(October 13, 2015) Researchers
at Lund University in Sweden have found a new way to capture energy from
sunlight – by using molecules that contain iron. The results are presented in
the latest issue of Nature Chemistry. The hope is to develop efficient and
environmentally friendly solar energy applications.
Solar energy is an inexhaustible resource that we currently
only utilise to a very limited extent. Researchers around the world are
therefore trying to find new and more efficient ways to use the energy in
sunlight.
The technique the researchers in Lund are working on is
solar cells consisting of a thin film of nanostructured titanium dioxide and a
dye that captures solar energy. Today, the best solar cells of this type use
dyes containing ruthenium metal – a very rare and expensive element.
“Many researchers have tried to replace ruthenium with iron,
but without success. All previous attempts have resulted in molecules that
convert light energy into heat instead of electrons, which is required for
solar cells to generate electricity”, says Villy Sundström, Professor of
Chemical Physics at Lund University.
Researchers at the Chemistry Department in Lund, in
collaboration with Uppsala University, have now successfully produced an
iron-based dye that is capable of converting light into electrons with nearly
100 per cent efficiency.
“The advantage of using iron is that it is a common element
in nature. It can provide inexpensive and environmentally friendly applications
of solar energy in the future”, says Kenneth Wärnmark, Professor of Organic
Chemistry at Lund University.
By combining the experiments with advanced computer
simulations, the researchers are able to understand in detail required design
concepts for the iron molecules to work. This knowledge is now being used for
further developing the iron-based dyes. More research is needed before the new
solar cell dye can be used in practice, but there are high hopes.