry-Ångström, SE-751 05 Uppsala, Sweden
b, KTH Royal Institute of Technology, Department of Chemistry, SE-10044 Stockholm, Sweden
An efficient transfer of holes from the oxidized dye to the counter electrode is a crucial step
for the performance of a dye-sensitized solar cell (DSC). In solid state DSCs this step is
performed by hole-conductor material. We show that a small hole-conductor molecule has in
contrast to larger polymers the capability to regenerate dye molecules in the pores of the dyesensitized
TiO2 nanoparticle electrode efficiently also for thick (>5µm) electrodes. However,
the performance of the solar cells with the small hole-conductor molecules is poor due to a
less efficient charge transfer to the back contact. Polymer hole-conductors, which may have a
good hole conductivity, also have a high molecular weight, which makes these polymers
difficult to infiltrate into the smallest pores of the electrode.
Adding conducting polymers to the small molecule hole-conductor enables better transport
of the charges to the contact and reduces recombination, and therefore increases the
photocurrent. This new device construction with a small molecule efficiently regenerating the
dye molecules, and a polymer conducting the holes to the contact is a promising pathway for
solid state dye-sensitized solar cells.
© SEFIN 2012