4 research outputs found
Importance of the Reorganization Energy Barrier in Computational Design of Porphyrin-Based Solar Cells with Cobalt-Based Redox Mediators
The shift from iodide-based redox
mediators in dye-sensitized solar
cells toward octahedral cobalt complexes has led to a significant
increase in the efficiency. However, due to the nature of this type
of complexes the driving force required for the regeneration of the
dye is very high, and this limits the achievable efficiency. Here
we show that the large driving force is a direct consequence of the
large reorganization energy of the dye regeneration reaction. The
reorganization energies for charge transfer between a simple zinc
porphyrin dye and two popular cobalt-based redox mediators is calculated
using ab initio molecular dynamics with explicit solvent. These results
are then combined with a Marcus-based extrapolation scheme to obtain
the reorganization energies of more than 5000 porphyrin-based dyes.
We propose a scheme for scoring the performance of the porphyrin dyes,
which is able to identify already known high-performance dyes in addition
to a number of even better candidates. Our analysis shows that the
large internal reorganization energy of the Co-based redox mediators
is an obstacle for achieving higher efficiencies
Electrochemical Control of Single-Molecule Conductance by Fermi-Level Tuning and Conjugation Switching
Computational screening of functionalized zinc porphyrins for dye sensitized solar cells
<p>Poster presenting our recent paper in which we have performed a computational Density Functional Theory based screening of 1029 functionalized zinc porphyrins dyes for use in Dye Sensitized Solar Cells. We present the fundamental and optical gaps and use these to asign a level alignment quality to the dye candidates.</p